I am planning to build a 408 iron block stroker and I am planning to use Mahle pistons (4.030" with -12 cc dish). These look to be good pistons for my daily driver, NA engine. However, they do not have offset piston pins so they will be subject to more rocking and possible piston slap during warm-up.

Does anyone have any experience with the Mahle pistons in a stroker? Are they quiet or do they have a noticeable slap during warm-up?

I could ask this same question of anyone with a stroker and 4032 alloy pistons without offset pins. Another alternative that I'm seriously considering is a set of custom Wiseco 4032 pistons with offset pins. Please share your experiences if you have a stroker. Note, I asked these same questions on LS1tech.com, but I’ve not had any takers on the questions.

Thanks,

Steve

 

I couldn't help you ... I know my Diamonds were about the same price and have offset pins. They are off the shelf pistons as well.

 

Flyer,
What about your Diamond pistons? How do they sound on initial startup and after driving for a few minutes?

Thanks,

Steve

 

One of the things that concerns me about the 408 stroker engines is the amount of piston skirt that comes out the bottom of the bore. The 6.0l blocks are not a deep skirted block like the C5R blocks. With a 4.0" stroke crank there is an alarming amount of skirt that is un supported at BDC piston rock.

Richard

 

Still can't help ya my friend ... pistons are on the table still.

 

I was told that's why DIamond stopped making pistons for the 4.100 Eagle crank.

 

My iron block 402 is built with Diamond pistons and Scat 6.125 rods has absolutely no piston slap.

 

What pistons? -12?

 

Flyer - Yes, the -12 cc Mahle pistons with the 1.105" Compression Height.

Richard - I agree that the skirt is coming out of the bottom of the cylinder. However, this is true on the stock pistons with the stock 3.622" stroke and the 6.098" rods. The stock pistons are taller from crown to skirt, too. If my math is correct, the wrist pin on a stroker piston with a 6.125" rod and on a 4.000" crank is .162" closer to the bottom of the cylinder than a stock wrist pin. The stroker piston's skirts have a modified design not only to clear the counter weights, but to enable more of the entirity of the piston to stay in the cylinder bore.

I wish that GM made a tall deck (like 10" +/- a couple of tenths) cast iron block for trucks. In fact, I've written them suggesting this some time back. The deck height is not a powertrain packaging issue with the trucks like it is in a car.

The World Products Warhawk block will be available in a tall deck, but it's too expensive for what I'm planning.

Steve