magnum head people unite!

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SRT_DSTRHOLC

SRT_DSTRHOLC

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what is your timing set at? Initial and total and what octane and compression are you running?
 
I never made it past the machine shop. both heads had the usual Magnum head crack between the intake and exhaust valves.
I hope you magged your heads before you put them on, or you might get a big surprise.
 
ProStreetDuster said:
I never made it past the machine shop. both heads had the usual Magnum head crack between the intake and exhaust valves.
I hope you magged your heads before you put them on, or you might get a big surprise.
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X2X2 (it happened to me with 2 sets of magnums) I wouldn't put a penny into stock cast magnums on a performance motor .02
 
I am running them. Pulled them myself from a 95 Grand Cherokee. Must have gotten lucky with no cracks. Machine shop checked them out. I am running XE256 comp cam. Installed Chevy beehive springs and retainers. Deck height was .060 with flat tops and valve reliefs with .028 gasket. 20 degrees initial timing and 52 degrees total. It likes timing and I am yet to hear it ping on 91 octane. I'm thinking about bumping it up a little more.
 
wow 52 total???? i have like 34-35 and im scared to go any higher
 
74Burntorange said:
yes i did and they are the car. thanks for concern.....
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What do you mean "they are the car"?

And 32-34 degrees is all you should need for total timing. They are pretty efficient heads and don't generally require alot of timing. But since every application is different you just need to play with it and listen for spark knock. If you hear spark knock back it off until you don't hear it anymore then another 1-2 degrees.
 
I am running an accel dist. I have not heard a ping yet. And I am not kidding that my total timing at 3000 rpm with the vacuum advance hooked up is around 52*. I was told by a couple of guys on here that it is fine. Should I plug my vacuum advance and just run it mechanical at around 34*?
 
Badart said:
I am running an accel dist. I have not heard a ping yet. And I am not kidding that my total timing at 3000 rpm with the vacuum advance hooked up is around 52*. I was told by a couple of guys on here that it is fine. Should I plug my vacuum advance and just run it mechanical at around 34*?
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Badart vacuum advance does pull the timing up to a high amount as you see but it's only there under light throttle if it's hooked to the correct port on the carb. When you floor it there's no manifold vacuum to pull the advance canister so the total timing will only be what ever your mechanical timing is. That's why it doesn't ping at WOT. Vacuum advance is mainly to help gas mileage so if you unhook it you'll loose mpg.
 
fishy68 said:
Badart vacuum advance does pull the timing up to a high amount as you see but it's only there under light throttle if it's hooked to the correct port on the carb. When you floor it there's no manifold vacuum to pull the advance canister so the total timing will only be what ever your mechanical timing is. That's why it doesn't ping at WOT. Vacuum advance is mainly to help gas mileage so if you unhook it you'll loose mpg.
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thanks fishy
 
I am running 16 initial and 34 total. I have 10.58 to 1 compression and have a Comp Cams 280H cam. I run 91 octane but can get away with 89. I even had to use 87 once and as long as I didn't get on it to much it did not ping.

Jack
 
I run 17 degrees initial and 33 total on my magnum headed 360. I have 10.6:1 compression with a Comp XE268H cam. This combo gives me 185-195 psi of cranking pressure.

With the good chamber design and ideal quench of 0.039" I run and 89 octane and like Jack I have run 87 in a pinch.

The magnum head is an excellent choice for a performance motor and will easily support 400 HP in stock form.
 
I am apparently lucky on several fronts, but my almost stock 360 Magnum heads (just a 3-angle valve job and MINIMAL bowl clean-up.. nothing else) have not cracked, and with the aid of 10 pounds of boost from my Vortech blower (entry-level, small V-1, S-trim) made 445 RWHP on av-gas. I don't know what the timing was/is.... I have never had a timing light on it... stupid, I know.:angry7: I play guitar by ear, too.... :cheers:

When it was unblown, I ran 34 degrees of total mechanical advance. Ran good with that settting, but I have no idea what the low number was. I set my timing with a dial-back light after the maximum has come in (2,200 rpm.)

One of these days, I'll put a light on it.... probably will have a heart attack when I see what it's set at.... LOL!

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18 initial, 34 total in by somewhere around 3k. Bored one day and I kept bumping the timing until the starter began to kick back. Close to 30 initial and 46 total and not a noticeable ping on 91 octane. My compression isn't as high as some of yours though.
 
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