leadfoot455
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Post by leadfoot455 on Jul 30, 2014 22:37:53 GMT -5
Ok so I read back 15 pages and can't find anything, I have never run the vacuum advance, always been told I didn't need it that it was more for highway driving. I have been watching some you tube videos and I understand how it works and that it advances the distributor at higher RPMs. Seems like people are about 50/50 on this but I'm wondering if anyone has any good solid information on this and if it's worth running? Just want my motor running at its best! Thanks in advance.
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Post by clong527 on Jul 31, 2014 8:59:10 GMT -5
Personally I prefer to run it I tried my motor last year without it and can't say that there was a real big difference just seemed like it did a little better with its all preference I guess
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8ba11
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Post by 8ba11 on Jul 31, 2014 15:27:52 GMT -5
I'd take dist. Apart and slide the advance out and tach weld it then you can set timing at peak performance and maintain it through all rpm range. That is how all my engines are done and I've never had a problem. Or you can buy an advance lockout for an hei from most performance parts dealers.
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Post by jugulator on Jul 31, 2014 16:48:55 GMT -5
I wrote about this a while back,,
for a stock motor,,, Not a performance built derby motor,, so if your running a fancy groop,, baldwin or what ever,, stop reading,,,
ok stock dist,, ya ever notice how good a motor runs at 12 degrees advance ? purrs like a kitten,,
but don't try to start it hot,, It will laugh at ya,, so how can we have the best of both worlds ?
too bad you couldn't start the motor at a low timing setting and than advance after it starts..
what,, ? ya can ?... of course,, the vacuum advance can will do that ...
time your motor to 8 degrees BTDC,, with the advance disconnected ,, and a low idle so you know the advance weights are closed,,,
with that done,, connect the vacuum advance hose to manifold vacuum.. the motor will smoothe out,,
adjust your idle,,
...........................lenny
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Post by jugulator on Jul 31, 2014 16:51:32 GMT -5
now .. for more total advance,, some trick advance weight springs will help..
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Post by smashincwa on Jul 31, 2014 17:17:17 GMT -5
I wrote about this a while back,, for a stock motor,,, Not a performance built derby motor,, so if your running a fancy groop,, baldwin or what ever,, stop reading,,, ok stock dist,, ya ever notice how good a motor runs at 12 degrees advance ? purrs like a kitten,, but don't try to start it hot,, It will laugh at ya,, so how can we have the best of both worlds ? too bad you couldn't start the motor at a low timing setting and than advance after it starts.. what,, ? ya can ?... of course,, the vacuum advance can will do that ... time your motor to 8 degrees BTDC,, with the advance disconnected ,, and a low idle so you know the advance weights are closed,,, with that done,, connect the vacuum advance hose to manifold vacuum.. the motor will smoothe out,, adjust your idle,, ...........................lenny spot on. I liked the vacuum advance. |
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leadfoot455
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Post by leadfoot455 on Jul 31, 2014 20:27:07 GMT -5
Oh boy lenny.. you are going to turn me into a mechanic yet.. never messed with any of this kind of stuff before. My double roller timing chain last year was the first thing I have ever done that deals with timing. Stay tuned incase I screw this up.. do I still do 8° BTDC if my timing chain is set 4° advanced? Lol
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ron17t
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Post by ron17t on Jul 31, 2014 21:25:51 GMT -5
Advancing the cam, which is what your doing with a 3 way timing chain moves the power curve of the engine.The timing is still set the same way.
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Post by jugulator on Aug 2, 2014 19:46:08 GMT -5
Lenny, is that how you would set up any stock engine? (including 4 and 6 cylinder engines) or are you just talking small blocks? yes,,for carbed motors,,, ya just have to find the base timing for them,, |
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Post by SDderbyman47 on Aug 3, 2014 21:42:25 GMT -5
Now I am gona have to think about hooking mine back up.
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leadfoot455
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Post by leadfoot455 on Aug 4, 2014 10:41:55 GMT -5
Ok, here is the part I don't understand.. the line coming from my carb to the vacuum advance only has vacuum when you Rev the motor and get the RPMs up and no vacuum at an idle. So how would hooking this line up at an idle change a thing?
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Post by STROMI 121 on Aug 4, 2014 13:05:44 GMT -5
Manifold has vacuum when the engine is running, thus no vacuum while you start it.
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leadfoot455
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Post by leadfoot455 on Aug 4, 2014 13:06:50 GMT -5
connect the vacuum advance hose to manifold vacuum. ok, but isn't the point to advance the distributor at higher RPMs? Don't mean to keep asking stupid questions just trying to understand the benefits of hooking it up to the manifold vacuum |
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Post by STROMI 121 on Aug 4, 2014 14:26:15 GMT -5
Retard the initial timing for hot starts, advance the timing with the vacuum advance while its running. The mechanical advance (weights and springs) will advance the timing even higher at higher RPMs depending on which springs you use. At least that's what I understood he was saying?
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leadfoot455
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Post by leadfoot455 on Aug 4, 2014 14:40:50 GMT -5
Retard the initial timing for hot starts, advance the timing with the vacuum advance while its running. The mechanical advance (weights and springs) will advance the timing even higher at higher RPMs depending on which springs you use. At least that's what I understand. Ok gotcha. I'm running a 351M and they come set retarded. Last year I changed out the timing chain to a double roller from comp cams and set it 4 degrees advanced from what it was. I'll try hooking it up to the manifold vacuum tonight and see how it runs the way it is. Thanks for all your help. |
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