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prostcelica 06-16-2012 09:48 AM

Thoughts on a cam
I had i guy (that seems to know what he talking about) recomend a comp extreme marine cam. XM278H

Duration @.50 234 in. - 244 ex.
Lift .498in .5ex
LSA 112

The plan is sbc 350 .030 over, AFR 180cc heads, RPM air gap, Holley 670, 1 5/8 headers. 4 gear manual , ford 9" posi 355. It is a street car that will see the striip couple times a year. What do you guys think about the cam??

I know a roller would be better but I only have so much $$$ to spend

cobalt327 06-16-2012 10:50 AM

I don't see the AFR's needing anything like that kind of split duration, the exhaust side of those heads is better than that.

I think it will want more gear than that.

painted jester 06-16-2012 11:04 AM

That cam also has a smoother idle and strong bottom end , Designed specifically for marine performance!!! And exhaust in water that restricts flow!!!!

I'd pass on the recommendation to run the marine cam on the street , Those are just my thoughts! :thumbup:


probird 06-16-2012 11:11 AM

my favorite cam for hot rods has been the comp cams magnum 280.
great sound and power. good vacuum, etc. Theres probably better cam profiles made now but your best bet is to call comp and ask there teck line.
They make this stuff.
Don't forget its the total package to make the best driver.

prostcelica 06-16-2012 12:00 PM

Thanks for the input guys. I think ill pass on the marine cam. Comp just replied to my email and recomended there extreme energy 274. Probably best to listen to the guys that grind the cam. :)

Anybody out there have this cam?? if so how is it for power?? idle quality??

vinniekq2 06-20-2012 02:31 PM

would you consider using a flat tappet solid cam?smoother idle and good throttle response.Talk direct to comp or the manufacturer you choose.Spend a little time explaining "exactly" what you expect. Ask three times and see where the overlap comes,pun intended.Lobe separation angle and intake lobe centre line are just as important as lift and duration.With AFR heads you dont need a lot of cam. Talk to afr and look at their website for results they get with their products.
AFR was an excellent choice,your engine will make a lot of usable power

Mr. P-Body 06-20-2012 06:25 PM

For the 4-speed, I would agree with Comp, if a flat hydraulic is what you want. XE274H is a very popular grind and makes power to 6,000 without problem in the small block. It will be "lumpy". Springs should be about 120 at the seat. Duals are the best idea. We use Sealed Power lifters on these cams.

Vinnie has a good point. A flat tappet solid is a "happy medium" between a hydraulic and a solid roller. The XE grinds are excellent. Comp's solids seem to be rated a little higher in duration than their hydraulics. They don't "act" it. If you're thinking "230 @ .050", go for 236. Great manners and a broad power band. We've used many in Pontiacs, but also a few in small blocks, with similar results.

Use lifters with the EDM hole in the bottom (Comp has them, as does Crower and others). This will insure lobe "life". If your budget can stand it, go for the 4-7 "swap" (firing order change).

Springs need to be 140-150 at the seat. A true dual spring is called for. Break the flat tappet (hydraulic OR solid) cams "in" with only the outer springs installed. Install the inners and run it again.



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