I've set the timing on a couple older engines and am familiar with loosening the clamp at the base of the distributor to advance or retard the timing by turning the distributor. However, I've never worked on one with a vacuum advance. When I loosended the clamp at the base of my '54 235's distributor and attempted to turn the distributor, all I did was turn the distributor against the spring tension on the vaccum advance. When I released the distributor the spring tension moved it back to the original position. The only other bolt/clamp I've located at the base of the distributor is the octance selector which is set at "0" and from previous posts I've learned to leave it alone. Am I being too gentle with the distributor and need to give it a good twist against the vacuum advance's spring tension to advance or retard the timing? Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Distributor - Embarrassed to As This may not be what's happening to you. Look at the vacuum line and see if it isn't trying to return the distributor back to its original position. These things can be a lot stiffer than you realize. Hope this helps!
RE: Distributor - Embarrassed to As You may not have loosened the clamp enough or like the man said , the steel vacuum advance line may be pushing the Dizzy back when you let go of it . Look at the base as you're twisting it , if the dizzy's base is rotating where it goes through the clamp and into the cylinder block , you're doing fine , maybe you'll need to fiddle with it a bit more but -DO- get the ball on the pointer , dead nuts . -Nate
RE: Distributor - Embarrassed to As I, too, have the vacuum advance on mine. Like the other say, loosen the collar clamp just enough to have some friction and then set it where you want. My new setup had an issue because I changed from an advance that sat at about 45 degrees to the engine and the new one sits at 90 degrees. This meant I had to rebend the vacuum line to the carb because it got pushed up against the fuel pump and wouldn't let me turn the distributor to where I needed it. I just gently pushed the tubing over to make room, being careful not to kink the steel vacuum line. I adjusted the collar clamp so it takes a fairly good amount of effort to move the timing. You will find when you turn counter-clockwise that the vacuum advance will compress until the internal spring is collapsed before the distributor will move. Once you set the distributor a bit and release it, the vacuum advance will push the arm back to the stop and you can see how it runs. If you do this with the engine running you may see the engine want to die if you hold the distributor advanced for too long so just make short quick adjustments and then see how it idles.
RE: Distributor - Embarrassed to As Well here goes..I had to move my octane selector to time my 235. I had the same problem that the distributer would spring back after I put the BB in the 'hole'. After I moved the octane selector,I don't remember advance or retard, I was able to time as mentioned. I might be wrong but it seems that the octane selector acts like a cam in relation to distributer position.
RE: Octane Selector Yes this is so -but- the purpose of the octane selector is to be able to make minor field adjusments to the correct basic timing if you get a bad batch of fuel that causes " ping " . -Nate
RE: Distributor - Embarrassed to As I sure appreciate all the responses. Bossman was right on target with the tip that the distributor was not going to turn (counterclockwise) until after taking up the vacuum advance's spring tension... then a little more pressure. One last item... Nate & Bossman indicated a steel vacuum advance line, but mine is just a plain old rubber line like you might find going to the windshield wipers. Is that a problem? Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Vac. Advance Tube NOPE ! it'll be fine , right as rain . If it has threaded connections at each end , you can look up the correct steel tube from The Car Shop or Inline Tube , buy the tube that matches your _engine's_ year of manufacture ! . -Nate
RE: Vac. Advance Tube Like Nate said, either works fine. Mine was originally set up with the steel line that routes with the gas line to the carb, forward on the engine, over the top, right to left, with a clamp that holds it to the thermostat housing, then back towards the carb. It looks nice if you can bend the tubing to have two parallel lines. MIne is kind of junked up right now because I have had to make several alterations. I will replace them once I am satisfied with the whole setup.
RE: STEEL Engine Tubes They look really great ! they're available in stainless steel too . Mine are all junky bent up rusty and patched with rubber hose ~ it's a POS work truck remember . I'd love to one day replace all with spiffy seamless stainless steel ones , including the vacuum wiper to dual action fuel pump one.. -Nate
