I've been working too long on this so I took a break but I have a question.

Opening and closing events on my cam are 49 and 13. After checking several times I get 52 and 10.

1) Am I advanced or retarded 3 degrees?

2) Do I have a bigger problem because it should be 16 and 52?

I can't think straight right now.

 

You didn't give a lot of info so I'll take a guess.
You have those figures backwards. I'm taking for granted you're talking about the intake events?
If so then you're retarded 3 degrees. Again taking for granted it's the intake and your those are your at .050 numbers then you have a lobe that's 242@.050 and they're recommending you install it on a 108 ICL. Right now you're on a 111 ICL.
It's simple, take the intake duration, 242, divide by two=121, then subtract the recommended ICL, in this case 108. That leaves you with 13*btdc.

Hope this helps.

 

Yes that's all correct cutlassefi.
The cam is the same for intake and exhaust 13/49 and 49/13 at .050. It is 242 at .050 with a 108 CL. Lobe center is also 108 so the cam is ground straight up. I was hoping it was advanced. Guess I need to do that..............maybe tomorrow when I'm thinking with a clearer head.
Thanks again

 

Glad I could help but you have a 496 right?
With a single pattern cam ground on a 108, in at 108, you'll have fantastic low end torque. But you're midrange and high end will suffer.
And to clarify, it is recommended to be installed straight up, it's not ground straight up.

With a 4.500" arm and 496 cubic inches I would have gone in another direction, unless you were trying to move a Sherman tank. I'd leave it where it is, at the very most advance it just a couple to 109. With stretch that'll take it to 110.

Jmo.

 

A 66 Cutlass convertible is similar to a Sherman tank. I may just put it straight up and forget about it. I'm thinking this combo will peak about 5500 rpm and idle somewhat smooth. Your thoughts?

My dynamic compression was on the low side when I did the numbers. One reason I didn't want it retarded too much.

 

Like I said I would have gone in another direction, i.e. 238/246 on a 112, in at 110.
Look at this one and the intake/exhaust spread, plus the lobe sep. I think it's safe to say yours will peak way before this.
http://realoldspower.prophpbb.com/topic830.html

Again jmo.

 

Static compression is 10.73. My calculations show a dynamic CR of 7.66. I think that is a little low which is why I wanted to advance it some.

 

I still think its the wrong cam, by a bunch.
Dynamic compression is only part of the total equation.