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did you make a thread about comp ratio?
1 cyl at 70lbs?
I would back timing couple degrees
keep an eye on plugs and verify heat range
go hotter on cyls that aren't clean
could have stuck ring/s and exercise them by accelerating and using engine
and gears to slow quickly, no brakes.
could even use something like a decarb fluid
I didnt make that post. Just this one. I think these plugs I put back in are hotter, I'll check them in a week or so for carbon. I have been exercising the motor quite a bit, lol. Hard not to push that pedal. I gear down alot too, love the sound of that m22. There used to be stuff you could spray in the carb, it would clean the carb and the cylinders. I remember the instructions said to rev it up and spray in, it would bog down from that, then when can is almost empty it said to let off the gas and let it bog out or die. Sit for 15min while the cylinders soak that crap up, Then start it up and rev the **** out of it. I remember if it had carbon in there it would belch black smoke for about 5 minutes. It was supposed to clean the cylinders and pistons and rings. Odd I can't find that stuff anymore. Guess its cause everything is fuel injected now. Wouldn't want to put it in there and foul the injectors or sensors. I''ll keep a look out for that stuff or a substitute.
Pinging isn't a symptom of a "tired" engine. Pinging is a symptom of carbon build up in the combustion chamber, acting like glow-plugs that randallsteel mentioned, or any driving condition where the fuel ignites before full compression like under heavy load, lean fuel delivery, extreme heat, overly-advanced timing, or any combination of these things.
A 12:00 timing tab isn't indicative of "old". Timing tabs for Corvettes/Chevrolet v-8s have been at 1:00-2:00 on the timing chain cover since at least the 283ci engine of '57.
How about some pics of your timing tab?
That's the best I can get. It's right at the top as said timing light has a hard time getting it.
Pinging isn't a symptom of a "tired" engine. Pinging is a symptom of carbon build up in the combustion chamber, acting like glow-plugs that randallsteel mentioned, or any driving condition where the fuel ignites before full compression like under heavy load, lean fuel delivery, extreme heat, overly-advanced timing, or any combination of these things.
A 12:00 timing tab isn't indicative of "old". Timing tabs for Corvettes/Chevrolet v-8s have been at 1:00-2:00 on the timing chain cover since at least the 283ci engine of '57.
How about some pics of your timing tab?
I wonder if my carb is too lean. I followed instructions when I got it. It's a holley quick fuel brawler 650. I adjusted all 4 corners one at a time pulling as much rpm out of one. Then back it back down to idle, do the other side, back it back down, then move to the secondary, do same. There all open the same amount, about 3/4 to half a turn. They start you at a full turn out. I thought it may be rich still. I only get about 210 miles on a tank. Couple guys said I should get a about 260+. So that's why I thought it rich. Think I should try a bit richer? Thee goes the fuel mileage lol
It was supposed to clean the cylinders and pistons and rings. Odd I can't find that stuff anymore. Guess its cause everything is fuel injected now. Wouldn't want to put it in there and foul the injectors or sensors. I''ll keep a look out for that stuff or a substitute.
GM dealers use to have the spray you are talking about.
That's the best I can get. It's right at the top as said timing light has a hard time getting it.
That doesn't look like standard GM/Chevrolet and that tab appears to have had some extracurricular modification done to it. Sorry to be a pest about this. Can you upload a couple more from 1 foot further away, 2 feet further, and the entire front of the engine with fan to intake? I'm not as interested in seeing the tab as I am the timing cover and other front-of-the-engine components.
I'm curious why there appears to be a mix of blue and orange paint.
While we're at it, can you get a photo of the engine stamp as well? It will be just below your AC compressor, on the block at the base of the starboard side head.
