Camshaft?

[rickb33x]

Helping a young racer out to get an engine built for him with parts laying around. Not the most ideal way to do it but hoping you all can help out.
USRA hobby stock rules. They either run 602 crates with a 6200 rpm limit or open engine(9.5:1/360cid limit) with no rpm limit, which his engine being open. open has a claim rule on heads and intake but its what we have.
2 bbl rochester no mods with 1/2" adapter, 2701 edelbrock intake
991 gm open chamber head(1.94/1.50 valves) NO PORTING ALLOWED
stock cast 350 crank(10/10), 6.0 sir eagle rods and 140 cl mahle pistons(464g)
truck exhaust manifolds or LT-1 exhaust manifold with a short extension past the firewall.

I have a cam that has very short run time on it that he can use and just wondering what makes more sense how to install it.

Its a comp cams thumpr street/strip cam 12-601-4 hyd flat tappet. 235/249 at .050/, .489 intake/.476 exh lift---107 lobe sep. rpm range is 2200-6100 for the cam.

With it being a 2 bbl restricted engine would advancing it help or does it make more sense to run it straight up?

[mt-engines]

Not sure what the ICL is but I'd run close to 102 degrees and a tighter LSA. No need for all that exhaust duration IMO.

Will your cam work? Yes
Is it optimal? No

See how it works and let us know.
If you can run a very tall spacer between the adapter do it and port them.

[af2]

Helping a young racer out to get an engine built for him with parts laying around. Not the most ideal way to do it but hoping you all can help out.
USRA hobby stock rules. They either run 602 crates with a 6200 rpm limit or open engine(9.5:1/360cid limit) with no rpm limit, which his engine being open. open has a claim rule on heads and intake but its what we have.
2 bbl rochester no mods with 1/2" adapter, 2701 edelbrock intake
991 gm open chamber head(1.94/1.50 valves) NO PORTING ALLOWED
stock cast 350 crank(10/10), 6.0 sir eagle rods and 140 cl mahle pistons(464g)
truck exhaust manifolds or LT-1 exhaust manifold with a short extension past the firewall.

I have a cam that has very short run time on it that he can use and just wondering what makes more sense how to install it.

Its a comp cams thumpr street/strip cam 12-601-4 hyd flat tappet. 235/249 at .050/, .489 intake/.476 exh lift---107 lobe sep. rpm range is 2200-6100 for the cam.

With it being a 2 bbl restricted engine would advancing it help or does it make more sense to run it straight up?

It will sound cool in the pits....
Mike can and will get you the cam you need!

[Walter R. Malik]

If I was forced to use that camshaft, I would find some 1.3/1 ratio break-in rockers to use on the exhaust side; i.6/1 on the intake side.

The intake to exhaust duration is way to much spread for a 2 barrel engine.

[F-BIRD'88]

I'd start with that cam degreed in on 102° in c/l.
Work from there.
Idea: Running hyd lifters on intakes and solid lifters on e hausts will alllow you to play with exhaust running duration ± a bit. See the effect on that car ± ex lash changes.

[rickb33x]

Is it possible to have just the exhaust reground to a more suitable duration?

[CamKing]

Is it possible to have just the exhaust reground to a more suitable duration?

Yes.

[rickb33x]

Will this also cause less lift on the exhaust?

[dannobee]

First question is what size and type of track?

You might be better off having Mike grind him the right cam, even though it'll set him back a little money. Walter was saying that the exhaust duration was too high. I was thinking that the intake duration was too low. The heads would likely not need more than 0.540" lift though.

[rickb33x]

3/8 clay dirt oval but likely running the bottom in the turns in the main events.

[F-BIRD'88]

3/8 clay dirt oval but likely running the bottom in the turns in the main events.

Degree it in correctly on cam card specs and run it as designed. 107° LSA. I believe the installed phasing is 103°/111° in/ ex centerlines (.050" events).
Its more about driving.

[CamKing]

Will this also cause less lift on the exhaust?

You can regrind it to less lift, or more lift.
You can regrind it to less duration, or more duration.
You can regrind it to a 106 LSA, or a 108 LSA