Vibration After New Motor

[Garagekulture13]

I bought an Antique Engine Builders touring motor from a friend of mine. He bought the engine new and after about 800 miles he decided he wanted a V8. So I jumped at the deal and put the motor in my 31 Tudor. Now I rode with him in his coupe while the motor was in his car and it ran very smooth. Well from the beginning the said motor has had a vibration in my car. It is rpm related. It doesn't matter if I'm in neutral or riding down the round at higher rpms I have a very noticeable vibration. I can feel it a lot in the steering wheel. Otherwise the motor has ran great. I would like to take some longer trips in the car but the vibration worries me. Any help would be much appreciated.

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[1929]

That motor looks real good, if he said it was fine, why would it be a problem now . Just an idea, how about jacking up the car and spin the front wheels as fast as you can to see if there is any vibration.

[1929]

Originally Posted by 1929

That motor looks real good, if he said it was fine, why would it be a problem now . Just an idea, how about jacking up the car and spin the front wheels as fast as you can to see if there is any vibration.

My mistake, I noticed this also happened in neutral.

[leo]

Is it possible that your motor mounts are too tight? I recall reading another post about engine mounts being too tight and not absorbing most of the engine vibration.

[BillCNC]

Maybe realigning the clutch assembly?

[Purdy Swoft]

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From what I see it looks like you are using original type rear mounts . I would first loosen the bolts that attach the engine to the rear mounts for adjustment flexibility . If you are using the original type front yoke motor mount , the castellated nut under the front crossmember only needs to be tightened just enough to get the cotter pin through the nut. If the nut under the crossmember that connects the front mount yoke is too tight it will cause vibration .

[lindy williams]

It appears that you have an original steel fan. Check it carefully for bent blades and proper fit on the water pump shaft. Also naturally for cracks.

[Garagekulture13]

Originally Posted by Purdy Swoft

From what I see it looks like you are using original type rear mounts . I would first loosen the bolts that attach the engine to the rear mounts for adjustment flexibility . If you are using the original type front yoke motor mount , the castellated nut under the front crossmember only needs to be tightened just enough to get the cotter pin through the nut. If the nut under the crossmember that connects the front mount yoke is too tight it will cause vibration .

Sorry for the poor pictures. I took these last night after I got off work. I put loctite on the rear motor mount bolts. That's why there is no safety wire. The other picture is of the spring and nut for the front motor mount.

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[Garagekulture13]

Originally Posted by lindy williams

It appears that you have an original steel fan. Check it carefully for bent blades and proper fit on the water pump shaft. Also naturally for cracks.

Yes I did. Thanks. My friend let the fan go with the motor because he knew it was a good fan. He gave me a mini class on fans including an example of a cracked fan blade. I'm always open for new information.

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[Dave in MN]

Try removing the fan belt to eliminate an out of balance fan from your search. The motor can be run for a short time without it turning. Good luck on your search.

[chap52]

Interesting, please keep us posted on what you find. Thanks, Chap

[Bulligen]

It looks like there is some galling of the washer at the front motor mount washer. It appears that it is not snug at all. Could the engine be jumping up and down to cause the vibration. add some extra washers or a longer stiffer spring and see what happens. Just an observation ! I wish you good luck with it! Roger

[Richard in Anaheim CA]

1. Check for vibration with the fan belt off.
2. Front mount should be totally stock. No rubber bumpers etc. Two springs top and one on bottom. Make sure they are the correct springs, not something else
tighten bottom nut only until cotter pin fits. The engine should be able to visibly "rock' when applying power.
3. Big bolts through rear mounts, into clutch housing must be "tight".
4. Use new frame rubber pads inside and outside of frame and DO NOT cinch the through
bolts tight. Just snug so the rubber can do it's job.
Yes some of these are repeats of others posts. Thought maybe this might add something

Good Luck

[Bill G]

What about the two shims between the top end of the block and the two top bolt holes for the flywheel housung.. Something simple to check

[jhowes]

I HAVE HAD A SIMILAR PROBLEM WHICH I INTEND TO RESEARCH IN ANOTHER MONTH OR SO. WHAT PUZZLES ME IS SOME OF YOU HAVE SUGGESTED THAT A MOTOR MOUNT THAT IS TOO TIGHT WILL CAUSE THE VIBRATION. iT WOULD SEEM THAT NO MOTOR MOUNTS AT ALL WOULD NOT TRANSLATE INTO UNACCEPTABLE VIBRATION. IS THE MODEL A ENGINE SUPPOSED TO VIBRATE TO THE EXTENT THAT THE MOTOR MOUNTS ARE NECESSARY SO THAT YOUR TEETH DON'T RATTLE OUT? I THINK THAT SOLID MOUNTS WOULD RESULT IN A ACCEPTABLE LEVEL OF VIBRATION. THE MOUNTS MAKE FOR A SMOOTH RIDE. JACK

[Richard in Anaheim CA]

The early 28 Model A had a solid engine mount to the front cross member. That was very quickly changed.

All engines vibrate. Tight motor mounts do not "cause" vibration they dampen and isolate the vibration from the frame.

4 cylinder engines are the hardest to isolate vibration. Modern 4 cylinder engines have elaborate balance shafts to do the job. We are stuck with springs up front and rubber between metal mounting brackets.

Original springs in front are the accepted "best" to use. All the after market stuff has proven less effective.

Biggest problems with rear mounts is old dried out rubber and torquing the bolts down tight so the rubber can't do it's job.

[Bob C]

I agree with Bulligen, need to replace the spring on the front mount. Bert's sell the correctly made springs.


Bob

[Garagekulture13]

Just wanted everyone to know that I'm still here and listening. I will try the suggested asap and let you all know the findings. I really appreciate everyone's input.

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[Garagekulture13]

Update: just saw this. I went out to have another look at the front motor mount and I saw the crank pulley is rubbing. Not sure how this happened. Also all the copper dust in the picture is from the block sealer I ran through the motor as Antique Engine Builders recommends.

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[daren007]

Mounts don,t cause vibration.