Sunday, August 13, 2017

Tech: Pancake cooling exhausts

Here we are going to look at the exhaust systems for the VWs that came with the Type 4 originally, like the 411, 412, 1972-1979 Transporter, and 1980-1983 Vanagon. All of these engines were installed as a rear engine location with a pancake cooling system. We will also look at some off road exhaust systems that work with the stock cooling in an open bay vehicle.

Street: Let's start by looking at the combination of the stock cooling system and a stock body.

The stock muffler is the obvious first choice. This system was how VW equipped the car initially, but from a performance standpoint, it leaves a lot to be desired. This is especially so if you change camshafts, intake system, etc., or if you increase the displacement of your engine with a big bore kit and/or a long throw stroke crankshaft.

EMPI is one of many companies that offer a 2-tip system for the Bus and VW 411/412


The first aftermarket system is what many suppliers sell called a Monza exhaust system. Though many people find it attractive with two large chrome exhaust tips, it's not the most desirable. This system basically has short pipes that dump the exhaust fumes into two muffler, which each have a chrome exhaust tip.

The Type 1 equivalent of this exhaust system (four tip or GTwas found to flow as well as a stock muffler. Since this system is not a header (or extractor), this system is not the best decision if you've made modifications to your Type 4. Get the Bus header listed below to get the most from your engine.

Systems like this have long been a staple of the Type 4 performance scene.


The best place to get an exhaust system for this application is CB Performance, a Bugpack dealer or Mr. Bug (EMPI) dealer. They offer them in many different applications and are reasonably priced. The only thing I wish they'd offer would be a stainless steel option. Exhaust systems made of stainless tubing don't rust and maintain a better appearance. They typically last years longer than the commonly used mild steel tubing.

It becomes obvious that as you increase the power of your engine, you'll want to run larger diameter tubing for the exhaust system.

BAS of Germany offers this nice Bus system to get the power for your Bus.


On the other side of the Atlantic, in Germany, BAS Ahnendorp offers one of their headers for the Bus. It bolts up to the later model dual port Bus heater boxes with stainless tubes and aluminum-coated silencer. A lower cost version is offered with plain steel tubes also. This system and the Tangerine SuperHeader are your only real options if you have a highly tuned engine in a Bus/Vanagon or 411/412.

Offroad: In this application, there is only one option. It is available from European Motorworks (They don't have any T4 stuff yet online) and is only available with a stinger (megaphone). The exhaust is only usable with a rear engine sand rail, as the exhaust pipes are routed towards the transaxle bell housing, up alongside the bell housing, and come together at a collector located above the engine. The megaphone exits above the fan shroud. I will see if I can get a picture or illustration of this unique exhaust system. It is available directly from European Motorworks or from FAT Performance.

Type 3

If you are looking to do the Type 4 conversion for your Type 3 (Notchback, Squareback, Fastback, or Type 343 Karmann Ghia), these are the exhaust systems to be looking at. I cover this subject in more detail in my technical article on installing a Type 4 in a Type 3.

The first option is to modify the stock Type 4 muffler and heater boxes. Fabrication of the components will probably be required, but if you have the skills and are building a really mild engine, this might suit you.

Until recently there were no options in a specific header for this conversion. But that has changed. Two manufacturers are now offering exhaust systems that fit nicely in the Type 3.

The American option is the SuperHeader from Tangerine Racing. Although it wasn't designed for this conversion, Jake Raby has reported that the header will work on a Type 3

The UK's Turbo Thomas offers one of the few headers for those Type 3 owners with a Type 4 engine. This header, along with one of their mufflers, makes a great exhaust for your Type 3.


The other header comes from the UK. Turbo Thomas offers a Type 3 specific header to his customers and it looks like a winner too. This header utilizes the standard type quiet pack mufflers or turbo style muffler. They will even make you a special one that fits between the rear apron and the engine for additional ground clearance.

The Type 3 header differs in that exhaust must travel farther back, as the stock Type 4 fanshroud is still in place. These systems take that into account and exit right where it should be.

The word is that Jake Raby has once again commissioned A-1 Muffler to make another system, this time a header for the Type 3 with a Type 4 engine. Whenever I get the official word from Jake, I will be sure to post the new information here along with any pictures, if available.

Thanks go to Rolf Christensen, Ron "Plastermaster" Roberts, Ephraim "Ephry73" Castillo, Rich Craig, Tom "Tom Notch" Hansen, and Jake Raby for all of their help in gathering the information and supplying photos. Thanks guys!!

Tech: Upright Cooling exhausts

Most of the people that are reading this site are interested in converting a Type 4 engine into an upright engine. So, with that conversion, a custom exhaust is required.

Street: This is probably the most popular application at the moment. There are many people who are looking to install a Type 4 into their street Bug (like me) and they want to know what they can use to finish the installation.

Chris Stanford modified a stock Type 4 muffler and heater boxes for his stock 2.0 powered '74 KG convertible.



Our first look at upright street exhaust systems lies with a very simple system that mimics the stock setup. These systems generally consist of either stock heater boxes or j-tubes, along with a shared muffler. These systems are popular in Europe, as they are usually more economical than a tube header.

The first system we'll look at uses a modified stock 411/412 muffler (the original ones need to be shortened, as they are almost as wide as a Bug) and shortened 411/412 heater boxes. It is necessary to shorten the heater boxes else the muffler will stick out from the body, kind of like another bumper. From a performance stand point this isn't the best choice, but if money is tight and you have the necessary skills, it does work.

Many of the European tuners offer a muffler similar to this that bolts on to shortened heater boxes for sound control.


British LA Performance, and German firms Klaus Kaefer Tuning, and CSP all sell muffler systems similar to what I described above. The beauty of these systems is the simplicity of installation, maximum ground clearance, and stock appearance. They are also economically priced, as they don't require expensive tubing benders to produce.

