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Bihili
02-26-2013, 01:00 PM
Looking at Ebay I see factory dual point distributors for sale.
One said it was a factory 57 Corvette.
Another ad said it was a factory 56 six cylinder.

In the 70's I had a Mallory dual point but never gave it much thought.
Were these an option in 55-57 or standard on some engines?

I don't remember any discussion about these. Probably because we all have HEI's

markm
02-26-2013, 01:43 PM
Spec. HP SBCs in the 50s/60s used dual points, no 6 cyl did that I ever saw, unless the one in 54 Vette did.

mrwrenchman
02-26-2013, 04:48 PM
Dual point distributors came on engines Corvette and passenger cars with dual quad carbs. Don

markm
02-26-2013, 05:00 PM
Dual point distributors came on engines Corvette and passenger cars with dual quad carbs. Don

Add to that Fuel Injected ones.

mrwrenchman
02-26-2013, 05:06 PM
I stand corrected I forgot about the FI's . Don

Rick_L
02-26-2013, 07:03 PM
I'm not thinking that 57 FI cars had dual points, but later ones did. But I think that 56-57 2-4bbl engines did. (Not sure here what had what when.) The distributor was not the kind with the window cap, it had a similar body to the 55-56 single point distributor.

Remember that a factory FI engine had a cable drive for the fuel pump. These are rare and command big $$, let the Rochester FI guys have them.

The best non FI dual point distributor is from early 60s Corvettes with 2-4s. It has a mechanical tach drive also and the familiar window distributor cap.

The factory dual point setups used one set to open and the other set to close. This lengthened the dwell without the points bounce you'd get from the same dwell with a single point distributor. They had the same 8 lobe points cam that a single point distributor had.

The Mallory dual point was a bit different in that they used a 4 lobe cam and each set of points only fired every other cylinder in the firing order.

Dual points are not needed with a good modern aftermarket CD box like an MSD or Mallory.

Bihili
02-27-2013, 08:15 AM
I looked at the Ebay ad incorrectly.
The dual point distributor for six cylinders was for 1949 to 1952.

http://www.ebay.com/itm/121061137314?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

markm
02-27-2013, 11:39 AM
I am confused why did they make a dual point dist for 49-52 inline 6 bangers.

markm
02-27-2013, 05:01 PM
I forgot to mention I have a really nice exanple of one of these Delco DPs for a v8 and it needs a new home.