Re Introduction - and 944s thoughts

[Kudzu911]

Good Morning,
Looks around, it's like going back to your old high school, walking down the halls, looking at the lockers. WTF is he talking about ? Well Long time ago, I was one of the first Mods in this forum, and broke out the 951 forum different handle of course we all move on. So as the wheel turns I've got a 87 944S living in my driveway, so 73K miles one owner, tracked it and spun the #2 bearing, owner towed it home from the track. I've got a good ( or maybe just ok ) 2.5 8v that is to be the donor for the lower end.

So questions- So do I swap just the bottom end from the donor under the head and run it? or should I just pull the crank and swap that? Anyone have a good video or write up of pulling and then setting up the 16V head? preferably without the unobtanium tools?

pulled the head off the donor engine, some discoloration in the cyls but nothing that will catch a nail, so thoughts ?

and yes I do have a 911 project too why not have 2 Porsches that don't run.

Matt

[944 Ecology]

Easiest thing to do would be to remove the engine, mount on an engine stand, remove the head (after marking the position of the exhaust cam sprocket), remove the #2 piston and rod, remove the main bearing web, remove the crankshaft and replace with a good crank, then replace the #2 rod and put it back together. (the pistons are different...)

I would guess about a 20 hour job. Add 10 hours if you don't lock down the exhaust cam sprocket. Ask me how I know.

[Kudzu911]

This is a 944S 87 I was under the impression that other than the head, the motor is the same as a 2.5 8v? Am I mistaken? Ok so explain a bit about the lock down exhaust cam sprocket please!

[walfreyydo]

The 944S motors run a higher compression, 10.9:1 vs the NAs which are lower. I believe this is because of the difference in pistons as I dont think the stroke is different. I dont believe the exhaust cam sprocket has timing marks so if you dont mark it, youll need a dial gauge to re-align it to TDC when you go to set the timing again. The process is shown in this video from Irina: https://www.youtube.com/watch?v=rm6d_Ntvgi0

[9FF]

Originally Posted by walfreyydo

The 944S motors run a higher compression, 10.9:1 vs the NAs which are lower. I believe this is because of the difference in pistons as I dont think the stroke is different...

Partially true, don’t forget that the US na’s were de-tuned and as a consequence they ran a much lower compression piston. The rest of the world ran 10.6:1 pistons in the na’s and everyone got 10.9:1 in all the 944 na’s towards the end of production.

But yes, the 944S pistons were different due to the four valve cutouts instead of two, and they were all 10.9:1cr, and the 944 2.5L na and S blocks were basically the same albeit they had different engine type stamps.

[TibetanT]

Totally agree with what Mike said here above!

If it were me, I would open the lower end and replace all the bearings as well as add new bolts and nuts for them. Also, flush out all of the oil passages...I mean everywhere even replace the oil cooler if you find one...just my opinion.

As far as the crank is concerned, you may find that the crank is just fine. Cranks can take a lot of beating and since the bearing is made of a soft metal, you may find that sending the crank out to a shop to get polished is all that may be needed. If you have the skills and tools, measure it for specifications. If you do not have the skills or tools, get a machine shop to do this task for you.

1987 944S is a good car !

Good luck with your projects, and "Welcome back" to the slippery slope.

[Fast Freddy 944]

Huh?