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I got a 1984 300 that will get the manifold glowing red from 15 miles of regular highway driving. I checked the plugs, which have less than 200 miles, and they were light brown. The intake and exhaust are as free flowing as they they can be with almost no restrictions, other than the air filter. The engine temp stays cool. What could be causing this?
How is the engine running? Does it seem down on power? Possibilities are distributor timing is off, or timing gear has worn badly and the cam timing is really late, which would also show up a late ignition timing when checked with a timing light.
Could be flooding it, but you should smell that at the exhaust.
Try looking at the above. That should be a decent start as to what's happening.
I had the same thing happen to me when I initially started my rebuilt engine. Started it and was happy that it was running listening to everything looking for leaks notice the exhaust is cherry red.
after adjusting the timing I’ve never seen it happen again
How is the engine running? Does it seem down on power? Possibilities are distributor timing is off, or timing gear has worn badly and the cam timing is really late, which would also show up a late ignition timing when checked with a timing light.
Could be flooding it, but you should smell that at the exhaust.
Try looking at the above. That should be a decent start as to what's happening.
Power seems pretty good through 1st, 2nd, and 3rd, but 4th takes a while to get up to speed. Exhaust doesn't seem to rich or blow any smoke. How would I adjust the timing on this?
I had the same thing happen to me when I initially started my rebuilt engine. Started it and was happy that it was running listening to everything looking for leaks notice the exhaust is cherry red.
after adjusting the timing I’ve never seen it happen again
You need to see where the timing is now before adjusting. If really low, you then need to find out if the distributor hold down is loose and it slipped, or if the timing gears has worn. If the distributor is tight, and the rotor will move back and forth as it should, I would be concerned about timing gears.
Oreilly's keeps a decent Innova timing light in stock.
Every time I've read about a glowing hot exhaust manifold, it was due to the timing being too far advanced.
First things first, make sure your timing mark is correct.
Pull the #1 spark plug and shine a flash light down it. Rotate the engine until you can visually see the top of the piston come up as high as it will go. Work it back and forth to be sure the piston is at the very highest point. It doesn't matter if it's on the compression or exhaust stroke.
A long ratchet with a 15/16" socket on the end of the balancer is the easiest way to do this.
Now look at your timing marks. Your timing mark should be pointed at 0, or at least very close to. If it's not, you need a new harmonic balancer because it's slipping.
Once you've confirmed your timing mark is good, check the timing with a timing light.
Disconnect the vacuum advance (if equipped) and use a timing light to confirm your timing is around 6 - 10°. 6 is stock, but you can go up to around 10 or so for a little extra pep. It shouldn't really be any more than that on a stock setup.
If you need to adjust, there's a bolt at the base of the distributor. Loosen it and slowly rotate the distributor. This is easiest to do while the engine is running, since you can keep checking the timing.
The glowing exhaust manifold comes from retarded ignition timing.
Your engine uses a feedback carbureted and ignition system.
If it is not working properly the timing will not advance.
Once the base timing is set you need to see if the timing advances when you rev the engine.
The glowing exhaust manifold comes from retarded ignition timing.
Your engine uses a feedback carbureted and ignition system.
If it is not working properly the timing will not advance.
Once the base timing is set you need to see if the timing advances when you rev the engine.
You are right on the feed back system but no one asked what other things have been done to the motor as EFI EXH manifolds did not come on feed back motors.
So was a carb & distributor swap also done when the EXH manifolds were done?
He could still be running the factory carb & dist. with the EFI manifolds but if the rest of the feed back system is not in place and working, most are not working at this age, then yes it locks the timing.
I am running EFI manifolds with the factory carb & intake but mine, 81 F100, is not a feed back system and uses a vacuum advance dist.
Dave ----