These systems may not be the best for a performance engine, but they work fine on a near stock engine that isn't asked to work hard. So if you are looking to convert that stock 1.7 to upright cooling and aren't worried about racing the Honda down the street, this option maybe your choice.

Eddie Brown followed the Cali method for his 1911cc Type 4. What's unique about his system is the muffler placement, behind the rear apron.


For most mild upright conversions, a very cost-effective exhaust system is to use the stock Type 4 heater boxes and a header meant for the Bus. The heater boxes will have to be shortened though, as they will place the header/muffler too far out and interfere with the rear apron. The most common heater box used for this conversion is the dual port used on the early Type 4s. Joe Cali of Next Generation details this conversion in his book.

TriMil produces what is commonly known at the "FAT" header. This system is an economical choice for stock or near stock upright street conversions.



For those engines that need more flow than out of a standard Bus header, there are alternatives. The first alternative is available from FAT Performance. Their ES731 exhaust system includes head pipes, a header, and dual quiet pack mufflers. This system is also available from any TriMil dealer, so if your local VW shop carries TriMil, inquire with them on the cost of this header. When installed in a Bug, it looks real similar to a header on a Type 1 engine.

Some people have complained about the quality of the fit of this exhaust, but others have praised it. I have also recently learned that TriMil was purchased by another company, AC Industries. My source there tells me that some of the sealing issues at the headpipes can be fixed with their 3/8" laser cut flanges. I hope that AC Industries is willing to invest some time and money into their Type 4 prodcuts of the TriMil line, as their products could fill a need for moderate priced exhaust systems that the Type 4 community has been needed to fill.

Tangerine's SuperHeader is a complex system, but dyno runs have shown it produces the most across the board power.



The Tangerine SuperHeader for a Bug is a great choice if you are looking for a wide range of power. This system is well suited for the German Look sedan, as its broad power band and high mounting makes it a natural for cornering. This header is available with optional "silencers", QuietCan and Phase9, to quiet the exhaust note, but they are placed up high so that you don't need to worry about scraping the exhaust in a dip.

The Tangerine SuperHeader is a 4-2-1 design and has consistently done well in dyno pulls. Each header is custom assembled for the customer, so most modifications are easily accomodated. This header is available in 1⅝" and 1¾" tubing and is available with optional heat exchangers. That way you can have the big power of that cc monster and still have heat in the front seat.

Tangerine Evo system for Type 4 powered Beetle. Note that this system exits through stock exhaust holes in apron.



A new addition to the Tangerine Racing line of exhaust systems for the Type 4 engine is their Evo header. This is what Chris Foley, proprietor of Tangerine Racing has to say about this new exhaust system:
A breakthrough in collector design allows shorter and more precise pipe lengths without crossing under the sump. These headers feature the same 4-2-1 design as the original Super Header, but with an improved layout and enhanced performance! The Silencers exit from the stock valence cutouts.

The shorter primary tubes on the Evo make it suitable for the more mild Type 4 conversions. This system also clears the sump, so you can add an external deep sump for increased oil capacity at the pickup tube.

This is the ultimate setup for those of you looking to build a stock sleeper. Imagine a stock height Bug with no modifications except a nice Type 4 and this exhaust. Everyone's jaw would drop on the freeway as you merge into traffic without breaking into a sweat.

A-1 brings a traditional VW merged header to the Type 4 conversion. Dyno results have shown it produces the most peak hp.



In the tradition of the Type 1 merged header, the A-1 Performance merged header is currently the king of the hill when it comes to horsepower. Jake Raby and myself played a hand in getting this header designed, fulfilling a need for a traditional header for the Type 4 conversion. This header, available in 1⅝" or 1¾", uses any of A-1 "Phat Boy" style mufflers. Unless your engine displaces over 2500cc's or is designed to live at 8,000 rpm, the 1⅝" with a 2½" Magnaflow muffler is going to get you the most power out of your engine.

When installed with one of A-1's mufflers, from the outside the exhaust looks just like a merged header on a Type 1 engine. This is great for those of you like myself who like the traditional Cal-Look, but who also want the benefits of the Type 4 engine. Of course, care must be taken when driving with such as system, but I've done it for years and never had a problem. This header also makes adjusting valves easy and keeps the heat from underneath the body.

Ron "Plastermaster" Roberts commissioned A-1 to make a Sidewinder for his 2270cc Type 4 powered 1973 Karmann Ghia coupe.



The first half of 2005 brought another exhaust header from A-1 Performance. This time Jake Raby of Aircooled Technology enlisted A-1 to develop a Type 4 version of A-1's Sidewinder exhaust system. The first system was developed for Ron "Plastermaster" Robert's 2270cc Type 4 powered 1973 Karmann Ghia coupe. You can see from the photos that this system places the muffler high into the body and maintains good ground clearance.

This system, ideally suited for German Look sedans and daily drivers, diversifies the options available from A-1. This system would also work great for those that are building street versions of Class 11 racers, as the high muffler placement allows for a skid plate to protect the engine and exhaust.

The downside with the Sidewinder, according to A-1, is that the muffler selection is limited to a couple of 2½" mufflers and to the 1⅝" tubing. For most Type 4 conversions, that is the best size, but if you must have a big cc bruiser or a high spinning sprinter, then the standard A-1 header is your best option, as it has more high-flow options.

If you live on the other side of the Atlantic, you have many choices too. There are exhaust manufacturers from mainly England and Germany. I can only speak from what I've heard about these systems, as I only have seen (actually own) one exhaust header from an European manufacturer. If you are on this side of the Atlantic and want an European system, make sure you take in account the current exchange rate of currency and for the shipping.

