question about accel vac advance unit

[bk53]

Its taken me a year to get back to this point,
is there any trick to this accel vacuum canister.
I'm trying to turn counter clockwise but it doesn't seem like
i'm finding whatever it is I'm supposed to be turning in there.
I push the 3/32's allen wrench in till it won't go anymore but
turning it seems to have no effect.

Thanks

Bill

[Richard in Florida]

Originally Posted by bk53

Is there any trick to this ACCEL vacuum canister?

They can be very frustration but here's what I've learned about them. The manufacturing quality is such that sometimes a bona fide 3/32" wrench won't go into the female adjustment part. Try rounding the very end of your wrench just a little.

When you insert it to make an adjustment, apply a little pressure on the wrench while you fish for contact inside. Also, when you're actually making an adjustment, push the wrench in a little while you turn it.

[bk53]

Thank you sir! will do.

[Ross F-1]

Try pushing the rod back into the can while you are fishing for the socket on the screw. The diaphragm is sloppy and unguided, and the screw can get off center.

[bk53]

thanks! I got some adjustement! woo hoo I'll make to the efv8 meeting tomorrow. and I'm driving this gal the 30 miles to work monday. Its still 100 out so I'll commence to washing the old gal around 9 Pm. I think both you fellows would like this old truck. I tried to take her to the PO's wifes funeral but had a vacuum leak. diagnosed and fixed that with some propane and red rtv. It only has to last 500 miles. I know the navarro manifold doesn't leak but I don't want to risk it with new carbs till the rings seat. Sorry if I sound like a sap but, well i suppose you do know my excitement.

best regards.

[Ross F-1]

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I assume you are using either a Bubba's distributor or an MSD? What did you set the max vac advance to? I'm using 8* based on some advice I got elsewhere. I'm also using manifold vacuum. It runs great!

[bk53]

I need to run thru some old posts here instructions wise again. but I set max mechanical to 20 and I'll dial in 8 more on the vacuum. yes this is a bubba conversion and so far its everything I heard it was. fresh motor doesn't hurt.

[Ross F-1]

I asked Richard in FL for his recommendation on vac advance, not sure if it was on here or on the Flathead Forum. He said 8*, which is 2.5 turns in from bottomed on the advance unit I have.

[Richard in Florida]

Originally Posted by Ross F-1

I asked Richard in FL for his recommendation on vac advance, not sure if it was on here or on the Flathead Forum. He said 8*, which is 2.5 turns in from bottomed on the advance unit I have.

Just to be clear, I use 20 mechanical and 8 vacuum because after a LOT of experimenting those numbers seem to work really well for MY engine in MY car. For another engine in another car, they may or may not work as well. However, they're good places to start.

Always start with just mechanical; tweak that until you love the way it runs. Then add the vacuum and see what happens. You may need to adjust your idle SPEED, but leave the timing alone unless it pings.

If it pings a little under acceleration, back off your mechanical a degree at a time until it no longer pings.

PS --- I made a simple but extremely useful fixture that lets me read and adjust both mechanical and vacuum advance in converted Chevy distributors, both points and magnetic trigger. If anyone would like to see it and is interested in making one (mine's wood!), PM me your e-mail address.

[Ross F-1]

That's where I am too, Richard, 20 + 8. The thing is, long before I can get mine to ping, it starts running hot. I'm perfectly happy accepting where I'm at, running cool, and last tankful I got 15 mpg -- not all highway miles, either. For a truck with the profile of a brick wall, that's hard to beat.

I'm about to set out on a trip to the lowlands, and I'm anxious to see how lower altitude affects things.

[Ol' Ron]

Your mext project is an AF meter to check the air/ fuel ratio during acceloration and cruise. This may also improve performance and economy.

[bk53]

thanks fellas. much appreciated.