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compression height?

Posted: January 28th, 2010, 8:20 pm
by zeekracing
I have deciede on which way to do the stroker. 258 crank and rods, 30 over pistons. I was checking out summit racing for pistons. They had three choices for the compression height: 1.585, 1.592, 1.581. I have not got a block yet but I don't plan on decking the block unless it is needed. What is the stock height? Which one do I need to go with?

Re: compression height?

Posted: January 29th, 2010, 3:15 am
by dwg86
The stock height is some where around 1.601... I think. The 1.592 will be the closest to the deck, out of the 3 choices, but will still be around .038 below the deck.

Re: compression height?

Posted: February 1st, 2010, 4:49 pm
by woodjeep
I have the silvolite 3241 hc pistons in my build. The pin height is 1.592 which gave me a .035 deck height . I did not shave the head for quench. When i gave the block to my machine shop..SK Speed on long Island, I asked about shaving and quench and he looked at me like I had 2 heads. He asked how many rpm's i would normally run this at and when i told him it would probably never see 3000 he laughed and said I would not have to begin to worry untill I passed 6000. Then I laughed and told him it would see that for a second or 2 as it was exploding . It's not going in until the spring so its only half built. The crank/pistons and cam are in,,The heads done but the pan is not on so I can lube the cam closer to the install date

Re: compression height?

Posted: February 1st, 2010, 6:43 pm
by SilverXJ
Compression height is pin height. Not sure what you are asking. As for the deck clearance you don't have to start to worry about piston to head collisions until, .040"

Re: compression height?

Posted: February 2nd, 2010, 4:23 am
by dwg86
woodjeep wrote:I have the silvolite 3241 hc pistons in my build. The pin height is 1.592 which gave me a .035 deck height . I did not shave the head for quench. When i gave the block to my machine shop..SK Speed on long Island, I asked about shaving and quench and he looked at me like I had 2 heads. He asked how many rpm's i would normally run this at and when i told him it would probably never see 3000 he laughed and said I would not have to begin to worry untill I passed 6000. Then I laughed and told him it would see that for a second or 2 as it was exploding . It's not going in until the spring so its only half built. The crank/pistons and cam are in,,The heads done but the pan is not on so I can lube the cam closer to the install date
You shave the block to get a better quench. I don't understand what your machinist is saying. I would think you will have more problems with detonation with a larger quench and with your engine running at a lower speed under a load. For example pulling a load going up hill. I am no expert but I had to run 89 octane in my stock 4.0 after I put a cold air intake on it, or it would ping bad. My stroker has less quench, .043, and higher compression, and I can run 87 octane pulling a load with no detonation.