MarkRobinson

I have a set of 944T pistons & rods & assume the cranks are nearly identical if not identical.

For my Porsche-boat, a 944S engine (head) would be prettier & flow more than a normal 2v motor & since I'll need to customize the engine anyway, am considering using a 944S engine I stumbled upon.

There are plenty of vehicles out there without sodium-filled exhaust valves...and since the lake water averages 68 degrees, keeping the water/oil/intercooler cool shouldn't be a problem.

I can also have the exhaust ports, piston tops, and custom header ceramic coated by Swain before this venture.

Have i missed anything that's a common issue with using a 4v head? Intake/exhaust wont matter: going custom.

The only thing I've not studied is what the compression will end up being: will I lose compression with the 4v head or gain compression?

Thanks for any input.

Mark

lee101315

Nice project.
You will gain compression by using a 4V head, you'll have to use custom pistons to get the correct compression ratio.

MarkRobinson

I'll be using AEM Engine management and E85 fuel (104 octane); I can work with higher then normal compression ratios.

I'd probably want to avoid anything over 10:1 or so, but the 951 pistons have quite a bit of dish to them.

Mark

Ski

Old Glastron Carlson?

lee101315

Youd have to fly cut the stock 951 pistons if youre going that route. If you do a quick search, there are a few members here who did use 951 pistons with a 4 valve head. Raceboy is a user that comes to mind..

MarkRobinson

Yes an '80 CVX 20 Intimidator: rare, less than 100 built in '80, Mercruiser/SBC setup (most were BBF/jet & about 10mph slower).

Lee: I"ll do that, thanks.

MarkRobinson

I don't see any posts...figured the 944S guys might have some input...nope.

Mark.

MooreBoost

with a 944 S head and the 951 bottem end, the compression ratio will be 9:5.1

blown 944

Check with Chris white for some pistons he had. I would at minimum get those and change to the rraast rods. Preferably even better rods.

Depending on boost needed you shouldn't have to do too much using that head.

However, I personally like torque better so I'd stroke it