couldn`t find an answer !
Thread Starter
Teching In
Joined: Dec 2005
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couldn`t find an answer ! am not sure if the question am going to ask is being answered before or not , but i really searched for it .. i know that the LQ9 heads are 71 cc along with the stock flat pistons , and i also know that the LS1 heads are 67 cc with the same stock flat pistons .. ls1 stock bore is 3.9 Vs 4.0 for the LQ9, and i also know that both champer compression is 10.1 ????? 
what i dont know is why a different chamber size has the same compression when the pistons are both flat ?
is there is something i dont know ?
P.S:am not a newbie
what i dont know is why a different chamber size has the same compression when the pistons are both flat ?is there is something i dont know ?
P.S:am not a newbie
compression ratio will change whenever you change any of the volumes in an engine - swept volume (bore and stroke), chamber volume of the heads, even changing gaskets (thicker or thinner) will affect the compression ratio.
A certain head and combustion chamber does not have a compression ratio associated with it. Only on a specific engine will they have a specific compression ratio.
A certain head and combustion chamber does not have a compression ratio associated with it. Only on a specific engine will they have a specific compression ratio.
Thread Starter
Teching In
Joined: Dec 2005
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thank u grimes , i really know that the head gasket has a big rule in compression when i ordered a .55 gaskets and after installing everything i realized that i milled the heads .2 and got a thicker gasket shiiit , what am trying to learn is .. what is the relation mathmatically between bore Vs stroke Vs chamber size Vs compression
i.e what if i use heads that is 4.0 in bore along with a 3.9 bore and a 3.62 stroke , chamber Volume is 62 cc , head gasket is .45 . flat pistons WHAT will be the compression .. what is the relation ! thats what am asking about
i.e what if i use heads that is 4.0 in bore along with a 3.9 bore and a 3.62 stroke , chamber Volume is 62 cc , head gasket is .45 . flat pistons WHAT will be the compression .. what is the relation ! thats what am asking about
No problem at all.
Well, basically compression ratio is:
(entire volume of space including chambers with piston at bottom dead center) / (entire volume of space including chambers with piston at top dead center) =
compression ratio
That is a very generalized equation, but it will give you a good idea to start with.
Hereis a pretty decent car craft article that will answer your question in detail:
http://www.carcraft.com/techarticles/982/
Well, basically compression ratio is:
(entire volume of space including chambers with piston at bottom dead center) / (entire volume of space including chambers with piston at top dead center) =
compression ratio
That is a very generalized equation, but it will give you a good idea to start with.
Hereis a pretty decent car craft article that will answer your question in detail:
http://www.carcraft.com/techarticles/982/
Thread Starter
Teching In
Joined: Dec 2005
Posts: 47
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thank u again and again , it is a great article .. very helpful this is exactly what am talking about , guys u have to read this if want to learn about compression in order to manipolate it the right way ,,
a question came to my mind .. what is the LS1 stock Clearance volume ? stock piston deck height ?
a question came to my mind .. what is the LS1 stock Clearance volume ? stock piston deck height ?
