Guys I tore down my 75 455 last night and it has some serious ridge on it. Measuring with my finger nail I would say between 5-10 thousands. I was hoping for a cheap rering job but didn't win the lotto! I will bore guage it tonight. How far out would acceptable for a stock 50,000 mile rebuild? I might need a good cheap piston that doesn't have any destroke in it like a chevy rebuilder piston does. If these things are already 50 down. Are Buick rebuilder pistons destroked? How much would zero decking the block give me with a stock replacement piston? I'm willing to bet almost a full point! Can you buy .050 stroker pistons? Can the crank be offset ground to give a .050 increase in stroke? Are the KB at stock compression height or stroked? Also I was a little conncerned about all the casting flash in the lifter valley! Looked like someone beat it with a hammer! Is this normal???????? Thanks! :eek2:
Lifter Valley Every BB lifter valley I have seen looks like cr*p without cleanup. Just look for core shift - make sure there is meat around the lifter bores, especially if you're going to bore the block. Core shift up top = possible too thin cylinder walls. I can't help you with current "cheap" piston selection. I would go at a minimum to hypereutectics vs the cheap cast pistons, and forged seems like money well spent.
Yeah looks like I'm going to have to do it right:ball: Really I'm pretty happy with the block and liking it more and more each day. This is my first 455 tear down but to me the core shift looks minimal to none. I'll clean up the casting flash before sending out for machine work. Really amazing how much the 455 Buick differs form other GM and how light weight the casting is! If I go this route then I need to get a new cam, rebuilt heads, crank turned, and new pistons. I still want to make as much streetable power as possible with iron manifolds and A/C, PS, and PB. Probably still go with the 113 cam. But how do I get a decent compression ratio! Like 9-9.5??????? 87 friendly?????
to be 87 friendly you have to stay under 9.0:1 but up to 10.2:1 will run on 93. To get the compression up I would get the forged pistions and have your shop deck the block untill the piston is at 0.00 to 0.008 in the hole. I would also look for a set of 71' or earlyer heads if it is in your price range(look on ebay you might be able to get a set that somone did for less that it would cost to do yours.)
So Speed pro is the way to go for $380? What about a stock stage 1 engine, didn't they use cast? What about KBs? Do you know if stock replacement pistons are destroked? What is the stock compression height? Thanks!
My Poston catalog shows cast pistons for $219 at 10.0 compression ratio in standard, .020, .030, .040, or .060. Hypereutectic for $269 at 10 to 1 with small chamber. 9.85 to 1 with large chamber heads with .040 deck clearance and .040 head gasket. They also have forged at 10.25 to 1 for $369. Jarrot
The forged pistons are not really 10.5:1 there like 9.0:1 mabye unless you deck the block. I think the JE piston from TA are close to 10.0:1 or better out of the box.
I like the sound of that Poston piston for 219.00:Brow: I wonder why they call it a high RPM cast??? I assume they mean 6K but is it any different then a rebuilder piston??? Probably just a stock replacement. That should work fine for what I'm doing. Maybe I'll use this piston with a 71 head and run 93 with a POS113 cam. What do you think?
