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zephyrdave

37 LZ V12 questions

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I had the engine fired up for 20 seconds before I found the no oil pressure problem. Engine runs fine. Pump gear is pressed onto camshaft, they are not just one piece. I believe the early v12 oil pump gear was pressed onto a  round shaft at the end of the cam. Later engines went to D shaped shaft. I suspect gear is spinning on shaft or broken teeth. 

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Manuals, or Boos-Herrel catalog, show a simple diagram to help visualize gears he refers to.

 

OilPumpGears.JPG.23e333743502190d82aa25048fe10718.JPG

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Posted (edited)

Could be what you say but the large center gear is  removable for cleaning etc. may not have been put back in during  reassembly. Gears are accessible  behind  a bolt on cover rear of block in front of flywheel. 

Edited by 38ShortopConv. (see edit history)

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The center gear is there, I can see it when I remove the pump. One thing I do know is, this is creates a lot more work. 

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Yes,  Damm!  could be a lot of work if gear on cam is slipping! Both heads off, all valves out, pull cam.  Maybe that is why motor needed rebuilding, sudden loss of oil pressure. Could gear be Tigg or Migg? welded in place? Theres a lot at stake though. Good luck and keep persevering.  

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I would get in touch with the shop that rebuilt the engine and ask them to fix the problem. You may have to do the R &R of the engine and let them do all of the other work. They messed up and should be held responsible.

 

You should also check that the camshaft is turning when you turn over the engine. The press on timing gears do slip and teeth do break off.

 

If you want to do the job yourself, you should pull the engine to check the gear, you have to remove the flywheel and the cover over the gear. I would think that it is easier to do this on an engine stand than pull the transmission and oil pan to get the flywheel off.

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The owner will be talking to the engine company. I suspect they will probably say bring the engine in, so that means I will have to pull the engine and get it to them. Like I said, the engine fires up and runs fine.

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Before I take the engine out, I took the pump off and looked up the hole. I noticed that the idler gear did not seem to be in the right place, it looks like it is off to one side of the hole towards the rear of the engine. I turned the engine over by hand and the idler gear did not move. Went to the internet of course to research. Found a V8 ford forum where someone had a new rebuild and no oil pressure. They took the engine out and found that the idler gear was installed upside down so no gear engagement. I'm sure that's what's going on here. If you can see in the pic the gear is off to one side. I think ford V8 and lincoln V12 have a similar setup. The idler gear has a "snout" on one side. If it is installed upside down, it puts the gear out of alignment with the other gears.

oil pump hole 37 007.jpg

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Do you have the correct pickup tube and screen for the M-15?  Not the same as the original.  I got mine from Mac's.

Abe

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On 3/24/2020 at 2:52 PM, zephyrdave said:

Before I take the engine out, I took the pump off and looked up the hole. I noticed that the idler gear did not seem to be in the right place, it looks like it is off to one side of the hole towards the rear of the engine. I turned the engine over by hand and the idler gear did not move. Went to the internet of course to research. Found a V8 ford forum where someone had a new rebuild and no oil pressure. They took the engine out and found that the idler gear was installed upside down so no gear engagement. I'm sure that's what's going on here. If you can see in the pic the gear is off to one side. I think ford V8 and lincoln V12 have a similar setup. The idler gear has a "snout" on one side. If it is installed upside down, it puts the gear out of alignment with the other gears.

oil pump hole 37 007.jpg

That looks like it could be your problem.  Can you turn the gear with a long screwdriver? That would tell you if it’s engaged with the cam. 

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Problem solved!  Pulled engine. Removed flywheel and then gear cover. Gear had been installed backwards by the engine shop. It was also jammed up against a cast knob on the cover. I removed idler gear and re-installed on the shaft properly. There is now room between the gear and cover, and the gear will now engage with the other gears. 

37 oil pump gears leaking heads 002.jpg

37 oil pump gears leaking heads 004.jpg

37 oil pump gears leaking heads 005.jpg

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Done a little investigating. I have an empty V8 block on the engine stand. I placed the idler gear and cover on and the gear should be running in the center.  On the V8 , pre 49 blocks, the idler gear will not go on the cover wrong because the cover has a hump cast into it to prevent that.  I thought I had a V12 cover laying around but couldn’t find it. Can’t remember if the V12 cover has that cast in hump or not . Maybe someone here has one to look at. The covers are different between the V12 & V8 except for the 36-37 V12. The V12 cover will have a part number with an 86H prefix.  

4E4506EA-5400-4111-B8CD-97CAA35B1609.jpeg

9E399E25-8658-44ED-8AE8-346C79C9205E.jpeg

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Glad you found it! I see the V12 cover does have the cast in knob.  It’s a miracle that the cover didn’t get broken when they pulled the bolts up.  

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It comes down to who put the cover on? previous owner, machine shop or shade tree mechanic along the way. It looks a bit sludgy in there  up against the snout flange in the picture for a new rebuild. May be not. The good thing is you have found the problem and no apparent damage done. 

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The cover and gear were installed by the engine machine shop who "rebuilt" the engine. . The owner never touched the engine. They also painted the engine after it was assembled, including the aluminum heads. Owner told them he specified don't paint the heads. They pulled the heads to remove the paint and reinstalled the heads using the same gaskets and also had never used thread sealer on the studs. There was coolant coming out the top of the studs and around the perimeter of the heads like crazy. I made some calls and found out that the person with experience in the shop had quit just before this engine was worked on. They also forgot to install the bolt and thick washer that hold the crank pulley on. I also had to rebuild the carb that they said they rebuilt. My friend paid a lot of money for this "rebuild". Anybody know of a good lawyer? 

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Thanks Dave for including us in the findings step by step, with helpful photos!  A good lesson learned by many now to pack away back in our memory & to keep an eye out for should we ever need it.

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Page one second March 11 post I mentioned crankshaft web   oil gallery welch  plugs. Before you fit pan you could check if they have been replaced. About 12.  After a crank grind they should be removed and the oil sludge trap cleaned out along with any crank grindings. Theres a large hole behind them for sludge to collect, the later LZ motors didn't have them from 39? on.  New plugs are pressed in, tricky job  with threaded bolt and nut. Easier with motor out! Those grey felt pro head gaskets are best.   Happy Days.

Edited by 38ShortopConv. (see edit history)

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Glad that you found it. The photo that you posted showing the idler gear had me wondering, I could not figure out why there were no gear teeth showing.

 

Before you reinstall the engine, check all of the other sources of low or no oil pressure. There could be more than one thing wrong. They may have left out the pressure relief valve, thinking that the one on the pump would do the job.

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My 39 has those crank plugs, they were removed and the crank cleaned, plugs replaced. Fortunately, the guy that did my engine was a good experienced mechanic with an amazingly equipped machine shop. Unfortunately, he went out of business before my friend was ready to have his engine done.(long story). The plugs in his crank look like they haven't been touched. 

 

The rest of the engine checked out OK. As for the pic looking into pump hole, you have to look real closely and you can see the edge of the gear teeth towards the rear of the hole. They are now in the center of the hole.

 

Edited by zephyrdave (see edit history)

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