Conversion Engines For  VW Type 1 Vehicles 

Select from the buttons below for detailed specifications of our two base engines offered for the VW Type 1 application. You can also use our Engine Wizard to customize each of these base engines into your dream engine. That’s one of the differences in our program, we originate, and we create. We don’t imitate 🙂

At Aircooled Technology we don’t create engines based on Type 1, 1600cc platform; what we do create are superior engines that seamlessly integrate (100% bolt in arrangement with NO CUTTING of the car!) into your Type 1 VW application that is based on the robust “Type 4 ” or “Porsche 914” platform. The Type 4/ Porsche 914 engine is bigger, stronger and more powerful than the 1600 base engine and transforms your car into a unique character. These engines have a maximum factory displacement of 2 liters, and we can increase the original HP of these engines by over 100%, while only increasing their displacement by 12%. This is accomplished through 2 decades of research, development, and dedication to our cause. Yes, we can build a 3 liter, daily driver engine, making over 250HP from a 1,700- 2,000cc Type 4/ 914 engine. Yes, I said that. 3 liters. (well, 2,913cc, but close enough)

Yes, this engine will bolt directly into ANY Type 1 VW, kit car, or etc. If a Type 1 engine will fit, then so will our MassIVe engine!

Read below for the details of why you need our Type 4 based engine in your VW that’s destined to be different, and how you’ll receive instant respect at any club, or VW show!

The Original Aircooled Technology Test Vehicle, The Bluebonic Plague as fitted with its first Type 4 Conversion Engine in the mid-1990s.

I wrote the below in 1999; today in 2018 nothing has changed.

There are several reasons for considering a power upgrade for your type 1. The biggest are those things that everyone who contacts wants.

-Cool running
-Modern Performance

Yes, it is true.. You are not alone. 95% of those who have commissioned us to create their dream engine over the past two decades have had the same desires as you… They want a driver vehicle with good manners, that isn’t difficult to drive, and that simply works. They also want it to haul ass. We deliver!

The biggest benefit of type 4 is that it is a later product of VW, well engineered and effectively designed. The type 4 engine was designed primarily as a solution to problems encountered with the type 1 over three decades of experience. These engines were used to power the Porsche 914, as well as the one year only Porsche 912E, and also the two- ton 72-79 VW Bus. Yes… These engines are overkill in many ways, but we don’t believe in overkill.. Overkill is just enough…

The type 4 engine is a true joy to have a Beetle, Ghia or Thing, no matter the year. We have fit these engines into split, and oval window beetles (with no cutting!), as well as the very last VW Beetle to have been shipped from Germany into the USA. Its the rarest of the rare, 1980 triple white cabriolet that came to us with 27 miles on the odometer, and with the original paper dealer license plate! The power and reliability are hard to explain. When type 1 is converted to type 4 power, the need for first gear is very seldom, and cruising speeds are better for today’s modern driving requirements. This allows us to configure your vehicle with altered gear ratios, that make better use of the incredible torque of the Raby- built power plant.

The type 4 engine is a very rugged unit made of better materials than the type 1 engines. The conversion is a very straight-forward procedure, and with one of our specially outfitted, complete engines or engine kit, it is a bolt-in item. We’ve developed flywheels, clutches, cooling systems, and throttle systems that make our engine a direct fitment into your Type 1. 

Below you will find my collection of reasons why I have converted all of my personal vehicles to type 4 power. Hopefully, these will answer a lot of your questions about what a type 4 engine is and why we feel it is a superior upgrade for the daily driven VW.

The Type 4 is bigger- Its bigger in EVERY way! The fact is the smallest Type 4 engine built by VW was 1700ccs, the largest Type 1 engine ever offered by the factory was 1600ccs, this means the smallest Type 4 is still bigger than the biggest type 1. Here we can effectively increase the stock displacement of a 2 liter Type 4 engine by only 12%; yet increase performance by 100% over stock. Doing more and making more with less is a key to a long life. Imagine a 180HP engine that only 12% larger displacement than stock… Try that with a Type 1!

