Hi,

I started a new thread since this is of a different nature than my previous misfiring/rewiring issue. While I'm waiting for my wire and connectors to show up from Delcity, I decided to go after the sticky distributor advance. I removed the Dist and when I got down to the advance portion, it was sticky as suspected, but when it was retracted, the small spring would still have tension on it, but the large spring was loose and would shuck back and forth. Even when it the mechanism was extended, the small spring was stretching, but the large one was just barely tight. Basically, the large spring isn't doing much of anything as far as pulling the advance mechanism back to retracted position.

Does this sound like I need a new large spring, or is this typical?

Also, what type of screw goes in the end of the shaft where the rotor goes on. It is recessed and looks like a small allen. I can't find one that will turn it and suspect if it is an allen it is stripped.

Thanks for any tips.

Bill.

 

Bill,

USA spec distributor, quite different to ours in the colonies due to emission requirements I guess.

The spring (mechanical advance) is a 2 stage affair.

The small spring is doing quite OK I reckon.

The larger one is probably not the original, read on.

There is NO screw in the end of the shaft of the HE distributor, that ended with the PreHE. Lucas used a "plastic o/ring" to secure the 2 shafts, and that was successful, NOT. Simply removing a stuck rotor (they all are) will shatter that o/ring and the outer will rise up, quite quickly, and the 2 springs get stretched and generally buggered up. Maybe these plastic o/rings are available again, dunno, I use a small brass washer and a standard o/ring, and ALWAYS remember to push down on the star wheel whilst pulling up on the rotor, that way all the bottom junk stays intact.

I reckon someone has had this happen, and sorted it as best they could on the day. The advance curve is controlled by these springs, and changing them alters the advance curve, obviously, but it is NOT a hit and miss affair. Back in the day, there was a machine in most Auto Electrician workshops used to reset distributor advance curves. I reckon they are long gone these days.

My memory (HAHAHA) has the larger spring coming into play at about 75% of total movement. It really is the "top end" of the rev range spring.

This will also all depend on the vac capsule on your car, as some have vac advance/retard all in the one unit. Top end rev range detonation was a constant issue with the HE engine.

I think some serious hunting will find the correct (or very, very close) springs for you.

Try XK's Unlimited in San Loius Obispo, as they have helped me over the many years with odd stuff.

Merry Christmas. Lunch time down here, and HOT, see ya.

 

Hi and thanks,

Turns out I should have read "the book" a little closer. Turns out the big spring is not supposed to be in play until furthur out in the advance.

Oops.

Thanks though.

PS. Why do they say you should check compression with all plugs out? I don't see how they could effect each other.

Curious.

Bill.

 

The plugs out for comp test has been that way as long as I remember.

Something to do with "rotational speed",. "less load on the starter motor/battery", etc, and I have always done it that way.

The V12 with 12.5:1 comp ratio would certainly rotate faster with the sparkers out.

Dont forget to jam the throttle discs (carby/ies in my days) wide open, so max intake of air is possible.