I run a 125" Fiat altered, the motor is a 460 block from a 1971 Thunderbird, the heads are TFS standard Cobra Jet style, I use alcohal for fuel, the cam is a Clay Smith solid roller (280 deg @ .050 with .745 lift at the valve) the crank was a Scat 4.300 stroker lite weight with 6.700 Scat rods, Maule flat top pistons, zero deck, 4.440" bore.
With this motor I was consistantly running 8.50 ET @ 154 MPH with the car and myself weighing 2150 pounds.
I scattered the motor in Sacramento last month and replaced it with an identical set up except it went to a Ohio Crankshaft 4.500" stroke 4340 crank that is NOT a lite weight version (about 4.6 pounds heavier) and 6.800" rods, Diamond flat top 4.440" pistons The cam is the same cam that was in the other motor, the rockers, valves, springs, EVERY thing else is the same! The old motor came out at 13.12 CR and the new motor is 13.19 CR due to the extra .200" storke. Every thing else is identical, even the timing! Its just 557" now as opposed to 530" it was before.
Now I struggle to make 8.75 et and 149 MPH with the car!
Could the extra weight of the crank really eat that much et? over two tenths?
Any one got any ideas? I need to find those two tents before the final ANRA race in Bakersfield in three weeks!
Thanks for reading and thinking about this, I am sure someone way more knowledgable than I am will come up with the answer!
Thanks Guys,
Kim Lee
ANRA NE II 2011 Points Leader (hope to stay that way if I can)
With this motor I was consistantly running 8.50 ET @ 154 MPH with the car and myself weighing 2150 pounds.
I scattered the motor in Sacramento last month and replaced it with an identical set up except it went to a Ohio Crankshaft 4.500" stroke 4340 crank that is NOT a lite weight version (about 4.6 pounds heavier) and 6.800" rods, Diamond flat top 4.440" pistons The cam is the same cam that was in the other motor, the rockers, valves, springs, EVERY thing else is the same! The old motor came out at 13.12 CR and the new motor is 13.19 CR due to the extra .200" storke. Every thing else is identical, even the timing! Its just 557" now as opposed to 530" it was before.
Now I struggle to make 8.75 et and 149 MPH with the car!
Could the extra weight of the crank really eat that much et? over two tenths?
Any one got any ideas? I need to find those two tents before the final ANRA race in Bakersfield in three weeks!
Thanks for reading and thinking about this, I am sure someone way more knowledgable than I am will come up with the answer!
Thanks Guys,
Kim Lee
ANRA NE II 2011 Points Leader (hope to stay that way if I can)