1970 olds cutlass timing issues again
August 29th, 2011, 07:10 AM
#1
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Thread Starter
Join Date: Jul 2010
Posts: 46
1970 olds cutlass timing issues again
need help with timing!!!!
Is a 350 timing tab the same as a 455 timing tab?
for Oldsmobile engines which way do you turn the distributor to retard/advance?
recently changed the water pump and got that all hooked back up.
decided to install a fuel pressure gauge and it was reading 3 lbs of pressure... decided to call and eldebrock tech guy and he said that my 750 cfm its pressure range should be anywhere from 4.5 to 6. changed out the fuel pump with one from auto zone and my fuel pressure gauge now reads 6. but still when i would get on it....(wot). after 5 secs it start feeling like its not gettign gas but the fuel pressure gauge is still at 3.5-4. we decided to mess witht he timing and now that pinging noise that i heard before came back under load around 2100rpm. i need to find the sweet spot for my timing, someone please explain in deatail how to properly adjust timing, i do have vacume advacne hooked up and my dad was saying something about my weight in the distrubutor could be too light bc when we hook up vacumm advance it just up and moves the knotch on the harmonic balance over to the left towards the passenger side. please help me to get this straight.!!
ive got an olds 455 with a comp hydrolic roller cam if any of that helps. i dont know much about it bsides it has eldebrock rpm performer heads on it and eldebrock intake but need help get timing figured out!! please respond. thanks. josh
Is a 350 timing tab the same as a 455 timing tab?
for Oldsmobile engines which way do you turn the distributor to retard/advance?
recently changed the water pump and got that all hooked back up.
decided to install a fuel pressure gauge and it was reading 3 lbs of pressure... decided to call and eldebrock tech guy and he said that my 750 cfm its pressure range should be anywhere from 4.5 to 6. changed out the fuel pump with one from auto zone and my fuel pressure gauge now reads 6. but still when i would get on it....(wot). after 5 secs it start feeling like its not gettign gas but the fuel pressure gauge is still at 3.5-4. we decided to mess witht he timing and now that pinging noise that i heard before came back under load around 2100rpm. i need to find the sweet spot for my timing, someone please explain in deatail how to properly adjust timing, i do have vacume advacne hooked up and my dad was saying something about my weight in the distrubutor could be too light bc when we hook up vacumm advance it just up and moves the knotch on the harmonic balance over to the left towards the passenger side. please help me to get this straight.!!
ive got an olds 455 with a comp hydrolic roller cam if any of that helps. i dont know much about it bsides it has eldebrock rpm performer heads on it and eldebrock intake but need help get timing figured out!! please respond. thanks. josh
August 31st, 2011, 04:01 PM
#6
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Join Date: Oct 2009
Location: Poteau, Ok
Posts: 40,648
Since you don't know if your timing tab is correct or not, I would do the following:
Turn your distributor ccw (decline) 2 degrees at a time and drive it again and see if it pings. Keep doing it until it stops pinging. You will have to raise the idle up after each time. That will get the engine to a timing that will not destroy it! Then note the timing on the tab!
The reason why your timing is advancing when you reconnect the hose is because it is hooked to the manifold vacuum port on your carb. (the right side facing the carb)
My suggestion is to take the vacuum line for the vacuum advance, from the right side (facing the carb) and move it to the left port, and cap the right port. You will have to raise your idle speed back after this. I've found some engines seem to like the stock hookup. You will also have to reset your idle air/fuel mixture again, when you do this.
If you don't have any real power after doing the above, then I would suggest recurving the distributor to the engine.
I hope this helps!
Turn your distributor ccw (decline) 2 degrees at a time and drive it again and see if it pings. Keep doing it until it stops pinging. You will have to raise the idle up after each time. That will get the engine to a timing that will not destroy it! Then note the timing on the tab!
The reason why your timing is advancing when you reconnect the hose is because it is hooked to the manifold vacuum port on your carb. (the right side facing the carb)
My suggestion is to take the vacuum line for the vacuum advance, from the right side (facing the carb) and move it to the left port, and cap the right port. You will have to raise your idle speed back after this. I've found some engines seem to like the stock hookup. You will also have to reset your idle air/fuel mixture again, when you do this.
