Magnum Camshaft help?

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chaditotx

chaditotx

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Magnum block, Edelbrock heads... looking for a roller cam that will put me in the 450+ hp range, thats easy on the valvetrain (if there is such a thing). This car will be a weekend driver, occasional strip / shame a Mustang type. The motor is going into a Demon with a 2800-ish stall and 3.91's. I had a cam suggestion earlier for a Comp XR286, 286/294 .544 .5.41 (236 242 @.50), and it still seems like a good cam for what I am doing, I was just wondering about longevity of the valvetrain at that lift? Assume hardened pushrods and roller rockers (steel) etc.

Last question, with stock pistons and 58cc Edelbrock heads, how much Compression ration can be gained from decking? A guess is fine...
 
If you are using magnum heads (you mentioned hardened pushrods) remember that cam is rated using a 1.5 rocker ratio. that would put your lift up around .580 with 1.6 rockers, by my calculation.
 
I run a 230/237/110 Hughes cam, at .549/.581?lift. I wouldn't want any bigger for street. The torque peak is already pretty high, and it likes an 11/1 starter gear with a stick. The 2.45 auto low will want a gear in or near the 4s, like 4.10/3.91s, and at least a 2800TC. So pick your poison,lol. The bigger the cam, the worse this gets. I could do with a lil less, but the 11/1Starter is waaaay more fun.If you are not married to 450 hp, I would give up a lil, to gain some down-low giddy-up and not have to run that big a gear. Of course with a 518, itsnobigdeal.
 
May sound like a dumb question, but magnum block what? 5.2 or 5.9?

Compression is something you'll need to measure for. Even with the later model magnums, pistons were still a little ways in the deck and the only way to get anything closer than a ballpark is to break out a burette, clay, and piece of acrylic. There's a good thread in the how to section...detailed and a little of a read, but it'll give you everything you need to know to accurately know your static compression ratio.

All that being said, I'm going to step on a limb and assume you have a 5.9...with a stock bottom end advertised at 9.1:1, and 58cc chambers (assuming the advertising is accurate) should* put you around 9.5:1

Otherwise, longevity of any valvetrain is based on the correct matching of parts and operating within their intended usage.
 
Are you just trying to embarrass someone specific, or is there a time you're looking for? Have you modified your suspension and chassis to effectively get all the time you can out of it? Or are you OK turning your tires into expensive clouds of smoke in pursuit of shaming someone?
 
I was wondering about that... I guess they may have specced the cam off LA rockers.
 
qkcuda said:
If you are using magnum heads (you mentioned hardened pushrods) remember that cam is rated using a 1.5 rocker ratio. that would put your lift up around .580 with 1.6 rockers, by my calculation.
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I was wondering if they did that... Figured lift from LA instead of Magnum. Using Magnum heads
 
txstang84 said:
Are you just trying to embarrass someone specific, or is there a time you're looking for? Have you modified your suspension and chassis to effectively get all the time you can out of it? Or are you OK turning your tires into expensive clouds of smoke in pursuit of shaming someone?
Click to expand...
It ran mid 12's just fine with the 340 in it. Trans brake, Super stock springs, drag shocks up front, snubber and old M&H Race masters. Probably drag radials this time around. Roll of time slips in the dash as fat as a Lone Star can. I do have a friend that likes his Mustangs ;)
 
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Mid 12s isn't exactly slow...

But, if there's something I've noticed on here, as opposed to seeking out and achieving a hp number, describe everything about your car as it sits right now, then give a goal in ET/mph and the folks on here like IQ52 can aid in pointing you in a direction.
 
txstang84 said:
Mid 12s isn't exactly slow...

But, if there's something I've noticed on here, as opposed to seeking out and achieving a hp number, describe everything about your car as it sits right now, then give a goal in ET/mph and the folks on here like IQ52 can aid in pointing you in a direction.
Click to expand...
I'm kinda weird like that . I want to build something with some longevity, but want to take full advantage of the roller cam and the flow on the Edelbrock heads. I will have some hours in cleaning the ports up I am sure. I'd like to run some low 11's at least.
 
chaditotx said:
Magnum block, Edelbrock heads... looking for a roller cam that will put me in the 450+ hp range, thats easy on the valvetrain (if there is such a thing). This car will be a weekend driver, occasional strip / shame a Mustang type. The motor is going into a Demon with a 2800-ish stall and 3.91's. I had a cam suggestion earlier for a Comp XR286, 286/294 .544 .5.41 (236 242 @.50), and it still seems like a good cam for what I am doing, I was just wondering about longevity of the valvetrain at that lift? Assume hardened pushrods and roller rockers (steel) etc.

Last question, with stock pistons and 58cc Edelbrock heads, how much Compression ration can be gained from decking? A guess is fine...
Click to expand...
 
Disregard last one lol. I ran Hughes HER2836AL in my Dakota with the same heads and a procharger and it was an awesome cam, mild and made great torque. Dakota is way heavier but ran easy low 11s with a 3000 converter and 3.90 gears.
 
Cbeck out LXguy's build here,or check www.Magnumswap.com .3400 weighted Dart,well prepped chassis & drivetrain ( unported EQ small valve heads,Comp 224/230 @ .050" hyd roller... 11.70's @ 116-117 trap speed, kinda rocks....
 
If I remember right he had less than $2500 in the engine.
 
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