std bore 400 compresson problem
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Member
Joined: Nov 2007
Posts: 115
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From: parma,OH
Car: 91 camaro RS
Engine: 350, forged 355 in the works
Transmission: 4 speed goin to th400
Axle/Gears: stock 9bolt, 3.27
std bore 400 compresson problem
ok im building a std bore 400 i want to fun forged pistons and have low compression and i have 60cc heads,
the question is is there a place that sells thes pistons in a dish
or can i use pistons for a 5.7 rod on the stock 5.565 rod to get a taller piston to deck witch in return will do the same as a dish piston and then run a 350 crank like a 377 just not .030 over, so that will make a 372cid with atound 8.7-1 to 9.6-1. ive done plento of searching and cant find nothing,
to me it seems like it should work fine, just want a couple of opinions b4 i spend my money, and there should b no clearance problems because of the shorter stroke.
the question is is there a place that sells thes pistons in a dish
or can i use pistons for a 5.7 rod on the stock 5.565 rod to get a taller piston to deck witch in return will do the same as a dish piston and then run a 350 crank like a 377 just not .030 over, so that will make a 372cid with atound 8.7-1 to 9.6-1. ive done plento of searching and cant find nothing,
to me it seems like it should work fine, just want a couple of opinions b4 i spend my money, and there should b no clearance problems because of the shorter stroke.
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: std bore 400 compresson problem
What CR you looking to get ?
Your small chamber size is going to limit you as the normal 22-26cc 400 piston dish gives about 8.5 with a 76cc head.
JE # 232514 has a massive 36cc dish and still gives 8.7 on a 60cc head using 5.7 rod.
Head change would be cheapest option to lower CR
Your small chamber size is going to limit you as the normal 22-26cc 400 piston dish gives about 8.5 with a 76cc head.
JE # 232514 has a massive 36cc dish and still gives 8.7 on a 60cc head using 5.7 rod.
Head change would be cheapest option to lower CR
Thread Starter
Member
Joined: Nov 2007
Posts: 115
Likes: 0
From: parma,OH
Car: 91 camaro RS
Engine: 350, forged 355 in the works
Transmission: 4 speed goin to th400
Axle/Gears: stock 9bolt, 3.27
Re: std bore 400 compresson problem
im lookin to run about 10lbs on the 400
but yhe question is can i use pistons for a 5.7 inch rod on a 5.565 rod the piston sits farther from the head and will give me more compression room in return it will lower my compression, its a very tight budget build, and the heads have crazy money in them from my 350 i had b4 this
but yhe question is can i use pistons for a 5.7 inch rod on a 5.565 rod the piston sits farther from the head and will give me more compression room in return it will lower my compression, its a very tight budget build, and the heads have crazy money in them from my 350 i had b4 this
Thread Starter
Member
Joined: Nov 2007
Posts: 115
Likes: 0
From: parma,OH
Car: 91 camaro RS
Engine: 350, forged 355 in the works
Transmission: 4 speed goin to th400
Axle/Gears: stock 9bolt, 3.27
Re: std bore 400 compresson problem
and i really think thar 800 is to much for what im willing to spend on pistons i would rather gey a used set off of here for 160 and get it bored then spend that
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: std bore 400 compresson problem
1.560 CH ( stock 400 w/ 5.565 rod ) to 1.425 CH ( 400 piston for 5.7" rod ) difference is .135" .Add the 0.025 block deck height and you have a quench of 0.160 without a gasket!
Google "quench height " and see how important quench is in preventing detonation especially under boost
Better price
http://www.summitracing.com/parts/STL-H615CP/
Thread Starter
Member
Joined: Nov 2007
Posts: 115
Likes: 0
From: parma,OH
Car: 91 camaro RS
Engine: 350, forged 355 in the works
Transmission: 4 speed goin to th400
Axle/Gears: stock 9bolt, 3.27
Re: std bore 400 compresson problem
i was told to only run forged pistons for boost,i did the research b4 i asked ad with a 5cc dome it was a 9.6 to 1, i mean i can make up some compression if i just used domed pistons rite?
or just used the stock 400 crank and made it up there
or just used the stock 400 crank and made it up there
Thread Starter
Member
Joined: Nov 2007
Posts: 115
Likes: 0
From: parma,OH
Car: 91 camaro RS
Engine: 350, forged 355 in the works
Transmission: 4 speed goin to th400
Axle/Gears: stock 9bolt, 3.27
Re: std bore 400 compresson problem
ok i looked and with 7.8cc domed piston and the 350 crank and 60cc heads with 5.565 rods its 9.3-1 on 3 different calcs
http://www.summitracing.com/parts/TRW-L2311F/
these r for 5.565 rods and useing them on a 350 crank will give me the same CR, would this work?, and is it safe to boost a 372 with cast 350 crank
http://www.summitracing.com/parts/TRW-L2311F/
these r for 5.565 rods and useing them on a 350 crank will give me the same CR, would this work?, and is it safe to boost a 372 with cast 350 crank
Last edited by 5.0slayer; Oct 13, 2009 at 07:14 PM.
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Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: std bore 400 compresson problem
I wouldn't because 372 is a revver
Ask the guys over in 3rd Gen Power Adder, what CR you can run with what boost first
https://www.thirdgen.org/forums/power-adder/
Then you can work back to see what pistons will give you the right CR. Just guessing otherwise.
Ask the guys over in 3rd Gen Power Adder, what CR you can run with what boost first
https://www.thirdgen.org/forums/power-adder/
Then you can work back to see what pistons will give you the right CR. Just guessing otherwise.
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