Thanks, I will take all that under advisement and recheck everything and post here. I just ran the engine up to operating temps ( fan on at 185F ) and for the 1st time ever, when I throttle into it to approx. 22-2400 rpm, them temp comes down dramatically and fans shut off. This is with no vacuum can attached and reading now 15 in/hg manifold vacuum. Base is set at 45 btdc and obviously, I can't leave it there but that is at idle, no mechanical involved. The distributor was just curved on a dizzy machine and should be good. Weights are not sticking.Old as Dirt wrote:What is idle rpm? Could the idle be high enough that the weak springs are allowing the extra advance and the weights not returning home?
What vacuum can? and only 10 degrees @ the crank is only 5 degrees at the distributor.. sure?
BBC's will tolerate around 52 degrees total @ cruise..
Think I would be around 26-28 degrees initial, 10 degrees max for centrifugal and 12-14 vacuum.. and make sure the vac can unloads when you romp on it so the timing goes back to 34-36 under a good load..
When I lower base timing back to 36 and start throttling into it, the heat starts climbing again when rpm is back up to 22-2400. Put it back on 45 btdc and heat starts going away, especially when I begin to add throttle back up to 22-2400.
I am really beginning to wonder about cam degree being off and/or balancer. At this much timing, engine is still responsive but exhaust note is much quieter than previous. Engine has never seen this much idle vacuum ( 15 in/hg at full engine warm up, idle at about 740 rpm ).
All this is sitting still in the shop in Park. I have not checked what the vacuum advance can do since jacking up the timing this much as I was only getting about 8-9 in/hg previous at idle so about 10 degrees was all that was happening. Now I have some vacuum.
The 52 target all in @ cruise sounds good to me, just need to check balancer mark for accuracy and if ok, may check cam but degreeing in the car will be a time consuming pta for sure!
I am extremely encouraged that any
timing change has brought the temps down, even if it is not a realistic number to leave it at. This at least tells me all the other changes are working and it may be as simple as bad balancer or as pita as cam timing wrong. Of course I will have to reset idle air on carb once this issue is put to bed.
Thoughts?