TR2/3/3A Replacing the cam shaft

[Nobbster77]

Well...you can change the cam bearings, but you will have to open the rear plug, so the tranny must be removed to do it for the rear bearing. That said, you should not have to change the cam bearings because of the bad lobes. The bearings receive clean, pressurized oil from the oil filter, so they should not be contaminated...and if they are contaminated, then all your rod and crank bearings will also be contaminated. Honing of the cam bearings will introduce grit and metal into the oil gallery, so I would not recommend that either, unless you plan to clean out the entire engine oil system.

I short, unless the cam bearings are notably bad, I'd run them Opps as is. They do not wear very fast, and even if they are worn, they were not the cause of the lobe problem.

Yep forgot it’s still attached to the gear box. It’s always hard discussion as to how far you go . I have finished rebuilding my 3A engine and found that the Cam timing was out by a tooth and a half from standard, which was apparently common. I pulled the oil gallery plugs and the was quite a bit of debris. The oil pressure was fine before the strip but the big end bearings were down to copper. Fitting a new timing chain and a vernier timing gear will help considerably but what ever you do don’t buy a cheap timing chain. I rebuilt a customers engine with a cheap Moss chain and had to replace it due to noise, fitted a Heavy duty one, no issues . Pulling the filter head and cleaning is a good idea. I would still undo a big end bearing cap and check the shells, as they can be changed with the engine in the car, the oil complete with metal from the cam world have been circulating through the bearings for some time. If you can get someone to operate the clutch while you are underneath, check for crank movement. If considerable you need to replace the thrust washers which can be done with the engine in place
Rgds

Steve

 

[CJD]

One more tip that you probably already know, Steve...What kills the tensioner (aside from bad material from many repros) is when the hardened chain links cut through it. The solution is to carefully sand the outside of the links smooth, where they have sharp edges from the stamping process. That will ensure a long tensioner life.

 

[Nobbster77]

That's a good tip as the sides of some of the tensioners are almost razor sharp. Again I'm not a fan of the Moss tensioner , they compress very easily. Would also recommend replacing the crank gear as they wear unevenly if the chain has stretched .It also helps loads when setting the cam timing as there is very little slack to compensate for but no previous marks to use when installing the cam.

 

[sp53]

The metal shavings mostly were in the bottom of the pan and in the oil filter canister. I have not looked in the peruse regulator yet. The shaving stuff looks different from the oil by its color. I can see the difference kinda clearly I think. I took the oil pump off and the oil pump looked fine inside and the oil around everything in the pump looked like clean oil. There was some of the shaving colored oil on the outside of the screen on the fixing end, and actually not much or any metal chunks on the oil screen. The stuff on the screen is mostly the red goop gasket sealer I used. I will get off the oil pressure deal soon and take it apart and clean it.

The cam bearings look like they should work out fine. They appear to be plenty thick enough without a bunch of deep scaring. I plan to order gaskets and other parts now that I feel better about the size of the pistons.

thanks for the support steve

 

[sp53]

What are your guys suggestions for oiling the cam before I install it. My thoughts are to use motor oil and spread it around throughout the area with my hands plus do the same to the cam by spreading an oil bath everywhere on the cam and surrounding areas. I have some break in stuff around here somewhere, but it might be old, but I guess it is oi----l and I think I used it last time.

Thanks steve

 

[CJD]

If you plan to start it soon, just straight motor oil is the way to go. If it will sit for some time, then use something like this, which is a really thick lube that will stay on the cam for a long time:

Amazon.com: Genuine GM Fluid 88862587 EOS Assembly Lubricant - 16 oz. : Automotive

Amazon.com: Genuine GM Fluid 88862587 EOS Assembly Lubricant - 16 oz. : Automotive

www.amazon.com

 

[sp53]

I started the car yesterday Feb14 and started the repair around Dec10. I let it run at 1800rpm for ten minutes and then drove it around the neighborhood and to the gas station. It ran excellent, so I pray this cam will work out. I am going to adjust the gas pedal some and drive it more like John suggested. I should know in a short time if the cam is a keeper.

When do you guys think I should adjust the valves again?

On the Ford truck forum this guy with a new high dollar 390 took all the precaution and had a cam failure. He went through all the stuff I did before figuring out it was the cam. Those guys took a while to find it and figured it was fuel, a tooth off, or distributor advance. In the end they blamed the way out of town manufacture. The one thing I had in common was he need a higher idle to drive it. This time with the new cam my idle is stronger, so I am optimistic.

steve

 

[CJD]

Outstanding! Just in time for the spring driving season too.

Oh, forgot...anytime between about 100 and 500 miles on the tappets.