Basically the same cam, but you're saying the reduced lsa will increase the torque
Side will!
6421 is smaller than a stock hp cam. the 6400 is real close to a stock hp but even better it's on a 112 LSA and not 115 LSA like a stock one.
That move helps, I’d go further… ummm, narrower.
Yes,
Rem.
A quote from DVs BBC book, p. 97: ' If maximising HP & TQ are the goal, spreading the LSA to improve the idle & low speed drivability is a very counterproductive move. The correct answer here is not to spread the LSA, but to go for less duration'. [ Italics in original ].
That is why I recommend Isky cams: single pattern & most grinds are on 108 LSA.
BINGO!!!!! Nailed it! 100%
Next up in the power production enhancement, exhaust!
David Vizard has excellent books on this. Well worth the price and time to read. I suggest to the OP to pick up one or several of his books before making a cam choice.
This make a lot of sense. I have noticed this through the years of looking at different cams and manufacturers. Lunati and Iski has always stuck with that 108 and Comp at 110. I mean on their standard run of the mill cams.
Comp Cams uses the 110 LSA as a compromise as the 110 vs the 112 shows a good gain in low speed torque. As the LSA narrows or gets lower, the gain becomes less.
(Generally speaking as far as I have seen.)
As the LSA narrows, the idle becomes more and more choppy. This is often not so well liked by a lot of people. It makes driving a manual trans a little more difficult for some. This is also why Comp stays at the 110. It’s a decent balance between a decent idle and low speed torque is what they’ll tell you.
The move from a 110 to a 108 is IMO, a good move, one I have done and will continue to use. I have called Comp Cams up and requested a modification to one of there off the self cams to be moved from the 110 to a 108. There happy to do it for you. You can ask to talk to a tech and ask about moving the lobes or singular lobe to achieve this is the way to go.
It’s all about the valve timing, the results and the goal your looking to achieve. Be prepared to give them every last bit of detail you know of. It only helps them help you. The more they know, the better the result.