Re: New Engines: 557 or 572
 

I run a 6.70 rod in mine but we needed to order custom pistons cause we couldn't find a dished piston to bring down compression for the blower. Lunati said we could have ordered a flat top piston for a 6.70 rod but we would have needed to mill a dish into the piston and I didn't want to do that.

We also had to go .030 over due to some tapers in the bores so I'm actually at 580 cu in.

Re: New Engines: 557 or 572
 

there is more to running a dish piston then just for compression with a blower motor you did the right thing

Re: New Engines: 557 or 572
 

The only thing we did wrong was totally miss the mark on the cam.... ohhhh, I've learned so much since then and have also switched builders..... :eek: :drink:

Re: New Engines: 557 or 572
 

Wouldn't the growing popularity of the 557 vs 572 be a piston speed issue ?
4.375 stroke equalling more durability & reliability ?

Re: New Engines: 557 or 572
 

So MC: What did we learn from this experiment? It's always good to have extra motors on E Dock!!!!

Re: New Engines: 557 or 572
 

it could be but rod length also efects piston speed

Re: New Engines: 557 or 572
 

I have run 4.600 bore -4.500 stroke for over 8 yrs with no less
than 6800 chips. It all depends on the height of the block,length of the rod,and pin placement in the piston.
I will run my power for how long it takes.If you want to run a larger enough cam solid rollers are the only option.
I don't get it some times and I know it drives engine builder's
nuts.Power boaters will spend days or big $ on detailing ,but taking a couple of hours to run through the valves or at least an inspection is out of the question.Its cheap insurance in my book,I like to pull the valve covers after every hard run.
Big """ would be my choice just depends on the combination
your looking for. Good luck I'm a little envious that your building spares.

Re: New Engines: 557 or 572
 

MAY I please ask a question I have a 502 30 over so it's a 510? or 509? next time I freshin up what would be a good stroker set up what size crank and rods? I HAVE MERLIN 310 R M HEADS ON IT . CAN IT BE BUILT TO 540 550CI'S. THANK YOU ART :D

Re: New Engines: 557 or 572
 

you could run a 139cc head to knock the compression down. I run a 4500 bore 4500 stroke 6.700 rod flat top piston on a 139cc head 60,000 copper gasket never had any problems 9lbs of boost.

Re: New Engines: 557 or 572
 

What block are you running? probably shouldn't go over 4.25 crank with 6.385 rods, 4.53 bore, 548 cid.