What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Locked Distributor setup

anwat

anwat

1/2 ton status
 Premium
Joined
Apr 28, 2019
Posts
801
Reaction score
609
Location
Long Beach, CA
I know I read the answer to this question somewhere on here before, but I can't find it. When setting up a locked out distributor, do you want the rotor to have the trailing edge touching the the spark tower for the #1 plug? That way when it's at full advance, the leading edge will be touching? Or am I exactly backwards? And yes, I'm talking Chevy.
Found out why my truck wouldn't stay timed correctly:

IMG_1390.jpg
 
Why did it chew up the gear? Is it the wrong material for the cam? What does the cam itself look like?
 
The cam gear doesn't look too bad, from what I can see. There's a little brass on the edges of the gear, but no defects I can see. I sucked everything I could out with a vaccum hose, not too much in the way of brass down there...To answer your question, the gear that got chewed up was an oversize gear. I don't think it needed an oversize gear, I think it wasn't meshed properly and it just chewed itself up. The new gear is a standard size, it feels plenty tight to me. I checked it with some die, and it looks to be hitting evenly all around. I'll pull it out after a few miles and see what it looks like. Possibly too much drag from the high volume oil pump?

Image-1 (1).jpg
 
nvrenuf said:
The oil pump shouldn't cause excessive wear.
Click to expand...
Higher pressure pumps do add a lot of strain to the drive gear - kinda like throwing an anchor out and causing more drag.
That’s often a issue with the bronze gears used on street duty.

For added longevity with a brass/bronze gear you can cut a .030 deep groove in the bottom ring of the dist. housing to supply some added oil directly on the gear teeth.

John went with a proper steel drive gear option on his wiggle-stick - it’s more money but definetley the way to go.

IMG_9067.png
 
Last edited:
If you look closely at the distributor in the top photo, I just filed a groove in there, although I did it at an angle so I wouldn't garf up the new gear. As for why bronze, I'm glad whoever put it together before me used bronze, otherwise I'd probably have a chewed up cam gear, too. I can change out if this one doesn't get chewed, but it would seem to me that no matter the material, if it meshed properly, it wouldn't look like that...it may wear, but it would have worn evenly.
As far as the timing goes, I just put it in the middle of the post for now and I'm going to see if I can find an adjustable rotor for that distributor. It's at least running for now.
 
Yep, keep a good eye on it as you would regardless of what composition, just to make sure everything is good
Cut up a few filters
 
anwat said:
If you look closely at the distributor in the top photo, I just filed a groove in there, although I did it at an angle so I wouldn't garf up the new gear. As for why bronze, I'm glad whoever put it together before me used bronze, otherwise I'd probably have a chewed up cam gear, too. I can change out if this one doesn't get chewed, but it would seem to me that no matter the material, if it meshed properly, it wouldn't look like that...it may wear, but it would have worn evenly.
As far as the timing goes, I just put it in the middle of the post for now and I'm going to see if I can find an adjustable rotor for that distributor. It's at least running for now.
Click to expand...
Nice !
I did not notice the groove already cut in your picture - I put up a pic of a vertical groove figuring you had the gear off and would be able to do ( should have considered that your gear was already installed…) but ain’t noth’n wrong with following the angle of the teeth for an added oil path.
Possibly a little extra zinc additive in the oil might gain you a bit of longer gear lifespan.
 
anwat said:
I know I read the answer to this question somewhere on here before, but I can't find it. When setting up a locked out distributor, do you want the rotor to have the trailing edge touching the the spark tower for the #1 plug? That way when it's at full advance, the leading edge will be touching? Or am I exactly backwards?
Click to expand...
I think that's correct. Is your lockout adjustable or do you have to go in 1-tooth increments?
 
I found an adjustable rotor that fit, so now I can adjust without too much drama. I've got 10 base, and the rotor has 10, so I'm sitting at 30 total now, I'm going to adjust up from there and see how it sounds and what happens with the vacuum. Prior to yesterday, though, I was counting teeth and using a mirror to make sure the pickup was lined up.

I know you don't want that sitting on the oil pump drive, but how much above it should it be? I have an adjustable collar for depth, so I'll drop it in until it bottoms out and then put it maybe 1/8 up from there? I know there should be a little up and down slack, but how much? I'm thinking I may not have been deep enough, since it looks like the top of my drive gear wasn't contacting the cam gear since there's no wear on the top....
 
anwat said:
I found an adjustable rotor that fit, so now I can adjust without too much drama. I've got 10 base, and the rotor has 10, so I'm sitting at 30 total now, I'm going to adjust up from there and see how it sounds and what happens with the vacuum. Prior to yesterday, though, I was counting teeth and using a mirror to make sure the pickup was lined up.

I know you don't want that sitting on the oil pump drive, but how much above it should it be? I have an adjustable collar for depth, so I'll drop it in until it bottoms out and then put it maybe 1/8 up from there? I know there should be a little up and down slack, but how much? I'm thinking I may not have been deep enough, since it looks like the top of my drive gear wasn't contacting the cam gear since there's no wear on the top....
Click to expand...
We’ve had issues with this on a well utilized 454 block that had been substantially decked from many years of racing service and the dist. would not even bottom down to the intake boss much less have proper gear alignment.
We had already invested in a nice MSD dist so we used shims instead of an adjustable collar and set the thickness at .250 to get it right - but that was with excessive block decking to compensate for so your call at .125 sounds like a good starting point.
 
You must log in or register to reply here.

Latest Posts

Top Bottom