1973 Z1 Maui

I’ve had some big distractions keeping me from the project.,here is where I am.
the bashed tank and body work are still on Oahu, I think making progress, hopefully.
the motor is back together. I plastigauged the new bearings and cams. Clearances are good.
I assembled with new gaskets and lots of assembly lube. 
with the cam cover off I cranked with the starter until I saw oil come out of the bearings, good sign. 
I checked valve timing about ten times.
I’ll be doing a test run in the garage soon, when I can get a little time, if all goes well I’ll synchronize the carbs and wait for the tank.
 

I was wondering what happened!  Good to hear your engine is OK.

Hope things are going well on this motor?  Any updates?

I stepped away for a big home project, back to it now.
The failed intake cam bearings, twice, really has spooked me. I removed the engine, split the cases and I’m looking for a reason. I thought the culprit may have been “pc 30”, the o ring type seal between the cases and between the oil pump and the lower case. Had to split the cases to see the one between the cases. Both are intact. I’ve included a photo of the one between the cases. I’ll now have to go through every aspect of oil delivery checking the pump dimensions (again), passages, cam bearing clearances, etc. when I finally reassemble I’ll need to somehow try to recreate oil flow to the head without running it. I want to see flow up there.
Needless to say, it would be easier if I found some obvious screw up, I’d be mad at myself but at least I’d have a reason. This is very frustrating, I’m not accustomed to this type of thing. It’s a simple oil system. 
If I can’t find a way to fix it I’ll have to part it out and lose a lot of cash.
Tank and body work still at paint shop on Oahu, waiting for paint, repairs are complete. Slow process.

Just wondering about the torque on the cam bolts?  If they are too tight the oil won't get into the gap between the bearing and the cam to float the cam.  Since the cam is steel it's the bearing that takes the hit.

You sound frustrated, but you are right...it's a simple system.  It's a high volume low pressure system.  The pump picks up oil and pushes it up the center bolt of the filter.  Oil flows through the filter and up through the bypass port, into the main gallery.  There is a port on the right side where you can check for oil.  Just crank the engine over and you should get oil very quickly.  From the gallery oil flows to the crank bearings.  It also flows up the outer front head bolts and into the head galleries that are connected to the cam bearings.  From there the oil flows down to the valves and back into the sump through the main tunnel in the center of the engine.  

If you crank the engine over you will very quickly get oil up into the head.  I did it once with the valve cover completely off.  It makes a bit of a mess, so you may want to put the valve cover over top of the cams and just peak under one end.

Maui I am confused, in Feb it looked like you had this sorted ? - Are you saying the cam issue has happened again since then ? Is it the same bearing that has failed in the same way ( is it only one bearing that is an issue ? ) has the bearing turned again ?
Keep your chin up pal there is enough experience within the membership here to help you get to the bottom of this 

Yep, intake cam bearings. I didn't let any spin but they are damaged. 
I'm starting over. 
Oil pressure light goes out right away so it's not a lack of pressure, it's just not getting to the bearings in enough quantity.
Lots of assembly lube was there so it isn't startup. 

Sorry to hear that, it's really putting you through the mill ! Ref the below
Is it both sides or only one ?
Is it viable to drill out the gallery plug to clean it out and replace with a threaded bung ? (not sure how else you can be sure it's clear)


 

I’d like to keep it as stock as I can, I’m thinking of assembling the head and cylinders and somehow testing flow, have to work on that idea.
I’m not sure how torque can affect oil flow or damage the bearings but I think the manual has too high a spec. It’s a 6mm bolt. Manual says 105 inch pounds. The generic chart says 6mm is torqued at 76 inch pounds max. I’m going to use the lower number. 
it has heavy duty studs but I don’t see how that could cause this, there are a lot of hot rod Z1s out there running HD studs.
im also going to blow backward from the cam oils holes. I did all this initially but I’ve got to figure out what I’ve missed. 
 

wrote:

Sorry to hear that, it's really putting you through the mill ! Ref the below
Is it both sides or only one ?
Is it viable to drill out the gallery plug to clean it out and replace with a threaded bung ? (not sure how else you can be sure it's clear)


 

Yes you can drill and tap the oil galleries. 2 on the side and one from the rear.   I use brass plugs and teflon tape. DONT over tighten and crack the hole
Dave

Cam bearing caps are line bored with the cyl. head. Are you sure you have the correct matching cam bering cap to the head bearing and position?
Some pics of the suspect cam bearing cap area would be helpful.

wrote:

I’d like to keep it as stock as I can, I’m thinking of assembling the head and cylinders and somehow testing flow, have to work on that idea.
I’m not sure how torque can affect oil flow or damage the bearings but I think the manual has too high a spec. It’s a 6mm bolt. Manual says 105 inch pounds. The generic chart says 6mm is torqued at 76 inch pounds max. I’m going to use the lower number. 
it has heavy duty studs but I don’t see how that could cause this, there are a lot of hot rod Z1s out there running HD studs.
im also going to blow backward from the cam oils holes. I did all this initially but I’ve got to figure out what I’ve missed. 

You will be fine at 76.  Just make sure your oil galleries are clear.  Check the lower oil inspection port first.  Then check the head.