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COMP CAMS 280H

Posted By: 1DGEMAN

COMP CAMS 280H - 07/11/19 09:22 PM

Has anyone here ran this cam magnum 280H? It would be going in a 72 340 4sp Duster 3.55 gears 255 70 15 rear tires stock intake headers 2.5 exhaust and a mighty Thermoquad. A local guy has a new one in the box for a good price. I may put 1.6 rockers on it.

Thoughts?

Thanks, Rod
Posted By: Mattax

Re: COMP CAMS 280H - 07/11/19 09:38 PM

Yes - assume the grind hasn't changed. Ran it for about 80 K miles.
It should be OK with that rear assuming you don't run real tall tires.
Idle is a bit lumpy. Use 16-18* BTDC for intial and should be able to get it to idle around 800 rpm
Definately need the matching springs - watch valve cover clearance - although I assume that was mostly a fluke in my case.
But if your going to the expense of changing rockers - I'd look at a cam designed for a mopar in that same lift range and spend the money that instead.
Its not just the 904 lifter, but also the dwell time at the top that more specific cam can have an advantage.
Posted By: topside

Re: COMP CAMS 280H - 07/11/19 10:01 PM

230 @ .050, 110 CL, .480 lift (.320 lobe). With 1.6 ratio, .512 lift.
255/70-15 is about 30" tall, isn't it?
Sounds like it's gonna need some gear; Comp site says 3.55-3.91 & 2500 stall for 340-360...
I agree with Mattax on Mopar-specific cams. but it's not my money...
FWIW, I tend to run more exhaust bias on anything that'll have an exhaust system.
Posted By: BSB67

Re: COMP CAMS 280H - 07/11/19 11:33 PM

Personally, I kinda like it. A little old school, but a good cam. I would go this way verses a modern fast rate cam. 1) the valve train will be happier, 2) it might rev better/higher than fast rate cams. 3) the 4 speed will tolerate the additional idle lumpiness.

If you want the best cam, consult with an experienced cam guy like Mr. Porter.
Posted By: Mattax

Re: COMP CAMS 280H - 07/12/19 12:50 AM

Tire rack shows a Cooper radial in that size as 29"
That's much taller than what I ran with only a little smaller gear (3.23) and TurboAction 3800 (3000 brake stall).
But with the four speed the gearing might work out OK.
Tallest tire I ran was just over 26". usual street tires were (and are) 25.5" dia.
Quickest time and best mph at the track was on 24" (225/50r15 Yok 008 which was an autocross-roadrace tire)
13.77 99.5 through manifolds and full exhaust. With better traction and gearing it you can go quicker than that.
Posted By: bobby66

Re: COMP CAMS 280H - 07/12/19 03:37 AM

Pretty close to my Racer Brown SSH-38C. Ran 7.90 in the 1/8 in my '66 Charger. Stamped rockers, stock Edelbrock springs.
Posted By: J. Hammer

Re: COMP CAMS 280H - 07/12/19 04:18 AM

There are many better cams but if its extremely cheap go for it. The similar racer brown , Isky 280 mega or UD .842 hyd stuff will kill it but it doesn't sound like you race it so you wont know the difference.
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