That doesn't look like standard GM/Chevrolet and that tab appears to have had some extracurricular modification done to it. Sorry to be a pest about this. Can you upload a couple more from 1 foot further away, 2 feet further, and the entire front of the engine with fan to intake? I'm not as interested in seeing the tab as I am the timing cover and other front-of-the-engine components.
the tab is not modified. Its jagged like that because its impossible to see the numbers on it, so its made with valleys and peaks so you can line it up by counting peaks or valleys were you number is. its only like that until about 16 degrees before. O is in the first valley, its 4 degrees to the next valley. Thank god its like that or you would have to draw a line on it to tell were to line it up. Also, I had to get that close with picks to see it. If I move 6 inches more away its too high and you cant see it at all. You can tell its right at 12 oclock because you can see the head of the fuel pump in behind giving reference. Dampner is blue and orange, motor is orange. THis may help. Had a bad day and out driving the clutch packed it in on the A/C. Took out all the belts, lol. SO bought new ones from lordco. They were too short???? So went back, they checked numbers and they were right, but they said there are 2 350 motors, and I have the High Performance one and the belts are bigger. Got new belts they fit. Had a chunk of old belt and sure enough the number on it matched the longer belt number. So apparently I got the good motor anyway. If I went new Id go with the builders advice and get the one I said above anyway. THe newer 4 bolt main engines are much more robust. Also explains why it goes like a scalded dog. It does feel peppier than other 350s Ive had. Vettes are light tho, so that too.
There used to be stuff you could spray in the carb, it would clean the carb and the cylinders. I remember the instructions said to rev it up and spray in, it would bog down from that, then when can is almost empty it said to let off the gas and let it bog out or die. Sit for 15min while the cylinders soak that crap up, Then start it up and rev the **** out of it. I remember if it had carbon in there it would belch black smoke for about 5 minutes. It was supposed to clean the cylinders and pistons and rings. Odd I can't find that stuff anymore.
Seafoam products are what you want. There’s a spray as you describe, and a liquid to pour in the tank. One application of each cured an old motor of carbon deposits for me. Hopefully they are sold where you are.
You can tell its right at 12 oclock because you can see the head of the fuel pump in behind giving reference. Dampner is blue and orange, motor is orange.
I suspect you have a mismatch of parts that could be causing timing problems. C3 Corvette 350 engines had the timing tab at about 1:00-2:00 when viewed from the front of the engine. It also appears from the pics that the relationship between the tab and the balancer shows much less "overhang" over the balancer than I've seen in other examples. If yours is indeed at 12:00 then it seems you, at minimum, have a later timing chain cover. Trying to time a standard Corvette balancer to a 12:00 timing tab would make your timing so far advanced that it would ping like CrAzY! Is there another (perhaps homemade-looking) line on your balancer about 2" away from the deep one?
Check out this message on Jalopy Journal that seems to match your issue – they start to identify the issue about 1/2 way through the first page of the thread: https://www.jalopyjournal.com/forum/...#post-11966616
To really understand what is going on here, providing the block # off the back flange where it connects to the transmission as viewed from above would go really, really far.
I suspect you have a mismatch of parts that could be causing timing problems...
Nice catch!
The blue paint on the harmonic balancer, and on the timing tab on the timing chain cover, also indicate that something is amiss, or at least that someone has been in there before.
This is why we always ask for photos. I even made a thread about it, with a fun video of a harmonic balancer and the replacement, both GM Corporate Blue.
The blue paint on the harmonic balancer, and on the timing tab on the timing chain cover, also indicate that something is amiss, or at least that someone has been in there before.
This is why we always ask for photos. I even made a thread about it, with a fun video of a harmonic balancer and the replacement, both GM Corporate Blue.