If you don't have any real power after doing the above, then I would suggest recurving the distributor to the engine.
I hope this helps!
August 31st, 2011, 06:25 PM
#7
Registered User
Join Date: May 2009
Posts: 1,452
Maybe this isn't to me?
He asked a lot of questions that I didn't. But some of them are similar to what I'll need to know, eventually.
August 31st, 2011, 07:02 PM
#8
CH3NO2 LEARN IT BURN IT
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,888
Do yourself a huge favor and take your distributor to someone who has a distributor machine (or send it out). Bring along your cam specs. convertor stall, rear end gears, carb size & rear tire diameter. Tell the tech what transmission your running as well.
Trust me on this.
There are 3 timing events that are in the distributor in a street driven car. Initial... say 10-14*, then the vacuum (non-ported) which should be another 10-12*(ish) then the centrifugal which brings in the remaining 10-16*(ish) for a grand total of 36-42*, all in at a certian RPM depending on your set-up.
Generally a street car with 350-400 horse will like it "all in" at about 2700-3000 with good gas 93 octane or better.
When you changed things from stock you absolutely now need to recurve your distributor. The stock 350 curve is obsolete now. With all the Edelbrock goodies you should be able to run a rather aggressive timing curve as the alunimum parts generally allow more timing and compression due to there better heat dissipation thus retarding spark knock to a good degree.
There are other "super-tuning" secrets but this is a big one. Dialing in the carb is next.
Trust me on this.
There are 3 timing events that are in the distributor in a street driven car. Initial... say 10-14*, then the vacuum (non-ported) which should be another 10-12*(ish) then the centrifugal which brings in the remaining 10-16*(ish) for a grand total of 36-42*, all in at a certian RPM depending on your set-up.
Generally a street car with 350-400 horse will like it "all in" at about 2700-3000 with good gas 93 octane or better.
When you changed things from stock you absolutely now need to recurve your distributor. The stock 350 curve is obsolete now. With all the Edelbrock goodies you should be able to run a rather aggressive timing curve as the alunimum parts generally allow more timing and compression due to there better heat dissipation thus retarding spark knock to a good degree.
There are other "super-tuning" secrets but this is a big one. Dialing in the carb is next.
September 1st, 2011, 06:39 AM
#9
Administrator
Join Date: Oct 2009
Location: Poteau, Ok
Posts: 40,648
Do yourself a huge favor and take your distributor to someone who has a distributor machine (or send it out). Bring along your cam specs. convertor stall, rear end gears, carb size & rear tire diameter. Tell the tech what transmission your running as well.
Trust me on this.
There are 3 timing events that are in the distributor in a street driven car. Initial... say 10-14*, then the vacuum (non-ported) which should be another 10-12*(ish) then the centrifugal which brings in the remaining 10-16*(ish) for a grand total of 36-42*, all in at a certian RPM depending on your set-up.
Generally a street car with 350-400 horse will like it "all in" at about 2700-3000 with good gas 93 octane or better.
When you changed things from stock you absolutely now need to recurve your distributor. The stock 350 curve is obsolete now. With all the Edelbrock goodies you should be able to run a rather aggressive timing curve as the alunimum parts generally allow more timing and compression due to there better heat dissipation thus retarding spark knock to a good degree.
There are other "super-tuning" secrets but this is a big one. Dialing in the carb is next.
Trust me on this.
There are 3 timing events that are in the distributor in a street driven car. Initial... say 10-14*, then the vacuum (non-ported) which should be another 10-12*(ish) then the centrifugal which brings in the remaining 10-16*(ish) for a grand total of 36-42*, all in at a certian RPM depending on your set-up.
Generally a street car with 350-400 horse will like it "all in" at about 2700-3000 with good gas 93 octane or better.
When you changed things from stock you absolutely now need to recurve your distributor. The stock 350 curve is obsolete now. With all the Edelbrock goodies you should be able to run a rather aggressive timing curve as the alunimum parts generally allow more timing and compression due to there better heat dissipation thus retarding spark knock to a good degree.
There are other "super-tuning" secrets but this is a big one. Dialing in the carb is next.
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