Engine Running Hot on One Side
- Thread starter AZCOWBO
- Start date
Screaming Metal
Active Member
Well....I believe Ted, Mike and OneFingerJohn pretty much have you covered. Admittedly, SOMETHING ain't right on the side thats overheatig, just gotta find the right answer. Before you just jump in and start doing things willynilly, check the simple things first. Do as Ted said, get a cheap can of carb cleaner, spray the intake first to eliminate the vacc. part. when you hit the leak, its gonna idle up real fast, do it 2 or 3 times to mke sure thats the only leak. If no leak....look at the Timing.
A tuneup by a master mechanic won't cause your motor to overheat.
Check your timing, as Ted Mike and RPM said.
You might even want to look at the sparkplug numbers.....I've seen one accidently get, making one cylinder run hot. And Ron is right, a fan blowing will give you a flase reading.
Its probably the timing but check all this out, you don't wnt to hurt that motor.........
A tuneup by a master mechanic won't cause your motor to overheat.
Check your timing, as Ted Mike and RPM said.
You might even want to look at the sparkplug numbers.....I've seen one accidently get, making one cylinder run hot. And Ron is right, a fan blowing will give you a flase reading.
Its probably the timing but check all this out, you don't wnt to hurt that motor.........
Screaming Metal
Active Member
I looked over the post really carefully agian...(someimes it takes twice before my old brain will absorb it all, Ha!), If the motor was fine before, but isn't now, after a tuneup, said tune gotta have something to do with it. Every-once-in-a-while, something wierd will happen at the same time your tuneup occurres.
Theres 2 small airbleeds in the throat of the carb, get yourself a end of the toothpick, on the side thats running hot, stick that end of the toothpick into that air bleed. Crank the motor up and do as Ron said, take the fan belt off, or better yet, cut a big piece of cardboard to block most all the wind off your pipe. AIM your heat gun just a little ahead of the curve in that exhaust pipt.....this is the hottest flow. Now start your motor and let it run takeing reading.
Now, pull the toothpick out, be careful not to break off the end into theorifice. If the motor ran cooler with the orifice plugged, the cylinder is too lean.
Now.....I've had SB Chevys have vaccuum leak in thelifter valley below the intake....but usually thats followed with smoke since you can pull a oil mist from in there.
The power valve won't affect 1 cylinder. A flow problem affects the whole bank or 2 or more cylinders. If it idles good, down load and don't hunt as Mike said, I'd say you got a jet problem, a valve too tight, a wrong sparkplug in one hole (only seen it happen 3 times in 30 someodd years....but its enough to look for), or a leaking/seeping head gasket on the one cylinder.
If its the head gasket, usually you can look into the radiator after the thermostat opens and you'll see air bubbles, and the water temp will come up really fast.
Check the simple things first....as usually timing won't affect one cylinder only. If you check everything and still can't find the problem,
1.run a pressure check on your cooling system.....
if nothing...
2.stick a 1 step cooler sparkplug in that one cylinder an see how it acts.
On our racing motors, sometimes we'll have several different jets in the carbs, and some cylinders at the ends of the heads will be hotter due to the other cylinders heating the coolant ahead of that cylinder....in turn making a alraedy hot cylinder all the more hotter.
In a street motor you don't have to worry about such things, unless your TOO lean on a end cylinder. I agree with everyone here....something was changed to make it run this way. Either a jet or a plug or something somewhere. Things just don't happen for no reason. Its probably something really simple.....
Theres 2 small airbleeds in the throat of the carb, get yourself a end of the toothpick, on the side thats running hot, stick that end of the toothpick into that air bleed. Crank the motor up and do as Ron said, take the fan belt off, or better yet, cut a big piece of cardboard to block most all the wind off your pipe. AIM your heat gun just a little ahead of the curve in that exhaust pipt.....this is the hottest flow. Now start your motor and let it run takeing reading.
Now, pull the toothpick out, be careful not to break off the end into theorifice. If the motor ran cooler with the orifice plugged, the cylinder is too lean.
Now.....I've had SB Chevys have vaccuum leak in thelifter valley below the intake....but usually thats followed with smoke since you can pull a oil mist from in there.
The power valve won't affect 1 cylinder. A flow problem affects the whole bank or 2 or more cylinders. If it idles good, down load and don't hunt as Mike said, I'd say you got a jet problem, a valve too tight, a wrong sparkplug in one hole (only seen it happen 3 times in 30 someodd years....but its enough to look for), or a leaking/seeping head gasket on the one cylinder.
If its the head gasket, usually you can look into the radiator after the thermostat opens and you'll see air bubbles, and the water temp will come up really fast.
Check the simple things first....as usually timing won't affect one cylinder only. If you check everything and still can't find the problem,
1.run a pressure check on your cooling system.....
if nothing...
2.stick a 1 step cooler sparkplug in that one cylinder an see how it acts.
On our racing motors, sometimes we'll have several different jets in the carbs, and some cylinders at the ends of the heads will be hotter due to the other cylinders heating the coolant ahead of that cylinder....in turn making a alraedy hot cylinder all the more hotter.
In a street motor you don't have to worry about such things, unless your TOO lean on a end cylinder. I agree with everyone here....something was changed to make it run this way. Either a jet or a plug or something somewhere. Things just don't happen for no reason. Its probably something really simple.....
Mike
Well-Known Member
I'm just wondering if he might have a small chamber 305 head on one side, increasing cylinder pressure and thereby chamber heat. Of course it might have 305 heads on both sides and one of them is a crackling, as most of the 305 heads are.
Not enough info, is there?Actually, there will be four air bleeds in the front of the carb and four in the rear. (Yes, I know, some Dominators are three circuit) The idle air bleeds will be the outermost orifices. That is the one SM suggests plugging. The inner orifices are the high speeds and will have no effect on this particular test.
Ted Brown
Member
Like they are saying, it has to be the tune or the reading in the first place, as it ran fine before either the tune, or the hot reading??? strange huuummmI'm just wondering if he might have a small chamber 305 head on one side, increasing cylinder pressure and thereby chamber heat. Of course it might have 305 heads on both sides and one of them is a crackling, as most of the 305 heads are.
Actually, there will be four air bleeds in the front of the carb and four in the rear. (Yes, I know, some Dominators are three circuit) The idle air bleeds will be the outermost orifices. That is the one SM suggests plugging. The inner orifices are the high speeds and will have no effect on this particular test.
