Distributor Options for 8BA

[Smitty]

What mechanical advance distributor options do I have for an 8BA other than camshaft change and crab?

Steve

[Dodge]

Modify a Chevy small block dist to fit. Lots about it on line.

[flatheadmurre]

If you want mechanical advance only there are mallory units...and just about any post style that have the right rotation can be machined and tweaked to work.
I don´t like the look of HEI...last mech/vac i did was an accel from a chevy...dirt cheap and some lathework...the challenge is to adapt the curve if you don´t have a distributor machine.

[JSeery]

Might take a look a Bubba's site, he has some information of converted distributors.

http://www.bubbasignition.com/49-53-...nversion-.html

http://www.bubbasignition.com/49-53-...ion--pg2-.html

http://www.bubbasignition.com/mallory.html

http://www.bubbasignition.com/hp.html

[chap52]

Here is Bubba's link:
http://www.bubbasignition.com/

[tubman]

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I have two Mallory dual point mechanical advance distributors on my cars. I have a newer model with a conventional looking cap on the '51 Merc in my '51 club coupe and an older "Flattop" (refurbished by "Bubba") on my"hot rod" motor. I am very satisfied with both. If you buy one of the new Mallorys, it will probably have SBC advance curve that is too much for a flathead. "Bubba" can fix that for you as well.

[Ol' Ron]

Running an engine with only a mechanical advance does not allow for proper tuning. An engine requires one advance curve and carb setting for economy and another for power. This can't be done without a vacuum advance component in the timing. The only distributors available today are the converted Chevy and the MSD, However the MSD does not have an adjustable mechanical advance.

[JSeery]

I know O Ron is a big fan of vacuum advance, however I have run mech only on a lot of engines and was always happy with the results! These were street engines, you can run fixed advance on a race engine.

[tubman]

I removed a "vacuum over mechanical" converted SBC distributor from my '51 when I couldn't get it to run right, and replaced it with the mechanical-only Mallory, which improved the performance greatly. I believe the advance in the first distributor was not working properly. I agree with "Ol' Ron" that adding a vacuum advance will probably yield maximum performance, but I didn't have the time or resources to check it and re-curve the SBC unit.

Bottom line is that the flathead Ford, with it's "short" advance needs will probably function better than most engines with mechanical advance only.

[flatheadmurre]

For performance as in maximum power you don´t need the vacuum...it´s for economy and running the engine as tuned as possible in cruise.
So if spending some extra $ for gas isn´t the issue the mechanical only will work just fine.

[rotorwrench]

I'm original from the flat lands of Kansas but was close enough to Colorado to climb a lot of hills too. A flathead with an automatic timing control will keep the engine from overheating in the hills and definitely get better mileage. Model As had the mechanical lever but the V8s got too complicated to go that route plus operators of A-bones seldom knew how to operate the thing so automatic control was developed. For all around operation on the street, the vacuum/centrifugal timing control combination is best over all. The centrifugal will work OK but it likely won't get the mileage and may get warmer than normal under certain conditions. An efficient running engine is a happier engine and will likely last a bit longer between overhauls.

Aircraft engines are set to full advance on the magnetos with a starting aid to allow an efficient start without kick back. They are not the most efficient but they're set up for reliability more than efficiency.

[Smitty]

So where would a crab distributor fit into the scheme of things? Earlier camshaft in 8BA block or stock distributor?
I am anticipating problems with souped-up motor and stock 8BA distributor?
Steve

[rick r]

I reworked an early 1980's Chrysler 318 electronic dissy for my 8ba. Has both mechanical and vacuum advance, also, looks vert much like the original Ford unit. If you want more info on the conversion, e mail me at [email protected]

[rick r]

I reworked an early 1980's Chrysler 318 electronic dissy for my 8BA. Has both mechanical and vacuum advance and looks like the original Ford Lodomatic. If you want more info on the re-work, e mail me at [email protected]

[40 Deluxe]

Originally Posted by rotorwrench

I'm original from the flat lands of Kansas but was close enough to Colorado to climb a lot of hills too. A flathead with an automatic timing control will keep the engine from overheating in the hills and definitely get better mileage. Model As had the mechanical lever but the V8s got too complicated to go that route plus operators of A-bones seldom knew how to operate the thing so automatic control was developed. For all around operation on the street, the vacuum/centrifugal timing control combination is best over all. The centrifugal will work OK but it likely won't get the mileage and may get warmer than normal under certain conditions. An efficient running engine is a happier engine and will likely last a bit longer between overhauls.

X2 X3 X4 etc., etc.,

[JSeery]

I understand the theory behind using both mechinical and vacuum advance, but my practical experance has shown little difference. One vehicle I ran full mechinical was used to tow a large boat, lots of mountain driving, and very little loss in mileage (and I keep close tabs on mileage). The combo setup is going to be better, but not always worth the effort.

[rotorwrench]

The centrifugal set up is easy if done on a machine whether it's a GM or Chrysler unit. Dialing in the adjustable vacuum can could take a bit of trial and error but shouldn't be a difficult thing. Changing to a crab is more difficult in time and parts and the crab gets more limited as the performance level of the engine increases. Folks like Ol' Ron & the distributor guys, that have worked with this before, could give pointers on vacuum can adjustments. Same with centrifugal advance unit curves as well I'm sure. Vacuum connection would be to manifold pressure so you can run as many carbs as you want.

If a guy plans on racing or doesn't care about mileage for mostly around town driving, just use a centrifugal unit like an old Mallory or equivalent. Ol' Ron noted the difference it can make before and it may not be much but there is a difference.