01silvy

I could be wrong but dosent the LSA affect where the meat of the power is? A lower LSA like 110-112 should produce low end grunt where an LSA like 114-116 puts the power curve up in the revs dont it?

Or do i have it backwards?

Hemi2Slo

No you're right, but the intake duration plays a big part in it too. A wider LSA will also give you a broader power band, from what I understand, but a narrower LSA will make more peak power. But I could be wrong also.

dirty_old_chevy

dude, I would think you'd be better off to get a 212/218 cam on a 106 lsa if you really want that 3* overlap. A huge exhaust split really cuts in to the power duration of the piston stroke. In my books, that means less torque

dirty_old_chevy

not that i am recommending a 212/218 on a 106, I just think there are better choices.

Hemi2Slo

Well I wasn't actually planning on buying this grind, though if I had the spare money i'd try it just for the heck of it. But I don't have the 400 bucks to waste on it. I'm happy with my current cam, very happy. I was just lookin for opinions on somethin like this. I'm always curious about off the wall stuff like this....

dirty_old_chevy

yeah, I like the off the wall stuff too. I just punched some numbers in and your 212/242 on 112 +4 has a power duration of 123*. A 212/218 on 106+0 has a power duration of 145*, with the same amount of overlap. Keep in mind that the overlap doesnt need to be a positive number for the cam to have overlap. That is just overlap duration at 0.050'' tappet level. Overlap at advertised duration is worth comparing as well.

Hemi2Slo

You know, had had never thought of overlap at advertised duration. That is a good point. But I'm a little confused by what you mean by 123* and 145* power duration. I've never heard it put like that. Is that degrees of camshaft rotation?

dirty_old_chevy

power duration... degrees in crankshaft rotation of the effective power stroke. Advancing the cam or adding more exhaust duration decreases power duration. Basically it has to do with when the exhaust valve opens during the power stroke. A bunch of exhaust duration opens the exhaust valve sooner, cutting the power stroke short. This can cut down on torque, mainly on the low end and midrange.

dirty_old_chevy

of couse you dont see that when you advance the same cam because you are also closing the intake valve sooner, increasing the compression duration, which in turn raises the dynamic compression ratio. I believe the cams you listed would have a relatively flat torque curve, but not pumped up as high as it could be.

Hemi2Slo

Well, by that information, it all makes sense. You learn somethin new every day. Preciate the info......