Mixture screws do nothing, replaced carb, still nothing.
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Simple math.
Determine the diameter of the balancer. Then figure the circumference (pi times the radius squared if I remember my math correctly) then divide the circumference by 360 (360 degrees in a circle) that’s how many fractions of an inch PER degree. Multiply that number by 36, that how far from TDC you need to measure for your new timing mark.
You can also use this method for marking the balancer every 90* for setting valve lash.
Most engines like 34-36 degrees for best power. Normally, the vacuum advance would add another 15 degrees for best economy at cruise. Since your distributor doesn’t have vacuum advance that’s one less thing to dial in.
Determine the diameter of the balancer. Then figure the circumference (pi times the radius squared if I remember my math correctly) then divide the circumference by 360 (360 degrees in a circle) that’s how many fractions of an inch PER degree. Multiply that number by 36, that how far from TDC you need to measure for your new timing mark.
You can also use this method for marking the balancer every 90* for setting valve lash.
Most engines like 34-36 degrees for best power. Normally, the vacuum advance would add another 15 degrees for best economy at cruise. Since your distributor doesn’t have vacuum advance that’s one less thing to dial in.
The advantage of following Matt’s guidance is beneficial in particular if: (1) the harmonic balancer has slipped; and, (2) you may not be sure the harmonic balancer is of the same OEM size. Either (1) and/or (2) would not be unheard of. Be certain your zero timing mark is established at TDC on the compression stroke. A piece of tissue paper works well to get close (remove #1 cylinder spark plug), once you’re close a chop stick dropped into #1 cylinder works great to dial in top of the piston stroke to set TDC.
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From: Chesapeake, VA
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I have now put it 2 sets of plugs. I didn't keep the ones that were in it when I bought it. The first set I put in were ACDelco Rapidfire #19360569 gapped at .035. (I stupidily didn't check the gap) The car ran at 8 degrees with these.
Then I did the compression test and everything went bad. Still had the Rapidfires. The Rapidfires looked black and wet. Less then a month old. I assumed this was because of whatever is causing my first problem of running so rich.
I replaced the Rapidfires with ACDelco R45S #19362366.
Then I did the compression test and everything went bad. Still had the Rapidfires. The Rapidfires looked black and wet. Less then a month old. I assumed this was because of whatever is causing my first problem of running so rich.
I replaced the Rapidfires with ACDelco R45S #19362366.
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Have you tried this?
In reading through the thread, I didn't happen to see what make/model of carb you had or replaced. My first question is this, how much manifold vacuum are you pulling at idle. If you have a lopey, (or semi lopey) cam, your idle vacuum will be poor. With that being said, do you have enough vacuum to close the power valve and/or the main jet metering rods? These can be fixed with a lighter spring or screw adjustments, or new power valve, but you'll have to have some basic info first, again, what is your manifold vacuum.
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The simple answer is no. Timing is the arrival of electric charge at the spark plug - that is all, nothing more, nothing less. It's the arrival time of the electric charge. Electric charge will arrive at one of three points in time: BDC, TDC or ADC.
Gap size can influence engine performance (i.e. the ability or inability to perform work), but in & of itself gap size does not affect timing.
Gap size can influence engine performance (i.e. the ability or inability to perform work), but in & of itself gap size does not affect timing.
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Joined: Jul 2018
Posts: 26,259
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In reading through the thread, I didn't happen to see what make/model of carb you had or replaced. My first question is this, how much manifold vacuum are you pulling at idle. If you have a lopey, (or semi lopey) cam, your idle vacuum will be poor. With that being said, do you have enough vacuum to close the power valve and/or the main jet metering rods? These can be fixed with a lighter spring or screw adjustments, or new power valve, but you'll have to have some basic info first, again, what is your manifold vacuum.
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In reading through the thread, I didn't happen to see what make/model of carb you had or replaced. My first question is this, how much manifold vacuum are you pulling at idle. If you have a lopey, (or semi lopey) cam, your idle vacuum will be poor. With that being said, do you have enough vacuum to close the power valve and/or the main jet metering rods? These can be fixed with a lighter spring or screw adjustments, or new power valve, but you'll have to have some basic info first, again, what is your manifold vacuum.
Before this new problem, vacuum pressure was low at 14 but stable. Advancing the timing raised pressure to 18. The old carb was missing springs on top of the metering rods. With the low vacuum, maybe that's why they wernt there...
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Well I think I have found the issue. And by "I", I mean a very nice mechanic who helped me out.
