TR2/3/3A TR3/4 Cam Bearing Install

[TR4nut]

Got my 3A engine back from the machine shop after some balance work, and after cleaning the block up I attempted my first install of the cam bearings. I think this topic came up a while back so I thought I'd share some photos.

First step in this is join a club, then step two is make friends with one of the guys in the club that has an install tool similar to this one:

Just threaded rod, with some nicely turned aluminum mandrels that work all the magic.

Here's a shot of how the tool fits into the front cam bearing location:

The other end of the tool is used to pull the bearing into position:

And here is a shot with the bearing pulled in - the tool is sized just right that it also pulls the bearing out. The install procedure usually takes several tries to get alignment perfect so the removal is just part of the process.

Bearings were installed rear to front. The rear one went in with one try, the small middle one four tries, and the last one about eight before I finally figured it out. The rear bearing has 3 holes that are critical - the middle and front only 2. The front was tricky in that I picked the wrong 2 holes in the bearing to use to match up to the engine. If anyone else does this, its the oval hole and the small hole. A small mirror was invaluable to check fit, as well as a probe which in my case was a small allen wrench to make sure the holes were open:

Other the making sure oil holes are open, it is very important to make sure that the set screw fits in the bearing properly, otherwise you run the risk of distorting the bearing when you install the screw. I checked each bearing by threading in the screw and made sure it didn't bind - you can just see the screw poking into the bearing slot in this photo. This also shows why you better install the copper washer with the screw, otherwise the screw is long enough to foul the cam:

Other that being a little tedious, it was actually fun because the tool worked perfectly. I think I owe my friend a breakfast for letting me borrow it.

Off for some business in Calgary this week, then back to the install!

 

[TRDejaVu]

Great photos and description.

 

[TexasKnucklehead]

That "church-hill tool #MH-xx" was manufactured by the same person in the same club that loaned me his rear axle bearing removal tool. The advice that comes with those tools is... priceless. The BCF has been a huge help for my restoration, but the guidance and support from local club members is amazing. -Not excluding Randy.

I was lucky enough to not have to replace my cam bearings. I suppose there is an exception to every rule, as I can't think of another bearing that hasn't been replaced. Still, I'm glad Randy documented the procedure so when I do have to do it, at least I know who to ask.

Jer

 

[TR4nut]

The BCF has been a huge help for my restoration, but the guidance and support from local club members is amazing. -Not excluding Randy.

Tex-

Well since you are at least a couple months ahead of me, I'm not trying to support you at all, I'm trying to catch up! So while it may look like support, it just might not be!

Seriously, I echo the comments about this forum helping me, it really keeps me enthused about the hobby. And by virtual club I can take on the persona of someone who actually knows what they are doing. But the friends I've met in my local club have really pulled me through, and they know the truth better!

Randy

 

[tdskip]

Interesting thread guys - thanks.

 

[mallard]

Great work Randy and thanks for the pictures of the process. I took the easy route and had the machine shop install mine.

 

[BL50]

Anyone know where I can find the tool referenced in this post? Thanks!

 

[CJD]

I don't, but I have other ideas...

I have been known to make my own tool using a scrap cam shaft. I welded an old bearing shell onto the end lobe of the scrap shaft and drifted the bearings into place. Of course you have to start at the back and work to the front.

When I had a lathe, I would cut the parts for cam bearing installers I needed in about 30 minutes. That's about $70 in machinists costs if you farm it out.

 

[BL50]

Thanks. I've read about a number of do-it-yourself tools but I think I'll just try to find a machine shop that knows a bit about British engines!

 

[TR4nut]

Thanks. I've read about a number of do-it-yourself tools but I think I'll just try to find a machine shop that knows a bit about British engines!

That's a good idea unless you have a good club contact with the tool - John is right, the tool I used was home made, borrowed from a club member. I've considered having one made as it is quite handy when you need it, but haven't had the need yet to get it done.

 

[TR3driver]

I made one years ago, but I've managed to lose it. Probably in my Dad's garage some place. When the time comes, though, I plan to just make another one.

I've forgotten who it was, but someone on another site was just having troubles because the shop he used installed the bearings wrong. Having the tool is no guarantee of knowing how to use it.

 

[Jerry]

I can see installing the bearings, but many of the engines I have worked on required honing to make the cam fit. So how did you do that? My machinist has a hone that is lone enough for the engine and may be honing more than one bearing at a time to keep it all straight? I don't have one of those in my toolbox!
Jerry

 

[TR3driver]

Should be no honing required; the cam inserts are sized to fit from the box and don't fit the block tightly enough to deform during installation. That's why they have pegs to locate them.

 

[Jerry]

That make sense, but my machinist had one set that he had to hone. He was really ******!

jerry

 

[CJD]

I would be concerned about honing soft bearing material. The tiny chips of stone would likely imbed in the soft bearing, and later work against the camshaft. That's why most bushings (not cam bearings usually) are reamed after installation. I'm not saying for sure that it won't work, just a concern.