Does anyone out there have a link or knowledge about the bore and stroke of the 944 NA motors throughout the years? I know I put 84 and 89, but the reason is for purposes of an engine rebuild. I am interested in using 2.7 connecting rods on a motor that is not a 89. Does anyone know if the 89 NA motor has not only a bigger stroke but a bigger bore also?

I intend to get my hands on some Euro pistons for my year and use 89 2.7 connecting rods. Right now I am acquiring more info for the construction of a modded 944 motor. My other question would be, should I use european pistons for that compression or should I use 89 pistons (if there is a bigger bore). And would I have to sleeve the motor if I bore out? My goal is around 10.6:1-11.0:1 compression. This will also require the use of a higher lift camshaft than the stock spec one. Lemme know what I'm getting myself into in regard to the bore and stroke of an 89 2.7 NA motor and its components on a motor before that power increase.. Thanks

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The 83-87 944 2.5 motor has a bore of 100mm and a stroke of 78.9mm and compression of 9.7 The 88 944 is also 2.5 ltr with a bore of 100mm and a stroke of 78.9mm but the compression was 10.2. In 1989 the motor went to 2.7ltr this was done with a larger bore of 104mm and the stroke remained the same at 78.9mm but the compression went up to 10.9. As you can see the 2.7 rod is the same as the earlier rods in length.The 100mm Euro piston will work with a standard rod and give you a 10.6 compression.

 

The bore and stroke through 88 N/A was the same. 1989 The bore was 104mm and the stroke was 78.9mm. which is the same stroke as the 83 thru 88 N/A. Hope that helps. The info was taken from the shop manual.

 

Thanks very much for the info, right now I am looking for longer connecting rods. I notice the S2 has a stroke of 87.8. Would the connecting rods from that car be compatible? I am looking to retain the stock 100mm size but I would like to stroke up instead. Would it be possible to use S2 connecting rods on an NA crank? What about the stroke of 84.4mm on the 924 GTS? Would I even have to have a custom crank to achieve a high stroke that would get me around that range of 10.6-11.0???

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people use cranks to stroke the engines, like the S2 crank and then its something like 2.8l i think... yeah i dont know

 

If you use a longer rod with the stock crank you'll slam the piston into the cylinder head. You need to use a 3.0L crank to stroke a 2.5L to 2.8L.

 

see i did know

 

I didn't know that <img border="0" title="" alt="[Eek!]" src="eek.gif" /> We wouldn't want any slamming to happen now would we <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> <img border="0" alt="[oops]" title="" src="graemlins/oops.gif" />

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