Distributors and Superchargers

Distributors and Superchargers

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By Rono - 16 Years Ago

I was talking with a guy who raced supercharged Fords back in the 50's and he told me that if I'm running a VS-57 blower, I should use a mecanical advance only distributor. I thought that all the '57 and later Y-Block distributors were both mechanical and vacuum advance? So would you block the vacuum port if you're running a blower? I see that Mallory has a non-vacuum electronic Y-Block distributor now. Would this be a good option?

Rono

By Hoosier Hurricane - 16 Years Ago

Rono:

Just leave the vacuum advance unhooked. Set the mechanical curve to suit.

By Rono - 16 Years Ago

Thanks John! Definately the most economical way to go.

Happy Holidays Smile

Rono

By Joe Johnston - 16 Years Ago

Had the same set up included in a parts lot I bought many years ago. NO vacuum advance on the Mallory dist but it had dual points and large dual external condensers. Also there was a vacuum hose connector that ran from the side of the Y-Block fuel pump to possibly the manifold to equalize the pressure. At least I think that is where the extra hose went to as it stuck straight out horizontally away from the block in addition to the vacuum lines going up to the wipers or intake as they were there also.

By Rono - 16 Years Ago

Joe;

I just bought a new fuel pump that will need to be modified with a vacuum port as you described. I'm just not exactly sure where to drill and tap the top of the pump body and I understand it does make a difference. It does connect to the blower I've been told as a boost reference. Also, below is a link to the new style Mallory electronic distributor. This one being sold through Speedway Motors, but there are probably other vendors.. It's a little less expensive than the Y-Block MSD distributor and has no vacuum advance. Looks like a nice billet unit.

http://www.speedwaymotors.com/Mallory-Block-Ford-Electronic-Distributor,10895.html

Rono

By Joe Johnston - 16 Years Ago

The "extra" hose connection was in the middle of the vertical surface (when mounted on the engine) and pointed straight out away from the engine. I may still have a picture and if so I will send a PM to you. Certainly looked like it would be easy to drill and tap with no problems.

By Hoosier Hurricane - 16 Years Ago

Rono:

The pressure port has to be on the back side of the diaphragm. There is a stem seal on the diaphragm, and the pressure has to enter between the diaphragm itself and the stem seal. That way the pressure assists the spring when the boost is "on". Most fuel pumps have a small vent hole in that area, so that if the diaphragm leaks, gas won't go down into the crankcase, rather it will leak out the vent hole. Putting the reference tube in the same area as the vent is what you need. If you don't use the vent hole for the pressure line, be sure to plug the vent hole. Also, I once received a rebuilt pump that had no stem seal. Couldn't pressurize that one.

By Rono - 16 Years Ago

Guys;

Thanks alot for the fuel pump info. The new pump I got is an EdlebrocK HP for a BB FE ford 390, 427,428. It has 3/8" ports and rated at 110 GPH at 6psi. I'll study the pump and take a picture of it with a spot marked on it where I think to drill. If I can figure out how to post the picture to this string I'll do it.

MERRY CHRISTMAS!!

Rono

By Rono - 16 Years Ago

John;

The vent hole on this Edlebrock #1724 fuel pump is about 1/4" in diameter. Are you saying that I can tap this vent hole and install a hose fitting to it? This would be alot easier than trying to drill a new hole in that location.

Rono

By Hoosier Hurricane - 16 Years Ago

Rono:

Yes.