Better Quality Components- We no longer work with Type 1 engines primarily due to continual component degradation in regard to component quality. Today its virtually impossible to build a Type 1 engine that isn’t comprised of a majority of components that are made in China, Brazil, India, and Mexico. Luckily the type 4 engine hasn’t been “whored out” as badly and the money-grubbing wholesalers haven’t had parts made in these areas that are not known for their quality. Here we HATE junk parts and feel that if we build your engine with them that we have “wasted our lives and wasted your money”.

A performance attitude – For years VW enthusiasts in Germany and the UK have chosen the type 4 engine for their type 1 vehicles. The type 4 engine was Porsche’s choice for use in the mid-engine 914. The base engine is superior for a better performing and longer lasting application. The type 1, when originally constructed was an economical means of transportation. However, with added displacement, it’s reliability and longevity is affected in some form. This is not true with a type 4. When properly assembled a type 4 of 2.3 liters, making 180HP or more can be driven daily and offer a life equal to the well- known 1776cc type 1 based engine. Starting with a bigger engine from the beginning is a sure way to add reliability and longevity to your vehicle while giving a big boost in performance. The type 4 engine can be taken to over 3 liters in displacement, while type 1 is at its maximum at 2.4 liters.

No, you won’t hear this from those who primarily build Type 1 engines. They don’t want you to know that our engine can be implemented into your car. In the land of VW performance, we stand alone; yet, in Porsche circles, our engines are well- regarded, and respected. 

“Stock” Performance parts – I feel that stock parts are in most cases 95% better than any aftermarket version. The type 4 engine has super duty parts that work well when modified, even heavily. With the type 4 it is possible to build a performance engine of 2.3 liters with only modified stock parts and only the use of aftermarket pistons, cylinders, and camshaft. The Type 1 is an engine that needs the aftermarket to gain performance. This promotes the chances of part failures due to low-quality assurance.

The stock parts in type 4 are hard to beat. For instance, I have seen engines with severe valve failures (6,000+RPM) and destroyed parts, but the crankshaft still keeps its integrity, as well as the connecting rods. These parts are Virtually Indestructible.

Aluminum alloy engine case – The engine base for the type 4 is a unit composed of high aluminum content, much stronger than Magnesium used in type 1 engines. This translates into a longer living engine that has superior resistance to wear. The Type 4 crankcase is also made of die-cast aluminum which separates it from the sand cast aftermarket crankcases that are commonplace in the Type 1 world. 

The type 4 engine seldom sees the need for aligning bore machining. The type 1 engine usually needs to align bore attention after 75,000 miles or less. The type 4, on the other hand, can sometimes see over 200,000 miles and not need to align bore services. What this means is better oil pressure and longer lives for bearings.

Added oil capacity – The type 4 engine has the capacity to hold another 1 quart of engine oil over the Type 1. This aide in keeping a constant supply of lubricant to the oil pump and bearings. Unlike the type 1, added oil capacity sumps are not usually needed, even in performance applications.

Factory oil filter – The type 4 engine is factory equipped with an oil filtration system. Unlike the traditional full flow oil systems available for the type 1, the type 4 system utilizes the factory oil pressure relief to bleed excess pressure from the filter during initial startup. Anyone who has ever blown a filter on type 1 can appreciate this. This system is also self-contained in the engine, and has no external parts, with the exception of the removable filter unit. This gives fewer chances for oil leakage or blown oil transfer lines.

Oil cooling – The type 4 engine has a more efficient oil cooling system and a larger oil cooler. When converted to upright configuration the oil cooling system actually works more efficiently. It is not uncommon for a 2.3-liter type 4 to have lower oil temps than a 1776 type 1 with a highly modified aftermarket oil system

Pushrod tube design – The pushrod tubes on a type 4 engine utilize O-RING design and seal off well for longer periods of time than a type 1. The system can be tricky to learn. After perfecting it is superior to the type 1, as it allows the pushrod tubes to relax during engine expansion and temperature changes. The pushrod tubes are removable with the engine assembled and in the vehicle. There is no need to remove cylinder heads to repair oil leaks.

Removable lifters – With the easy removal of pushrod tubes comes easy removal of cam followers as well. This will allow the inspection of the cam and lifters without disassembling the engine, a big help for engine builders and periodic checks.

