ehall

Chris
For engine machinist/racing newbs like me, would you give me a quick explanation of why the piston to wall clearance is different from street to race cars? Which is tighter tolerance, the racing blocks?

Markus951

If using stock rods 3.0 crank isnt there a problem that pistons will start to move up from the block a little? If so, can you modify stock pistons (shave some material from the top) Are the stroker rods (carillo, pauter) shorter than stock ones- or is it just a designe of the rod (to avoid rods to meet oil pan) why people are installing them on 2.8 strokers?

Has anyone build a stroker with stock rods?

Markus

Chris White

Not sure how I missed this question – but here is the answer –
With the JE pistons and Darton sleeves you have different expansion rates. The pistons will expand more the cylinders (true of all iron block engines) so a certain amount of cold clearance is necessary to get to the correct hot clearance. Race engines run hotter prolonged combustion temps so it is necessary to have a little more cold clearance.

Chris Whte

Chris White

The point of contact with the stock rods is at the edge of the crank girdle.
You can do the stroker with either shorter rods or custom pistons (different pin heights). Since I do mostly sleeved engines I go with the custom pistons – and they usually end up being 3.0 liters since I can do104mm pistons…

Chris White

TonyG

jturbo

I don't care which kit you get, or if you simply order the correct parts to do it yourself.

But no matter what, DO NOT use stock rods.

User Pauter or better yet, Carillo.

TonyG

jturbo

Thanks Tony.

I have looked at the following kit from Powerhaus. The kit includes the following:

4 Custom forged lightweight connecting rods
Lightweight custom 2.8 liter Mahle 8:5:1 pistons, rings & wrist pins

What do you think of this set-up?

TonyG

jturbo

I would not touch a project like this unless the engine was sleeved first.

The stock bores are fragile aluminum bores. Anything goes wrong, you get major scoring.

I'm assuming that you're using a 3.0L crank. Correct?

Sleeve the engine ($1600 for the sleeves including installation). Install the proper length Carillo rod and a JE piston. Make sure that you calculate the static compression and have it dish volume set according to what ever your needs are.

Again... it costs more to do it right. But in the long run, you'll have far less problems and much greater reliability.


"Basic Kits" like the one you quoted are just that.... a basic kit. Fine for a street car that is not making over 350Hp to the wheels for short burts only. But if you want a setup that will be reliable for sustained loads (track events), you need to get away from aluminum bores, and sleeve the thing.


TonyG

jturbo

Tony,

What size Carrillo rods and JE Pistons do you recommend?

TonyG

jturbo

I would get a piston made that uses a minimum of a stock 944 turbo rod length. Let the piston pin fall where it needs to. In otherwords, don't let the piston dictate the rod length. The pistons can be had pretty much anyway you want them.

You don't want to use a shorter rod setup.

If you want, tomorrow, I can get you the exact specs for the piston pin height, and rod length.

Do you know what you want the static compression set at (what fuel are you running)? What head gasket are you going to use, and what is its compressed thickness?

Also, if you sleeve it, it will cost zero extra to take the bore out. No point in staying at 100mm.



TonyG