Matching cam with intake question....

[Imo Apita]

Little sidestep from my other thread here...
I understand the concept of matching components.
Now how closely do you have to match cam & intake?
Can they be 500 rpm apart?1000?Exact match?
For instance an intake advertised as 2000-5500 rpm, can the cam be 2500-6000?2500-6500?1500-5000?
Or are the max torque and max HP rpm points more important?
Can I run a cam with 4000 rpm max Torque and 5000rpm max HP on a 2000-5500 intake?
Am I confusing myself here.....:withstupid:
Thanks guys.

 

[arneoe]

Please state which engine you want to use. Normally there are not many to choose from if you have a standard hood. You must use low to medium raise manifolds to have sufficient space between air cleaner and the hood.
Arne

 

[Imo Apita]

That doesn't really matter Arne, more of a generic question.
I need to modify the hood anyway, cut and grind and glue or a L-88 hoodscoop.
But since you're asking, the plan is an overbored 350 with a Offenhauser DP manifold.

 

[damoroso]

To me there's more to it. It's not so much matching the cam and intake, it's matching everthing as much as possible with the end in mind. Matching the cam, heads, intake, exhaust, comp ratio, carb, all that stuff. I've found that usually starts narrowing the choices pretty quickly. That being said, the intake I've choosen for my BB build has a wider power band than the cam. It starts building power at 1500 and stops at 6500. It's also a DP by the way. I did that because I can manipulate the cam a bit by degreeing it. The cam pulls from 1800 to 6200. I can degree the cam to match the intake on the low end. So, since you can move the cam around a bit, to me, it makes sense to have a broader ranged intake than cam. If I had to choose, I think I'd choose the mismatch at the high end. I think I'd like the power as quickly as possible (and I'm kind of a torque guy anyway, hence the BB!) you may rarely see the top end of your rpm range....

 

[Imo Apita]

Thanks Damoroso, those are the answers I'm looking for.
I'm still tearing down this engine but I'm also thinking about the build already.
Did you port the DP in any way?
According to this:
http://www.exeterautosupply.com/Docs/Offenhauser catalog.pdf
Page 4, the DP should run from 2000-5500.
So cam wise everything from 1800 should be good (manifold wise that is)?
I'll be using ported 461 heads with the large valves.
Looking at a 11-1 compression 383 stroker kit.

 

[damoroso]

Aside from hp numbers, what's the goal here? I think you have to consider that because you're likely going to have to do some trans work, and possibly some rear end work too if you reach higher hp numbers. And with the 3 speed automatic, it'll still be a pain at higher highway speeds. That's why I went to a 2004r trans.

No, I didn't do any work to the intake, it's actually a GM Performance piece pn 12363420. Not the cheapest part to be sure. My feeling on working the intake was, I don't don't think it's necessary for what I'm after. I did put lager valves in the heads and did just a bit of "pocket" porting just to clean things up a bit from the factory casting. The intake, and heads are gasket matched, so that's good enough for the daily driver application that I have in mind for this car. I'm only running (by calculation) a bit over 10:1, certainly not more than 10.5:1, as the block was decked, the heads were cleaned up and the pistons are for a 10:1 ratio. I'm going to run pump gas so I didn't want to go over 10.5:1. I want the car to have streetable manners and dependibility to take the car on long road trips, be able to BBQ the occasional GT500 Mustang or metric beer can exhaust car. That's why I chose the parts combination I did.

Hope this helps!