advance curve

gtxrt

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on a stock, say 1969 440 when is the distributor advance all in by.
 

AR67GTX

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I don’t think it will all be in at 2500 on a “stock” distributor with that heavy gage, elongated eyelet spring that was commonly used. I bet that spring doesn’t let it all in until 4500 rpm or higher. I have a number of those I’ve taken out of distributors. But for a tuned distributor with a 4 speed, all in by 2500 would be a good goal.
 

Master Gunner

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Yup, a factory stock dizzy would be lucky to be all in at 4000 RPM, You try to shoot for 2500 with a performance tuned one.

Mark
 

PRHeads

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I’ve tested a few stock ones with the big spring that has the loop in it.
You think it’s all done by 3000-ish, but the last bit of advance allowed by that big spring comes in very slow.
“All in” takes about 4500 to get there.

I ran into it a few times where the timing was set at around 3000 or so, say like 36*, but then at 5k it could be close to 42-45*.
Rev it until the advance stops climbing, or as high as you’ll be turning the motor while driving.
 

gtxrt

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thanks all for the replies. wasn't going to recurve, didn,t want for it to ping, but i sent it out for a conservative curve. something like 12* initial and all in by 3200 rpms, what do you think ?
 

1967coronet

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It all needs to work together. Cam , intake , stall if auto trans and distributor advance.
Get them all coming on at the same rpm range.:steering:
 

AR67GTX

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thanks all for the replies. wasn't going to recurve, didn,t want for it to ping, but i sent it out for a conservative curve. something like 12* initial and all in by 3200 rpms, what do you think ?

I think that would be good for an auto transmission, stock converter and 3.23 gears. If a 4-speed it could be brought all in quicker - say 2500 rpm.
 

gtxrt

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Hughes 2000 stall, 2.94 posi with a small one size over stock cam. 3900 lbs. what am concerned about is 9.5 compression with iron heads.
 

Master Gunner

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Hughes 2000 stall, 2.94 posi with a small one size over stock cam. 3900 lbs. what am concerned about is 9.5 compression with iron heads.
First, if you're going to play the Mopar game learn the correct names. "Posi" is a GM name, and most Mopar people will laugh at you for using it, we have "Suregrip" limited slip diffs.
Next, 9.5 with iron heads is no big deal, run pump premium and you should have no problems. You must be looking for highway mileage with that gear and stall, that heavy a car would really like a 2500-2800 stall and 3.54 gears.

Mark
 

gtxrt

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Master Gunner, let me say this, am 64 and since i was 17 having a 1968 gtx conv. since then having about 12 more gtx, rt, and 69 an 1/2 super bee six pack and 4 or 5 c-body cars all for hobby and not making any money just for the love of cars. i have been playing the mopar game. unless this is a quiz on grave yard cars lol, i aways say posi. on your advice thank you, 9.5 iron that is good news you think it's no problem, just trying to do best thing. on your question yes trying to build a nice highway cruisier, quiet and as much power i can make with out negative side affects, had a a lot of fast street cars you know loud, big cams rough idle, not pleasant to drive to far. want different kind of car now that am old lol. :thumbsup:
 

AR67GTX

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I have had some issues running my stock (68) 440/auto on 93 octane. I think from what most Mopars guy say, the rated 10:1 motors probably were really no better than 9.5:1 in actuality. To solve my pinging problem I put a FBO advance limiter plate in my dual point for 18 crank degrees mechanical advance and set initial timing around 15 degrees for 33 total. With that much initial advance and a moderately quick curve it has a strong idle and off-idle response and doesn’t ping. I probably have some carbon in my chambers that doesn’t help.
 

Master Gunner

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I hear you bro, my next project is going to be a 66-68 C body that I can float down the road at about 80. Not gonna sat how old, but lets just say we were in high school at the same time.
 
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