compression with 274cam

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DusterBoy15 said:
well i heard i can run both cams with a stroung enough single spring
and i am getting the 4.10 gears but i would have to run 11.0 compression meaning higher octane like 96? 100? or even 91 but i still dont know if i should get it. what would be the power diff between the 2
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Possible, but think of it these 2 ways

2nd spring in a cyl head is like the shock to the leaf spring
2nd 2nd & 3rd springs protect the valve from the piston in the event of a failure of the outer #1 spring.

I would do dual springs with spring seats to prevent the walk.
 
well thats what bjr suggested for me and hes done it alot this is why im following what he said
 
Comp says a dual from there listings but they have the new conical springs that are very good, I just put a set on a sbc with a much larger cam then the XE284 they 145 on the seat and 340 open. Very nice springs, they are the new tech. but they are a bit more in cost.
They also don't fatigue like a std dual spring or single. They are better from harmonics stand point also at high rpm's.
 
Don't know why Dusterboy15 is trying to skimp on valve springs by not using what's recomended but I suspect it's cost. No argument about the benefits of the beehive springs but they are going to cost more to install than the recomended dual spring.

Dusterboy15 you really need to rethink what your goals are for your car. The last I heard you were using essentially stock heads. You are now taking about cams that the heads can't support. If your car is primarily a street car you will be much happier with the XE262 or XE268 cam (or the Voodoo equivalent) than the two you are talking about and those do not require double springs.
 
I think that he's factoring in the cost of the duals and the machining of the pad for duals verses the cost of the conical springs that wouldn't need the machining. It would almost be the same cost, as you would have to have different retainers and hardened locks anyway.
 
Can you do the beehive's with mopar valves now? When I checked they didn't have the locks and retainers.
 
dgc333 said:
Don't know why Dusterboy15 is trying to skimp on valve springs by not using what's recomended but I suspect it's cost. No argument about the benefits of the beehive springs but they are going to cost more to install than the recomended dual spring.

Dusterboy15 you really need to rethink what your goals are for your car. The last I heard you were using essentially stock heads. You are now taking about cams that the heads can't support. If your car is primarily a street car you will be much happier with the XE262 or XE268 cam (or the Voodoo equivalent) than the two you are talking about and those do not require double springs.
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???????????????????
then i guess either i havent posted what im doing to my heads or you havent seen what im doing...

the heads will be ported or gasket matched
bowl ported
bowl blend
back cut valves
75 degree cut on the bowls and lil more
but i guess ill stay with the xe274

ALSO IT IS MOSTLY A STREET CAR BUT I DONT CARE BOUT GAS MILAGE WITH THIS CAR. ITS NOT MY DAILEY DRIVER. IF I CARED BOUT GAS, I WOULD DRIVE A HONDUH
 
I would say about 9 to 1 and the 274 xe would do good ,that's what I had in my 340 with a 4 sp,3.91 .You are not gaining much hp upping the comp. ratio ,for a street car anyway compared to the problems ,pinging, more fuel cost per. gal.ect.Been down that road! 100 horse spray would be cheaper and more h.p.,more fun too! Herb McCandless mopar expert said in his sem. you don't need more than 8.5 -9.0 the very most to make power in a street motor !Get the cam that your heads will flow ,not much more. I had yrs. ago a 340 with the old H. E. 268-454 lift comp. cam that ran great with 3.23 's ! Excellent cam in a mild street 340! :D
 
DusterBoy15 said:
???????????????????
ALSO IT IS MOSTLY A STREET CAR BUT I DONT CARE BOUT GAS MILAGE WITH THIS CAR. ITS NOT MY DAILEY DRIVER. IF I CARED BOUT GAS, I WOULD DRIVE A HONDUH
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If it's mostly a street car then it's much more important to be making power down in the 1000-3000 rpm range than 4500 rpm up where you seldom run the engine. As you select a cam with more duration you keep moving the power band up the rpm range. The XE284 cam is not going to be making power where you need it with a street car.

My recommendation had no consideration for fuel mileage.
 
oo ic but theres always other ways to move the power range back down but i wont be going 284 just yet i will be getting a spring that will work with both
 
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