1931 Buick 60 series engine vibration

[nat]

Brian_Heil

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Posted Wednesday at 10:44 AM (edited)

"A couple of comments on engine balance"

 

Brian;

      When I first glanced at your lengthy post that started with"round and round and up and down" I didn't have time to go down a rabbit hole and thought you might be  someone who hasn't had much to do since Oprah was taken off the air.

     I read your post and realize that you aren't making this up as you go along.  Thanks for the well written treatise.

     P.S.

     I may send you a PM on an unrelated topic.  Fell free to block me before I do so.

Nat

     

[Str8-8-Dave]

Ok guys;  I may have finally found a good bet on the source of vibration in my car and it turns out to be front engine mounts.  The 1931 Buick Specs and Adjustments clearly states engine alignment must be correct when installing the engine in the chassis.  For front mounts that means with rear mounts assembled with bolts loose, front of engine should be aligned so front engine mount bolts drop through the holes (which are actually tubes welded in place) then drop loosely thru the chassis bracket holes.  I wasn't around when the engine was reinstalled in my car so before I do anything I will loosen the rear mount bolts, which the Specs and Adjustments manual states must be loose until front mounting holes are lined up, then I will make sure front mounting holes are lined up correctly.  Misalignment of front mounts COULD BE an issue, but it's not the whole story.

 

What SURELY IS an issue is front bolts are supposed to pass thru the timing cover and there should be an insulator pad made of rubber and canvas between the timing cover lugs and the chassis bracket at the bolt holes, then below the chassis bracket there should be an identical rubber and canvas pad, then a flat washer, then the nut and lock washer. 

 

Umm- we have some missing parts according to the following pictures.  I made this discovery yesterday and it looks like there is some kind of canvas pad (no sign of rubber) between timing cover lugs and chassis brackets but pictures under the chassis bracket show only a nut and lock washer present.  So now we have a direct path for engine vibration to be transferred directly to the chassis because the head of the bolt is in hard contact with the timing cover and nut and washer under the chassis bracket are in hard contact with the chassis.  

 

I spent hours yesterday on the internet trying to locate suitable material to make anti-vibration cushion pads from.  No one seems to have anything in the way of pads made of rubber and canvas or suitable material to make them from.  Does anyone know of a source?  

 

One idea I had was to make pads from canvas reinforced rubber tail pipe hanger strap which is a layer of rubber, layer of canvas and another layer of rubber.  Another way might be to use non-metallic woven brake lining with hard rubber washers.  If anyone has a better idea or knows who sells something like this, I would really appreciate hearing from you.

 

PS:  Edinmass- if you see this, I should have listened to you a long time ago when I first started talking about this issue.  You told me I should look into engine mounts as a source.  

 

My head get harder with my ancient age....

 

Thanks

Dave

 

 

Read Engine Mountings from pages 81-83 the 31 Specs and Adjustments manual for 8-60, 8-80 and 8-90 series below.  

May car is an 8-60.

 

 

 

 

 

This is the left front engine mount bolt, metal to metal contact from head of bolt to timing cover.  You can see the edge of

an insulator pad sticking out of the space between the bottom of the timing cover and the chassis bracket.  It looks lik

canvas only, no sign of rubber.

 

Below the chassis bracket where the Specs and Adjustment manual says there should be an identical insulator pad and a

flat washer to insulate the bolt from the chassis bracket there is only the nut and a lock washer, so now, there is a path for

engine vibration to travel from the engine to the chassis.  The image is reversed because in order to get into the small space

under the chassis bracket the picture was taken with the Selfie camera setting.  That's the exhaust head pipe flange in the 

upper left corner of the picture.

 

Here is the right front mount.  Bolt head is again in solid contact with the timing cover.

 

Beneath the chassis bracket in a reverse image is the nut and lock washer, no insulator or flat washer in sight.

 

 

 

Edited March 2 by Str8-8-Dave
Arrange pictures, add captions. (see edit history)

[pont35cpe]

27 minutes ago, Str8-8-Dave said:

If anyone has a better idea or knows who sells something like this, I would really appreciate hearing from you.

I`ve made pads from the sidewall of a worn out tire.

[nat]

     The rubber used in those universal exhaust hangers are bits of old tires.

     Lock washers aren't very effective when clamping mushy materials, (like soft wood or rubber).    You might use a jam nut, locknut or drop of low or medium strength Loctite. 

 

      

[drhach]

Have you tried McMaster Carr? They sell industrial motor mounting material. 

 

rubber mounts | McMaster-Carr

 

Not usre if they would have anything that would do the trick, but maybe worth a look. 

[Str8-8-Dave]

McMaster Carr was one of many sources I checked out.   They didn't have anything.  All their reinforced rubber washers are 0.110-0.140 thick.  That's pretty thin for isolating a heavy engine from the frame mounts.

[Robert Engle]

My 32 Buick has a cross drilled hole in the bolt threads and a castlated nut is used.  Cotter pin through the nut and bolt when done.

 

Bob Engle

[nat]

     Later they used nuts and bolts with "Dardelet" threads which have the same profile as acme thread but lock by wedging together when tightened.

Edited March 4 by nat
Forceps at birth (see edit history)

[MarkL]

Commercial truck mud flaps, very durable.

[Str8-8-Dave]

I tried a bunch of different sources for fabric reinforced material to make new insulator pads from for my front engine mounts and finally discovered a seller on E-bay that sells 5/16" thick 2" x2" pieces of salvaged aircraft tire material.  4 piece lots were priced just under 8 bucks.  What was missing was the required 1/2" hole in the center of the pads.  I made a plywood holding fixture made of 3 6" x 6" 3/8" thick plywood.  Top layer had a 1/2" hole that is centered over a 2" x 2" window in the second layer of plywood.  The third layer serves as a support pad.  I drilled 2 more holes on a diagonal center line about 1" from 2 diagonally opposite corners to allow the fixture to be thru-bolted to my drill press table.  I successfully drilled 1/2" holes in the 4 insulator pads, cleanly cut, with a wood working bit. 

I will post an update with pictures after installation in the car.

 

Dave

 

Pictured are the 4 fabric reinforced pads I found on E-Bay along with a holding fixture I made to safely and accurately drill the 1/2" bolt holes in the center of each pad.

 

 

With the holding fixture loaded with a rubber pad and bolted to the drill press I got nice neat holes centered accurately and drilled with my hands safely away from the

action.

 

 

Edited March 13 by Str8-8-Dave (see edit history)