Larger surface area – The type 4 is more heavily finned than the type 1. This allows for better efficiency in the cooling system. Type 4 has fins everywhere!!! These fins are placed in the best possible areas for heat dispersion. This means larger displacements are available, with no loss of cooling efficiency. The Type 4 engine has 26% more cooling fin surface area than a 1600cc Type 1.

Higher ratio rocker arms/ valve train – The type 4 benefits from a higher ratio rocker arm. This allows the use of less lift at the cam on performance applications. We have found that many type 1cam grinds placed on type 4 billets work well and add lift to the valves.

The valve train on the type 4 engine is easier to work with, It has twice the attaching hardware of type 1 and is better designed for maintenance. Valve adjusters are larger in diameter and keep their adjustments more precisely. Here, we use Genuine Porsche 911 valve adjusters.

Larger flywheel/clutch surface – The type 4 has 3 possibilities for clutch selection, either 200mm conversion, 210 or 215mm. Each of these is larger and hold better than the units used in type 1. These stock modified (pilot bearing inserted) transporter flywheels and clutch components are super tough and will hold high horsepower, and will correctly engage with the stock 12-volt starter in type 1 vehicles. The 210 flywheel and matching stock parts used in my 2.6-liter type 4 powered beetle will hold good enough for a successful 4th GEAR BURNOUT @ 6,000 RPM!!! When using the 200mm RAT conversion flywheel all popular Type 1 clutch assemblies and components can easily be applied.

Cylinder heads – All Aircooled Technology engines feature 100% brand new cylinder heads! The cylinder heads used on the type 4 engine are equipped with large ports with near straight intake ports, and bottom exiting exhaust ports, like the Porsche 4 Cam Carrera engine, or the legendary Mezger designed Porsche Flat-6. The straight flow design of the inlet ports is a real torque building characteristic. The stock cylinder heads on type 4 engines were subject to slight design flaws and need some attention to have longer lives. We have found the tricks needed to help these heads live long powerful lives and all of our engines are based on brand new, modified cylinder head castings.


General- All of these factors and much more that we have not stated are proof that type 4 is a superior replacement for the type 1 vehicle. In 27 years of experience, I have found that these engines are tough. To drive a type 4 powered type 1 is a true experience. All of my personal cars are powered by the Type 4 based engine and yours should be too~


2270cc Type 4 (roller cammed) engine fitted to Beth Raby’s late VW Super Beetle with DTM V2.0 cooling & air conditioning.

Some Common Type 1 Conversion Topics 

The Type IV engine will fit in conversion state into any aircooled VW vehicle. This includes the Beetle, Ghia,Thing, early bus and the Squareback and Fastback! The Porsche Speedster replicas as well as early 912 Porsche owners can also convert their cars easily,and it still fits well, as a bolt up!

Very, very seldom do we find it necessary to cut the engine bay of the vehicle for the Type IV installation. Almost every engine bay we have needed to trim for install was due to the vehicle being previously damaged from rear end collisions.

How big is it?

The Type IV engine is very similar to the Type I in design. Internally the SMALLEST Type 4 engine is bigger than the BIGGEST Type 1 factory engine ever produced. The outside of the engine isn’t that much bigger at all, which is why the Type 4 is right at home in any Type 1 based vehicle. The factory cooling system, that is not used in an upright conversion, is the single biggest difference in size between the two engines. Here at RAT we ONLY utilize our own DTM Cooling System to convert the Type 4 engine to upright for use in a conversion application, the specs below are accurate only if the engine is converted using the DTM system. When converted to upright the Type 4 is actually easier to perform tuning and repairs to, this is due to the fact that the TIV engine equipped with dual carbs is a whopping 2″ more NARROW than a TI with the same dual carbs. This allows for easier access to spark plugs, and carb adjustments. Engines with DTM cooling systems are even easier to repair, as there is virtually nothing to interfere with the part being removed/replaced. The engine installs the same as any Type I engine. Below is a general difference in physical size between the two engines.



