Pelican Parts Official Guide to the 914-6 Conversion (2024)

[Click on Photo]

Figure 1: 914-6 Oil Tank

Figure 2:
914-6 Five Piece Sheet Metal Kit

Figure 3:
914-6 Heat Exchanger (left side) Figure 4:
Original 914-6 2.0L Six Cylinder Motor Figure 5:
Cut-away view of 914-6 with Engine Installed

Figure 6:
After-market 2-Piece Sport Mount
(Vellios)

Figure 7:
Sport-mount shown installed

Figure 8:
911 Muffler Under Stock 914-4 Rear valance

Figure 9:
After-market Aluminum Oil Tank
(Vellios)

Overview
There is little doubt that the ultimate project for a 914 is the 914-6 conversion. When Porsche originally built the 914-6, they seemed to touch upon a really great idea. Yet to many, the follow through seemed lacking. After about three years of production, the 914-6 was discontinued. The original 914-6 had a slightly modified version of the 911T motor, which many thought was slightly anemic. Garnering only 110 Horsepower, this six cylinder motor is only 10 HP greater than the European 914 2.0L engine introduced in the years later, with similar torque output (see comparison chart). There is some debate, however on how Porsche rates it's motors. The 914-4 motor, designed by VW is most likely rated at an average horsepower rating, whereas Porsche HP ratings are listed at the minimum HP. Thus a 100 HP VW motor and a 100 HP Porsche motor are not likely to be comparable in overall horsepower.
The goal of this guide is to introduce you to the project and give you a little information on what is needed to perform the conversion. We shy away from giving information on upgrading your wheels to the five-lug pattern and other suspension modifications, because you can do the whole engine conversion independently of everything else.
Many people often ask about the differences between the early 914-4s and the 914-6. Here's a summary of them, and there's probably some missing, so drop us a line if you can think of anything else that can be added to the list.

914-4 cars used a derivative of the VW 411 motor, the 914-6 used a variation of the 911T motor. The 911T motor has generally been thought of as horse-power limited, yet quite reliable. 914-6 motors were generally serialized beginning with the numbers 640. The 914-6 cars were always identified by their VIN number, which began with the numbers 914. The four cylinder cars' VIN numbers did not begin with 914.
The 914-6 used a triple-throat Weber Carburetor system, whereas the 914-4 used Bosch MPC fuel injection. A different fuel pump was used to supply the carbs, as well as a different relay board to run the fuel pump.
The 914-6 was originally equipped with disc brakes and larger calipers than the 914-4. The front brake and suspension system was generally very similar to the 911T, however, the rear calipers and rotors were unique to the 914-6.914-6 rear brake calipers are quite difficult to come by, and look identical to the 914-4 calipers from the outside. However, they have a larger brake piston inside. The 914-6 also came with a 19mm master cylinder, whereas the 914-4 had the 17mm one. Torsion bars are from the 911T.
The 914-6 engine uses a dry-sump which requires a separate oil tank. This oil tank is shown in Figure 1. This oil tank is mounted on the left side of the engine compartment in-between the fender and the inside panel of the engine compartment. Four separate oil lines are required to connect the oil tank to the engine.
The engine of the 914-6 requires different sheet metal to fit inside the engine compartment. Five separate pieces comprise the 914-6 sheet metal kit. This sheet metal is shown in Figure 2. There is no plastic engine rain tray on the 914-6 due to interference with the carburetors. Additionally, the engine lid springs are 'softer' because the engine lid tray is missing, making the entire lid slightly lighter.
The 914-6 shipped with a different version of the 901 transmission. Although rare, this transmission is generally not desirable, because it was an early tail-shifter model which generally had trouble shifting in any situation. A very few number of 914-6s shipped with the Sportomatic transmission. Good luck finding one, though.
The 914-6 shipped with a five-lug pattern on it's wheels. Most cars were equipped with the optional Fuchs alloys used on the 911, however, some 914-6s shipped with five-lug steel wheels. There was also a five-lug version of the Mahle wheels available.
The 914-6 used a motor mount that was welded into the car, attached to the rear of the firewall. The 914-4 motor attaches to two motor mounts that hang down on each side of the car.
The 914-6 had a different steering column and ignition switch. The ignition switch was located on the dashboard, instead of the steering wheel. The 914-6 also had an electric windshield washer instead of the spare-tire pressure-fed system used on the 914-4. The 914-6 also used a different steering wheel which cannot be interchanged with a 914-4 wheel due to the differing spline patterns.
The instruments in the dashboard were different in the 914-6. The tachometer read up to 8000, the speedometer read up to 150, and the temperature gauge was combined with the fuel gauge. The 914-6 also had a hand throttle for the engine, located right in front of the shifter.
The 914-6 had a 914-6 emblem on the rear, and a five-lug pattern spare. Additionally, it is rumored that there was a specific 914-6 jack.
The 914-6 heat exchangers are completely different from the 914-4, as is the muffler, and the rear valance panel. The stock left side heat exchanger is shown in Figure 3.