Germany's BAS Ahnendorp offers many different systems, like this one. The ground clearance of this system is great for road racers and anyone else concerned with bottoming out their car.


Probably the most well known of the European suppliers is BAS Ahnendorp of Germany. They have a large selection of exhaust systems in different sizes and materials. BAS has been manufacturing exhaust systems for the Type 4 for a long time and their products are well received in Europe. These systems are very popular with the German Look Bug owners, as they mount up high and provide ample ground clearance.

Until the A-1 header became available, the BAS headers were the most common pre-made system used by American Type 4 owners. I purchased a BAS # 21152 header, but elected not to purchase the mufflers, as I was going to have a muffler fabricated similar in style to the later released Sidewinder muffler. Although I'm now going to run an A-1 (since my car is a Cal-Look car, the A-1 looks better with it), I'm going to keep the BAS header around for a future build. This header cost me just over $400 to purchase and ship to southern California.

UK's Turbo Thomas offers this header with many different muffler options. Stub tubes are available for both exhaust port styles.


For those of you in the UK, you have two excellent manufacturers to turn to. The first is Turbo Thomas. Turbo Thomas sells a nice 4-1 header that utilizes their muffler setups. They are also willing to modify their designs to suit your needs, so Turbo Thomas is definitely a company to check out.

One of the unique features of the Turbo Thomas header is that they offer at least four different types of mufflers to complement their header. Thes include a single quiet pack(QP) type muffler, dual QP (like you see on a lot of Type 1 engines), a large turbo style muffler (2½" and 3"), and a "road racer dual muffler system". The latter muffler setup is for those that need any ground clearance they can get.

LA Performance offers many different systems, including this dual turbo muffler header.


The next British company is LA Performance. Lee Arnold, the LA of LA Performance, has developed a couple of different header designs for the upright Type 4 conversion. They even have a dual turbo muffler setup that may do well with a more high performance engine. LA's header shown on their green 1303 (curved windshield Super Beetle) appears to be a great system, though the ground clearance is going to be an issue for most. It also doesn't clear a deep oil sump, so keep that in mind.

Just a note: BAS Ahnendorp also offers an exhaust system for installing a Wasserboxer engine into a Bug.

TriMil has long been the first name in offroad headers.


Offroad: In this category, we start off with an obvious choice: the excellent TriMil 4 into1 header. This exhaust utilizes 1⅝" tubing and includes it's own head pipes. They are extremely popular with the desert racers and FAT Performance even sells one that uses 1¾" tubing. Be warned though: this exhaust is loud. Its pipe exits upward, at about ear level. I'd prefer to install a free flowing turbo muffler to make it easier on the ears. To minimize the sound, I suggest that you invest in their u-bend collector, or attach a muffler to the end of the system. I've experienced TriMil headers on Type 1s with a turbo muffler, and the car was reasonably quiet,

Another option in development is coming from A-1 Performance of Santa Ana, CA. Jake Raby has again commissioned A-1 to build him a well performing system, this time an off road header. There isn't much more information to report at this time, but as soon as it is available, I will make the update here.

This unique offroad system is available from BAS of Germany. It features twin silencers and is available in stainless steel for long life.


For those of you on the other side of the Atlantic, BAS Ahnendorp offers their "Trike and buggy exhaust system" that looks pretty nice. It has stainless steel tubing for a long life with dual silencers.

Although this system isn't the cheapest system available, it's unique design makes it well suited for street going open bay vehicles, like Baja Bugs and fiberglass dune buggys. This system is one to consider if you live in a state that requires the exhaust system in your buggy to be protected under a cover. Using a fiberglass cover from the body, you can make holes in the cover for this system's exhaust tips.

Thanks go to Rolf Christensen, Ron "Plastermaster" Roberts, Ephraim "Ephry73" Castillo, Rich Craig, Tom "Tom Notch" Hansen, and Jake Raby for all of their help in gathering the information and supplying photos. Thanks guys!!

Tech: Porsche 914/912E exhausts

By popular demand I will be covering the Porsches, the 1970-1976 914 and the elusive 1976 912E. Both of these cars were Type 4 powered and utilize unique exhaust systems.

I must first preface this part by stating that I am not an expert when it comes to Porsches. I'm a VW guy, but that doesn't mean I don't like Porsches. Actually, that is far from the truth. I do enjoy Porsches, especially the two models we are covering here. So if what I write here is false or I'm missing some facts, feel free to contact me and let me know.

914: The 914 is a unique vehicle in the Type 4 line up. Unlike the rest of the Type 4 powered vehicles, the 914 is mounted mid-ship, so its exhaust system is unlike any other. The stock heater boxes that originate at the exhaust port and travel almost all the way to the rear valance. There the boxes bolted to the stock muffler.

A comprehensive test of the 914 headers was available in the February 2002 issue of Grassroots Motorsports magazine. I would suggest that you see if that back issue is available and get a copy if you are looking to familiarize yourself with the 914 options.

The Tangerine Racing SuperHeader is shown here with both stages of muffler for maximum sound reduction. This system comes highly recommended by 914 owners.


There may be more options for the 914, but these are the ones that I am most familiar with. Probably the best exhaust system for the 914 is the SuperHeader from Tangerine Racing. Chris Foley, owner, is a regular 914 racer and is very meticulous about the construction of his system. Numerous dyno tests have shown that the SuperHeader provides a wide range of power.

Another option to the Super Header is the custom fabricated heater boxes. This way you can have a race header but still retain the heat for those cold mornings.

Kerry Hunter's header for the 914 is another excellent choice for the 914. Although it doesn't quite produce the power like the Tangerine offerings, it's price performance makes it a worthwhile acquisition for most 914s.


