415LS

Is it any forged drop in Pistons for ls3 with higher compression then stock..? Reason for this is that I want add compression without needing to rebalance rotating assembly

Che70velle

iTrader: (6)

Wrong approach in my opinion. Balancing an assembly is power. Harmonics fight power, and balancing the assembly will do nothing but help you make power, for around $250. So…if it’s compression your after, why not just cut the heads and look at a .040 headgasket? What compression numbers are you aiming for?

Corona

They make flat tops and domes ....
you just need a good site that lists the top piston manufacturers...

google this Site they have pretty much anything and everything for the LS

LSXceleration, LLC

Texas Speed and Performance Also...

momofx

Yep I've been waiting 3 weeks for my pistons now, 3 more to go lol. Who ever thought a day would come we would be scavenging for parts like this when about 2 years ago you had a 101 options all in stock lol :/

pdxmotorhead

Yep and as the racing season settles down the demand always goes up.. Everybody wants to finish "over the winter"

Summitracing

We add 2cc's of dome volume to our LS3 pistons to get a bit more compression out of it...11:1 with 70cc and .040 piston to head. That goes up to 11.6 with 66cc chambers and even a bit more yet if you tighten to .036 quench. It's the SUM-3269434065-2

415LS

Hi summit
is the piston/pin weight in same range as stock..?

415LS

“Drop in pistons”means approx same weight on piston/pin so it’s no need for rebalancing rotating assembly
those forged piston you refer to which is off the shelf is approx 100 gram lighter then stock ls3 pistons

415LS

hi, sort of agree with you if I been living in us, but I’m in Sweden where a balancing cost me 650$… and im on limiter budged, else i bought a complete balanced stroker assembly..
I’m heading for 12 or higher ratio, and I already milled head ,030 and using .040 gasket
i want 12 or higher as I will run e85

Che70velle

iTrader: (6)

$650 even if heavy metal is not required? Tungsten is very expensive, I get that, but not always needed…

01CamaroSSTx

iTrader: (3)

Get the heads milled to .060-.070 and that should get your compression up. I know Mavn did this on his LS3 heads with a stock bottom end and running E85.

415LS

Hi 150$ Extra for tungsten…

415LS

if i mill so much I loose the alignment intake/hard and need to mill my intake manifold and still have Hypereutectic pistons… but it’s a solution if no pistons found

Summitracing

We developed our 6.2L liter Pro LS pistons with a net 2cc dome to build a bit more compression. SUM-3269434065-2 would be the standard bore Gen. 4 rod version and SUM-299927406522 would be the standard bore aftermarket 6.125 rod version. The Gen 4 rod version weights 537 grams average and the pin is 124 grams average. The shorter 6.125 version will come in roughtly 425 grams with a 105 gram pin. Running a .040 gasket will help. Our compression ratios are figured with .045 piston to head net clearance. If you are ALWAYS going to run E-85, Wiseco has a K447X7 12cc domed piston designed for aftermarket 6.125 rod which is .005 over and the height is about the same as ours (.004 in the hole at 9.240)

383z

iTrader: (2)

Simply mill the heads and use a thinner gasket. That doesn't cost much at all.

jdwtx85

Hi, seeing if you could help with a ballpark answer. On the stock ls3 piston if you mill the heads and thinner gasket you run into ptv issues. With your .2cc ls3 stock rod piston, is there ample amount of ptv room? Say you mill the heads to 66cc and thinner gasket, could you run say a 236 240 112 or something in that area.

Thanks

Jimbo1367

IIRC…….. Vengeance Racing used to offer drop in forged pistons. Might be worth Googling them

Summitracing

Sorry for the delayed response.

There should be ample PTV clearance with our -2cc dome pistons for the stock rod LS3 and your combo. Our Pro LS pistons sit .005" in the hole with the stock deck height of 9.240". They are designed for large solid roller cams and rarely require flycutting. Our recommendation for minimum piston-to-valve clearance is .060" intake and .090" exhaust. The thickness under the pocket is very thick and allows for a good amount of flycutting if necessary. The minimum intake pocket to top ring groove distance of .080" allows the intake relief to be .270" (.070" deeper) and the exhaust depth to be .270" (.120" deeper). Don't go further than necessary to maintain maximum strength.

We did a PTV test on a stock LS3 a while back. That's completely stock heads, deck height, pistons/rods, etc. Just changing out the camshafts with our Pro LS cams. When we tested on a stock LS3, the valve drop on that head was .128" on the intake. Our SUM-8710R1 Stage 3 LS3 version cam had .081"/.103" clearance. The stage 4 SUM-8711R1 had .076"/.096". We tested the standard stage 4 SUM-8709R1 as well which had .061"/.092". Remember this is with stock 0cc true LS3 flat tops with no valve reliefs. Things open up with our 6.0/6.2 pistons above designed with valve reliefs for cathedral and rectangle port heads.