Engine
One can write endlessly about which engine is best to use in a 914-6 conversion. There are plenty of types, and you should probably pick the motor based upon what performance you would like to get, coupled with what engines are available. 2.0L 911T motors are probably the most common, and the most affordable, but they don't pack too much of a punch.These motors are almost identical to the original 914-6 2.0L motor, shown in Figure 4. 2.7 911 motors are powerful, but they aren't very reliable. The 3.0L SC motor seems to be the best and most reliable, but it requires a modified flywheel to fit the 901 transmission. 2.2L and 2.4L engines have a good mix of reliability and horsepower, and are generally the way to go. The 911 motors (2.2L & 2.4L) in the S-type basically have all of their power curves geared towards the top end, and don't really fit as good street motors. The 911E motors (2.2L & 2.4L) have good low-end torque and good drive-ability. The 911T motors have less horsepower than the E and S motors, and and a very uniform torque range coupled with high reliability. This, of course, is a matter of opinion, and undoubtedly will vary depending upon who you talk to.
The best advice on acquiring the motor is to obtain the best condition motor as possible. Remember that 911 engine rebuilds are very expensive (new pistons and cylinders alone cost around $3K), so condition counts for a lot. Before you pick up a motor, it would be nice to have some paperwork on it to make sure that it was properly maintained.
A very good upgrade for your motor is to install the Carrera pressure-fed chain tensioners. It is often said that it is not whether your chain tensioners will fail, but when. With the engine out of the car, this upgrade is definitely worth it. If tensioners fail, the valves could potentially hit the top of the pistons, causing catastrophic damage to the engine. The entire kit costs about $425, and is worthy insurance against destroying your motor.
Once you have your motor, you will have to acquire a motor mount. The 914-6 motor is shown mounted in the car in Figure 5. There are generally two types of mounts. The first and easiest mounts to the existing 914 engine mounts. This is called a quick-six mount, and looks very much like the 914 engine mount bar. The primary disadvantage to this mount is that you need to modify the shift-linkage bar.
The second type of mount is sometimes called the sport-mount. Modeled after the original mount, it is welded and bolted onto the backside of the firewall in the engine compartment. This mount is shown in Figure 6 and installed in the car in Figure 7. There is a second part of the mount which is attached to the engine. The primary disadvantage of this mount is that it requires a small bit of welding. The good news is that the welding can be done after the engine is installed in the car. In this case, the mount is bolted to the firewall - a joint that is strong enough to withstand the initial drive to the welding shop. To weld the mount with the engine installed, you will need to remove the proportioning valve, and push the gas lines out of the way. After the welding is done, you need to replace the proportioning valve, and rebleed the brake system.
It's important not to forget that you will also need an accelerator linkage. Several different varieties exist, depending upon who makes them. There are some brackets which bolt on to the transmission. The stock 914-6 accelerator linkage bracket requires that two holes be drilled and tapped into the intermediate plate of the transmission. You will most likely need an accelerator cable, bracket, and linkage rod that extends up into the engine compartment.

The 914-6 engine can be identified by its serial number. An original 914-6 engine will have a serial number in the range 6400001-6420270 (my sources tell me that's the range; the last number may be slightly off). The serial number is located in a different location than the 911 serial number. The serial number is located on the top of the engine near the oil breather housing, and should be visible from the top of the engine compartment. The serial number on 911 motors is located near the fan housing (on 911s, this would be the rear of the motor).

