Hi All, My 67 Service manual says to check the timing with the car in drive with the e-brake on and the wheels blocked. I have been told by others to check it in park. Can anyone help with this? Thanks and pray for Spring!
I would think Park is fine. I doubt that 50 RPM is going to make much of a difference in timing. The only thing I check when the car is in drive, is the RPM. I can see trouble brewing with a car in drive an nobody in the drivers seat.
The difference is more like 300rpm, but Adam is right. There isn't going to be much difference, if any, between the two. I have sometimes, just to make sure, set it in park and then just checked it in gear...really quickly.:eek2:
If you are running a mild cam, idle speed can be a real PITA to get right with an auto trans. Add a/c and power steering to that and it only gets worse. When I first put the cam in mine, my old qjet was full manifold vac. to the dist. The cam makes low vacuum at idle. When I would turn the steering wheel when the motor was cold, the advance would drop out, slowing the engine down even more, and then the choke pull off would close, flooding it out, and it would stall. Put the a/c on and just forget it, I couldn't set the idle speed to save my life. Even when warm it idled shi!!y. What I wound up doing was using an adjustable advance that was limited to about 6 degrees, and Carmen set up the new curve for me. I also had to stretch the choke pull off spring in a weaker direction to compensate for the lower idle vacuum. (On the '66 carb the pull off is able to come apart if you pry off the steel cover.) That solved the problem. The dual quads use ported vacuum, so I never had that problem but the idle is a little less smooth than I would prefer. Especially with the a/c running. :bglasses: Oh yeah, my idle speed varies about 100 rpm from drive to park.....about 200 including the a/c load.:Brow:
I think the real consideration is whether your out of gear idle speed is HIGHER than the RPM where your mechanical advance curve begins. If it is, it might be better to set your initial timing with the car in gear, or the idle speed set appropriately lower.
That's a good point Larry.......I never thought of that.....it may be beneficial to set it up so the mechanical advance starts above 800 rpm's or maybe even more.:bglasses:
