Steve's Nova Site is an automotive enthusiast website dedicated to the 1962 - 1979 Chevrolet Nova, Chevy II and Acadian automobiles. We work together to preserve, restore, drive, show, race and provide fellowship for these classic cars. This is one of the best places to find information about parts, rebuilding, restoration and racing. This website is not affiliated with GM, General Motors or Chevrolet in any capacity.
Lets see if i can remember some numbers:
With everything hooked up even the vacuum advance, between 1,000-2,000 rpm... 10 initial, close to 22* with the centrifugal advance, and the vacuum advance put it all together at 40* advance... so 18* from the vacuum advance...
I ran the timing a few different ways before i figured out i should check the centrifugal advance, because to get 30* advance without vacuum the initial timing had to be set closer to 20* which made the car run like hell!!!
Man that is one crusty distributor. Can you buy a new distributor? It would go a long way toward getting this solved.
Basically, for a stock small block, you would set the crank somewhere between 5-10* at idle with the vacuum advance disconnected and the vacuum source on the carb plugged.
The centrifugal advance in the distributor would add 15-25*, the rate depending on the springs and the weight of the centrifugal weights.
The vacuum advance will add 5-15* or so (depending on the vacuum canister) when the engine is under low load.
You just have to experiment with your individual car. The camshaft is going to have a big effect on where you set all of this. The lower the vacuum at idle, the more timing it's going to need on the crank.
Freiberger did a fair job in that video until he got to the point of setting the distributor at high rpm and letting the base timing end up wherever. That's a goofy way of setting the timing as it depends on the centrifugal curve of the distributor. Not the best way to set timing for a street car.
__________________
1969 Nova
350
TH400
8.5" Ten Bolt 3.42 Posi-traction
Man that is one crusty distributor. Can you buy a new distributor? It would go a long way toward getting this solved.
Basically, for a stock small block, you would set the crank somewhere between 5-10* at idle with the vacuum advance disconnected and the vacuum source on the carb plugged.
The centrifugal advance in the distributor would add 15-25*, the rate depending on the springs and the weight of the centrifugal weights.
The vacuum advance will add 5-15* or so (depending on the vacuum canister) when the engine is under low load.
You just have to experiment with your individual car. The camshaft is going to have a big effect on where you set all of this. The lower the vacuum at idle, the more timing it's going to need on the crank.
Freiberger did a fair job in that video until he got to the point of setting the distributor at high rpm and letting the base timing end up wherever. That's a goofy way of setting the timing as it depends on the centrifugal curve of the distributor. Not the best way to set timing for a street car.
Its for an inline, im already going to buy a new distributor probably, 90 dollars at rock auto though! The only weights i can find are for V8's, i didnt know if there was a difference between them, but a new distributor for the extra HP i added to it cant hurt a bit!
Its for an inline, im already going to buy a new distributor probably, 90 dollars at rock auto though! The only weights i can find are for V8's, i didnt know if there was a difference between them, but a new distributor for the extra HP i added to it cant hurt a bit!
From the pic they look like any other springs/weights to me....
"I ran the timing a few different ways before i figured out i should check the centrifugal advance, because to get 30* advance without vacuum the initial timing had to be set closer to 20* which made the car run like hell!!! "
So your only getting 10* cent. adv. at 3K rpm's? does it keep advancing after 3K rpms?
Usually the problem with stock dist is two fold at least in my experience-
1-too much advance built in and 2-comes in too late
#2 can be fixed with weights and springs #1 needs a stop put in (pita-imo)
I guess what im thinking is you can play with this dist a bit and try to get 15*
out of it-you might be ahead of the game, My thought is a new dist is gonna give you too much cent. adv and not allow you to run enough initial...
Two questions, At what inital setting doe it idle best? at what total does it run its best?