If the Tangerine SuperHeader is too expensive for your wallet, then I'd suggest looking into getting a header from Kerry Hunter. This system performed well in the Grassroots Motorsports tests, but I've yet to hear from someone who owns one on how it does. This header does feature 1½" tubing, which is smaller than the Tangerine's 1⅝".

This means that the Hunter system will probably do well with the stock size engines, but it will probably choke off the engine that is larger or driven to higher rpms. If the car budget is tight and you don't mind losing the heater boxes, the Kerry Hunter header should be on the top of your shopping list. You might get every last horsepower from you engine like you would from a Tangerine SuperHeader, but then you'll be saving some money.

For those on a tight budget, the Bursch header is the winner. Although it won't give you every last drop of power from your engine, it does well on the street.


The next two systems use the stock heater boxes, or the pricey stainless replacements. The Bursch header is the best option if you want to retain the heat in the cabin. This means that the Bursch header will be fine for a stock or near stock street car, but not the best option if you intend on racing. It may not flow as well as the Tangerine or the Kerry Hunter systems, but then that doesn't matter when you are trying to warm up on your morning commute to work in the winter.

The 914 Monza exhaust system is fine as a replacement for the stock muffler, but if you are looking to gain some power and to make your engine more effecient, look elsewhere.


The last option I will cover is the "Monza" system. I wouldn't even call the Monza system a header; it's actually a muffler replacement with custom tips. As a result, the performance is the lowest of all of the systems I listed here. The one appealing facet of the Monza is its affordability, and some do enjoy its sound. If money is tight, and you aren't looking to win the next SCCA race then the Monza system maybe for you.

912/912E: Take a '76 911, remove the six cylinder and replace with a 914 spec 2.0L and you get a 912E. As a result, the 912E, made only for one year, 1976, is a unique car. This unique combination means that the 912E requires a special exhaust system

The Tangerine Racing SuperHeader for the 912E allows the 912E to become quite a suitable platform for both the track and the street.


Tangerine Racing sells a version of their well-tested SuperHeader for the 912E. It utilize 1⅝" tubing and can be purchased with two different "mufflers", so you can tune your exhaust to your engine.

If you want the most performance for your 912E, invest in a Tangerine SuperHeader. For such a capable and unique Porsche, it's worth the investment and is practical if you've ever seen the prices for replacement parts.

Jake Raby of aircooledtechnology.com runs a Tangerine Superheader on his 912E with a custom built 2056cc. He's told me that his 130hp engine has gotten near 40 miles per gallon at upwards of 80mph, while making a trip in excess of 1,000 miles. That kind of efficiency is only possible with a well designed header.



A-1's system for the Type 4 powered 912 and 912E


A-1 Muffler and Raby's Aircooled Technology have teamed up again to produce another exhaust system for an early 912 with the Type 4 engine. This header, similar to A-1's Sidewinder header, places their Magnaflow muffler on the left side of the car and places the exhaust tip in the stock location.


Like the other A-1 systems, this header does away with the heater boxes, but you are gaining a lot less restrictive system. I've seen many of the other A-1 headers and mufflers, and I've had the opportunity to talk with both Jake of Raby's Aircooled Technology and with Tiger of A-1, and let me tell you, this system is a well designed system. A-1's attention to detail in fabrication is superb.

Bursch 912E header provides a economical alternative to the stock system and the Tangerine system.


If your budget is modest and you require the use of the heater system, Bursch manufactures a header for this unique platform. Due to its similarity to the 914 systems, I will say that its use should be regulated to a stock engine. Reports from 912E tuners have said that the Bursch header is a fine replacement for the stock muffler, but it doesn't equal the power potential of the Tangerine SuperHeader.

356/550 replicas: information on the Type 4 conversion in the 356/550 replicas.

another paragraph on this conversion.






Thanks go to Rolf Christensen, Ron "Plastermaster" Roberts, Ephraim "Ephry73" Castillo, Rich Craig, Tom "Tom Notch" Hansen, and Jake Raby for all of their help in gathering the information and supplying photos. Thanks guys!!

Tech: Custom-made exhaust

Custom-made exhaust

If none of the systems that in my other article seem to fit your unique vehicle, then your only option is to have a custom header designed just for your car. Kit cars are a prime example of a car that may need a custom exhaust system.

A couple of the manufacturers mentioned in this article have, in the past, designed and built custom headers for vehicles that standard systems won't fit or are undesirable. These include Tangerine Racing (Manchester, CT, USA), A-1 Muffler (Santa Ana, CA, USA), and Turbo Thomas (Astwood Bank, Redditch, UK). Look them up and see what they can do for you.

Tom "Tom Notch" Hansen uses this custom exhaust
on his 2.6L Type 4 powered Type 3 Notchback.
Another option is to look locally for a muffler shop that has the facilities, know-how, and experience to build a well designed header. Ask to see some of their previous work, talk to people who've they've done work for, and ask questions. It's not a cheap process to do, but a well-designed system will make a great engine like the Type 4 either a tuning nightmare or a purring cat ready to pounce.

A good resource on designing your own header for a Type 4 is available here: http://www.e21motorsports.com/kendanielson/headers.html. Ken Danielson did a lot of research, learning about the ins and outs of designing a header. He has a lot of great links to other sources to make you informed. If you are considering fabricating your own header, make sure you spend some time reading this web page and it's links.

Thanks go to Rolf Christensen, Ron "Plastermaster" Roberts, Ephraim "Ephry73" Castillo, Rich Craig, Tom "Tom Notch" Hansen, and Jake Raby for all of their help in gathering the information and supplying photos. Thanks guys!!

