LT4/stroker need info
Thread Starter
Instructor
Joined: Mar 2001
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From: kissimmee,fl.
LT4/stroker need info
What is the best stroke/rod combo?I have been looking at the 3.750 stoke 5.7 rod combo would like input on this, and do I need to run a small base circle cam or can I get enough clearence between the rod and cam just by doing a little work on the rods?I will have the motor out for a few other things and just thinking maybe while its out I should play a little. :D
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: LT4/stroker need info (Rolla Dunkin)
i would go with the 3.75 and 5.7 combo, i thought that longer rods were better if you went to the bigger stroke and kept the Bore the same
Burning Brakes
Joined: Nov 2001
Posts: 1,241
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From: Houston TX
Re: LT4/stroker need info (Rolla Dunkin)
you can get a million different answers to this...
bottom line is that the rod/stroke ratio is close to irrelevant. what you need to decide is whether or not you will force induction in the future (nitrous, blower). if so, then you want the ring package to be lower on the piston, in turn necessitating a shorter rod (lower piston pin).
if it's to always be naturally aspirated, then go for the biggest cubes you can. generally, you'll also want the longest rod, as this makes the piston lighter, and lowers side thrust. engines with compression heights as small as 1" are still durable and oil tight.
eagle makes a really nice crank that's 3.875" stroke. put some 6" rods on that. .030" is roughly 395 cubic inches. (might as well call it a 396, i think eagle does.)
bottom line is that the rod/stroke ratio is close to irrelevant. what you need to decide is whether or not you will force induction in the future (nitrous, blower). if so, then you want the ring package to be lower on the piston, in turn necessitating a shorter rod (lower piston pin).
if it's to always be naturally aspirated, then go for the biggest cubes you can. generally, you'll also want the longest rod, as this makes the piston lighter, and lowers side thrust. engines with compression heights as small as 1" are still durable and oil tight.
eagle makes a really nice crank that's 3.875" stroke. put some 6" rods on that. .030" is roughly 395 cubic inches. (might as well call it a 396, i think eagle does.)
Instructor
Joined: Sep 2001
Posts: 159
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From: McKinney Tx
Re: LT4/stroker need info (MSR)
Yes as MSR said the longer rod is all good unless your running a bigger power adder. You have both 5.85 and 6 inch rods to choose from on these chevy kits. You can use a better crank if you do 6 inch rods that has bigger counterweights that will make balancing easier as well. These cranks won't clear the skirts with a 5.7 rod and matching piston and you'd have to turn the crank down on the lathe. :chevy
