[Johnny406]

I have a rebuilt single points distributor that I am about to convert to electronic with a Accel points eliminator kit.

Should I convert it to full mechanical or select a specific canister for it? The one currently mounted says MS-440 18.

My car is now making just over 10Hg at idle.

Thanks,

[INJUNTOM]

I would try to set it up to get the curve you want without vac advance. You have near zero vacuum at WOT.

I also replied to your post at PZ

["QUICK-SILVER"]

Conversion shouldn't change timing function, so if the engine ran good before, it should run the same after, timing wise.
Vacuum advance doesn't work at WOT, isn't suppose to.
Depending on compression ratio and state of tune, vacuum advance and how much, should make for better cruising, better gas milage and cooler engine temperatures.

You'll just have to drive/try it and see what the engine likes best. If it ony holds 5 gallons of fuel, you need all the help you can get.

[Sun Tuned]

Ideally you will want a vac can that operates between 4 inches and 9 inches of hg. vac.

Not so hard to do a few years ago but now that they have discontinued production of many of the selections we had, the best bet is to find one that operates in these parameters and don't worry about the amount of adv it ends up being, then mechanically limit it to about 10-15 crank degrees. still you may need to check the operation of it after you limit it if it was say offering alot of advance in unmodified form as just cutting half of the advance total off of it will not get the result you're looking for as far as where it now operates.

Maybe call me and I can explain this much better than typing a novel about it.
901-412-4414.

You can make your own very quickly and efficiently.

[Kenth]

What SunTuned said, or connect the ignition vacuum advance to a "ported"/"timed" source and adjust the idle circuit in carb accordingly.

[INJUNTOM]

Maybe get one of the adjustable advance units?

I'm pretty sure Johhny plans to race this car, so mechanical advance would be what he may want to focus on most.

[Johnny406]

Thanks guys for your input. Yes I will race the car more than anything. I was looking at the Crane adj units. Reading the instructions was mindblowing, they call for the operator to adjust it until they hear detonation/pinging, then back off until you don't.

I found a link that had all the GM part numbers for different canisters and their advance rate. Unfortunately my better half exited out of it. I'll try to find it again today. Sun Tuned, I would like to take you up on your offer and call you.

Thanks,
John

[Johnny406]

Found it

http://www.corvette-restoration.com/...c_Adv_Spec.pdf

[INJUNTOM]

Originally Posted by Johnny406

Thanks guys for your input. Yes I will race the car more than anything. I was looking at the Crane adj units. Reading the instructions was mindblowing, they call for the operator to adjust it until they hear detonation/pinging, then back off until you don't.

I found a link that had all the GM part numbers for different canisters and their advance rate. Unfortunately my better half exited out of it. I'll try to find it again today. Sun Tuned, I would like to take you up on your offer and call you.

Thanks,
John

What are you doing reading the directions? That'll mess you up.

You adjust it with an advance timing light so you can see what changes you made and adjust accordingly. I believe screwing it in gives more advance.

Like I said Johhny, with the way your car is your racer, you'll want to get your 32 - 38 degrees without the vacuum for best performance. From there you can give it another 10 degrees or so of vac advance to help with mileage.