Roush Engine Experts.

[olddog]

Originally Posted by jhv48

I have a 427 SRTW with the MSD mechanical advance distributor. I went to put the timing light on it and the light showed over 20degrees on the wheel at idle. But, there is a blue timing mark that someone has put on the wheel that is at about 2 degrees BTDC. So, how do I set the timing on this thing? The specs say 31-34 degrees at 4000 rpm. So, what do I set the idle timing at? Or should I run it up to 4000 and set the timing at 32 degrees? And what is the blue line for?

If this is a mechanical only - no vacuum advance - distributor, I would say set it at the high rpm. The spec seems odd to me. I would think the mechanical should be all in by 3500 rpm at the highest. I would get some help and map out what it is doing. See where the timing is at 1000, 1500, 2000,,,,,,, until it quits advancing.

If it has vacuum advance, you should disconnect and plug the vacuum line. Then see where it is at, when at an idle. This should be at 10 -16 depending on the cam.

For a street driven car, personally I feel it should have a vacuum advance. To me mechanical only is for race only applications, where you only care about WOT operation.

As for the blue line, it could have been put there for many reasons. It is possible that someone found that that is the true piston TDC and marked it rather than move the pointer to correct the problem.

[jhv48]

Fans were on the entire time I was stuck in traffic. I switched them on and left them on.

I reset the timing to 15 degrees and will check it out this afternoon when the temps are hot again.

[Chilibit]

At idle or thereabouts there is no huge advance dialed in.

It would be interesting to see if the fans come on at 100c on the dash board. I think that there is no linkage between the fan sensor and the dash gauge. If they come on at 100 or pretty close then the dash readouts are probably pretty close.

Does it run this hot at night when the ambient is way down?