hmd

NZ951,

I am planning on doing 2.7 later in the year on the 2.5 block, not 2.8 just to get some safety margin.

I am planning to put in some steel sleeves and get locally custom made forged pistons (about US$900) and be done with it.

My friend S2 just had a rebuilt because his piston coatings were flaking off, this is an original factory engine, just go to show even factory coating can have problem.

NZ951

So we need sleeves on 104 and 106mm bores?

If thats the case:

JE low compression pistons: $695.
Sleeves: ???

Chris White

Since you asked….
I have been sleeving blocks for a while and have a dry sleeve ‘kit’ available for $2750. Sleeved block, JE pistons, rings, wristpins. The block is plateau honed ready to go. “some assembly required!”
The first set of wet sleeves with integral deck are on the way – I anticipate that set up will run about $500 additional.

Not that this is a sales pitch…but make sure who ever you get to sleeve your block has some experience with 944 / 928 sleeving. I have about $5k in specialized tools that were custom made for this work, without them you stand a pretty good chance to suffering from a failure.

Chris White

NZ951

Well, I would have to check there is a Porsche racing series here, but I dont know if anyone has sleeved to be honest. Hmmmmm pre-made sounds attractive. A block would be too heavy to ship I imagine.

Skunk Workz

What kind of failures are we talking about? Sleeves come loose? Or?

hmd

NZ951,

don't know about NZ but here in OZ there are plenty of people that get their 2.5 block sleeved, there is a very popular 944 challenge race series here thus more people doing these type of works.

Chris,
If I am sleeving with steel sleeves why would I need people with 944 experience?

Matt Sheppard

I have a 2.7 "kit" I am looking to sell. It's a steel sleeved (104 mm) 951 block w/ 968 oil squirters and some oil galley mods all done by Garrity along with the Ross pistons he speced , forged 951 rods and a stock 951 crank - matching bal. shafts and '87 oil pan included. I'll want $2K for it.

Motor had 10K on it when I tore it appart. The assembler did not do a thourough job w/ it - the rods were wobbiling on the piston pins and the Ross piston/cyl. clearance spec was HUGE. The thing had so much piston slap that I took it out, considered doing a 3.0 w/ it and have since given up hope of ever getting the $$$$ required to do it right (104.5 mm Mahle 968 turbo pistons, rebore, deckplate hone, Carrillo rods, 968 crank, full balance, engine management, 2.7 head. . .).

I was planning to offer it soon, but saw this and thought you might be interested. I have the invoice from Garrity for $3000+ for just the block work, pistons and forged rods. I would not use the pistons personally, but. . . The rods would need rebush small end minimum. Ollies charged me $50 last time I did this. PM me if you want more info.

Otherwise, good luck w/ the project.
There is no replacement . . .

Matt Sheppard

There was also some discussion re blocks cracking w/ 106mm bore/sleave combo. Danno's AMW engine IIRC. Seems to me that 106 might be getting a little thin for the alusil block, but I'm no engineer.

I do know Garrity would only go 104 for this reason. I am running a head he did for sombody else (bought it from 2nd party, but had reciept) and I will say he knows/knew his stuff when it came to machining.

hmd

We should all get 6.0 LS2 Engine

NZ951

You know, melb is only 3 hours flight away... I have credit with the airline... I wonder if I should come smack you around before or after dinner tonight.

Porsche-O-Phile

I'm sure Danno will chime in here, but as I recall the primary reason his cylinder cracked was due to a crap sleeve job, not necessarily the thickness (or thinness) of the cylinder wall. I've seen the engine - it's a stress-induced looking crack, not a blowout. I'm not saying it couldn't happen (see my concerns above) but it's just another thing to consider if you ARE sleeving.

Anyone know what the difference in rates of thermal expansion are between the steel liners and the alusil blocks? Enough to induce destructive stresses? What about at operating temps? This is a hardcore engineering problem whenever you're dealing with dissimilar materials. You also have to consider that if Danno's failure was due to a poor sleeve job, it COULD happen to you. It's one more risk you take. I'll probably just say "screw it" and go oversized to 100.50 mm. I'm leaning that way, anyhow.

hmd

It depends whether you can run with mine, Autronic tuned 99 STi with stroked 2.2 ltr, garett bb turbo + with your renta-bomb.

NZ951

Well, I can run with a stroked 2.2 EVO 6.5, so the wrx will be childs play

Skunk Workz

Seen "stress-induced-looking" cracks in highly tuned motors before...sometimes they are more of a problem of localized heat than different thermal expansion rates.

hosrom_951

Question: Would it be 'better' to get aluminum sleeves instead of steel since putting steel sleeve in an aluminum engine wouldn't be suitable due to different tolerances between the two materials and temperature etc......?