Model A engine rattle

dynaflash_8

dynaflash_8

Member
So its been a while since iv posted on here, mainly because iv been driving my car everywhere. Well i went out to start the car this evening to go get a burger, and noticed that the engine was quite noisy. i know the valves rattle a bit (non adjustable) but it sounded like the bottem end was making a bit of noise too. I heard that the rods have shims that you can take out to adjust the clearance, iv just never done it. Whats the trick to doing so? I also run Valveoline VR-1 50 weight oil in it.

Marty .
 
1) drop pan
2) remove rod or main caps, do 1 at a time
3) plastigauge to check clearance, micrometer to check for out of round journal.
4) if shims are available remove to take up clearance, they should peel if laminated shoot for .0015, no less than .001 or more than .002.
 
INTERFERENCE FITTING OF BEARINGS

When I purchased my car the engine made a real racket especially after the Breakfast on the
beach run last year. I replaced the timing gear, (it was a real mess) and found this procedure on
the web. I have done it on the rods but not yet on the crank.
Mike Flanagan has posted his description of interference fitting of the main bearings in the
Model A engine. Because of the weight of the flywheel and the flexibility of the Model A crank,
plastigauge my not be a reliable method of adjusting the bearing clearances.
Here's Mike:
How do you check the clearance on the bearings? It is not QED but can be done if you can lay on
your back and work with oil and grit and grime falling in your eyes.
First you gotta drop the pan, let it sit overnight to get all the oil that will fall out to do so. You are
still going to get oily. Pull the damn oil pump out and lay it aside. You can shine a flashlight up
in there to see which way the tang is oriented to reinstall and with it out there won't be so damn
much blood on it to clean off it.
Then I start with the center main. This one requires that the valve cover be taken off as the nut is
in side there. The other nut is between 2 and three outside on the other side. Remove the cap
being careful to keep the shims on the same side as they came from. Visually inspect the bearing
for cracks and places at both the front and back that look as if it has been compressing the babbitt
and pushing it forward or to the rear. Bad signs if so. To check the clearance, use a piece
of aluminum foil .002 thick. The heavy duty she buys to do heavy-duty things is .002 but the
regular like you cook a baked potato in is .001 so you fold it. You want a piece as long as the
cap and about 1/2 wide. Lay this in the cap and with the SHIMS BACK IN THERE put the cap
back on and tighten it up. Now you want to see if the motor will turn with the obstruction in
place. Stick a 6" punch in one of the balance holes in the crank throw so the pull will be
consistent each time you check. You are looking for lockup with the obstruction in there and
free without. The shims are increments of .002 or .003 depending on which the rebuild used.
The steel shims are generally in .002 and the brass in .003. Peel 1 increment from one side at a
time, one from one side and if that doesn't lock it up then do one from the other side. Yes it
tedious; just be glad you didn't by a space shuttle. Once you get this bearing to lockup then
remove the obstruction and replace it and tighten it up again and see if it will rotate. If it won't
turn with the 6" punch then put that dame shim back in and run it another 3k.
Do the rear next then the front. The rods adjust exactly the same way. When you finally get a
bearing adjusted like you want it put some pre-lube (engine assembly lube) on there before
putting it on there for the last time. Torque to whatever you has been using (75 minimum) and
go. The rod nuts torque to 40.
To put the pan on there install the oil pump using a 3/8 fine thread bolt in the plug hole in the
side of the block to retain the pump while you install the pan. Finger tight as the threads are
actually national pipe threads but the bolt will work in there. Get some 5/16 all thread and make
yourself some cheaters by cutting 4 pieces 4 or 5 inches long. Screw them into the pan rail and
let 'em hang down. Slip the pan over them and start a nut. Then it is a matter of tightening the
nuts incrementally in turn and thereby winching the pan up against the spring on the pump.
The gaskets and sealer is a matter of choice but my opinion is that the silicone belongs in the
bathroom. I use permatex red personally. When you put it all back together put some of the oil
down the dist hole so the valve galley is oiled. It should not have lost any oil but I like to make
sure. Lotta work laying on your back
 
might try your timing pin turn it around and start the engine
press in alittle on the timing gear at idle
if the noise goese away you timing gear is loose
also you can short out is cylender witha srew driver and if the noise changes you have a loose rod or wrist pin
 
Are you sure that the crank is the source of your 'rattle' ?? As the others have mentioned, adjusting the clearance with the engine in place is one dirty/oily/PITA job..
Is this a noise that just started ?? Have you really pin-pointed the noise?? It may be any number of things, such as , something as simple as a cracked side pan or some other issue.. All I'm trying to say is that a little extra time finding the exact cause of the noise may make life a lot easier..
 
Patrick L. said:
Are you sure that the crank is the source of your 'rattle' ?? As the others have mentioned, adjusting the clearance with the engine in place is one dirty/oily/PITA job..
Is this a noise that just started ?? Have you really pin-pointed the noise?? It may be any number of things, such as , something as simple as a cracked side pan or some other issue.. All I'm trying to say is that a little extra time finding the exact cause of the noise may make life a lot easier..
Click to expand...

Im not actually sure if the crank is the sorce of my problem. I know i have some piston slap when the motor is cold. Just seems more noisy than iv ever noticed. I drive this car ALOT. 7 days a week if i can. I just am a little bit paranoid of the babbit i guess. :(
 
I would short out the cylinders as buzz desribed not too sure about shoving the timing pin into the fiber gear while the engine is running though.
 
Marty dont go adjusting things right away. I would wate a little what iv learned is strange noises come and go even though it may sound like its comeing rom your crank it could be play in a ****** bearing or something thats makeing noises you here. you might want to give it more time and do some more inspecting and perhaps get someone who knows As inside and out to listen to it and drive it before u do anything.
 
50-wt oil is pretty heavy for winter. I wonder if some things just aren't getting oiled properly.

Steve
 
Check the oil in the pan. Is the oil milky on the dip stick? This should be SOP before you start up the car for a run, along with water level in the radiator. Loosen the drain plug and see if there is water in the bottom. Oil thinned with water is not good for the motor And makes a hell of a knock. Bob.
 
Mike V.
You mentioned Mike Flanagan, what ever happen to Mike I never see any posts from him? He was a awsome character I spoke with him several times on the phone years ago and he seemed to know his Model A well..

Bill Stipe
 
If you want to be a real Model "A" Mechanic after checking the timing gear, drop the pan and have a look now before you drive it more and possibly cause costly damage. A loose bearing may not have broken and can be adjusted some but more pounding will break babbit for sure. If you don't like the sound look for the reason. An inexpensive mechanics stethoscope will point out the noise. take off the fan belt before using the scope you may find the noise at the fan or generator.
 
my motor starting kocking lightly. took the fan belt off, it still knocked ,tooked the timin g pin and pushed against timing gear (carfully)and it quit knocking. Tooked timing cover off and found that there was no camshaft thrust plunger and spring in it!! I put one in ,no more knock.
 
29 Red Rocket said:
Mike V.
You mentioned Mike Flanagan, what ever happen to Mike I never see any posts from him? He was a awsome character I spoke with him several times on the phone years ago and he seemed to know his Model A well..

Bill Stipe
Click to expand...

Mike died as I recall about 6 or 7 years ago. There were some heated words between Mike and a few posters, then Mike quit posting and not long after that I heard he passed away.
 
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