I did the timing so many times the numbers are running together! I do believe the weights may be worn out, but at then again i've never seen weights and springs, i know the ones i seen on summit for the v8 didnt have any gap between the weights and the bracket... mine does, and it seems like the bracket cant fully advance because the weights cant engage past a certain point, like theres metal worn away from it... hard to explain but like i said i've never looked at another set of weights except the summit stuff...
the initial timing seemed to run best at 12* 10 and below it sounded choppy as heck! 12 was smoother, but anything past 12 got choppy again, the car at 3,000 rpm sounded best when i was running close to 20 degrees advance initially... but 20* advance at idle seems to be (detonating?) like a hammer comming down on the pistons, and to hear that over the open headers worried me!!!!
I would like to have a new distributor, to just go ahead and make sure everythings new anyways, since the head has alot of money into it, why not spring another 100 bucks to get the timing lined out!!
You keep mentioning 3000 rpm. Does the advance stop there? Those springs look kinda heavy to be all done at 3000. Clean everything up, and see if it still advances past 3000 rpm. Some springs are still going at 4500.
I understand the 3,000 mark, but not hitting 32* with 10* initial even by 3,000 rpm doesnt fit well with me, especially when inlines are rpm monsters, they are slow turning torque hungry engines...
I never hit past 3,000 rpm because the engine sounded like it was gonna blow! it was way to choppy at 3,000 rpm!
Have a look at this....http://temp.corvetteforum.net/c3/joe..._Recurve.shtml Look how small the diameter of the wire of the springs look compared to yours. Small springs advance quicker. You might have other issues if the motor doesn't like to go over 3000 rpm. Check oil pressure and valve adjustment.
Have a look at this....http://temp.corvetteforum.net/c3/joe..._Recurve.shtml Look how small the diameter of the wire of the springs look compared to yours. Small springs advance quicker. You might have other issues if the motor doesn't like to go over 3000 rpm. Check oil pressure and valve adjustment.
I understand that, but I dont think its the springs holding the weights back, the weights move very easily, i just dont think the weights are able to advance the bracket for the rotor all the way, and when the weights come back in the bracket doesnt even moves until the weights are fully resting, you can see where the curve of the weights are susposed to be contacting that bracket, but it doesnt anymore... But again i've never messed with the weights or springs, And i still dont know if the weights on the kits fit an inline distributor, if there is a difference at all?
I've seen a lot of the V-8 HEIs get so gummed up the centrifugal advance would stop moving. The only solution was to take the shaft out of the distributor and clean everything up with carb cleaner, lube it and reassemble.
Sounds like that's the problem with your I6 distributor, if it's stuck fully advanced the weights would then just flop around easily. If you're not comfortable with disassembly, get that replacement distributor and start over.
I've seen a lot of the V-8 HEIs get so gummed up the centrifugal advance would stop moving. The only solution was to take the shaft out of the distributor and clean everything up with carb cleaner, lube it and reassemble.
Sounds like that's the problem with your I6 distributor, if it's stuck fully advanced the weights would then just flop around easily. If you're not comfortable with disassembly, get that replacement distributor and start over.
tearing it apart would be a good learning lesson, and since im not in a hurry to get this thing running, i might clean it up real nice... and of course go ahead and buy another one cause im sure its not going to go back together like it came apart!!!
To get the shaft out you first drive out the roll pin that holds the gear on the shaft. Pull off the gear and any shims then spray the bottom of the shaft with carb cleaner and start to work it out from the top. It might take a few applications of carb cleaner and working it up and down to get it out. Once you get the shaft out you can take off the springs and weights and then try to get the star wheel off the shaft. Again carb cleaner will free it up. Clean out all the old hardened grease and varnish and lube the upper part of the shaft liberally with some moly grease. Clean up the weights and the pivot pins and lighly grease the pivot points. Reassemble the shaft, star wheel, weights and springs. Clean out the hole in the distributor housing using the carb cleaner but try not to soak the electronics. Grease up the lower part of the shaft and work it up and down a few times as you reinstall it in the housing to distribute the grease. Reinstall the shims, gear and roll pin and you're all set. If you plan to replace the pick-up coil, you'll have to do that while the shaft is out of the housing. It's obviously working though since it runs now. Have fun.
Linear Mode
