Motor Vibration

[Mitch//pa]

you can jump in different cars and i bet you'll feel different things in each one due to tolerance variations on these 80 plus year old canoes.
try what H.L. mentioned remove the belt it easy enough otherwise drive it

 

[whirnot]

The 1928 cars had the solid motor mounts on the front crossmember with little in the way of cushioning vibration. I understand that Ford would happily cut down the '28 front crossmember and put a later front motor mount with some flex to cushion the vibration. Not everybody took Ford up on that, however, so there are still lots of solid front motor mounted Model A's out there. Yours isn't one of those, I don't suppose???

BTW, those of you who acquired '28s with the solid front motor mount, did you convert them over, or Not??? This is supposedly a purist-leaning forum, so did you modify the '28 A's or leave them stock, even if stock meant a lot more engine vibration?

No it is the 29 spring mount. It is noticeable, like when shifting from 3rd to second. Definetly and engine vibration but not severe. 60? never. had it up to 53 once, it likes 45 better.

 

[James Rogers]

When it is at it's worst have you looked in the mirror? I can drive mine at any speed, throttle up or down or coast and I get no vibration in the mirror. They don't have to vibrate.

 

[whirnot]

When it is at it's worst have you looked in the mirror? I can drive mine at any speed, throttle up or down or coast and I get no vibration in the mirror. They don't have to vibrate.

As I expected it is probably normal. I can see fine in the mirror at all times.

Thanks

 

[CA Victoria]

I bought my roadster not knowing the engine history. De-celleration vibration was worst in a mid to high RPM range. I found the aluminum fan was not balanced, bought a new one from Bert's Model A Center (pre balanced) and it made a tremendous difference smoothing out a lot of vibration. Also updated the rear engine mounts, although it did not cure the problem I took care of the symptom and the vibration is hardly noticeable I have attributed it to an engine that was not balanced when built 30 years ago. It's really smooth and happy at 45 but can accelerate up to 60 if needed.

 

[leadpot]

Sometimes my 29 tudor will run smooth as silk at any speed. Other times it will vibrate badly at 40 -45. Guess it just depends on what mood the old girl is in - mystery to me.

 

[Phil]

The 1928 cars had the solid motor mounts on the front crossmember with little in the way of cushioning vibration. I understand that Ford would happily cut down the '28 front crossmember and put a later front motor mount with some flex to cushion the vibration. Not everybody took Ford up on that, however, so there are still lots of solid front motor mounted Model A's out there. Yours isn't one of those, I don't suppose???

BTW, those of you who acquired '28s with the solid front motor mount, did you convert them over, or Not??? This is supposedly a purist-leaning forum, so did you modify the '28 A's or leave them stock, even if stock meant a lot more engine vibration?

My early 28 Pheaton with solid front mount is about the same as our other three Model As with the later spring mount.

 

[BarracudaBoy]

I have the same sort of vib in mine going downhill under light throttle, but it hasn't changed (gotten worse) so I figure it's just a Model A thing.

 

[BILL WILLIAMSON]

Dog here, Ol' Bill's eating & said tell you, "If you got odd vibes or noises here & there at various times or conditions, just look the car over carefully, & if nothing important is DANGLING or LOOSE, just drive it"!!! Buster T.

 

[whirnot]

Dog here, Ol' Bill's eating & said tell you, "If you got odd vibes or noises here & there at various times or conditions, just look the car over carefully, & if nothing important is DANGLING or LOOSE, just drive it"!!! Buster T.

Dog, I think there may be some real wisdom there......

 

[colin1928]

I have had heaps of As and Bs engines and spent big on balancing both standard and counter weight assemblys some are as smooth and quite as you can get others have very strange harmonic s at different rpm s I have even swapped cranks and rods from 1 block to another only to change the harmonic s to different note and rpm
I can say that insert bearing engines will show it up double
Colin

 

[BILL WILLIAMSON]

I have had heaps of As and Bs engines and spent big on balancing both standard and counter weight assemblys some are as smooth and quite as you can get others have very strange harmonic s at different rpm s I have even swapped cranks and rods from 1 block to another only to change the harmonic s to different note and rpm
I can say that insert bearing engines will show it up double
Colin

Yes, Colin,
Most 4 cyl. engines have harmonic problems. I worked on MANY Datsun "L" series engines in the '70's, great engine, but many had harmonics at one speed or another, they'd drive you NUTS-----Like, VAROOM-VAROOM-VAROOM-VAROOM!! Bill W.