Can't get timing to less than 25 degrees?

[cbuczesk]

It looks like the shaft might be off a tooth. It should rotated clockwise a few degrees. Are the cam gear and damper showing TDC? 29 degrees total advance is fine. The staple looks like a wire from a wire wheel.

Chuck


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[882993md]

14 minutes ago, cbuczesk said:

It looks like the shaft might be off a tooth. It should rotated clockwise a few degrees. Are the cam gear and damper showing TDC? 29 degrees total advance is fine. The staple looks like a wire from a wire wheel.

Chuck


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Cam sprocket notch is lined up with groove in the pic. I guess I could pull the oil pump to verify and re-clock.

Howard
 

 

[cbuczesk]

I think it's off a tooth. But as long as you know it and can set the timing then why bother? My race car is off a tooth but the timing is where I want it and I'm tired of making oily messes to remove the oil pump. My OCD is losing this battle...for now.

Chuck


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[882993md]

Great news everyone:

I reinstalled the distributor, crossed my fingers, and checked the timing: it was 15.

So I twisted the distributor and lo and behold I had good range up and down the timing scale. I set it at 10. 

I think what also helped was the 8mm adjustment screw was loose from the disassembly. I notice I have more range of movement now for retard/advance. 

Howard

[Zed Head]

Hope your fingers don't get tired or cramped...

I didn't post it earlier but the gear on the oil pump is apparently a press-fit.  They've been known to slip.  There are stories about the gear slipping upward, causing the distributor drive slot to lose contact with the drive tang, or just spinning a bit and screwing up the ignition timing.  Something to consider if it changes again.

http://forums.hybridz.org/topic/115353-l28et-issues-oil-pump-shaft-gear-spun/

 

[cbuczesk]

All of the oils pump/distributor shafts that I've seen have the gear secured with a roll pin.

Chuck


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[Zed Head]

Just regurgitating stuff I've read, from people who seem to know.  Maybe they all pinned theirs before you saw them.

Here's another.

http://forums.hybridz.org/topic/106792-slop-in-the-distributor-drive/

[cbuczesk]

That's interesting. Most of my stuff is from 240Zs. Maybe the L28s were pressed on? I'll have to look at my spares. The two that were damaged, the replacement and my spare in the trailer are all pinned.

Chuck


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[Zed Head]

I'm tempted to go drop the pump on my seemingly all original 76 short block.  It's just sitting there wasting space anyway.

[Zed Head]

The locating dot/divot looks kinda like a pin, but it's just a shallow depression in one side of the gear body.  Nothing on the other side.

Edited November 5, 2017 by Zed Head