Tech: CT / CZ Engines

Occasionally I get asked about what size engine is the CT or CZ code VW engines. The owners believe they own a Type 4 but couldn't find any information. At first, I couldn't find this code in all of my references either. They said it looked like a Type 4 engine and it came out a 80-83 Vanagon. Common sense told me to assume it was a 2.0L code that I didn't have a listing for, as all of the Vanagons here in the US that were air cooled used a 2.0 Type 4.


After discussing this with my fellow contributor, Rolf Christensen, he said that the CT code was indeed from the early Vanagon, but that it was a 1600cc (technically 1585cc, yep Type 1 size). From his description, it sounded like a weird low cost option for those early Vanagons. He'd had only seen a CT a few times, but he gave me a general description from memory. I was still curious....



Just recently I was given the opportunity to look through a European dealer parts book. In that book, I finally found a listing for the CT engine code. This required a careful study of the parts listings. What follows is a description of this engine and it's characteristics.

Just the facts....




The CT / CZ crankcase itself is very similar to a Type 1 crankcase. From these diagrams from the parts catalog, you can see the oil filter flange that is molded into the crankcase. The oil cooler flange is similar to the Type 1 flange, but you'll notice that it's closer to the distributor. You'll also notice the four studs on the shroud end of the case for the Type 4-style fan shroud. The oil pick up tube appears to be identical to a Type 1, and the flange on top of the case looks just like the one used for an alternator/generator stand on the Type 1.




The CT and CZ engines used a "pancake" cooling system that looks similar to the Type 4, but is not interchangeable with the Type 4. The shroud is really similar to a Type 4, but the part number is a different series, so I'm assuming that it's different. The fan looks really similar to a Type 4, and my suspicion is it's the same. Check out the adaptor hub, number 14 on the drawing.



Here's a diagram of the engine tin pieces used with these engines. All of these pieces are unique to this engine, making finding replacements quite difficult.

The oil cooler has it's own exit point for hot air, so the air blown across the oil cooler isn't dumped back on top of the cylinders and heads. The hole in the firewall tin is reminiscent of the doghouse setup on the later model upright 1600s.

Number 11 on this drawing looks really similar to the tin marketed as "Cool-tin" or "Super tin". So it was a factory part after all.



Here's a diagram with the oil accessories like the oil filter, oil filler, breather tower, dipstick, oil screen and oil pump. The oil pump and the oil screen appear identical to their Type 1 counterparts. The oil breather tower bolts to the same flange, in what appears to be the same location as the generator / alternator stand on the Type 1.

The oil filter mount is in about the same location as the wasserboxer engine and is cast into the case. The oil filler is similar to the Type 3, Type 4 or the Vanagon Wasseboxer engine. It bolts to the lower bottom of the back of the crankcase and extends upwards.



From this diagram we get a closer look at the cooler flange. Note that it is placed farther towards the back (away from the flywheel). This would make for some difficulty if you wanted to use this crankcase in a Bug. The standard upright shroud wouldn't encase the cooler.

VW used a spacer to place the cooler away from the cylinders and to provide it with it's own air flow. By the way, the oil cooler has a unique part number, so there's probably something about it that makes different from a Type 1 doghouse, Type 3, or Type 4 oil cooler. It may be the Type 4 oil cooler with a provision for the oil pressure sending unit.



Here's an oddity: the intake manifold. Check out the weird bends and the low rise of the carb flange. It's definitely not the same manifold as we are used to seeing. These engines used a Solex 34PICT4 single barrel carb, the same as used on the '74 Bug here in the US.


This engine used a lot of other unique parts that I haven't spoken about yet, including valve springs, and complete exhaust system. The crankshaft also has it's own part number, meaning it was unique to this engine. I don't know how it was different, as it uses Type 1 main bearings, Type 1 rod bearings, Type 1 gears, and 215mm Type 1 flywheel. It could have been a cast crank, whereas the previous cranks were forged. The valve springs could have been stronger that allow for the control of the valvetrain during operation. All of these unique parts will make restoration of this engine quite difficult (and expensive) to return it to original.

What was difficult to determine was the difference between the CT and the CZ code. The only difference I've been able to find between the CT and the CZ is that the CZ engine uses dished pistons, most likely to lower the compression ratio and the fuel octane rating requirement.

Both of these engines share parts from the Type 1 series, Type 4 series, and from the Wasserboxer. An example are the rocker arms. The early ones are the 8mm found in the Type 1; later they changed to the 9mm adjuster, same as the Wasserboxer. To my best judgement, the following parts are essentially the same as the later model dual port Type 1 engines: crankshaft (as noted above), connecting rods (standard 1600cc Type 1), and heads (with the exception of the small 30mm exhaust valve). Type 1 parts could probably be easily be interchanged on this engine to keep costs low during a rebuild and to get some more power.

The CT/CZ engine also used parts from the Wasserboxer, it's larger, younger brother. The camshaft, the 261mm pushrods, pushrod tubes, and oil filter were all borrowed from the watercooled flat four that VW used in the later Vanagons.

Not as many parts were pulled from the Type 4 parts bin. Hydraulic lifters (which were used for the Wasserboxers later) and the thermostat are the only obvious Type 4 parts used in these engines. There are a few hardware parts that are interchangable, but not worth mentioning.

What all this means is that any experienced Type 1 builder can use off the shelf parts to get more power and life from this engine. They just need to realize that this engine is still a "Type 1", and it's limitations are the same.

It's problems.....

This engine was made available from May 1979 through January 1983 on the Vanagon, offering it as a low cost option for customers not requiring the Wasserboxer or diesel engine. The key part of this statement is "low cost". It's been reported that the dependability and power are marginal when compared to the Type 1 1600.

It's close resemblance to the Type 1 also means that a lot of the same problems with the Type 1 are true with the CT/CZ engine. The crankcase is made of the same magnesium/aluminum alloy as the Type 1 cases, so align boring is often necessary. The fragile material causes the lifter bosses to be fragile if driven hard or with a large camshaft. There are workarounds for these problems, like sleeving the lifter bores, but the problems do exist.

