my roadsters sbc 350 has all-in timing at 36 deg and initial timing at 19 deg… is the 19 deg mark ok or is it too much advance… the car starter cranks well with no kick back and no pinging or detonation anywhere in the power curve….i know 36 deg is ok, its the 19 deg at idle I'm questioning.
I agree with buffaloracer about it not being as it seems. 19 is pretty high for idle, and probably 2 much to crank up with, but if it's not kicking or pinging, then something is hinky. If it runs fine, with no issues whatsoever, then leave it be. But I suspect the balancer is no longer accurate, meaning you may not be at those indicated timing degrees, OR......you've got a spring issue in the distributor or some other issue that is allowing significantly less timing to start it (no kickback) followed by some advance to get 19degrees of lead at idle. -rick
Still got a vacuum can on the distributor? Vacuum unplugged for those numbers? Ported or manifold to vacuum advance?
I have mine (350 sbc) set up with 18 degrees initial and 36 degrees all in at 2600rpm...works perfectly.
Do you have vacuum advance disconnected when you check idle advance? Check TDC with piston stop to see if it agrees with the zero mark on your balancer.
I'd also suggest checking the harmonic balancer. I have a couple of older Corvettes ('67 and '68) and both eventually ended up with slipped timing rings. There are a couple of rebuilding services out there.
yes vacuum advance i plug off when timing this is a pertronics billet distributor not a converted stocker
That's a lot of initial but every combo requires tailoring, so there is no hard and fast number. I agree that it would be prudent to confirm things, but if it exhibits no ill effects, run it. More timing without improvement is not great, so if you can back it off and still have the same power, that's smart.
This is timely . I’ve been playing with my timing the last couple of days on my 303 Oldsmobile and I’m so far advanced that I ditched my harbor freight light for a real nice one from Amazon. Harbor freight light was 8 degrees high. Up and down a few degrees then drive it up a hill. It runs best at 24 initial degrees. I know something isn’t right but it doesn’t run too bad for a tired old engine. I did put a new timing chain in it before install.
Okay, I'll mention this then. Get it so it idles well. Write down the lowest RPM you can get and the timing there. Raise it 200, check and document again. I don't like holding RPM over say 2500, so I'd use that as the top to document, but you can rev it a bit more and see if it continues to advance. You now have the timing curve numbers. You can plot it on graph paper if you want. Again, this is just what the timing marks on your car show. Verify TDC on the damper really is TDC. @skooch , 24 is a whole lot of something or a bunch of smaller things adding up.
Absolutely nothing wrong with 19 at idle if the engine likes it and no ping or detonation symptoms. If your camshaft is a bit lumpier than stock it probably needs the advance. Sounds like a perfectly acceptable setup to me.
I appreciate your input, I know something isn’t right and I’ll keep plugging away at it but I’m putting miles on the car and it’s running pretty decent no detonation that I can tell. Don’t mean to step on OPs post.
yeah...it does have a lumpy roller cam....and I went out and rechecked everything, its actually at a tad more than 18
Engine like what it likes , Each one is different, I have/run any where from 13- 25 @Idle Vac gauge will help , If to hight ,cranks slow after hot / warmed up ,... Work around , Remote Start button , spin engine 1-2 sec Then flip power on to ignition , Like with a mag ..
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