Exhaust
There are two options for exhaust on a 914-6 conversion. You can go with the standard 914-6 headers (what most people do), or you can attempt to locate a set of 914-6 heat exchangers. The headers work well in the car. Their only drawback is that you lose heat in the car. I didn't think that this would be a big deal in my car, but it quickly has become one with the absence of a good defrost system. Used 914-6 heat exchangers can be bought for about $1000 a pair - a pricey figure but almost necessary if you want heat. An alternative is to build your own set of heat exchangers that surround the headers. This will be documented in a technical article at a later date.
The 914-6 uses a muffler similar to the 911. The 914-6 muffler will not fit under the standard 914-4 rear valance panel. Its tailpipe exits the muffler at about a ninety degree angle to the muffler. However, the stock 911 muffler fits fine under the rear valance panel beneath the bumper because its angled more like the 914-4 muffler. The 911 muffler can be seen under the stock 914-4 valance panel in Figure 8. 911 mufflers are quite plentiful and they look just like the 2.0L 'hotdog' mufflers under the 914. The 914 2.0L muffler bracket is a direct replacement for the 914-6 muffler bracket required to hang the 911 muffler.

Fuel System
The fuel pump needs to be matched for the type of fuel injection used on the six cylinder motor. When you acquire the motor and injection, you should try to get the 911 fuel pump that originally came with the injection system. Fuel pumps vary quite a bit, are difficult to distinguish, and cost about $250 new. Rebuilt fuel pumps are often unreliable, and are not generally recommended for use in conversions. In order to get the fuel pump to work properly, you need to jumper some wires in the electrical relay board inside the engine compartment. This is because the now-absent Electronic Fuel Injection computer originally controlled the fuel pump.
A set of triple-barrel carbs or the mechanical fuel injection will fit nicely into the engine compartment, although the engine drip tray needs to be removed for clearance. When installing a CIS system, there are a few things that you need to relocate on the motor in order to get it to fit in the car. An alternative is to cut some holes in the trunk; something that I wanted to avoid at all costs. Additionally, you will have to remove the engine lid latch, and replace it with some racing pin latches. The trunk springs will have to be removed as well. However, they can easily be replaced with gas-assisted shocks.

Clutch
The standard 914 clutch will work with the 914-6 conversion. The only piece of equipment that you need is an early 911, or 914-6 flywheel. This six-bolt flywheel is made to attach to the six cylinder crank and also mate up with the 901 transmission. The original flywheels were once hard to find, but now they seem to be in more than ample supply. It is recommended that you upgrade to a early 911 clutch with six springs in the disc instead of four. This is a worthy upgrade even for a four cylinder, and is very recommended for the installation of the six.

Transmission

On early cars, there is a hole already drilled in the engine shelf of the 914 (covered with a plastic plug in most cases). Drilling the holes is a relatively easy process, and can be performed with a standard hand drill.

Miscellaneous
In any job, there are short cuts, and then there is the proper way to go. There are lots of little things that should be done to the motor and the car when the conversion is done. Firstly, I would fully recommend cleaning up and patching any rust spots in your engine compartment - they will only get worse with time. This is a lengthy process, but well worth the time.
I would also recommend doing a full-service on the motor while it is out of the car. Make sure that the valves are adjusted. Replace the ignition wires with the stainless-steel ground type. Put a new cap, rotor, points, and new plugs on the engine. Also, check out and clean up the wiring if it needs it. Chances are slim that everything will go smoothly when you've reassembled everything - you want to eliminate as many failure modes as possible. Check all the oil lines on the engine for leaks or damage, and replace.

Another good thing to do is to take off the fan housing and check the brushes on the alternator. In order to replace these at a later date, you need to either drop the engine, or remove all of the Fuel Injection. It's worth checking now while the engine is out of the car. New brushes cost about $50 for a pair, but if you have to replace them at a later date, it will cost you several hundred dollars or several hours of time to get the alternator out. Make sure that you replace the fan/alternator belt as well.
The early 911 motors used magnesium valve covers. These covers have a propensity to leak oil because they expand at a different rate than the aluminum heads that they're bolted to. A very worthy upgrade is to replace them with turbo valve covers, which are made of aluminum, and have stiffening ribs to prevent them from warping and leaking. These covers will fit in the 914 chassis only after a small modification. The edge of the covers should be ground away in order to allow for clearance of the rear trailing arms. Usually, only the right side cover needs to be modified, however, on my car, both needed some machining to fit.
Replace all the gaskets and seals that are easily accessible. These include valve cover gaskets, muffler gaskets, exhaust pipe to head gaskets, injector seals, etc. You should also count on replacing all the vacuum hoses used in the fuel injection setup, and all of the fuel lines as well. Some of the metric hoses can be difficult to find at your local shop - we can provide you what you need to get the job done.
You probably will want to replace your tachometer with a six cylinder version since the stock 4-cylinder one will not work. You should match the tach to the engine since different engines have different red lines and different electrical attachment points.
Another item you may want to add to your list is a 911 starter. The 914 starter will work fine with the six cylinder engine, however, the higher torque required will wear it out much quicker. 914 starters are not known for their durability. A rebuilt 911 starter will last a long time.
You also might want to install a 911 temperature / oil pressure gauge in your dash. Most people usually install this in place of their combination fuel gauge, and then install an after-market fuel gauge in the center console. The oil pressure & temperature senders should be installed on the engine. Again, be sure to match the correct gauge to the correct sender.