Finding a CT/CZ in good shape is quite a rarity. These engines were generally driven hard, as it was pushing the Vanagon around, quite a bit heavier than the earlier Type 2s. It was even rumored that fresh from the factory the crankcases weren't as good as the Type 1 cases, but this is still a rumor, so treat it as such.

Where to use it....

I've had reports that these engines have been converted to upright cooling systems and increased the displacement to 1776cc, and that they are quite reliable. These upright conversions used a stock Type 1 fan shroud, modifired for an external oil coooler. They very well could have used one of the 911 fan style conversions.

I'd like to invite anyone with a CT or a CZ to contact me. I'd especially like to get some photos of this engine. If you do own one, email me. If you have any experience or knowledge about the CT/CZ engine, feel free to drop an email too, as I'd like to hear about it.

More info....

After posting this article, I posted a message to theType 4rum that's available in this thread. There was a lot of great information posted there, so if you are looking for more CT/CZ info, check it out. There's also a great article on these engines at Type2.com.

One of the regular contributors at the Type 4rum says that the Haynes manual for the '79-'82 Vanagons (Haynes #638, ISBN # 0 85696 638 x) has a lot of technical information on this engine. After glancing over the specs he posted, it confirmed my suspicion that it's internals are interchangable with the Type 1 parts.

Thanks to Rolf Christensen and the posters at the Type 4rum for their assistance in learning more about these mystery engines.

Tech: Type 3 Conversion

With the interest recently of how to convert a Type 4 engine for use in a Type 1 (Beetle, KG, 181, etc.) and in the early Type 2, many of the Type 3 owners have wanted to join in on the fun.

Actually, it's a natural curiosity, as both the Type 3 and the Type 4 engines utilize a lower profile cooling system (often referred to as a "pancake" cooling system) with the fan bolted to the end of the crankshaft and the shroud bolted to the side of the crankcase. They are on the opposite end of the engine from the flywheel. The fan blows the cool air over the cylinders and head and the shroud and engine direct it to the hot spots. The low overall height of the cooling system allows for a second trunk: one in the front (like in the Type 1s) and another trunk over the engine.

So, being the eager Type 3 owner, you want to know if this conversion is possible. Yes, it is possible, though it's not as easy as unbolting the Type 3 engine and bolting in the Type 4 engine. There are a few areas of concern when doing a Type 4 conversion into a Type 3 car: flywheel/clutch, intake, exhaust, engine/transaxle mounts, engine support bar, dipstick, fan intake boot, and oil filler. Each area will be a cause of interference, but most of the time it's relatively minor. Now let's look at each point and see how we can overcome them.

Flywheel/clutch: Because the Type 3 engine trans is basically identical to the Type 1, there's no point in me restating what I've already discussed in the flywheel and clutcharticles. Please refer to these articles for what you'll need to do in this area.

Engine / transaxle mounts: The added weight and torque of the Type 4 engine puts quite a strain on the engine and transaxle mounts. If you drive your Type 3 hard or if you modify the engine, you'll make the situation even worse.

The early Type 3s used a front transaxle mount (commonly called the nose cone mount) and two bell housing mounts (the same ones as the Bug cradle mounts). The transaxle is mounted to frame horns essentially identical to the Beetle. This method suspends the engine without any support on the shroud end. It is suggested that you provide support additionally with a rear engine support bar. This bar is bolted to the case underneath the fan shroud and is then bolted to the body.

Those of you with Type 3s with IRS (double joint axles or the tranny with CV joints) don't have the transaxle mounts at the bellhousing. These cars relied on the nosecone mount and a rear engine support bar. This setup works for a stock 1600cc Type 1, but additional support is recommended when doing a Type 4 conversion.

To support a full on Type 4 in an IRS equipped Type 3, it is suggested to get the torsion housing out of an swingaxle Type 3. It's a direct bolt in, but you will have to weld in brackets for the IRS diagonal arms. This will provide you with a nose cone mount, two bellhousing (cradle) mounts and the rear engine support bar.

For the really hot Type 3, other means of transaxle support are required. My personal favorite is the Gene Berg Enterprises's intermediate mount. It will provide a solid third mount for the transaxle and keep the nosecone end from lifting under those hard starts or powershifting. This mount is only usable with a Type 3 with frame horns, so the stock setup on an IRS car will not be able to use it.

Engine support bar: Now that you understand the importance of the engine support bar, we can look at what is required to make it. This bar requires some fabrication skills. For most Type 4 conversions, the stock Bus bar is more than adequate. You will have to cut about 1" off of one side of the bar, and provide some kind of bracket to mount the bar to the body. Dan Zink fabricated his bar mounts to bolt to the bumper bolts.

If your plans call for a lot of horsepower (like 200bhp+), I would suggest that you look into fabricating a larger, and stronger bar. My suggestion would be to manufacture it out something large like 1" square tubing. Pay particular attention to how the bar is mounted to the body; too weak a mounting and the next burn out you'll have a project for the next weekend. So, for the hot street crowd, I'd have a heavy duty nose cone mount, heavy duty cradle mounts, a custom engine support bar, and a rubber mounted Gene Berg intermediate mount. This combination should provide all of the support you'll need for spirited street driving.

Intake: The difficulty here lies in your choice of intake systems. The easiest way (in terms of fitting to the engine) would be to use the stock dual carbs from the 411/412 station wagens. They used really short manifolds and 34PDSIT carbs (the same carbs found on the '72-'74 US market Transporters). This would be an easy way out if you're in Europe, but these manifolds are basically non-existent here in the US.

