fred

I will degree the cam in to see where its set at to get the 110* .....Fred

MACDAD260

Hey Fred, Are you going to run your motor soon and check for reversion? If you are, I think I'll wait to hear what you find out before I install mine. Doug

Crazyhorse

Fred, I'll run it through desktop dyno to see what the IC change makes. Remember, you can't change the LSA, only the intake centerline.

Crazyhorse

ok, the XE268 cam makes 431@5000 degreed at 0 (106ICL), and makes 434@5000 -4 degrees (110 ICL). Take your pick but I'd put it in at zero.

MACDAD260

Crazyhorse,

Can you run that cam on Desktop Dyno in a Gen V 502 Mag? I'd like to see how it compares to Fred's motors.

Oh, and I'd really like to get together for lunch someday but, lately my schedule in Zeeland is pretty tight. I'll give you a call someday, though.

Thanks, Doug

Crazyhorse

Funny you should mention that. I ran it through a 502, same specs as the 454, and it makes less power in the 502 than the 454 by about 10 horsepower. If you were to switch to 1.8:1 rockers you'd pick that back up plus a little more.

fred

Crazy, why should I set it up at 106 ICL as opposed to 110 ICL.....is there any better of the two that would decrease the chance of reversion?...MACDAD260....I won't be running the motor until the spring....if it works well I will do the second motor....Fred

Crazyhorse

I'm just saying that if it was me installing the cam I'd put it in at zero. Low speed characteristics might be a little better but i really don't think you'd feel the difference.

fred

I was told that marine apps. like between 109-110 ILC, that would mean retarding the cam a few degrees from the way the manufacturer ground it, good for a 5hp increase over an advanced camshaft....Fred

rmbuilder

Fred,
I don’t mean to step on your thread, but there are some things to consider when you retard your cam. First, when you retard, you are not changing your LSA, duration, or overlap figures (the factors in reversion), you are altering the timing of your valve events. A retarded camshaft will delay the crossover point, and elevate HP and torque figures higher in your RPM curve. This will affect your low and midrange performance to some degree. It could be (depending on your SCR being high enough) compounded by a later intake closing point (by retarding valve events) bleeding off/lowering cylinder pressure making low and midrange lazy. It’s your call if the 5hp est. gains @ peak hp is an acceptable trade off for the possible loss of some low/midrange performance.
Bob