240dkw

So after seeing what happened to my cam oiler tube, and talking to another Z owner who had the same problem with major results. The front tube fell out and got caught in the timing chain. Trashed the bottom gear and of course bent a bunch of valves. So I decided to try to come up with a way to stop the tubes from fall down into the lower engine if they failed and am trying this to see it helps.

Well, I have been running Lucas oil in my car since I first started it up, mainly because of the zinc and cost. Nice to see it got a good rating.

I got the head done complete with new valve seats about 600 miles ago.

They all looked good, but of course I change them all, so that could have been one of the issues.

Ok I am really starting to believe I did in fact jump the gun on my motor, I went through everything while it was apart and all I could find is a small leak on the exhaust valves for 5 & 6, just like you said @Mark Maras. I did a quick lapping on them and it stopped the leak. I then cleaned the head up and put it all back together. It now runs great and the oil pressure is right where it should be. Nothing wrong with the carbs as well so if in fact it just decided to run really rich for a while I have no idea what caused it.

I had to check, the Patrol came with a 6, but it would have a P not a L and it was 4000 cc. My photo of the page is misleading as it is show where the different SN are located for all of the Datsun's. It is a L24 in the photo.

Jim: Pulled the speedo gear out of a spare 4 speed A tranny to see if I could see anything. It is a worm gear with 6 "threads" from the start to finish.

I do not have an answer for the teeth count, but I think you are correct as too all of the different tooth count colored cogs being different diameters as well . I am sure they compensated for the different diameters by off-setting the housing to bring the gear back in full contact with the main gear.

I am sure that I checked the movement of the pistons and made sure the cam lobs where up. And I cannot say enough as to it was not a puff of blue smoke, but a large plume.

It did not lose any oil, as it only ran while it was smoking for a hour or so while I was trying to find out why it was smoking.

That is close, the pressure did not shoot up, it started following the rpm’s. like the pressure relief was not working. At the exact time that my pressure problem stopped it started smoking. I pulled the head because of the smoke and the fact the leak down test showed something wrong with #5 and #6. I have just finished cleaning the head and changing the valve seals. Because I have not found anything wrong so far, l am going to put the head back on and run it. It is very possible that it is a very rich problem, before I put the carbs back on I will have a good look at them.

I did start there as well, I used a variable resistor and walked the gauge up and down the scale and it is working correctly a few days before this happened. I do not disagree with you as a coincidental problem.

The head gasket idea is what drove me to take the head off, but I can not find anything wrong with it. It has about 600 miles on a complete rebuild and has been running awesome with no problems until this one.

Captain: Sorry for the confusion, jonbill is correct. It has been running great, but with high oil pressure for about 100 miles or so. Then I checked the relief valve, all good with no modification. Started it up again and still had the problem.. Shut it down, installed gauge started it up and pressure was good at 61 psi. Shut it down and installed a new pressure sensor I had. Start it up and reading was good, but started running rough. Looked in rear view mirror and large cloud of blue smoke. This all happened in the space of 15 min. The two problems might not be connected as Zed Head eluded to but it seems to me that they are connected.

It smokes at idle and a greater amount(a lot) of smoke when reved up. The odd thing is that the higher oil pressure disappeared at the same time it started to smoke. Almost like something let loose. The smoke is blue.