midman

Rebuiding a 1931 90 Series Engine

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Hugh,

You can see the inserts in post #6. The rods and caps only have a couple of thousands clearance against the crank as you can see in post #8. I really didn’t discuss how he machined them other than I told him to go ahead with the inserts.

Chuck

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Spinney,

I had one of the rod bearings off but neglected to get the number before I installed them. I'll try to get them from the machinist and I'll post it here if he comes through.

 

On ‎4‎/‎21‎/‎2018 at 5:27 PM, Hubert_25-25 said:

Did they put any shims under your main bearings?  What did you use for your rear main seal?   Thank you.   Hugh

Hugh,

No shims on the mains. I used 5/16 rope seal on the rear main.

Chuck

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On 4/21/2018 at 6:59 AM, midman said:

lock but I’m not sure that will do it. Any thoughts

can you take a difrent shot of this bolt ? more side view ? can you safety wire it ? --kyle   

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Well , I was just about finished buttoning up the engine when I found two pieces I missed. Rule number 1 make sure you have everything cataloged .

Anyway one piece was a threaded plug for the rear of the cam (add 4 hours or work re-tearing down the bottom end, bell housing flywheel, etc.)

The other part is this small plug which I can not find where it goes. The machinist removed it but he does not remember where it came from. It is just .48 in diameter so I am assuming it is in the oil galley lines but I cannot find an obvious location. 

I am not going to button this up without finding its home.

Any ideas out there.

7602A226-1E3C-4D89-874F-DFCA205671F3.jpeg

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The only things applying thrust to the cam are the oil pump gear and the crankshaft drive gear.  I believe both of these gears force the cam to the rears to maintain contact with the cam thrust plate.  There should little in the way of forces that will work on the retaining bolt.  

 

The factory was not concerned with the bolt coming loose or they would have pinned it or wire locked it.  

 

Bob Engle

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The brass plug that you is looking for a home,  could it be part of the oil temp regulator system.  there are springs that may have been retained by that plug.  Just guessing on my part as I only know the 50 series engines.

 

Bob Engle

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Seems I had the answer to the wayward plug on my computer all along. No one knew where the plug went so I was stumped. I had gone over that block 50 times looking for where the plug might go.  Then I remembered when I bought the car I also got a pile of blueprints, so I figured I better start searching. I had donated the plans to the Buick Heritage Alliance and they gave me scanned copies. I went through every engine print I had, blown way up and started searching, inch by inch,  and there it was.

It was on the rear main bearing, I had been scouring the block. So after installing it I started reassembling again and  I'm almost back to where I was 2 weeks ago. So glad I didn't have to tear it down any further.

 

Plug.JPG

Missing Plug.jpg

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OK, Got a bunch of work done.

Reinstalled the bellhousing, flywheel, oil manifold, front cover and oil pan.

Installed the pilot bearing and clutch and the cylinder head. New head bolts, not high crown bolts like the old ones but this engine has been apart a couple of times at least so I was not comfortable reusing them.

Rebuilt the rocker assembly and started installing the pushrods.

Unfortunately I found a pushrod with some damage I missed on disassembly. I am not comfortable installing it so I am trying to track one down. hopefully one of my sources will have one. The pushrod spring cap was a little mangled so my guess is it was cocked on installation sometime in the past allowing it to rub against the rod.

Oh well, the install is stalled again during the hunt.

Cylinder Head 1.jpg

Cylinder Head 2.jpg

Pushrod.jpg

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