Posted By: Gumbydammit
4.310 bore X 4.500 stroke combos. - 11/21/11 07:42 PM
I have a buddy with a new 4.310 bore KB water block. He is wondering if a 4.500 stroke will cause only make torque down low and run out of steam at the top end of the track. I don't think so.
It is a Hemi with a good set of heads. T&D rockers, LSM cam, yadda yadda, all the good stuff. It is just getting a new rotating assembly.
If you had to put a rotating assy in a 4.310 bore block that was going to go in a 3400# drag car with a glide and up to 300HP of nitrous, which stroke would you go with? I know what I think. . .
It is a Hemi with a good set of heads. T&D rockers, LSM cam, yadda yadda, all the good stuff. It is just getting a new rotating assembly.
If you had to put a rotating assy in a 4.310 bore block that was going to go in a 3400# drag car with a glide and up to 300HP of nitrous, which stroke would you go with? I know what I think. . .
I'm on the 3rd next time and now reside at 4.391.This time I got a set of SV1's and sold them little 750's that kept me at 4/5 lbs of boost and 10.ohs and a 9.93 best on pump gas.By the way,my junk is 3850 with me & a full tank of gas.Got on the engine dyno last month and pump gas,28* timing and 4 lbs of boost netted 740 HP.On race gas & 10 lbs pushed it to over 900 hp with 850 ft lbs of torque @ 4900 RPM.Not too shabby considering I could not use my carbs or headers 
Bore size is simply not as critical as a head flow limitation on a Hemi, mainly because the valve motions angle toward the bore centers as they open, alleiviating much of the shouding that becomes an issue with a Wedge configuraion. On a wedge the valve action is straight and parallel to eachother, which means the edge of the valve stays at a fixed distance from the bore, with a hemi, the more you lift the valve the further away it moves away from the bore and closer to the center of the hole.
