Ok so who can tell me, can I use the h855cp flat top pistons from summit? Stock 350 using the Ta284-88 Bore (in): 3.800 in. Bore (mm): 96.600mm Piston Style: Flat top, with no valve reliefs Piston Material: Hypereutectic aluminum Compression Distance (in): 1.324 in. Wrist Pin Style: Press-fit Pin Diameter (in): 0.945 in. Piston Ring Thickness: 1.50mm x 1.50mm x 3.00mm Quantity: Sold as a set of 8. Notes: DurOshield coated piston skirt.
No sorry the compresion height is all wrong.... If you want bigh compression for low cost find a place that sells the gm 3.0 v6 flat top pistons as singles and buy 8... I actually have 4 spares in 30 over, pm me if intetested and if you can find 4 more you are set... These work out to about 10.6:1 compression. URL=http://smg.photobucket.com/user/seanbuick76/media/diamond%20pistons/DSC01491_zpse68eda62.jpg.html][/URL]
Manufacturer's Part Number: 1734-STD Part Typeistons Product Line:Silv-O-Lite Cast Pistons Summit Racing Part Number:UEM-1734-STD UPC: 800745018205 Bore (in): 3.800 in. Bore (mm): 96.520mm Piston Style: Flat top, with no valve reliefs Piston Material: Cast aluminum Compression Distance (in): 1.808 in. Wrist Pin Style: Press-fit Pin Diameter (in): 0.940 in. Piston Ring Thickness: 5/64 in. x 5/64 in. x 3/16 in. Quantity: Sold as a set of 6.
Yes, those would work. Looks like you can buy them in singles too... Just add 2 more,buy your rings and done deal.
I wouldln't believe so. I had the same question on my set up on my 455 running the 288-92h cam that has more lift and duration. Talked to JW and he said that wouldn't be an issue. Jw said that if I got close to or over 240 duration that is where I would see issues. the max duration on that cam is on the exhaust side ride at 230. You should be fine. If you want more reassurance. Private Message or call JW at Trishield Performance. Good luck with it.
Since these pistons sit further in the hole than stock you "should" not have any valve to piston clearance issues unless the heads are milled or the block milled. It is always best to check this yourself to ensure there is not interference BEFORE running the engine.
I'm not a fan of how low the piston sits down in block cept for boosted application. I would suggest the 340p(70 type hi compression piston) which is .030 taller or the h522p piston which is .050 taller with valve recession. Either way I would suggest to deck block .025 -.035 due to block being taller than blueprint spec at least this much . valve clearance should not be much problem still due to head gaskets being .043 thick. The 70 engine used a .020 head gasket which also brings compression up. So mathematically you could cut deck of block another. 020 to compensate for head gaskets being thicker. And bring compression ratio to the designed 10 to 1.
I was looking for the 340's in stock bore but didn't see them available. I'm not apposed to the 70's dish but sourcing them seems difficult
TA sells the 350 cast piston in 8.5 and 10:1 compression. http://www.taperformance.com/proddetail.asp?prod=TA_1602
I see Ta sells the 10:1 at a cost, the flat tops would be a better performer, no? I look at it like this: I might as well do it now, I can't undo something that's already been done, and I don't want to regret not doing something that I should of done after the fact
Marc, I was in contact with Jay (crank and block guy at the machine shop) and it seems that the consensus between the owner Brian, myself and Jay that if you don't re-use the original pistons (which you can if your budget is tight) then you should bore it and pick a new piston that will get you close to 10:1. The used std 70 pistons that you supplied would be best left under the bench... The "10:1" TA pistons or the 340P30's would be my choice. I'll let Jay know that this job is billed directly to you and not my shop, and he'll let Brian know that or I can call on Monday and talk to Brian myself. I told him that I'm just a consultant sans the fees, just trying to help a Buick guy out.
I am greatful for your guidance with this project Bob. Money for money flat tops with std bore compared to .030 over with dish Pistons, is there going to be a difference for a street cruiser. Trust me I'm not trying to be cheap in any fashion I'm simply being conscious of the cost vs gains for what I'm building. Although this seems drawn out seeing how I started happy with my bottom end and installing a cam but now given the opportunity to build it I might as well give it what I can afford Anyone have any experience with the v6 flat tops I the stock 350??
If I had to guess, I would put the bore and hone at $160-200, just to give you an idea, but it's not my shop. I'll find out Monday. Good money spent at this point. You need a good foundation.
No, the .030 over would be the way to go with one of the those pistons. If you were just trying to due a really budget-minded freshen-up, then you could re-use your old pistons and just ball hone the cylinders and install new rings. If you want to up the compression, then new pistons should be used in cylinders bored and honed to fit them. Using new std pistons in your block wouldn't be a good idea IMO. I don't know enough about available pistons for 350's and what their cr will be w/o cc'ing everything to find out, which we can do, but we need to know from the 350 guys which pistons will yield what cr with a stock deck height, heads resurfaced "a little" and a given gasket thickness.
Stock deck height is part of the problem on 350s . being .023- to .028 over spec then add .043 head gasket compared to factory hi compression head gasket at .020 thick. That's a lot of compression drop. Stock 10 to 1 piston yeild close to 9.3 at that calculation.
TA sells a .020" steel head gasket for the 350's. So if Marc were to use the 340P30 pistons, have a stock deck, use the .020" gaskets, and figure a stock head cc, cr would be around 9.7?
The first step is finding out IF the block needs to be bored or not. Then after you get your pistons mock up a piston to see how far it is in the hole and then go from there. The flat tops are an easy way to get about 10.5:1 or better and that 284 cam needs over 9.5:1 to run right.... Nothing wrong with the piston a bit in the hole on a. Open chamber headed engine... There is no quench even with a zero deck piston.
