Hi guy's, dealing with the same problem that all of us 350 Buick guy's have to deal with, trying to get some compression without spending a small fortune, or to better put it, trying to make power(compression) on a budget ou: Has anyone thought about using flat top 3.0 v-6 piston's in a 350? The compression height is a little low, but it has to be better than a dish??? The only other piston I found in a old Badger piston catalog was a 340 piston that had a small dish, but the compression height was up higher. The best piston I found was a race 3.8 piston that had a 1.868 compression height, was only offered forged, but from what I've heard it has been discontinued :ball: Anything else out there readily available on the shelf that will give some compression cheaply??? Thanks, Tom
Been there, doing it, have a few ideas in regards to this area. I got 3 sets of them now Tom :Brow: . Maybe if your really looking into a 350" we should talk. There are a few tricks out there if you look deep enough. lemme' know if you want to talk. OH and yea, the pistons you mentioned will point you towards 11-1 on a stock rod, depending on all the other variables. It could go up from there too..... :Brow: But be careful, there are specific part numbers you have to look for in the pistons. It took me awhile to round mine up to get what I wanted.
o.k. Hey Dave, If you would(and don't mind) PM me your phone #, I would be interested in chatting about 350's with you. :3gears:
I picked up a set of 3.0L piston for my 3.8L econo rebuild. Did it on faith because I never found anyone who's actually used them. These are a cast and heavy no name brand that came from ebay. The dishes measure out to 17cc. With a .019 steel gasket and .060 down in the hole I should have 9.2:1 compression. We'll see o No: .
Any chance on you posting some of these super-secret rebuild tips for the rest of us small block guys out there?
that about as good as it get's Without a bunch of expensive machine work(decking or mill heads) that quench number is about as good as it get's with what's available off the shelf as far as piston's go. Most engines are probably farther down in the hole than .060, unfortunately :ball:
Yeah, not optimum is a putting a good spin on it. But, it'd cost $$$ to get the block deck, head intake surface and intake worked on. Plus custom pushrods are more $$$ etc... I just want it to run reliably so I can enjoy driving the car for a while. Haven't really got to do that since I've had the thing. Then I can save up some pennies for a 350 with aluminum heads and a good flowing intake :Brow: . That'll be a couple years down the road and by then the parts may just be here. :sleep:
Did you check the following threads for info? http://www.v8buick.com/showthread.php?t=105822 http://www.v8buick.com/showthread.php?t=94176 HTH
Seems like I remember another good post that talked about using V6 pistons in the 350. The one I'm thinking of mentioned something about there being a difference in the pin boss gap. The rods have different little end widths, or something. Can't find the post though.
what will be the compression on a stock never been milled 350 with stock 1972 pistons 8.5:1, if u change the pistons to some flat top .030 3.0 pistons ??? anything special to make em work???something like this... http://cgi.ebay.com/ebaymotors/GM-B...hZ019QQitemZ8068567603QQrdZ1QQsspagenameZWD1V
need more info We really need to know what the compression height is on these piston's to figure out the compression.
Compression height on these is 1.802. http://cgi.ebay.com/ebaymotors/BUIC...categoryZ33623QQihZ019QQitemZ8068811196QQrdZ1 Plenty of calculators on the web. You can literally play number games all night. :grin: http://kb-silvolite.com/calc.php?action=comp
I think......... It's been quite a few months back, but I stuck a used 3.0 piston in a 350 that I have on the stand, and if I remember right the piston was -.087 down in the hole :eek2: ou: :ball: Might not be too bad of a piston choice if we mill our heads down to about 30cc's :grin:
Spmething you need to understand here. First off, people mis use or confuse the term quench and squish. Squish is what most people are reffering to when they talk about keeping the flat part of the pisotn against the flat part of the head, everybody calls this quench. On the 350 Buick engine, squish does not exist anyway, it uses a full bowl type open chamber, there is no flat area of head against a flat area of piston. So it really does not matter how far down in the whole the piston is anyway. Fedral mogul 496P is the piston we are playing with on Dave's motor, it is a true flat top, no dish, no notches, no nuthin. This piston has the exact same pin height and pin diameter as the 350 piston. same bore size. It is from a like late 70's ish or 80's ish 3.0 v-6 Buick. This piston will sit down in the whole a bunch, like the sotck 350 piston, but since there is no dish, you will have very high compression, I belkieve around 11.5 or higher depending on the deck height and chamber volume. the other option on the 350 is to use turbo v-6 Buick pistons if you want to build some sort of motor with boost. Quite a few chices for pistons for the turbo v-6 engine. Jim burek
Interesting... I just did a quick calculation. Bore 3.83 Stroke 3.85 Gasket Bore 3.9 (guess) Gasket Thickness .019 (guess) Piston Dish 0cc (flat top) Deck Clearance .087 (from Tom) Combustion Chamber 55cc CR= 10.67 Change the gasket thickness to .040 and we get 10.17. BTW, the compression height of the piston in the picture is 1.825.
I think only the 68-70 guy's will benefit being able to use the .020 steel shim head gasket. The rest of us who have a later block/heads get another kick in the teeth by having to use the .045 thick Felpro ou: :ball: Why does it have to be so difficult o No:
As long as you clean up the chambers and piston tops, it does'nt seem to be a problem. Otherwise, yes , I think they are a little more prone to detonation than the 455. Jim
