Solid Roller camshaft selection those of you running a 408 race application - lobe seperation

[Garrett Ellison]

On a 408;

2.02 - 105.02 LSA
2.08 - 105.68 LSA
2.15 - 106.41

For a 434;

2.02 - 103.56
2.08 - 104.26
2.15 - 105.03

A 26 cubic inch difference between the two. Notice how close the numbers are the trend of which they go. About a degree and a half tighter going to a larger engine. So is a 105 to tight? I don’t think adding two more wider is going to kill it.

According to D Vizard which is Chevy math for the 23* angle. Being the MoPar has a 18* angle, you could probably do with 2* less and be fine. 1* won’t show crap.

Very true with the four inch crank. I've seen that Vizard states in his seminars a positive correction factor of 0.75 for each point of compression over 10.5:1 and 0.5 of positive correction to LSA for each tenth of rocker ratio increase. So with 12.25:1 as stated by the OP, 1.3 degrees more of LSA. Anywhere from 106 to 108 should be in the sweet spot.

 

[HuntedDuckV351]

Thank you! Those Duration numbers are the exact ones recommended by Bullet Cams with a 108 center line and 104 LSA. I am still waiting to hear back from Racer Brown. What converter are you running?

Sorry missed the converter part.....was running a 904 and it was 5400ish....just switched to a glide last year and had a couple different numbers on it....first was 5500ish with a 4.56 and went 6.59 but it wasn't as consistent as I would have liked so got it loosened up but my guy went farther with it than I would have liked....it's now 6100ish and went 6.64 with a 5.00 gear. 14x32 tires.

 

[rumblefish360]

Thank you

This should help you out some.

 

[rumblefish360]

Very true with the four inch crank. I've seen that Vizard states in his seminars a positive correction factor of 0.75 for each point of compression over 10.5:1 and 0.5 of positive correction to LSA for each tenth of rocker ratio increase. So with 12.25:1 as stated by the OP, 1.3 degrees more of LSA. Anywhere from 106 to 108 should be in the sweet spot.

Thanks for that. Good to have it mentioned.
DV is a serious man when it comes to this stuff. It’s still his deep passion. He deals in facts because that’s what engineers do.

Which way do the correction facts work in?