308 head & XR280HR-10 Combo

-
6

65deuce

Member
Joined
Feb 12, 2008
Messages
23
Reaction score
6
I started building a new 360 and installed an XR280HR-10 camshaft.
230/236 at .050 and .541/.537 110° Sep.
The engine is a 1989 roller motor zero decked @ 9.8:1 with 308 heads that have had 2.02-1.60's installed. I 'm planning to use a an RPM Air-Gap. '69 Dart/ Auto 904/ 3.55 SG.

After the Under-whelming results that Desktop Dyno spit out, I'm beginning to have second thoughts on the cam. It's gonna be a driver but not daily, mostly weekend and cruise-in useage.
I was hoping to get some opinions on this combo and/or some input on this cam from anyone who might have had or has the cam.

How does it sound, any lope?
Any power output estimates?
How is this thing gonna pull?
General opinions on how this setup could be improved.
Thanks in advance..
 
What did the desktop dyno say it should make? Seems like a really nice combo of parts. What you didn't mention was what carburetor you're planning to use.
 
Are the heads stock? What else was done when they were cut for the 2.02s? What level did it spit out, and do you expect?
 
I knew I had forgotten something..750 CFM Holley. They just cut for new seats, guides are new too.
444 Max torque on DD looks pretty good, but it happens early then falls off quick.
363 Max HP?? I thought this would certainly crack 400 HP?

The Comp Cam Utility (CamQuest)is even more harsh...HOLY SMOKES!!
406 Max Torque
306 Max HP.

I assembled this engine about 2 year ago, and it's been bagged on a stand since then.
I remember convincing myself to not overbuild this project, but I certainly want it to be worth the time and money..
 

Attachments

  • Dyno Table.jpg
    16.1 KB · Views: 301
I'd venture a guesstimate of 380-400 HP and 440-450 Tq. The 2 computer sims you mention are both woefully inaccurate the majority of the time.
 
65deuce said:
I knew I had forgotten something..750 CFM Holley. They just cut for new seats, guides are new too.
444 Max torque on DD looks pretty good, but it happens early then falls off quick.
363 Max HP?? I thought this would certainly crack 400 HP?

The Comp Cam Utility (CamQuest)is even more harsh...HOLY SMOKES!!
406 Max Torque
306 Max HP.

I assembled this engine about 2 year ago, and it's been bagged on a stand since then.
I remember convincing myself to not overbuild this project, but I certainly want it to be worth the time and money..
Click to expand...

Sorry, but if they just cut for the new seats I wouldn't expect any more flow than with the 1.88 valves. You gotta know what you are doing when you install bigger valves or you can lose flow!
 
Luckilly the sims can't take much into account very accurately. I agree with Skrews' assessment.
 
The heads flow is the limiting factor here. There is also a lack of exhaust specs. Manifolds, headers, size of header primary and exhaust tube size.
An Engine like this wants to breath. Not just in. ;)
 
Air flow is what moves the needle on those programs.
You can have all the cam in the world, but if they heads are corking you, it falls.
 
If your looking for real #### a true Dyno is were its at!

If you want to see how the torque and hp curve is different between differant cams , intake or header/manifold These Desk Top Dyno programs work GRATE!!!!

Just don't get hung up on the ###.

I like you combo as well
 
You must log in or register to reply here.
-

Back
Top