86951Turbo

Working on my 86 951 I felt moving on to a 968 is the natural next project. At least the clutch job is easier on the 968. I've searched the archives, and can't seem to find a definitive how-to on the conversion. I want to build one to the 968 TRS specs w/ the 8V, K27 and Lower compression pistons in the 3.0L bottom. I think that covers general specs. Left 944 engine mount, left balance shaft cover and cap mod. Found RS Barn, but they do the service as a package. I want to build the motor myself. What mods are done to the 8V head and what engine management is used?

Thanks in Advance

Luis de Prat

Stick around. You certainly came to the right forum. Look up threads by boostfeen and 968TurboS.

RajDatta

1st off, do your research before you go farming any of this work out. There are a few vendors that act as middle man and have actually no experience doing such conversions. Speak to Kasturbo, since he just started the same project.
As far as easier clutch on a 968, if you are making a replica, you will be back to a 951 clutch setup so nothing new there .
You can't mix and match balance shafts. They are machined with the block. You will need to tap it for the oil feed and also need to tap your oil pan for the return line.
You can use a 2.7 head, which is a direct bolt-on. I can discuss with you further via PM.
Regards.
Raj

Thom

Are you actually refering to balance shaft covers ?
Since balance shaft bearings can be replaced I'm not sure why balance shaft covers couldn't be mixed.
AFAIK and observed there is only one mould for balance shaft covers (talking post '86 cars here), only difference being the 951 upper one being drilled for the turbo oil feed. The casting for the hole is here on 968 units ; I even think the part number is the same whether the hole is drilled or not - I'll have to check with the 968 & 951 ones sitting in my garage.
Also, balance shafts share the same part numbers between 951 & 968 so they should be perfectly mixable.
Am I correct ?

PorscheDude1

They are line bored prior to assembly. There for married together.

Thom

Still, they can be mixed.
A couple of years ago a friend of mine with a 968 had a stone break the lower balance shaft cover during a session on the track and had it replaced with another one ; to this day the car is still running perfectly.

RajDatta

Thom, there are lot of things that can be done, ie a scored block can be fixed and used. A set of bearing caps can be remachined but ideally you don't want tp mix and match these pieces when there is no need to.
To swap the upper bs housing just because you need the oil feed is not the best way. You are much better off tapping the housing.
Raj

968turbos2

Raj is right about tapping the housing. It is so simple that even sourcing the part is not worth it. Get the right tap from a specialty thread shop...mine ended up 5 minutes from my house called "Threads for the South" Took me 5 minutes to actually do but i must have pondered/discussed that mod for month.

968turbos2

If you get the diameter of the 944T oil feed hole and center the bit you will end up coming out in between the bearing half where you should. I put some oil on the bit and went through it like butter.

86951Turbo

A little research and help from Raj has me done to these items.

- 2.7L 8V NA Head
- 3.0L Mahle Pistons and Rings
- Turbo Intake Manifold, Left Mount
- Turbo Header + Cross Pipe
- Turbo Pulleys for Cam/Timing Belt
- Tap Left Balance shaft cover and Balance shaft cap
- Tap Oil Pan for Return
- Engine Management is completely up to me.
--- Aftermarket Standalone
--- Turbo DME/KLR
------ This option requires the 944 flywheel/clutch combo due to trigger issues.

Anything else?

RajDatta

Do understand, the dme/klr is the simplest way of doing it. You can do it using standalone which will require a new harness or changes to your harness.
Also don't forget
exhaust
wastegate
intercooler
throttle body
injector rail with fpr/vibration dampner
Injectors for low imp
larger fuel pump
I am sure there are plenty more items..
Raj

86951Turbo

I think I'm going to try the AEM Universal ECU w/ integrated knock control function, harness and wideband closed loop controller, and 3bar map rather than the AFM/MAF route. Is finding a 2.7L NA engine near to impossible unless you buy the car? nothing pops up when I try and search for one. LA dismantlers don't deal w/ 944's. Theres a dismantler up in norcal, but they're abit too pricy.

Just planning mode at the moment, but having a rode map sure helps.

Thanks again Raj!

RajDatta

I am surprised you can't find a 2.7 head. I saw a few of them for sale not too long back. Have you tried pelican?
Did you try posting on 951 forum. I am sure someone has one they can sell.
Raj

Techno Duck

1 pops up for sale every one or two months. Expect to pay around $1000 for a complete one with valves however.

boost feen

You will need to use the 951 bellhousing and clutch setup if running the 951 wiring and DME, KLR computers! Thus you will have to use a late 944 turbo torque tube or 944 S2 torque tube as they have the larger diameter driveshaft. Replace the 4 bearings in the tube as well as its a huge job to take it out later. So you basically have to take out the engine, transaxle, drop the rear suspension and once you have gone that far just finish taking out the front suspension. I recommend that before you do any of this lift the car up and steam clean the undercarriage, if you cant do this or have a friend that can just pay the $200 or so to have a shop do it. If not when you remove all this stuff at home it will have to be cleaned a lot more and the undercarriage will have to be hand cleaned in your garage which doesnt really work very well.