I have a 72 nova with a 327, curious on what is the best rule when it comes to setting the timing
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I have a 72 nova with a 327, curious on what is the best rule when it comes to setting the timing
My 327 used to love 8 degrees advance at 600 R.P.M. It was around 325 H.P. It used to pull to 28 degrees at full mechanical advance .
Here is how i set, just like an old man showed me, on a motor like this. Keep adjusting until it will not crank, then move it back till it will barely crank. Never have been able to trust a light ON A CHEVY.
What happens if you have a hi-torque starter?Quote:
Originally posted by chevydrivin
Here is how i set, just like an old man showed me, on a motor like this. Keep adjusting until it will not crank, then move it back till it will barely crank. Never have been able to trust a light ON A CHEVY.
(for automatic transmission) activate emergency brake , engine at operating temp , transmission in second gear,
acellerate car to 3500 rpm with foot on brake , slowly turn the distributor in the advanced direction untill the engine starts to ping,
then retard the timeing a little, lock the distributor.
turn the engine off and try to restart engine
if it starts fine leave it there,
if it labours when you try to start it , retard the timeing a little more (untill it starts with out labouring.
Yes this takes 2 people!!!!!!! LOL!
I usually start with the timing set so it just stops kicking back on the starter, then sometimes retard it a tad if there's pinging on hard pulling. Then put a light on it so you can get it back there easy next time.
that sure would be best if you are by yourself !
Thanks for the feedback, and advise I will try these out!!
Are you saying it.s best not to use light and set to 8 degrees? And time the motor high enought so it will crank okay? And what differnts does the RPM and haet on motor make? The piston will be in the same position no matter what will it not? Now I did have my motor timed by ear. I timed it where I would have the most rpm and still crank. When you put a light on it, you could evan see the line. Then I set it to 8 degrees[ 4 marks on the A side] and locked it down. But when you crank motor, it does skip, and white smoke comes out out tail pipes. And when it wrams up, it smooths out and stops smoking. Do you think it is timed to low? And I should step it back up? Thanks, John.
John, the damper may not be valid. Under the presence of ozone, gas, oil and grease, the elastomeric material that separates the inner hub from the outer ring will begin to break down. When this happens, the outer ring can slip in relation to the inner hub. When this happens, the slot in the outer ring is no longer clocked to the keyway cut in the inner hub and your TDC is no longer valid. Mr. Pope is saying that you can verify that the timing on the damper is about right by timing the motor by ear, then verifying the timing with a light to see if the damper is valid.
absolutely not....the piston will always travel the same path, but changing timing will determine when the spark hits in relativity to the piston, it could change it from btdc to tdc or atdc, the goal really is to get combustion to happen before the piston starts traveling down but after the rod has changed sides on the crank journal, that way when the combustion happens, there is the least amount of resistance.... if we have it directly at true TDC then it would push directly down on your crank, if its btdc it'll push the crank the wrong wayQuote:
Originally posted by Johnwalkeasy
The piston will be in the same position no matter what will it not?
Hi thesals;Quote:
Originally posted by thesals
the goal really is to get combustion to happen before the piston starts traveling down but after the rod has changed sides on the crank journal, that way when the combustion happens, there is the least amount of resistance.... if we have it directly at true TDC then it would push directly down on your crank, if its btdc it'll push the crank the wrong way
You might want to re-think the “included quoted part” of what you said. Cranking timing or idle timing, is set anywhere from 4-12 degrees, BEFORE top dead centre. Once the engine is running and gets off of idle, the timing keeps advancing to as high as 40 degrees btdc. In this way it creates compression and gives it it’s horse power and throttle response.
You might want to re-think the “included quoted part”
the compressinon is always there ,
piston speed (rpm ) is the factor timeing change is nessasary,
TIME is also a factor, the combustion process (the TIME the spark ignites to the TIME the peak pressure has happenen and starts to fall , 4-10 deg after top dead center, forces the rod down)
It always stays the same. it only changes with fuel quality-octane-
the piston speed at idle 750 rpm only requires the spark to ignite the a/f mix at 4-12 deg BEFORE top dead center , to run smooth ,
due to the TIME it takes to burn the fuel.
at 3500 rpm the piston speed is much much faster , but the TIME for the fuel to burn is the same, (fuel quality is the same,)
the ignition advances now around 36 - 40 degrees before top dead center,
the spark has TO occure SOONER so that the peak pressure is still 4-10 degrees AFTER top dead center.
Like when you pedal a bike, you push hard just before the peddle is at tdc when you start out, but the faster you go the sooner you can push the peddle to accelerate.
are you confused yet? LOL!
LOL. I think the world would be a better place if I stay away from motors. All I know is this. I bought a 1968 C-10 pick-up Truck about 2 months ago. And it ran good. After many improments it runs bad and smokes. Does anyone need any help with thier car.LOL. I guess I,ll time it by ear. Trun Dis. untill it runs the fastest and smothest and still will crank okay. Does that sound right? Also, could low timimg cause the motor to have white smoke? Also does anyone know how to build a good but kicken machine. John.
Well I set the timing up a little today. Moved the Dis. about 1". It is a little high I think. But motor don,t smoke anymore and it runs better. I don,t know where timing is set. Had it set like the book said. But it,s an old motor with a lot of miles and maybe sometimes you can thow the book out the window. Or maybe like one of you guys said the damper might be worng. I,m 57 years old and use to be a fair hand when it came to small block chevy,s. But you guys know a hell of a lot more than I did on my best day. Thanks for all the advice. Also, Kenyapep, Did,nt mean to cut in on your post. but did not want to start a new one about the same suject. I,ll bet this tread has help a lot of people. Thanks John.