The original issue of the mixture screws not having any effect on the engine, was simply because the choke thermostat was adjust wrong. I'm curious to know why the screws also didn't work on the old carburetor, but it's gone now so we will never know.
The new issue of the engine not starting unless timing is very advanced, the mechanic believes there is an issue with the MSD box. His recommendation is to get rid of the box and racing distributor and put a standard HEI back in. So that's what I'm going to do.
Once again, thank you to everyone who commented on this thread! I definitely don't know much, but I'm enjoying learning everything I can and very much appreciated all the help!
The original issue of the mixture screws not having any effect on the engine, was simply because the choke thermostat was adjust wrong. I'm curious to know why the screws also didn't work on the old carburetor, but it's gone now so we will never know.
The new issue of the engine not starting unless timing is very advanced, the mechanic believes there is an issue with the MSD box. His recommendation is to get rid of the box and racing distributor and put a standard HEI back in. So that's what I'm going to do.
Once again, thank you to everyone who commented on this thread! I definitely don't know much, but I'm enjoying learning everything I can and very much appreciated all the help!
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I’d suspect the aftermarket distributor before replacing the ignition box. The box just does what the distributor tells it to do (fire the ignition coil) based on the pickup coil or whatever is in the distributor.
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I’m no pro like many of the guys here, but a couple of suggestions:
Norm & Joe are right, if you have a suspicion that the internals were setup for a different purpose as compared to how you’re using it, you’ll need to chase that down before _assuming_ factory configurations will work. 50 years later, an Olds engine could be anything: wild cam, offset timing chain, weird compression ratio or whatever. If you have a suspicion something exotic is in there due to the previous owner, you’ll waste days & weeks chasing small stuff & getting nowhere since someone “knew better” than Olds for his purpose. What he/she did is for his/her goals is anyone’s guess. With luck, after digging in, you may find a silver lining of some good parts or cool setup, but finding out is key.
If you confirm that the engine is actually factory-ish, start your settings with something like a factory setup to make it easy on yourself: Qjet (75 & up, 48/74 primaries /“I” secondary hanger “DA” secondary rods, HEI /points distributor with 12-14° initial, all in at 34-36° @3000 rpm, Electric/HotAir choke, .035-.040 plug gaps, known good coil/cap/wires.
Wait for the MSD & aftermarket stuff until after you have a good running engine & are in a position to make it better. Don’t expect “different” to fix your problem.
Some new parts are junk, so aim at quality gaskets, distributor, cap/rotor, plugs and so on. If a part is sketchy, you’ll wonder if that’s the source of your problems. If they’re quality, it’s one less thing to question. Aim for USA made. Settle for offshore if you have to.
It’s a pain to have to dig deeper than you want to especially into someone else’s work, but a grumpy non-working motor may eventually make want to sell the car. Long run, if you want to enjoy it, you may have to dig in deeper than you wanted to. The plus side of that is once you _really_ understand it, it’ll be that much better when you want to tweak it.
For inspiration today, see the article about the guy recommending people _don’t_ buy an old Bronco. He’s got the right idea: Old cars sometimes need more effort than you want to put out. They’re always more effort than a recent Camry.
Hope this helps.
Cheers
cf
Norm & Joe are right, if you have a suspicion that the internals were setup for a different purpose as compared to how you’re using it, you’ll need to chase that down before _assuming_ factory configurations will work. 50 years later, an Olds engine could be anything: wild cam, offset timing chain, weird compression ratio or whatever. If you have a suspicion something exotic is in there due to the previous owner, you’ll waste days & weeks chasing small stuff & getting nowhere since someone “knew better” than Olds for his purpose. What he/she did is for his/her goals is anyone’s guess. With luck, after digging in, you may find a silver lining of some good parts or cool setup, but finding out is key.
If you confirm that the engine is actually factory-ish, start your settings with something like a factory setup to make it easy on yourself: Qjet (75 & up, 48/74 primaries /“I” secondary hanger “DA” secondary rods, HEI /points distributor with 12-14° initial, all in at 34-36° @3000 rpm, Electric/HotAir choke, .035-.040 plug gaps, known good coil/cap/wires.
Wait for the MSD & aftermarket stuff until after you have a good running engine & are in a position to make it better. Don’t expect “different” to fix your problem.
Some new parts are junk, so aim at quality gaskets, distributor, cap/rotor, plugs and so on. If a part is sketchy, you’ll wonder if that’s the source of your problems. If they’re quality, it’s one less thing to question. Aim for USA made. Settle for offshore if you have to.