Costs
Perhaps the most often asked question is "how much will it cost?" The answer, of course, depends upon the path taken, and the quality of the end product. The prices listed here are just a broad estimate for just installing the engine, and are not intended to be a price list. Prices fluctuate all the time, with respect to the quantity available. If you have the time and patience, good deals will arise. Here are some approximate prices on the basic components of the conversion:

A good core 911 motor with injection can be had for anywhere from $500-$4000 depending upon the condition. If you are going to have a top end job done on the motor (valves, guides, rings, etc.) then it will cost you about $2500 at a shop - less of course if you do it yourself.
The 914-6 sheet metal goes for around $400 for the fiberglass set, and about $600 for the metal reproduction set.
Used original oil tanks can be found in the $400 range, and new ones cost around $650. The after-market oil tank costs around $475. Count on spending about $550 when you include the filler neck, cap, dipstick, and filter console.
Oil tank lines typically cost between $100-$200 depending on what type they are (original vs. after-market) and what condition they're in.
Fuel pumps, if they don't come with the engine, cost about $250 new. Rebuilt and used ones are often not reliable.
The motor mount typically will cost $300-$500 depending upon which type you prefer. If using the quick-six mount, remember, you will most likely have to buy or alter your shift linkage bar, at a cost of around $100.
The accelerator linkage costs about $200 after you have bought all the brackets, and modified your transmission housing.
A good used 911 tachometer typically costs around $75.
A 914-6 flywheel costs around $300.
Used 914-6 heat exchangers cost about $1000 for a decent set. After-market headers typically cost around $400 new. An new after-market 911 muffler costs around $250.

As mentioned previously, all these prices are approximate. You may find the prices fluctuate widely depending upon the market, and the availability of the parts. Pelican Parts can help you assemble a complete 914-6 conversion kit without cutting corners. Give us a call, or drop us a line if you're interested in doing a conversion.

Another school of thought focuses around purchasing a 914-6 conversion project already underway. Very often, people don't realize how big a project this is going to be. They think that everything will just bolt together in a relatively short period of time. When swamped with the magnitude of the project, they often abandon it, and sell their entire incomplete project for pennies on the the dollar. I have personally seen many of these cars for sale, at prices worth about 40% of the total cost of the parts alone. If you don't like the project car, or have developed an attachment to your own car, swap the engines and resell the project car.

Summary:
Heres what you absolutely need to get the car running:

911 or 914-6 Engine
Fuel Injection System with Fuel Pump
Early 911 Flywheel (if not already on engine)
911 or 914-6 accelerator cable and brackets
Engine/Motor mount
914-6 Headers
911 Muffler & 2.0L 914 Muffler Bracket
914-6 Oil Tank, filler neck, cap, dipstick, rubber mounting sleeve, and oil lines
914-6 Sheet Metal (or fiberglass)
Exhaust gasket kit
Modified shift bar if used with quick-six mount

Heres what you should get to go along with the above:

Modified 911 Turbo valve covers to prevent leaks
911 tachometer (matched to engine type)
New spark plugs, alternator belt
New alternator brushes & alternator belt (highly recommended)
New Fuel lines & vacuum hoses
New fuel filter & oil filter
Carrera oil-fed chain tensioners
New cap & rotor & points
Stainless-steel ignition wires
New injector seals
Oil temp & Pressure Gauge

Conclusion
The basic conclusion to all of this is that the 914-6 conversion, despite the fact that the car was designed for the powerplant, is a huge project. There are very high costs - costs that can be minimized, but still are relatively high. Take your time, and acquire parts slowly, that way you'll be assured to get the best deal.
At any given time, Pelican Parts has a significant stock of new and used parts that we can supply to you at costs below our competitors. If you are looking for parts for you conversion, drop us a line and ask us for a quote.

Pelican Parts Official Guide to the 914-6 Conversion (2024)

References