Dougs951S

Does anyone have some 83 tolerance group 1 forged pistons laying around they'd let go of cheap? I'm considering doing something a bit unusual on my rebuild, may try and do a forged 9.5:1 turbo motor on a steady E85 diet using all factory parts.

Also can anyone answer conclusively what is different between the 83 Rarst forged rods and factory 951 forged rods? Are the rarst rods just as strong?

Ish_944

I have a set, but they are 10.6:1 and are located in Europe. Also not sure about cheap

Humboldtgrin

Are you using an early block? There are a few different 2.5L piston tolerances, group 0,1 and 2. I believe 83-85 are group 0. You should check up on that information before buying parts from different years thinking they will work.

Dougs951S

need some group 1 pistons, which was the "target" group when Porsche did the machine for all years and therefore the most common out there. As Humboltgrin stated, the pistons must match the block, which in my case is a group 1. The year is irrelevant for the most part, but FWIW it's an 85.5 block. That has nothing to do with tolerance group however.

Tiger03447

AFAIK, the rarst are forged rods, the later ones are cast...use the original rods, unless you go to Wossner or another aftermarket rod. Are you looking for strength or lightness? Carillo?

Dougs951S

looking to build a turbo engine and want as much strength as possible. Needs to be cheap, im a poor college kid. My engine grenaded so none of the factory parts of ok lol. I think I have a line on a set of forged 83 pistons and rarst rods, going to rebuild my megasquirted, E85 fed 951 engine at 9.5:1 compression.

Humboldtgrin

You might as well find a 2.7 engine and put rarest rods and 951 exhaust valves in it and see what it does.

Dougs951S

except that a 2.7 block is 1k, the head is another 1k, and no factory forged 104mm pistons exist. Also if I did have a 2.7 block and head, I'd be doing a 3.0

I can completely rebuild a 2.5 liter with new hardware, seals, bearings, rings, water pump, rollers, rebuilt head, forged rods and pistons, ect ect for less than the cost of obtaining just a 2.7 liter motor that will then need another 2k+ in parts before I'm satisfied with putting it back into my car. I'd love a 3.0 but right now in school its simply way out of my budget.

Oh and also the 951 exhaust valves dont fit inside a 2.7 head since they are too small

V2Rocket

Doug,
plyhammer has a 2.7 engine or 2 for about $1400 ready to run.
10.9 compression + boost....do it!!

Dougs951S

i probably would if i knew where to get some cheap 104mm forged pistons.

odonnell

Get a torque plate and bore/hone for 4.165" Wiseco SBC pistons split the set with someone else, pistons for $205. And you have a 2.79l motor...

http://www.ebay.com/itm/Wiseco-Pisto...xVAUcp&vxp=mtr

Not sure if the rods would work, I think people use the DSM rods.

V2Rocket

or spend $1300 and buy my sleeved S2 block and matching 4.125" 8v 3.0 turbo pistons...
add your 3.0 crank (or buy my spare ) and 951 rods and go to town...

konakat

I am curious about the strength of the 83 forged hardware. My early 84 should have the forged internals according to the block number and I was wondering about how much boost it could take on 93 octane. No e85 in my area :-(.

odonnell

http://www.roguetuning.com/944na_internals_-_the_limit

That's with cast internals. A lot of the failures seem to be detonation related, at least whenever I go on a search binge for "944 supercharger install"

944CS

I have a set of the pistons you need, but I am using the rods.