It’s a pain to have to dig deeper than you want to especially into someone else’s work, but a grumpy non-working motor may eventually make want to sell the car. Long run, if you want to enjoy it, you may have to dig in deeper than you wanted to. The plus side of that is once you _really_ understand it, it’ll be that much better when you want to tweak it.
For inspiration today, see the article about the guy recommending people _don’t_ buy an old Bronco. He’s got the right idea: Old cars sometimes need more effort than you want to put out. They’re always more effort than a recent Camry.
Hope this helps.
Cheers
cf
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Joined: Jan 2020
Posts: 2,908
From: Sarasota Florida
I’m no pro like many of the guys here, but a couple of suggestions:
Norm & Joe are right, if you have a suspicion that the internals were setup for a different purpose as compared to how you’re using it, you’ll need to chase that down before _assuming_ factory configurations will work. 50 years later, an Olds engine could be anything: wild cam, offset timing chain, weird compression ratio or whatever. If you have a suspicion something exotic is in there due to the previous owner, you’ll waste days & weeks chasing small stuff & getting nowhere since someone “knew better” than Olds for his purpose. What he/she did is for his/her goals is anyone’s guess. With luck, after digging in, you may find a silver lining of some good parts or cool setup, but finding out is key.
If you confirm that the engine is actually factory-ish, start your settings with something like a factory setup to make it easy on yourself: Qjet (75 & up, 48/74 primaries /“I” secondary hanger “DA” secondary rods, HEI /points distributor with 12-14° initial, all in at 34-36° @3000 rpm, Electric/HotAir choke, .035-.040 plug gaps, known good coil/cap/wires.
Wait for the MSD & aftermarket stuff until after you have a good running engine & are in a position to make it better. Don’t expect “different” to fix your problem.
Some new parts are junk, so aim at quality gaskets, distributor, cap/rotor, plugs and so on. If a part is sketchy, you’ll wonder if that’s the source of your problems. If they’re quality, it’s one less thing to question. Aim for USA made. Settle for offshore if you have to.
It’s a pain to have to dig deeper than you want to especially into someone else’s work, but a grumpy non-working motor may eventually make want to sell the car. Long run, if you want to enjoy it, you may have to dig in deeper than you wanted to. The plus side of that is once you _really_ understand it, it’ll be that much better when you want to tweak it.
For inspiration today, see the article about the guy recommending people _don’t_ buy an old Bronco. He’s got the right idea: Old cars sometimes need more effort than you want to put out. They’re always more effort than a recent Camry.
Hope this helps.
Cheers
cf
Norm & Joe are right, if you have a suspicion that the internals were setup for a different purpose as compared to how you’re using it, you’ll need to chase that down before _assuming_ factory configurations will work. 50 years later, an Olds engine could be anything: wild cam, offset timing chain, weird compression ratio or whatever. If you have a suspicion something exotic is in there due to the previous owner, you’ll waste days & weeks chasing small stuff & getting nowhere since someone “knew better” than Olds for his purpose. What he/she did is for his/her goals is anyone’s guess. With luck, after digging in, you may find a silver lining of some good parts or cool setup, but finding out is key.
If you confirm that the engine is actually factory-ish, start your settings with something like a factory setup to make it easy on yourself: Qjet (75 & up, 48/74 primaries /“I” secondary hanger “DA” secondary rods, HEI /points distributor with 12-14° initial, all in at 34-36° @3000 rpm, Electric/HotAir choke, .035-.040 plug gaps, known good coil/cap/wires.
Wait for the MSD & aftermarket stuff until after you have a good running engine & are in a position to make it better. Don’t expect “different” to fix your problem.
Some new parts are junk, so aim at quality gaskets, distributor, cap/rotor, plugs and so on. If a part is sketchy, you’ll wonder if that’s the source of your problems. If they’re quality, it’s one less thing to question. Aim for USA made. Settle for offshore if you have to.
It’s a pain to have to dig deeper than you want to especially into someone else’s work, but a grumpy non-working motor may eventually make want to sell the car. Long run, if you want to enjoy it, you may have to dig in deeper than you wanted to. The plus side of that is once you _really_ understand it, it’ll be that much better when you want to tweak it.
For inspiration today, see the article about the guy recommending people _don’t_ buy an old Bronco. He’s got the right idea: Old cars sometimes need more effort than you want to put out. They’re always more effort than a recent Camry.
Hope this helps.
Cheers
cf
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