Dimension Type 1 Type 4
Engine width (Carb inlet to carb inlet) 33-3/4″ 32″
Engine length (pressure plate to crank pulley) 16.5″ 18″ (no clearance problems in even early VWs and Porsches)
Engine height according to cooling system, generally 26-27.5″ Varies, no more than 27.5″ (no clearance problems)
Engine weight according to state of build No more than 30 pounds heavier than a normal Type I engine


 The Type IV engine will bolt right up to any 12 VOLT STD VW bell housing (transaxle) with no adaptor plates needed and without any machining of the transaxle. The bolt pattern of both engines Type I and Type IV are the same. Below we will state the needed mods to each vehicle to generally bolt a Type IV engine into it, we hope this answers a lot of questions.

Beetles(all years)

The Beetle is perhaps has been the most widespread vehicle to house a Type IV engine, Europeans have been doing it for over 20 years!. The Type IV bolts directly to the transaxle and even early vehicles rarely need any cutting of the engine bay. The beetle has a shorter input shaft and the TIV engine will require a modified flywheel to work correctly, we will cover this flywheel individually later. It is easy to find and modify, we even sell them 100% ready to install. The conversion can be accomplished with our DTM cooling system, which has been proven to be the easiest to install and most effective upright conversion kit commercially available. The Beetle is easy to convert, and it gives the car an entirely new character, no slower going up hills, and constant tinkering with small problems. In short, if your car has a 12-volt transaxle you can install a Type IV really easily, especially when you opt for one of our MassIVe conversions, we do all the small work to let you install the engine quick and easy.  The latest craze is coming with super modification of the “Super Beetle” it is called the German, or Euro look, and almost all these cars are equipped with large Type IV engines, Porsche brakes, Porsche Wheels and carbon fiber components. If you desire a car of this attitude, you definitely need a MassIVe conversion engine stuffed into the engine bay.

2270cc Aircooled Technology Conversion Engine fitted to Dave Worrell’s 1963 “Herbie X”. Installation by Dave McCutcheon

Karmann Ghia:

The Karmann Ghia is an excellent application for a Type IV conversion, and once again, no cutting is required. The Ghia’s attitude is one of more performance, it really needs it, especially since generally Ghias are heavier than Beetles, even from the factory, especially convertibles. This extra weight is barely noticed by a converted Type IV engine, it makes more than enough power to push the Ghia and make it perform to its physical appearance. The engine bay of the Ghia makes it easy for maintenance, and the DTM cooling system fits with no issues, and the decklid closes fully with no interference. Of all the conversions we do, the Ghias are the easiest, and really turn heads wherever they go. If you have a Ghia (any year) and want to boost the daily drivability or all-around performance, choose the Type IV for the job and you will be amazed. Ghias are really easy to work on with their engine bay, and that means a lot!

 Type 181(Thing)

When a “181” is converted to Type IV power it becomes a “481”!

A “481” is my terminology for a rugged vehicle that has the power needed to push a 2,700 pound, square-nosed, less aerodynamic vehicle down the freeway at speeds unparalleled by a Type I engine. The THING is a great candidate for conversion treatment, it’s designed, especially the engine bay, makes the conversion easy, and also makes it easy to get to when trying to do maintenance on the engine. The added torque of the Type IV engine is welcomed when it comes to better driving characteristics, crossing mountains, or cruising the speed limit on the freeway for hours. The stock gearbox of the THING will hold the power of the Type IV engine without problems, but for abusive or off-road applications it should be upgraded to either bus gearing or a better-built Type I gearbox. Our DTM shroud kits will fit into the “THING” and will do so without any cutting required. My personal “181” has been converted to a “481” and is now being restored. I drove it as a normal “481” for a year daily before deciding to add the suspension upgrades and make it a full time off road/play car. If your application is a THING, add a “Big Block” and enjoy higher top and cruise speeds as well as added acceleration.

Any Other Type 1 Based Vehicle:

 If you have ANY vehicle that currently has a Type 1 based engine fitted then simply fit one of our DTM converted Type 4 engines to it and just drive. The DTM equipped Type 4 will fit superbly into any engine bay that allows Type 1 engine fitment. 

Jake Raby