The Stovebolt Site Forums The Shop Area General Truck Talk Distributor rotation?

The distributor rotation on my 56-235 is CLOCKWISE with the main body of the vacuum advance on the left side. The vacuum advance unit on my 1960 is on the right side and the resource I'm using (Second Chance Garage)shows it as rotating COUNTER-CLOCKWISE. The distributor number for both the C & C-C rotation is 112403. I'd like to drop in a mini-HEI but am not anxious to screw up my new cam/oil pump.

Is that correct or a mistake in the SCG literature? The 1960 engine, generator rotation is still clockwise. Does the 57-60 engine use a different distributor drive gear on the cam to accomplish the C/C rotation?

In addition, that would reverse the location of the plug wires on the distributor cap...the same 153624 but going in a C/C direction from #1.

Am I missing something here??? Sure would appreciate some clarification.

My manual is a little too new to show a '60, but EVERY year shown after that is clockwise. I think it might be a misprint.

Stuart

Is the 1960 engine a 235 also? If so it will rotate clockwise too. To verify this, pop the cap off the distributor, lay it aside, have someone "bump" the starter switch and watch the rotor. I'm a little confused as to why the vacuum advance is on the right. It is possible that the distributor body on the '60 is in the wrong position. You may need to rotate it back to where it belongs and change the plug wires to match the new position.

I am disorientated by this discussion.

Does anyone have a 216/235/261 engine that has a distributor rotor that does not rotate clockwise? Is this what is meant by the "distributor rotation" (the rotor rotation)?

Does anyone have a pcture of a 216/235/261 in a conventional cab truck that does not have the vacuum advance mechanism on the right of the distributor? For the purpose of assuring correct orientation, here is a picture of the vacuum advance on the right side of the distributor on a 1954 235 truck engine.

I know that a vacuum advance on a passenger car 235 engine has a slightly different shape in comparison with the vacuum advance mechanism used on a truck - maybe the passenger car meechanism is mounted on the left side of the distributor? Does anyone have a photo of the passenger car vacuum advance on 54-62 235 engine?

Just to clarify....I was trying to figure out how the 235's up to 1956 had a distributor that rotated clockwise and according to my resource, the 1957-60 rotated counterclockwise. The source was:

http://www.secondchancegarage.com/public/department35.cfm

Several folks pointed out that the rotation of ALL 235's was clockwise. I mistakenly indicated that the advance unit on my 1960 distributor was on the right side. It wasn't, couldn't be...my mistake!!! When I say "left" I have my advance unit diaphragm vacuum inlet, aimed 90 degrees to the block....pointing directly at the pass. fender. In the same configuration as your picture, just rotated 90 degrees clockwise. The info from 2nd Chance had me wondering, as I am getting my 1960 engine back from a complete rebuild and didn't want to foul up a new cam/distributor gear with a new HEI distributor that wasn't correct for the vehicle.

I really appreciate the correct info and had no intention of causing additional concerns. Guess it just shows that you can't take as gospel, everything you read!!!! Thanks for the help!

Heck, you did not cause me any unnecessary concern. I was interested in seeing what you had.

If your vacuum advance in pointing towards the fender and the octane selector is centered on the bolt that holds it to the block, then you might have a setup that is like the distributor shown in the 1955-2nd Truck Shop Manual.

Does that picture at the link above look like yours?

I had thought that this picture was of a passenger car distributor (which I think that GM had incorrectly used in the 1954 Truck Operator\'s Manual.

That's an affirmative! I'm a bit manual "Challenged" outside of the 54 stuff!! That's the reason I found the SCG spec page so friendly for checking out the specs on my 1960 engine. I just, for the life of me, couldn't figure out how you could from one year to the next year, REVERSE the distributor rotation, use the same cam, and maintain the same engine, waterpump, and generator rotation!!!!!

The SCG site, with specs of both 6's and 8's up through 1960, just has so much good info on these engines. I wonder if the "descrepancy" might be in my interpretation of that specific piece of info. Thankfully, I've got the "Stovebolt" crew to head me in the right direction!!!! Thanks again for your responses and assistance.

I'm not close to home right now, so I can't check my iron. I see what you are saying about SCG. They have made a mistake. The same number distributor would have to rotate the same direction. They make the same reversal on the V8s.

The only factory chevy engine I know of that had a reverse rotation distributer was that rare factory gear drive cam big block. I seem to recall it was a marine application. It used a 2 gear cam drive instead of a chain or 3 gear drive, thus the distributer had to run backwards.