The best option is to use the Weber IDF and Dellorto DRLA series carbs. There are readily available manifolds for the Type 4, but that isn't the end of the story. The problem with these manifolds is that they are too tall. These manifolds, with carbs and 1.75" tall air cleaners will rise above the trunk floor of your Type 3.

The solution to this problem is to cut the manifolds (or these) down to a much smaller height. FAT Performance and Eurorace have done this modification in the past, so they are the ones to contact for getting this done. The people I've talked to say they've paid about $250 for new manifolds that the shop modified appropriately. It's not cheap for manifolds, but the IDF/DRLA carbs allow for a lot of tuning adjustability.

These manifolds could also use the TWM IDF/DRLA style throttle bodies. This provides the best of both worlds. You can use off-the-shelf components for the TWM throttle bodies, standard linkage, and get the power and tunability of programmable electronic fuel injection(PEFI).

The next option requires a lot of skill and knowledge. This option uses the stock fuel injection manifolds and throttle body. It would require a total adaptation of the stock Type 3 fuel injection parts and the stock Type 4 fuel injection parts. The other alternative is to use the stock manifolds and adapt aftermarket EFI components. Either adaptation is difficult to do, so it should be left to an experienced tuner.

Exhaust: The saying is "what goes in, comes out", and that's how we start the section on the exhaust system. I would first recommend that you read my tech article on exhaust systems. It will give you some background information concerning selecting exhaust systems in general, particularly size and type.

What makes this part of the conversion difficult is that there are no readily available exhaust systems for the Type 3/Type 4 conversion. You will have to be creative with the stock pieces and the readily available aftermarket parts. We'll look at the exhaust in two pieces: manifold (usually referred to heater boxes or jtubes) and the exhaust system itself.

The exhaust manifolds bolt to the exhaust ports underneath the heads and generally do a 90° turn to exit back. There two basic manifold suitable for the Type 3: the Bus/Type 4 heater box with twin port flanges (used through about 1974) and the later Bus single port manifold that exits towards the front. This later system merges the two exhaust tubes into one flange. Either system should work for a mild street application. Dan Zink removed the heater sheetmetal to just have the bare j-tubes for his Notch.

If you are looking for a higher state of tune than that, with a large camshaft, large valves (48x38, 50x40) and an insane displacement, you'll need to make a manifold out of larger tubing. They will need to mimic Dan's j-tubes mentioned in the previous paragraph, only with larger tubing. This is best left to an exhaust shop that knows what they are doing.

It should also be mentioned that one difficulty you may run into with the exhaust is the header/muffler clearing the rear body. The modified j-tubes mentioned above have been shortened 1" to bring the header closer to the engine and away from the body.

All of the people that I've talked to have used exhaust systems designed for the Bus. The Bus exhausts are designed to clear the fanshroud and still not stick too far beyond the body. For most Type 3 conversions, the header/single quiet pack muffler for the '72-'74 Transporters seem to be the best option. It features a 4-1 collector, inexpensively priced and easily modifiable for different muffler. This picture shows the header and Yoshimura motorcycle muffler that Dan Zink is using on his '65 Notchback. The finished exhaust looks good on the car.

The Bus Monza system is also usable, though the exhaust tips seem to stick out a bit too far and it's way too restrictive to get the most power out of your engine. I'd stay away from these exhausts, even if you are not looking to win a drag race, as the most efficient exhaust will reward you with better gas mileage, better smooth drivability, and cooler engine temps.

So, for the exhaust system it pays to do some careful measuring and trial fitting. This careful preparation will ensure that you have less problems after the engine is installed and running.

Dipstick: It's been found that the easiest way to accommodate a dipstick in this conversion is the use the long dipstick from a 914 case. A Bus case could also be used, but a machine shop would have to install the dipstick tube in the same location. Here's a picture of a Bus case that I've had this modification done to.

If you are looking to do an ultra clean conversion, it would be suggested to look at using the Type 3 oil filler and dipstick mounts on the body. It would probably be possible by modifying the Transporter oil filler/dipstick tube. That way you can check the oil and add oil to the engine without opening the engine cover. Some careful planning and a little fabricating, and no one will realize that deep rumbling in the back is a Type 4 engine, even at the service station.

My personal recommendation is that you also look into using one of Gene Berg Enterprises' oil temperature dipsticks. It is an inexpensive tattle tale to tell you when the oil temperature rises to the 227°F range. This dipstick, in conjunction with the stock oil pressure switch provides basic engine monitoring for an insignificant amount of investment.

Fan intake boot: WIth an air cooled engine, it is critical that the engine be fed a diet of cool air. On the Type 3 (and the Type 4 station wagen), this air was pulled in through vents in the rear fenders, direct to a rubber boot that connected the body to the fan shroud. Without this boot, the fan will pull in the hot air surrounding the engine, and will not properly cool the engine. You will want to mock this setup with your new Type 4 engine.

After a lot of research, it has been found that the 411/412 station wagens (Variant) used a very similar setup that is handy in this conversion. The boot flange that bolts to the Type 4 fan shroud is quite rare. A VW parts manual shows the part number as 021-119-609A and was installed on all years of 411 and 412 station wagens (Variants).

The most difficult part of solving this problem is locating this flange. You will probably have to check local wrecking yards, eBay, or maybe see if you can get your local VW dealer to check their shelves for an NOS one. Use this flange with the rubber bellows and clamps and your engine will be getting a supply of fresh air.

Oil filler: The various Type 4s used two different types of oil fillers. One was a plastic funnel bolted to the breather box on top of the crankcase, and the other was bolted to a flange on the rear of the case, just to the right of the oil pump. The easiest solution in this case is to take the breather/filler, cut down the filler and re-attach using a putty bonding agent like JBWeld. A fresh coat of black paint and no one will be the wiser.

