Camshaft and Intake Manifold suggestions

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Sodbuster
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Camshaft and Intake Manifold suggestions

Post by Sodbuster » Wed Nov 07, 2018 10:06 pm

Greetings, I am planning on re-freshening the engine in my Bracket Car over the winter. This is a Drag Race only 3000 lb. GM, G body with a 1.76 powerglide, 4.56 rear gears on 29 X 9 Hooiser slicks, with a 4500 stall converter and a 950 cfm APD carburetor. The engine is a 421 (4.155 X 3.875) SBC, 14.5-1 compression, Profiler 176X CNC Cylinder heads with 2.125 intake valves and Scorpion 1.6 rocker arms. I normally shift at 6800 and go thru the lights at 7000 (1/4 mile). I run both 1/4 and 1/8 classes and always foot brake. This is not a max effort set-up, consistency and 60' times are very important.

The current cam is an UltraDyne S/R, and is marked; 296/310 R6, 1520, D1543, .875R. My degree wheel and chinese dial indicator showed it to; .418 cam rise, 262 duration @.050 and 105 C/L in the intake lobes, and .418 cam rise, 272 duration @.050 and 107 C/l on the exhaust lobe, with a 106 lobe separation. This is a small base circle cam, and has to clear Eagle H-beam rods. The intake manifold is a Team G #7530.

The current cam is showing lots of wear and needs to be replaced, and from what I understand there are much better manifolds than the old Team G.

Any suggestion on a new S/R cam, and a single plane intake manifold will be greatly appreciated !!!!

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Re: Camshaft and Intake Manifold suggestions

Post by cgarb » Wed Nov 07, 2018 10:22 pm

I would suggest the Wilson/Profiler intake. The guy that dyno'ed my 421 was impressed with that intake out of the box. He told me a lot of the leg work was already cast into that intake vs having to grind it out of a factory new unported one. I bet that would wake it up some itself. As far as the cam, I let that up to someone who knows better than me, But I think what you have is ballpark close.

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Re: Camshaft and Intake Manifold suggestions

Post by Ericnova » Wed Nov 07, 2018 10:51 pm

Holley Strip Dominator, Dorton version.

If you keep the cam you have, put a 1.65 ratio intake rocker on it.

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Re: Camshaft and Intake Manifold suggestions

Post by pdq67 » Thu Nov 08, 2018 9:53 am

Since UDHarold is no longer with us, (may he RIP), look up Mike Jones and Chris Straub and ask them. Both good cams, imho.

And to this day, I miss Harold.

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Re: Camshaft and Intake Manifold suggestions

Post by WeingartnerRacing » Thu Nov 08, 2018 10:04 am

Edelbrock 2892 or a 300-110 Holley.
Eric Weingartner
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Re: Camshaft and Intake Manifold suggestions

Post by CamKing » Thu Nov 08, 2018 11:38 am

Cam# SBCR, R80465-82465-110
266/274 @.050"
.465"/.465" Lobe Lift
110 LSA

I agree with going with the Wilson-Profiler manifold
Mike Jones
Jones Cam Designs
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jonescams@bellsouth.net
http://www.jonescams.com
(704)489-2449

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Re: Camshaft and Intake Manifold suggestions

Post by splitdecision71 » Thu Nov 08, 2018 1:04 pm

CamKing wrote:
Thu Nov 08, 2018 11:38 am
Cam# SBCR, R80465-82465-110
266/274 @.050"
.465"/.465" Lobe Lift
110 LSA

I agree with going with the Wilson-Profiler manifold
This is very similar to my build and the cam that came with my short block is to big. Im looking at getting another cam. Would you mind coming up with a profile for mine as well?

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Re: Camshaft and Intake Manifold suggestions

Post by CamKing » Thu Nov 08, 2018 1:24 pm

splitdecision71 wrote:
Thu Nov 08, 2018 1:04 pm
Would you mind coming up with a profile for mine as well?
Just fill this out, when you have time. http://jonescams.com/drag-race/
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
(704)489-2449

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Re: Camshaft and Intake Manifold suggestions

Post by splitdecision71 » Thu Nov 08, 2018 1:58 pm

CamKing wrote:
Thu Nov 08, 2018 1:24 pm
splitdecision71 wrote:
Thu Nov 08, 2018 1:04 pm
Would you mind coming up with a profile for mine as well?
Just fill this out, when you have time. http://jonescams.com/drag-race/
Filled it out, thank you!

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Re: Camshaft and Intake Manifold suggestions

Post by Sodbuster » Thu Nov 08, 2018 10:16 pm

Thank You-All for taking time to respond to my post. I appreicate all of your suggestions. I have been looking at the Wilson-Profiler manifold, but also like the suggestions for the Holley Dorton and the Edelebrock Super Victor, I'll have to do some investigation and see how much room there is in the budget and which one fits. Also I hadn't considered a cam with that much lift, and will have to do some measuring, but if it fits I'm all for it. Thanks again to everyone !!!!

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Re: Camshaft and Intake Manifold suggestions

Post by KnightEngines » Thu Nov 08, 2018 11:14 pm

Cam# SBCR, R80465-82465-110
266/274 @.050"
.465"/.465" Lobe Lift
110 LSA

Mike - is that grind to run 1.6 rockers?
How's lifter life & valve train stability with a .465" lobe?
Would it be better to run, say, a .440 or so lobe & 1.7 ratio rockers instead?

Just wanna learn stuff!

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Re: Camshaft and Intake Manifold suggestions

Post by CamKing » Fri Nov 09, 2018 9:57 am

KnightEngines wrote:
Thu Nov 08, 2018 11:14 pm
Mike - is that grind to run 1.6 rockers?
How's lifter life & valve train stability with a .465" lobe?
Would it be better to run, say, a .440 or so lobe & 1.7 ratio rockers instead?

Just wanna learn stuff!
I recommended this cam, based on the OP's 1.6 rockers.
Since it won't be turned much over 7,000rpm, it's very stable on the valvetrain.
It's only better to get the required valve lift, by using higher rocker ratios, if the rocker geometry with the higher ratio is correct.
In this case, that would require the OP to switch to Jesel shaft rockers, and that's a pretty big price jump, for a small gain.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
(704)489-2449

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Re: Camshaft and Intake Manifold suggestions

Post by KnightEngines » Fri Nov 09, 2018 4:59 pm

Thanks Mike, appreciated!

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