Camshaft Bearings

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Model T Ford Forum: Forum 2013: Camshaft Bearings
Top of pagePrevious messageNext messageBottom of page Link to this message  By Rob Hughes on Thursday, June 27, 2013 - 09:37 pm:

Newbie here back at it...This afternoon I went to install my new roller timer I ordered from Langs. I had purchased a flapper time before from Langs but the car would barely run, so I put the old roller timer back in....Well now I know why it wouldn't run with the flapper timer, the camshaft moves up and down a lot! I think my bearings are shot on the camshaft. The engine makes a rattling noise when running so I am guessing this is where it is coming from. It has so much play as I am now scared to crank it much less drive it. I have my Ford Model T service manual which details the job, I have read the instructions several times over. My question is, is this a pretty straight forward job I can do on my own? Do I need to take the camshaft to a professional rebuilding shop and have it checked out while it is out of the car? I have basic hand tools, no special pullers/presses. Do I need those to do this? Any help or advice is greatly appreciated. Thanks, Rob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Friday, June 28, 2013 - 03:48 am:

It's pretty straight forward, but you need a couple of special tools, one for the camshaft nut holding the large timing gear: http://www.modeltford.com/item/3050BT.aspx
(It's a bit pricey for my frugal T mind , I was lucky & found an old wrench I could file to both fit and reach those nuts :-) )
and some type of lifter for the valve springs so you can pull the valves. The valve springs are much softer than modern equivalents so you can probably fab something up yourself to lift them - imagine some type of fork grabbing the valve spring keeper hinged from a hook up to a manifold stud, when you push on the outer part, you lift the spring. http://www.snydersantiqueauto.com/454

You would also need a suction cup on a pin and lapping compound for lapping the valves while they're out - perhaps you still have original two piece valves, then it's time to change them out to moderns before they break in service, ruining your day.

Anything can fail on a T after a century, but in my limited experience rod and mains fail long before the camshaft bearings, maybe some earlier owner overlooked the camshaft bearings when overhauling your engine? You need to look carefully when it's apart for other parts that may need attention. First you have to pull the radiator and the fan belt pulley on the crank shaft to get the timing cover off. Take pictures & show us - it's always fun to see T photos :-)

With the timing cover off, you can (besides the cam shaft issues) see if there is any flow of oil through the internal oil pipe - often it gets clogged by band lint and causes all sorts of bearing trouble in the front of the engine.
Just crank the engine swiftly and see if you get some oil flowing in the lower part of the big timing gear.

When you have the cam shaft out (hold the lifters up with clothespins or some other type of clamps) you can check it yourself with a caliper for wear of the lobes - there used to be .250 difference = lift between the lobe and the base circle of each cam lobe. It's easy to pull the clamps holding the cam shaft bearing halves together - usually the bearing surface on the cam isn't all that bad. There are slightly (0.003") undersize bearings available to compensate if the shaft is worn.

There are lots of other things to consider - this may turn into a complete overhaul of your engine, but you can start with pulling the timing cover to check and later the head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rob Hughes on Friday, June 28, 2013 - 07:34 am:

Thanks for the reply! I am pretty sure this motor was overhauled in the 70s when my grandfather owned it, at the time he may have not replaced the camshaft bearings if they were in good shape. It appears I need at least the two special tools you mentioned above. As I don't have a caliper I think I will take the camshaft to an engine shop and let them tell me if I need standard/undersize or oversize bearings. Also, to make sure the camshaft is straight. Since the engine doesn't smoke and has good power I am hoping everything else is ok.d


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Hatch on Friday, June 28, 2013 - 08:59 am:

Rob: PM me, I can hook you up with a friend close to you that may be able to help you. I am in B'ham AL. Dan


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, June 28, 2013 - 09:46 am:

The new bearings will be slightly out of round, which is not a good thing. They'll need to be pressed round, like this:




Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Thode Chehalis Washington on Friday, June 28, 2013 - 11:30 am:

What about the rear camshaft bushing?

Does anyone have a photo of a puller?

Would it make sense to only replace the middle and front bearings and not worry about the rear bushing?

What about line boring the cam bearings? Is it really required to make an improvement?

If the front bearing is badly worn, as in this case, what is the likelihood that the rear busing is just as bad?

This could easily turn into a whole engine tear down and rebuild. Maybe the question would be, why not just run it like it is? I have not heard of a catastrophic cam/bearing failure, they just make some noise and the timer rotor jumps around some but Model T's just seem to keep chugging along no matter if the cam bearings are tight or very loose.

I would be interested in other experienced opinions.
Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Friday, June 28, 2013 - 11:41 am:

Are they making good camshaft bearings? I've not heard anything positive. I really like that press fixture that Steve posted, but why should we have to do this?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rob Hughes on Friday, June 28, 2013 - 11:45 am:

Jim,

I would definitely replace all three with the camshaft removed. I can only assume the other bearings are badly worn as well. I would think if anything else was wrong (bad main bearings/bad valves/anything else) the motor wouldn't run so well, but the motor runs pretty good considering I have a 1/4" of play or more in the camshaft. And its noisy like a rattling sound. I did install an outside oil line with a sight tube so I know its getting oil. Its just a little scary to see the end of the camshaft able to move like that. From what I can tell looking it appears to mainly move up and down not in and out. The sound is worse at idle and revving in low gear or reverse. Once you get her in high gear she just chugs along. I would hate to have to tear the whole engine down if I just need new camshaft bearings...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rob Hughes on Friday, June 28, 2013 - 11:48 am:

