Just joined the forum, though I've referenced many times in the past for great info. I did a search on the topic, but most of the posts are quite dated so I thought of throw out a fresh one to see if there are any new opinions/products. My set up is a Gen 1 350, 4 bolt main. Will be running a forged, polished Eagle blower crank with blower keyways, SCAT h-beams, hyd roller set up, 671 blower. My question is that of longevity/reliability. I want a streetable engine that'll run on pump dinosaur. I've looked at the MAHLE pistons, and they look like nice forged units that don't get into the ring lands, but I've found nothing with people running them under boost. I'm open to suggestions, but want to stay round $500-$700 for the slugs. I plan on running it round 8.0-8.3 comp. Thanks in advance for any and all info.
8:1 forged TRW's have served well with my 355/6-71 motor for over 20 years. Did a total rebuild in 2010 and the pistons were still perfect. Don't know how much boost you plan to run, the 12 lbs I'm running is plenty for street. Also the guys here might be willing to offer more help if you do an intro.
Thanks very much for the info. I'm new to the site, I'm not sure where to post an intro, but am more than willing. Not very tech savvy, me, but definitely willing to give it a go.
The problem with stroker motors is they do often require the oil ring to be cut into the wrist pin cavity because the wrist pins have to be moved higher in the piston body. The fact that the Mahle piston your looking at doesn't is appealing from one aspect, but also means the rings are likely moved higher up to compensate, but this ring stack may not be friendly for boost if the top ring is to high to the deck. I would gladly take a piston with the oil ring into the wrist pin as long as you have a support rail in it, without one it can be problematic in a street engine. But you also have to have the top ring far enough down to keep it from being torched. When setting out to build any engine, you have the piston designed around your needs first, then you make everything else fit around that. Things like shorter connecting rods are more of a compromise and forgiving than a lifted top ring land.
like maybe you should keep the stock stroke, and run more boost to make up for the few missing cubic inches? seems to work for Dean Lowe, as he said...
I spent 30 minutes on the phone talking to two techs at Mahle about pistons for a OT blown motor. I recommend you do the same with whichever company you choose. Ring gap should also be discussed.
I looked into that awhile back. My solution was to build a 377"(4.125 +.030"bore, 3.48" stroke) Much easier to balance the compression, ring land, rod length and valve shrouding with the blower. Time will tell if the narrower deck between the cylinders will be a problem.
I'd make sure the top ring was down 5/16". Different manufactures have different ideas. I tell CP to move them down and Arias to move them up. Dean and Jim runs these blown engines; I would listen to them...
Just a thought: we all like JE pistons, but SRP are the same pistons/same service/appreciably cheaper! My racing was "sponsored by paycheck" so I HAD to be the "cheapest SOB in the Pits" when it came to race parts : I shopped everybody else's discards, all the race swap meets,(& the "end of the Swap deals" from those who "didn't want to take it home"!) Anything to keep it running!!
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