Stroker specific cams?

nm9stheham said
YR, this is the OP's stated goal for this engine/cam on page 1 of this thread. I'd suspect this has a lot to do with the results... this project/design is not about peak HP.

FWIW..... The other thing about narrow LSA is that it is going to make your lower RPM engine operation less torquey. Yeah, I know, narrow LSA moves the torque peak down and/or extend the higher levels of the torque band down, and it does make the exhaust pull-through work better at 'lower' RPM's.. but 'lower' is all relative and is still up in what I would consider 'mid range' RPM's. Once you go low enough in RPM the exhaust pull through stops and the intake reversion goes up with a narrow LSA, and the torque is gonna drop off the table. That is a reason all of the catalog 'torque' cams have LSA's up on the 112-114 range. If you are running certain forms of engine operation, too narrow on LSA just hurts low RPM operation, regardless of carb or EFI. All depends on what you are doing with the engine.

This is true is the cam timing is wrong. If you get the timing correct, the narrower LSA won't kill the bottom. There are two kinds of reversion. The really bad reversion when the close the intake too late. That's a killer.

Then you have reversion which occurs at overlap. Again, this is where a faster lobe is a big deal.

I can tell you the simple truth is if you are running that much displacement, and you are induction limited, a wide LSA is a killer. It always has been.

That's why I cringe when I see a cam with a 10 degree split and a wide LSA. All that means is the cam is short on duration, and they are blowing the LSA out to make a cam with the wrong timing RPM. That's all.

With today's lobes, you can get the timing correct and the narrower LSA is a huge advantage.

Again, on 340 inches I run 255 at .050, I can idle at 750 comfortably (as I've said before, I never let my stuff idle that slow...it's not a Toyota) and carry 9 inches of idle vacuum with a 105 LSA.

Modern lobes are a big deal. That's why several of us on here point it out so often. You don't have to compromise.