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Could someone tell me what this works out to?? #808842 09/20/10 12:27 AM 09/20/10 12:27 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	I was thinking about this piston for a forged replacement for a 400bb standard stroke ,standard length rods. Can anyone tell me what the compression ratio would be with these and 75cc heads?? http://cgi.ebay.com/ebaymotors/Wiseco-63...sQ5fAccessories www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808843 09/20/10 12:42 AM 09/20/10 12:42 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	You do realize that auction is for a single piston, they only have two in stock & there are R&L hand versions of those pistons

Re: Could someone tell me what this works out to?? [Re: 1_WILD_RT] #808844 09/20/10 12:48 AM 09/20/10 12:48 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	Yes I know. I have found a set of these cheap. I think i could make them work for a .035 overbore 400 but i didnt know if i would have to have any milled off the top of the piston. I can get a set of these new for 100. www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808845 09/20/10 12:56 AM 09/20/10 12:56 AM
Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH WILD BILL Senior Member of the Junior Dragster Club
WILD BILL Senior Member of the Junior Dragster Club Joined: Dec 2007 Posts: 10,542 BROOK PARK, OH	Try this

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808846 09/20/10 01:00 AM 09/20/10 01:00 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Well with a stroke of 3.38 divided in half is 1.69... a rod length of 6.358 & a C/H of 2.06 you get a combo height of 10.108 & the deck height spec of 9.98 you have .128 above deck to account for... A thick head gasket, an open chamber head & likely some milling on the dome... Is it worth it, you decide...

Re: Could someone tell me what this works out to?? [Re: WILD BILL] #808847 09/20/10 01:00 AM 09/20/10 01:00 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	Bill I have this calculator also but with this one i cant put in the compression height of the piston or the deck height. So I dont think it will be very accurate for me. www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808848 09/20/10 01:22 AM 09/20/10 01:22 AM
Joined: May 2008 Posts: 5,399 Aurora, Colorado 451Mopar master
451Mopar master Joined: May 2008 Posts: 5,399 Aurora, Colorado	That piston has a 2.060" compression height for a 440 RB block. In a 400 'B' block it will be 0.128" above the deck. I don't know if the piston can be milled that much, and you would still need valve pockets. Also, the top ring is going to be very close to the top of the deck.

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808849 09/20/10 01:30 AM 09/20/10 01:30 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	So if this is right then this piston will be - .072 in the hole before decking the block right? Bore Blck Comp height 73cc 232453 4.375 10.699 1.858 10.1 Dome Vol Gram weight -28.9 710 grams What would compression ratio on this be with a 75cc head and a .20 head gasket with surfacing .010 off the block???? www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: 451Mopar] #808850 09/20/10 01:30 AM 09/20/10 01:30 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Quote: That piston has a 2.060" compression height for a 440 RB block. In a 400 'B' block it will be 0.128" above the deck. I don't know if the piston can be milled that much, and you would still need valve pockets. Also, the top ring is going to be very close to the top of the deck. I think the ring would be ok, if you use an open chamber head which typically are .100 deep.. You'd need to chamfer the edges of the piston & cut maybe .030 off the dome.. On the other hand thats a good 440 piston & if you decide you can't use it I'd be interested..

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808851 09/20/10 01:32 AM 09/20/10 01:32 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Quote: So if this is right then this piston will be - .072 in the hole before decking the block right? Bore Blck Comp height 73cc 232453 4.375 10.699 1.858 10.1 Dome Vol Gram weight -28.9 710 grams What would compression ratio on this be with a 75cc head and a .20 head gasket with surfacing .010 off the block???? Are we looking at a different piston or?

Re: Could someone tell me what this works out to?? [Re: 1_WILD_RT] #808852 09/20/10 01:45 AM 09/20/10 01:45 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	Yes I have a option on these 2 different sets of pistons. Im thinking the second other one could work out better. www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808853 09/20/10 01:49 AM 09/20/10 01:49 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	A c/h of 1.858 will leave you .074 in the hole.. Not real good either..

Re: Could someone tell me what this works out to?? [Re: 1_WILD_RT] #808854 09/20/10 01:52 AM 09/20/10 01:52 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	Oh and I forgot to mention my compression goal is about 8.5 to 1 compression. Boosted set up www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808855 09/20/10 01:58 AM 09/20/10 01:58 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Are there valve reliefs? Without reliefs, with a .021 gasket your around 9.4-1... With a .039 gasket & 4cc valve reliefs your down to 8.75-1 so that set is pretty workable for what you want..

Re: Could someone tell me what this works out to?? [Re: 1_WILD_RT] #808856 09/20/10 02:12 AM 09/20/10 02:12 AM
Joined: Oct 2007 Posts: 846 Illinois moparmattkos OP mopar addict
moparmattkos OP mopar addict Joined: Oct 2007 Posts: 846 Illinois	no reliefs it is a dish with a -28.9 cc dish www.sikosracing.net Heads up Drag racing

Re: Could someone tell me what this works out to?? [Re: moparmattkos] #808857 09/20/10 02:19 AM 09/20/10 02:19 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Back to a .021 head gasket & the C/R drops to 7.52

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