Well. The balancer and the tab line up perfectly. I did get the piston stop and did the procedure turning it both ways, marking both, then the middle of those marks is tdc. The balance line was perfectly in line were it should be, and lined up perfectly with the 0 mark on the tab. So both the tab and the balancer are correct. It's now total timed to 36 degrees before, and is running fantastic other than it still pings accelerating. Just put old plugs back in which are cleaned and gapped to 35 as manual says. I think the Bosch plugs may be hotter too. Pistons and valves had little carbon on them, and the accel plugs I had put in were caked in carbon. So I think they were cold. Will check after a good amount of driving for carbon build up. Probably burning some oil. Took forever to stop all the leaks when I got it, especially the valve covers. So hard to seal those. I do get some blow by out valve covers so I figure it's burning a bit of oil. I put in seal additive and thick oil and it seems to be much better. No more leaks and hasn't dropped in level in a week. So not burning too bad. See a puff if blue some times at a red light when it's real hot. Figure that's fowling plugs. Hoping the Bosch ones are hotter and fowl less. Been doing alot of research yesterday and alot of the old 350s with 350 torque had the tab at 12 o'clock. So I figure this motor is older than my 73. All newer models have the tab at 2oclock. Also saw that the high performance 350 has a timing spec of 8 degrees under 800rpm were all others are 12. So it's lining up bang on. At 36 total time it's at about 8 degrees at idle. Just can't beat this pinging. Another posted my carb may be lean causing that. Could be as I adjusted it as lean as I could get it and still goes. One thing I did notice is when I had it retarded to 6 at idle it was much smoother at top end. Now at 36 total it runs real smooth up to 95mph, then from 95 to 120mph it vibrates. Might be lean. But my fuel economy says it's still a bit rich. I get 210 Miles per tank were I should be getting 260+. Trying to find that engine serial but haven't found it yet. One guy said under the a/c pump, another by the transmission. Haven't found yet, but under the a/c you can hardly see the motor. Too much going on there. Have to do an a/c pump, maybe I'll see it then.
You know what else is stupid on this motor. When I lost the a/c clutch last night I had to do belts. To get the alternator belt on you have to take the valve cover off or the alternator won't move enough to get the belt on. What a pain in the ***.
now that it is running better, time to sort the carb.
get a wide band O2 reader and continue to protect the engine.
knocking/pinging will break it,,, bad
There is no "serial number", but the engine stamp will tell you the build date, and as-delivered configuration. If it came out of a Vette, there will be partial VIN that corresponds to the last few (6 or 7?) digits of the VIN of the car it was assigned to.
That stamp pad is under the AC compressor. Just knowing if it is long and narrow (early), or square-ish (late) is relevant data.
I posted the link above to look up engine code suffixes. Please post more photos!
I had the same valve cover issue, a PO had put on stupid valve covers. I went back to the original ones, and my alternator belt fit again.
There is no "serial number", but the engine stamp will tell you the build date, and as-delivered configuration. If it came out of a Vette, there will be partial VIN that corresponds to the last few (6 or 7?) digits of the VIN of the car it was assigned to.
That stamp pad is under the AC compressor. Just knowing if it is long and narrow (early), or square-ish (late) is relevant data.
I posted the link above to look up engine code suffixes. Please post more photos!
I had the same valve cover issue, a PO had put on stupid valve covers. I went back to the original ones, and my alternator belt fit again.
If you mean the a/c pump, it's the long 500lb one. Lol. An A6 is what rock auto said when I bought a clutch yesterday. Old clutch was not coming off. Waiting on that now. It's a beast, not sure if it was because it was wearing out cause it would drop the rpm 300rpm at idle. On the hwy, being a manual you can feel it turning on and off while your driving. What a monster. New pump with correct 10oz of mineral oil is much smoother. By hand anyway. I still need a throttle advance solenoid for this new carb to stop the rpm drop at idle. Hoping to find one at a wrecker since there 150 bucks new. Plus the shipping. Gosh that's alot for a tiny plunger solenoid. Can't find numbers under pump. It's removed and still see nothing. Might jack it up to look at the transmission side if I have time.
It was easier to pull photos from Facebook Marketplace than to walk into my garage, but my 79's motor looks similar (though my timing tabs are in the offset location, not at the top as this one appears to be).
This stamp pad (circled) is squareish, indicating a late 70s, early 80s SBC.
The casting number (circled in the second photo), reads 14013679, so a 350 from 77-82, could be 2 or 4 bolt. The internet will find whatever number you see on your block.
It was easier to pull photos from Facebook Marketplace than to walk into my garage, but my 79's motor looks similar (though my timing tabs are in the offset location, not at the top as this one appears to be).
This stamp pad (circled) is squareish, indicating a late 70s, early 80s SBC.
The casting number (circled in the second photo), reads 14013679, so a 350 from 77-82, could be 2 or 4 bolt. The internet will find whatever number you see on your block.
Real hard to read, but there you go a number and letters. Small tab looks like T1025ckH
