Porsche 944s2 engine

[yannisalex2000]

I want to build an IT legal engine for my 944s2.The problem is that one engine builder tells me that installing sleeves and boring the sleeves to .40 over is the way to go and another recommends boring the block to .40 and installing the pistons without the sleeves.So my question is to sleeve or not to sleeve?

[924Guy]

I wouldn't sleeve it - just that you have to get the bores redone properly, given the Al/Si block. A 928 shop will have the technology. One of my crew guys had his S2 engine go through a total rebuild, track/street car... went with a mild overbore, new pistons and rings from Diamond, had a 928 shop out west bore the block (can't remember the name, will ask).

Biggest PITA in that thing was timing the cams. Ended up busting the teeth off one, as well as bending valves, due to the first (failed) attempt.

Anyway, he gave a stock piston to Diamond to pattern; much less expensive that JE, I'd recommend calling them. A spare set of rings with your order is a nice bonus! Standard with them, because they normally do V8 stuff. They should also be able to do the math, I think, to adjust the pistons for bore etc as needed.

So, who are you having build it, anyway? If anything, I'd suggest a 928 builder. If not - well, the engine's just too special to trust anywhere else IMO.

[924Guy]

Back already with your info.

Turns out the 928 shop actually sent his block to US Chrome for Nikasil plating and honing:

US Chrome Corp of Wisconsin
650 Oak Park Ave

Fond du Lac, WI 54935

(866) 922-5066

As for Diamond Racing:

Diamond Racing

Ask for Nick ([email protected])

http://www.diamondracing.net

+1 (877) 552-2112

(OEM Replacement design should be on file)

Hope that helps; feel free to email me direct if any further questions about the build...

We also found a very good machine shop in town, eventually, for the balancing etc... not sure where you're at, though - please add your location to your profile!!

[GKR_17]

Back already with your info.

...Nikasil plating

not legal for an IT build.

[NORRIS]

not legal for an IT build.

What if the OG block was Nikasil?

[joeg]

I believe Porsche did treat those bores OEM.

Sounds like a very expensive rebuild.

Porsche...accept no substitute!

[GKR_17]

It would be legal to apply a Nikasil coating on an engine that came with the coating as OE. In that case, it would need to be identical to the original spec (try policing that).

As far as I know, the only cars currently listed that came with Nikasil coating were the ITR Porsche 911's.

The 944's came with Alusil blocks, which is an alloy, not a coating.