Misc tips:

1). Steve Glavas made the suggestion to use the Type 4 fan shroud from either a 914 or a 411/412. These shrouds had a screw plug on the top of the shroud that allows easy access to the timing mark on the cooling fan. If you don't use this particular shroud, it will be necessary to remove the air intake boot to check the ignition timing.

2). Nate Morse of Nate's Aircooled Tech and Greg McGee (he goes by Piledriver on Shoptalk Forums) have designed and templated a piece that allows you to mate the Type 4 fanshroud to the outer half of the Type 3 housing. This allows you to use the stock Type 3 cooling bellows boot. You can download the PDF here at Type 4: Secrets Revealed.

3). There is a great discussion thread on the Type 4rum on Shoptalk Forums entitled "Best Type III Conversion Factory Parts" that includes a lot of great information in doing a nice looking Type 4 conversion in a Type 3 along with pictures.

4). Nate Morse has another discussion great discussion the Type 4rum entitled "New Project: 914 2.0L into '67 T-3". He shows how he is building a Type 3 with a Type 4 engine. His goal is modern performance with factory looks. The thread shows how he designed and assembled the bellows adaptor mentioned above. It's a must read if you are considering putting a Type 4 engine into your Type 4.

I want to thank Dan Zink, Tom Notch, Nate Morse, Piledriver, and Steve Glavas for their help with this tech article. I don't own a Type 3 myself (though I plan to someday), but these great guys do, and have done this conversion. They were kind enough to answer my questions and share their experiences. Thumbs up guys!!

Tech: Type 4 Upright Cooling

The recent rise in the popularity of the Type 4 engine lately has left a lot of people curious of what their options were in converting the Type 4 to an upright cooling system. There seems to be more well engineered conversions on the market than ever before, so it's a good time to install a Type 4 in your pride and joy.

The purpose of these conversions is to shorten the overall length of the engine, so it will fit in the engine bay or won't hang over as much as the stock cooling system. Some of these conversions allow for more cooling air, allowing you to extract more power out of the engine.

Some of these conversions require that the oil cooler be moved from inside the fan shroud to an oil cooler elsewhere. These can work fine if the car is constantly moving and a flow of air is directed to the cooler. My concern for this is for a street car in stop and go traffic. An external cooler will not have a fan constantly blowing across the cooler, and as a result the oil temperatures can rise to extreme levels. This shortcoming could be overcomed by installing a oil cooler/fan combination, in conjunction with an oil temp switch that activates the fan when the oil temp rises above a certain temperature(180 degrees F?). With this setup the oil temp could be regulated on the high side.

Let's now look at the different types of upright conversions currently available.

911 alternator

For many of years, conventional wisdom believed that utilizing the cooling fan from a Porsche 911 engine was the key to the best cooling setup. On the surface, it was an obvious conclusion: this fan cooled everything from a 2.0L to a 3.6L flat 6 air cooled engine, so it could definitely cool a hot Type 4 four cylinder. It wasn't until 2003 that we found out for a street car that the 911 fan wasn't the "best" option. The 911 fan is also the current fashion trend, as it was popularized by the Kafer Cup racers.

Due to the abundance of information on this conversion, check out this my tech article on the 911 fan conversions available for the Type 4.

Type 1 alternator

Probably the most obvious conversion utilizes the Type 1 alternator (or generator) and it's matching fan. These pieces, that are probably in the average enthusiasts's garage already, are familiar to you and are reasonably priced. This assembly can cool anything from a stock 1.7 on up to a large cc fire burner. The shroud design itself is what makes this assembly effective.

There are many options in this category, so I've created a tech article on the Type 1 alternator conversion.

Horizontal fan

A third option is the horizontal fan. This places the fan laying on top of the engine. Riechert Tuning of Germany offers this conversion (it's on the bottom of the page) utilizing the 911 fan and alternator.

The problem with the horizontal fan conversion is that the twisting of the fan belt makes it susceptible to throwing fan belts. The 90 degree turn necessary to reach the pulley for the fan is the weakness and makes this conversion not as common. This weakness is inherent. I haven't received any reports on people who've run this conversion, so I can only speak from speculation.

After reading my thoughts on the horizontal fan conversion, the late Joe Locicero of Oregon Performance Products sent me this information in an email. The Chevrolet Corvair, built from 1960-1969, featured an air cooled engine and a horizontal fan, and it had the problem I described. Here's Joe's comment:
The belt throwing problem on the Chevrolet Corvair was rectified some time back by a Chevy Agency in Conneticut (Zink Chevrolet, I think). They sold custom bodied Corvairs and also did some racing. The problem is that the belt elongates in proportion to the amount it streches from the resistance (load) pulley to the power source (crank pulley). The greater the length of the belt, the longer it streches. The elongation happens on the right side on the Chev Corvair (idler pulley side) and on the left side on the Reichert set up since VW's rotates clockwise. The elongated slack side of the belt rises out of the "fixed" pulley groove and the belt is thrown. A new belt is a temporary fix until the fiber plies start to separate. The lighter magnesium fan on the Corvair reduced the fan throwing episodes, but in time as the belt got older, it would start throwing again. A simple spring loaded idler pulley will temporarily "follow" the belt as the belt elongates.and retains the belt in the pulley groove. I personally tried it on my Corvair Turbo 150 rail in 1970 after I heard about it. Very simple fix. Never threw a belt after that. I'm not sure what Reichert is doing or has done about the problem.

The horizontal fan conversion isn't very popular, so the information about it is just as scarce. If you've run a horizontal can conversion on a Type 4 engine, please feel free to contact me and share your experiences.

I want to thank the late Joe Locicero of Oregon Performance Products for sharing his vast knowledge.