Which cam question, AGAIN

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duster360

duster360

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I asked this question once before, but here goes again. Last time it was different cams, but I have narrowed it down to these 2. The one thing I like about the comp cam is the power band peak is 6000 rpm vs. the Lunati 6400 rpm. Opinions appreciated. 99% street with an occasional run to clean it out.



http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=631&sb=2

http://www.lunatipower.com/CamSpecCard.aspx?partNumber=60404

67 Dart
340
Edelbrock 60779 heads
Edelbrock air gap intake
Hughes roller rockers
10.2:1 compression
Headers
4 speed
3.91 gear ( possibly 3.55 later )
 
Flip a coin. You're splittin hairs.
 
I'd go with the Comp cam. I have the XE 268 in my 340, and it is awesome. I can only imagine how the 275 would be.
 
I'd go with the Lunati. If you had to make a choice between the two, the Lunati seems to concentrate on exhaust and getting that exhaust out quickly with more lift and duration. I myself went with the 294S Comp. I love the solids but I may try an XE in the future for this reason.
 
Learned how to use the compression calculator now. The lunati will have a 9.2 dynamic compression and the comp cam will have 8.1. It is my understanding that I need to be between 7.5 and 8.5 to be in a safe zone. Especially for non expert tuners like myself.
 
Yeah, the intake closing event is earlier in the lunati so it should build more cylinder pressure. If I were you, I'd call a reputable engine shop like IMM or cam grinder and have a custom spec'd out for you.
 
duster360 said:
Learned how to use the compression now. The lunati will have a 9.2 dynamic compression and the comp cam will have 8.1. It is my understanding that I need to be between 7.5 and 8.5 to be in a safe zone. Especially for non expert tuners like myself.
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The timing figures on those two cards are VERY different. One is at .006, the other is at .050 tappet lift.

Change the closing event on your Lunati to 62 abdc and see what you get for DCR.
 
Good catch crackedback. I am still getting used to reading the cam cards, but I am learning. I will check into this a little further.
 
mopowers said:
Yeah, the intake closing event is earlier in the lunati so it should build more cylinder pressure. If I were you, I'd call a reputable engine shop like IMM or cam grinder and have a custom spec'd out for you.
Click to expand...

I called 5 different cam companies and they all suggested a cam they had on the shelf, except one. Comp cams, Lunati, Hughes, Howards. They only one that didn't was Clay Smith cams and the way I understand it is they don't stock cams, they grind them upon your order.
 
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