That was my other question, where would you get good quality cam shaft bushing that would not require a machine shop to modify for fitting....All that being said, I trust the forum members opinion, if ya'll tell me it's ok to run as is, I will run it. I can stand the noise, but can't stand the thought of doing catastrophic damage to my granddad's car...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, June 28, 2013 - 12:15 pm:

"Larry, we shouldn't, but we do.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, June 28, 2013 - 12:51 pm:

Another thing to check, make sure that the bearing has been bored on center. There are some out there that were bored off center. Along with the ones that the outside diameter is too small as talked about in another posting, I think they were .014 under sized.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Bamford, Edmonton AB on Friday, June 28, 2013 - 12:58 pm:

If you want to spend a little more but end up with a better engine, consider one of the replacement camshafts from Chaffins in CA. The advantage there is that Chaffin's will not only also sell you the bearings (of course) but will for a very modest charge, lap them in to your new cam's journals. I did this when I replaced the cam in my '24 Speedster with one of their 0.280 performance cams.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Thode Chehalis Washington on Friday, June 28, 2013 - 01:32 pm:

Here is past threads on in car rear bushing replacement.

www.mtfca.com/discus/messages/179374/234299.html

http://www.mtfca.com/discus/messages/118802/120939.html?1263428638

Bottom line, some say it may be able to be done but no one said that they have done it or showed the tools used.

More on cam bearing fitting at:
http://www.mtfca.com/discus/messages/50893/69190.html?1224785762

Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Friday, June 28, 2013 - 01:36 pm:

Rob

Wow! 1/4" of play ? If that's right, your bearings arn't worn, their non existant!

I would not even think about running the engine again until the cam bearings are replaced.

As far as the camshaft itself goes, it should be checked. Buy a caliper - not that expensive and a good investment.

And remember, as far as high lift cams go, thy're fine, but they increase HP. Increased HP (if its used) slightly increases your chances of joining the two piece crankshaft club.

Good luck!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, June 28, 2013 - 03:03 pm:

There is information here that should be corrected.

End play on a new cam bearing should be .002 to .002-25 thousandths, period, any larger, you have add, wear clearance.

Shaft clearance is the same, .002 to .002-50, no more, and no less, or you have, wasted clearance.

The problem with pressing the out side of the bearings, to make them round is the bearing after it is machined, will distort.

How ever much you move the bearing on the out side, say .002, the inside will be moved that much also.

Now on the newly made cam bearings that are being offered for sale, they are all smooth inside with out the 4 key grooves that are in the Ford bearings. So the only thing holding the babbitt in are the two holes that are drilled in the sides, and fill with babbitt.

Now the 3rd thing that is wrong with that, the babbitt along the part lines has nothing to key into, so when the bearing is broke open with the coal chisel, the babbitt on the sides of the part line, comes in and makes the hole smaller.

Also, when you static pour a cam bearing as it is made of cast iron, the babbitt when cooling will pull away from the shells wall, and the babbitt will be loose in the shell.

If you spin pour, the shell stays hot until the babbitt hardens, and is pushed hard to the shell, and will stay tight.

Rear cam bearings offered now, are no good to use, as they are oil lite. In reality, they are way to soft. There are no oil grooves, and indention to catch the oil, and to big for a wore cam.

At the time of grinding a cam, we always have the grinder regrind the mains , and front thrust true anyway.

In my opinion, money wise, your far better getting a new cam anyway.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, June 28, 2013 - 05:07 pm:

The 3rd line in the last post should read .002-25, not .002-50.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Friday, June 28, 2013 - 05:08 pm:

Herman, Our rear cam bushings are brass, not oilite. We offer them in stock size and 0.010 under for worn rear cam bearings on original or reground cams. I always check cam bearings in the block before installation on the cam. There are small variations in the diameter of the new cam bearings and sometimes large variations in the diameter of the cam bearing holes in the block. Especially the front bearing. Everything should be fit before installation.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, June 28, 2013 - 06:12 pm:

Never seen your bushings Glen. But the ones that have come through here in the last 5 years were oil-lite.

A lot of the machine shops that send in cams to be fit with Bearings, there is not much I can do with that, but if I have the block, then I try to prefit also.

Do your rear cam bushings already have the groove, and oil catch?

Years ago who ever was making them, they came at .005 under, and were made like they should be. But they quite, and that is when I started making my own.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Friday, June 28, 2013 - 06:22 pm:

Herm, We make them from stock brass bushings, Yes, they have the oil groove and notch. This is not an item we make for resale but I could look and see what we can do. Some items we make just for our own use because we are unhappy with what is out there like you.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, June 28, 2013 - 08:08 pm:

Yup, we have been making our own since they quit also out of old triple gear bushings.

This is the collet my brother-in-law made just to hold cam bearings, all hand made. It holds the cam bearing as a whole on the out side, and it runs true center where the collet grabs the bearings.

It has had thousandths of cam bearings run through it, as you know Glen.




Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Friday, June 28, 2013 - 10:08 pm:

Herm,
What's the last picture showing us? An automatic stop switch on your lathe set up?? Looks like some hard Babbitt shavings there--so good bearing stuff!
BTW, nice collet set up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, June 28, 2013 - 11:50 pm:

Ya Dave, I don't have to stand and watch it. I can work on other jobs besides. It has save spoiled work many times because of phone calls.

Herm


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