comp ratio for 383 ls1?
Thread Starter
Launching!
Joined: Jul 2010
Posts: 238
Likes: 0
comp ratio for 383 ls1? As tittle says, whats a good comp ratio for a 2002 ls1 383 stroker motor?
i will be using my 241 cast heads ported, this is the measurements from where will possibly be getting them machined:
Technical Specifications :
Intake Valve Diameter: 2.020"
Exhaust Valve Diameter: 1.570"
Intake Port Volume: 222cc
Exhaust Port Volume: 83cc
Chambers CNC Machined Yes
Chamber Volume: 64cc
also not 100% sure what head gasket size to use and piston dish size, will be using a diamond piston id say as may/may not go s/c down the track and being 3.905" bore, so looking for something that will work nice now n/a but will also work nice with a s/c if possible.
will be using a comp cams 231/239 113 cam, yella terra 1.7 roller rockers, morel lifters, double row timing chain, factory ported oil pump, 25% underdrive pulley and callies compstar crank and rods, looking at the texas speed kit assembly with a 3.905" bore.
just a little confused on which piston dish size and which comp ratio it will give me.
this motor is currently a 2002 346, 5.7 ls1
umm any more info required let me know, probably leaving something out.
Thanks Ben.
i will be using my 241 cast heads ported, this is the measurements from where will possibly be getting them machined:
Technical Specifications :
Intake Valve Diameter: 2.020"
Exhaust Valve Diameter: 1.570"
Intake Port Volume: 222cc
Exhaust Port Volume: 83cc
Chambers CNC Machined Yes
Chamber Volume: 64cc
also not 100% sure what head gasket size to use and piston dish size, will be using a diamond piston id say as may/may not go s/c down the track and being 3.905" bore, so looking for something that will work nice now n/a but will also work nice with a s/c if possible.
will be using a comp cams 231/239 113 cam, yella terra 1.7 roller rockers, morel lifters, double row timing chain, factory ported oil pump, 25% underdrive pulley and callies compstar crank and rods, looking at the texas speed kit assembly with a 3.905" bore.
just a little confused on which piston dish size and which comp ratio it will give me.
this motor is currently a 2002 346, 5.7 ls1
umm any more info required let me know, probably leaving something out.
Thanks Ben.
TECH Addict
Joined: Sep 2009
Posts: 2,481
Likes: 5
From: PA/MD
Try using wallace racing calculators....static compressoon ratio and dynamic compression ratio calculator....do you know the intake valve closing point in the cam?
For a good peppie motor you will want around 8-8.5:1 dynamic compression which depending in the intake valve closing point to get this dynamic compression you would want somewhere around 11:1 static.
Are your pistons going to be flush with the deck, or stick up out a hair?
If flush, look at a .040" gasket to keep your quench area tight
You will probably be looking at a flat top piston with a 8-12cc valve relief to get to where you want to be.
Hope I helped!
For a good peppie motor you will want around 8-8.5:1 dynamic compression which depending in the intake valve closing point to get this dynamic compression you would want somewhere around 11:1 static.
Are your pistons going to be flush with the deck, or stick up out a hair?
If flush, look at a .040" gasket to keep your quench area tight
You will probably be looking at a flat top piston with a 8-12cc valve relief to get to where you want to be.
Hope I helped!
I use this calculator and have built a few engine going by it. Always works real nice.
Read the article then download the calculator at the bottom of the page.
http://www.empirenet.com/pkelley2/DynamicCR.html
Read the article then download the calculator at the bottom of the page.
http://www.empirenet.com/pkelley2/DynamicCR.html
Thread Starter
Launching!
Joined: Jul 2010
Posts: 238
Likes: 0
Intake valve closes at 70 ABDC.
Yeh this might help a bit, umm should sit flush, will be using fly cut pistons due to the cam lift of 0.624 exhaust and 0.617 intake lift.
was going forced induction with a smaller cam, but for only the extra $1,000 or so over the internals i was going to do anyway have decided to go a stroker kit as the only extra cost is the crank and put any FI on the back burner for now.
Yeh this might help a bit, umm should sit flush, will be using fly cut pistons due to the cam lift of 0.624 exhaust and 0.617 intake lift.
was going forced induction with a smaller cam, but for only the extra $1,000 or so over the internals i was going to do anyway have decided to go a stroker kit as the only extra cost is the crank and put any FI on the back burner for now.
Last edited by ausls1; Jun 22, 2011 at 06:20 AM.
