944 2.7 8V Turbo ?

[J.C944TurboMan]

I have been toying with the idea of doing a 944 2.7 8V and adding the Turbo system !

Result a 944 2.7 Turbo more power or project to fail ?

Can this be done or has anyone done this already ?

Do you think the 2.7 will take the K27 Set up ?

What are the implications of such a thought !

All feedback welcome thanks []

 

[TTM]

You will be limited by the compression ratio of the 2.7 NA pistons, which won't allow you to run much boost.
If not replacing the pistons to do a proper, lower CR, turbo conversion, I would personally rather install a supercharger.

 

[ukmastiff]

Plus , having in mined the 3.0 turbo route is well proven , wouldnt a 3.0 turbo be far stronger and quicker than a 2.7 so why do the 2.7 route is my initial thought
( non spnnner handling thought of course [] )

 

[JM1962]

I thought (and I stand to be corrected) the turbo head had ceramic lined exhaust ports and sodium filled valves which the 2.7 doesn't and you can't put a 2.5 head on a 2.7 block.

 

[JamesO]

The 2.7 exhaust valves are easily swapped for the the turbo sodium filled valves and the ceramic lining isn't essential. Infact the ceramic lining has been known to fall apart and kill the engine.

Oddly the turbo exhaust valves are cheaper that the 2.7 exhaust valves.

 

[Lowtimer]

Barry Hart's very successful 3.0 Turbo 944 uses a 2.7 8v head on a 3.0 968 bottom end, with the pistons machined to reduce the compression.

 

[GC8]

The valves are larger in a 2.7 head James.


Simon

 

[TTM]

ORIGINAL: GC8
The valves are larger in a 2.7 head

2.7 intake valves are larger, exhaust valves are the same size.

 

[JamesO]

Yep they fitted fine in my 2.7 head.

 

[Ringo]

http://galerii.ecutec.ee/view_album.php?set_albumName=album26

On my project i used original 120kw engine turned pistons so the CR is 9,0:1. 120kw engine rods, block, and head.

 

[J.C944TurboMan]

Hi Ringo I love all the pic's and must say your 944T is looking fantastic ! May I ask what engine have you used ? Is it the stand 2.5T with all the extras ? I noticed that the exhaust sits very close to the oil sump , this will produce a lot of heat ! Would it not be wiser to try and have a cross over pipe made up that is further away from the oil sump ? for extra engine cooling . The other thing that Porsche did was house that metal water pipe over the exhaust manifold ! With the amount of heat comimg of the exhaust manifold it is like a constant kettle element ! []

 

[Ringo]

As said i used 120kw original block, head, pistons, crank, cam and rods. 944 S2 oilcooler system. Crossover look to close because of picture angel. In real life distance between oil sump is as original crossover. Crossover is also covered with heat wrap.

 

[os951]

you can't put a 2.5 head on a 2.7 block.

Why not ?

It requires just a small modification. Have done it, not difficult at all.

 

[333pg333]

The problem with the n/a head on a turbo car is heat absorption. The ceramic liners actually were designed for a purpose of course. I found on my stock 2.5L head that it possibly/probably was one of the main reasons I hit a 'ceiling' when on the dyno. We added a few extra psi and only yielded a minimal hp gain. We did gain a bit in the mid range but very little up top. Certainly this could be due to other shortcomings such as the stock throttle body and stock exhaust headers but most likely the stock n/a head. This car has a larger intercooler & pipes, cam, X-over, turbo, Exhaust system. It is also running Vitesse V Flex on the aggressive image. So there are only a few things left to look at as to why.

To the O.P., this sounds like one of those late night ideas. There's plenty of info on 2.7L conversions. You just have to do your research.

 

[333pg333]

ORIGINAL: Ringo

As said i used 120kw original block, head, pistons, crank, cam and rods. 944 S2 oilcooler system. Crossover look to close because of picture angel. In real life distance between oil sump is as original crossover. Crossover is also covered with heat wrap. 

Ringo, nicely done conversion. What psi level are you pushing? What are you doing for EMS? Those stock pistons and rods won't stand too much boost for very long. What fuel?

 

[Ringo]

Car is running on 1,1bar boost because of stock pistons and rods. I m using VEMS programmable ecu. Car is tuned on 98RON

 

[os951]

The ceramic liners actually were designed for a purpose of course

Directly taken from 944 Turbo Information Technik manual:


"The catalytic converter system with worlwide application in the near future requires that the exhaust gas to be supplied to the catalytic converter as hot as possible during the warm up phase of the engine. This is accomplished with cast-in thermal insulating exhaust port liners which prevent exhaust heat from being transfered into the aluminium walls and into the coolant"


Here's what happen when you try to fit 2.7L head to 2.5L block []

Making 2.5L head to fit 104mm bore block.

 

[TTM]

Isn't there any drawback to using a 2.5 head with the 100mm diameter combustion chamber on a 104mm bore block?

 

[333pg333]

Couldn't have said it better Olli. []

Thom, don't you mean the other way around, but I get the question and wondered the answer too?

 

[os951]

Isn't there any drawback to using a 2.5 head with the 100mm diameter combustion chamber on a 104mm bore block?

Honestly don't know, have done that modification though. I personally use 2.7L head which have far better shape intake ports compared to 2.5L version. Also i like it does not have those ceramic liners, which cause just trouble when they are 20+ years old.