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Grumpy and all others Cam HP vs. Cost


Guest Anonymous

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Guest Anonymous

I have the following engine

350 10.25CR with 64 CC Heads

750 DP Vic Jr.

492 Angle Plug Heads Port + Polish

 

One of the heads is cracked and the engine is coming out. I will most likely go back with AFR 195 with the factory port job.

 

Now... What cam to use? I have the following two cams which I have run in the engine. The XE294H ran a best of 11.95 @ 113mph with the valve springs set .200 yes .200 too high. I thought it was that the cam was too big so I swapped in the 292H and when check the spring noticed the problem. I ordered new springs and set to the correct height.(Both cam take the same springs). Car seemed to run much stronger but went road racing rather than drag raceing so do not have a valid ET for comparison. I supect thet the majority of the improvement was to due to the correct spring tension. I have now cracked a head and will pull the motor. Should I go with one of the cam below...

 

CompCams 292H-10 244/244 @.050 501/501 w/ 110 LSA

CompCams XE294H 250/256 @.050 519/523 w/ 110 LSA

 

Or go with a Roller as mentioned in the Hail the Gladiator Story CHP Mag with

Comp Cam Roller 254/260 @ .050 583/585 part # not known.

 

The artical claimed pek HP of 468 at 6800 with the 292H and 527 at 6400 with the roller.

 

Now, are these dyno figures true?

How much power would the 294XE make?

How much extra $ going to the roller?

Is there a better cam?

Is the extra expense worth it?

 

Thanks Guys,

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both those cams are slightly to large for max hp , trust me on this go with a #12-771-8 solid or 12-433-8 hydrolic roller if max hp is what your after , several 350 sbc engine builds in magazines and guys I know with 350-383 engines are slightly over 500hp with those cams!, and yes you will most likely need to get more valvetrain clearance for the increased lift and yes the NEW AFR HEADS that flow better will help a great deal

 

http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-433-8

 

http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-771-8

 

Im useing a crane #119661 in my 383 and its even milder and gets close to 500hp and I chose it because I was much more interested in a massive torque curve and ease of maintainance than peak hp,

http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=119661&B1=Display+Card

 

look here

 

http://www.airflowresearch.com/

Chevy Dyno Tested Packages

 

look here,

http://www.carcraft.com/editorial/article.jsp?id=868

 

http://www.bracketmasters.com/small_block_stroker_383_cu.htm

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Guest Anonymous

What do you meat that both cams are too large for maximum power. and if I want max power I should go with a larger cam. Now Im confused.

 

I want to go fast. If tq is what does then let me know.

 

I was asking about the price differential in the rollers vs the cams I have. Vs the power potential of each.

 

I should have adequate valve clearence with my flat top JE Pistons but I will check.

 

Please clarify your post.

 

Thanks

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sorry for the delay Im moderator on several sites and I get over 100 questions a day now, so sometimes I miss one.

the CompCams 292H-10 244/244 @.050 501/501 w/ 110 LSA you mentioned is a good match to those iron chevy heads because they NEED that extra duration to breath well at rpms over 6000rpm the CompCams XE294H 250/256 @.050 519/523 w/ 110 LSA

will loose more tq in the low rpm range but not give back a huge amout of hp more than the other cam so in my opinion its not that much of a gain, it will tend to slightly increase the power but narrow the peak of the torque curve quite a bit. the new AFR heads will breath way better and will not need that much duration to breath at similar rpms so cams with slightly less duration but better lift will more closely match your engines needs, that in your case puts you into a roller cam profile if your looking to get the most tq/hp from your engine because flat tappet cams don,t have the lift to duration ratio that will best suit your needs, if you look at the engines on the AFR site youll notice they seldom go over 242@.050 duration be cause the want to maximize tq/hp and the heads flow well enought that they don,t need to, keep in mind the minimum duration that allows the cylinders to fill at the rpms your engine runs at is what your after because the piston can,t start the compression of the fuel air mix on the compression stroke untill both valves are closed and the higher and longer the valves are held open the better the engine can breath, so what you need is the highest lift with the shortest duration that matches the cylinder heads flow and the engines rpm range, increaseing the flow allows for slightly lower duration in ratio to lift so that the cylinders still fill but the valves closeing slightly faster will gain you more effective torque simply because you can fill, compress and burn more fuel air mix, play with this DYNAMIC COMPRESSION RATIO PROGRAM,

http://cochise.uia.net/pkelley2/DynamicCR.html

 

youll soon see what Im talking about.

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Bubbafett, are you the fellow I talked to at Kershaw Sunday? I was driving the white 240 with the red 28 on it. Your post sounds very similar. I tried to email you but the email in your profile didn't work.

 

John

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