Cam quest - 351 W.

[fvike]

So a lifter got stuck the other day, and I'm wondering what cam to get.
I didn't know my cam specs before, and it turned out to be a Comp XE268H-10. Here are some pictures of the cam and lifter.

My engine is an 351 W with Edelbrock Preformer RPM heads (2.02 int. / 1.60 ex.), Air-Gap RPM manifold, BG Speed Demon 750 VE carb, I think it's about 10.5:1 compression ratio, can just remember being told that by the guy that got me the car.
So what cam should I got with?
I've tried all these in Dyno2000.

The safest thing to do is probably the Preformer RPM cam, which is of course matched to my heads and manifold. It's the only of the 4 cams that give me both 400 HP and over 400 lb-ft (406).

My old cam, the XE268H-10 has least HP (393) but most torque (416). This cam however only has a powerband up to 5800 RPM, and doesn't utilize the 6500 RPM range of the heads.

The other Comp cam, the XE284H-10 only beats the eddy head by 1 HP (401) and has the lowest torque. (384)

The Crane 440661 has most HP (402) but looses 19 lb-ft (387) to the Eddy cam.

So which cam should I choose? Any opinions? Other "contenders" ?

The car sees about 60% street use, 30% Open Track use, and 10% Dragrace.

 

[TOM B]

If your stuck with a Hydrolic cam Then I would go with the RMP cam if not then go Roller. use the 5.0 cams with there firing order to get the more choice's of cams and a few HP with the firing order change.
Whatever cam you choose dont forget to add lots of there cam lube for breakin as the Fricken EPA made the oil companys take out this anti-wear additive.

 

[chromedog]

i would have to say that was a bad break in... either that, or the springs are way too stiff. you mention cam specs, but were the springs matched to the cam? you could replace the cam, and not the springs, and have the same problem in 2000 miles. i think i would replace the whole shootin' match with the edelbrock kit, follow breakin procedure to the letter, and hope for the best.

 

[fvike]

i would have to say that was a bad break in... either that, or the springs are way too stiff. you mention cam specs, but were the springs matched to the cam? you could replace the cam, and not the springs, and have the same problem in 2000 miles. i think i would replace the whole shootin' match with the edelbrock kit, follow breakin procedure to the letter, and hope for the best.

I don't know. I didn't build the engine. All I've done to the engine since I got the car 3 years ago is swapping the intake and carb. But the heads P/N tells me this is not the bare head, it came with (those(?)) springs. My rockers are Comp roller tip 1.6.

I've rolled the pushrods on a flat surface, they're ok.

If your stuck with a Hydrolic cam Then I would go with the RMP cam if not then go Roller. use the 5.0 cams with there firing order to get the more choice's of cams and a few HP with the firing order change.
Whatever cam you choose dont forget to add lots of there cam lube for breakin as the Fricken EPA made the oil companys take out this anti-wear additive

The reason I'm not going for a roller cam at this point is that I hope to get to a open roadtrack event this weekend, and of course $.
So I need parts quick. The parts in store here in Norway is limited.
Also, I've read that roller cams don't have an advantage until you get to 275 duration @.050". My Speed Demon is for cams up to 240 duration @.050". is this true ?

 

[Max Power]

I use the RPM cam and it works great. They make a good kit with the the best lube containers. I would go with the RPM cam.

 

[57fairlane]

rotella oil . . .

 

[GoinBroke]

Yep - Rotella T and add some engine oil supplement such as GM EOS

 

[SoCalCruising]

I have never heard of the roller cam not having an advantage until 275 @ .050. I don't think that is true. A roller cam, even a hydraulic roller, will give you steeper ramps, opening the valve faster, and usually with more lift for a particular duration, than a flat tappet cam would. Your problem with changing to a hyd. roller would be your springs, pushrods and tappets. What you may lose, unless you get very good roller cam springs, is topend RPM capability. For open track, that could reduce your top speed, even though your acceleration should be improved.

Because of your relatively heavy track use, I would really consider going to a solid flat tappet cam, springs and lifters. This would not be nearly as expensive as (even) a hydraulic roller and it would improve your power and top speed.

 

[fvike]

Thanks for the help guys. I ended up getting the RPM cam.

SoCalCruising: I don't know what I was thinking when I wrote 30% track use. It's more like 10%. Spesifically 2 full weekends (6 days) each summer. Thanks for the tip anyway.