Very strange timing....

Bassman/NZ

Bassman/NZ

Well-known member
My C59A (stock except milled heads) runs best with the advance adjuster on the crab dissy pushed fully down as far as it will go, and feels like it would stand to go more if it were physically possible. If I run it at the centre mark or one mark down from centre, it is gutless and miss fires. The dissy has been fully recond by Bubbas. When I had the front timing cover off to replace the cam gear recently, the marks on the cam and crank cogs were lined up OK.
It's running OK with full advance, but just seems to me that it's not how Henry intended it to be. Very peculiar.
 
I had the same issue with the Distributor on my G series six cylinder engine but never got to the bottom of the problem, just drove the wheels off it :)
 
Maybe the mechanical advance is stuck or not working? That could cause you to have to use more initial timing to get it to run right. You might want to use a timing light to identify a place on the crank pulley that you can see when you have it on #1 - paint a mark at that place. Then just make a wire pointer of some kind. You won't know how much total advance, but you'll be able to see if the distributor is advancing. Just for eyeball purposes on an early style pulley - about 7/16 of pulley length (at the outside edge) is worth about 10 degrees of advance. This way, you can see how much advance is coming in off of idle . . . might help you diagnose the problem. Hopefully this is making sense.
 
Bored&Stroked said:
Maybe the mechanical advance is stuck or not working? That could cause you to have to use more initial timing to get it to run right. You might want to use a timing light to identify a place on the crank pulley that you can see when you have it on #1 - paint a mark at that place. Then just make a wire pointer of some kind. You won't know how much total advance, but you'll be able to see if the distributor is advancing. Just for eyeball purposes on an early style pulley - about 7/16 of pulley length (at the outside edge) is worth about 10 degrees of advance. This way, you can see how much advance is coming in off of idle . . . might help you diagnose the problem. Hopefully this is making sense.
Click to expand...
Thanks. Yes, I'll do that.
 
I do get that from time to time. Customer states the unit wont run correctly without huge adjustment of slide etc.
I would suggest removal and closely check point gap. Should very close to .015 on each set sometimes they will just wear in and close the lead set of points. We do everything possible to prevent wear and adjust on a machine running to center the advance etc with a dwell meter and dont use a feel gauge.
A rebuilt crab should not need any adjustment at all for a long time....
Let me know what ya find......
 
Hi Jim,
I've only done maybe 2-300 miles since the dissy was done, so I don't expect to find any problem there, but I'll pull it off and check.
 
look for vacuum leaks at the vacuum brake cap or the mounting of the crab to the timing cover. Where is the brake adjustment? I believe it should be all the way out and then in about 1-1/2 turn. You may want to inspect the brake piston leather shoe. Have you put a vacuum gauge on the engine?
 
Here is a picture of my crankshaft pulley and timing mark setup - will give you an idea as to amount of movement / versus degrees. Each mark is 10 crankshaft degrees apart from the other one:

CrankPulleyAndNewMount2 copy.jpg
 
Terry said:
look for vacuum leaks at the vacuum brake cap or the mounting of the crab to the timing cover. Where is the brake adjustment? I believe it should be all the way out and then in about 1-1/2 turn. You may want to inspect the brake piston leather shoe. Have you put a vacuum gauge on the engine?
Click to expand...
All good there, thanks. Dissy has done 300 miles on full Bubba's rebuild.
 
Found the problem. One pair of points had closed right up. Thanks for the help. I will still go ahead with installing a TDC marker.
 
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