My first 74 2.7 rebuild: are these bearings shot??

[marlinaness]

I building a 2.2E out of a 74 2.7 that had been rebuilt by somebody else. 1st time opening the cases. Are these bearings bad? Do they need replacing? Can I keep the big bearing? Can any of the experts provide any additional guidance on what you see here? The pistons had a few cuts from the valves on one side only, but the valves looked ok. Will be replacing all of that with 2.2E cams, pistons, and cylinders.

thanks again Marlin

[Lapkritis]

That far in... cheap insurance. A couple of those with the wear marks, specifically the flywheel end, would probably not plastigauge out.

[Henry Schmidt]

Originally Posted by marlinaness

I building a 2.2E out of a 74 2.7 that had been rebuilt by somebody else. 1st time opening the cases. Are these bearings bad? Do they need replacing? Can I keep the big bearing? Can any of the experts provide any additional guidance on what you see here? The pistons had a few cuts from the valves on one side only, but the valves looked ok. Will be replacing all of that with 2.2E cams, pistons, and cylinders.

thanks again Marlin

The bearings don't show abnormal wear but replacement makes sense.
Check to verify that they are not line bore bearings. If they are, replacement can be expensive and at times difficult to find. EI: .010 line bore with .010" crank is very hard to find.
If you know the history (mileage and use) you might consider dressing the bearings and having them dry film coating. New Glyco bearings are lower quality than previous versions so saving older (in spec) bearings sometimes makes sense.

The big issue you will have if you're planning to make a 2.2E out of a 2.7 is the spigot size. The bore in the 2.7 spigot is 5mm larger than the 2.2 cylinder spigot.
We have a system for converting a 7R case to small spigot so if you want to talk, I am generally available to talk. 7-5 tu-fri.

[Mr Beau]

Isn't there copper showing on some of the bearings? Those definitely need to be replaced, and you have to figure out why there's such heavy contact (e.g. warped case, bent crankshaft, etc).

[dtw]

Originally Posted by Mr Beau

Isn't there copper showing on some of the bearings? Those definitely need to be replaced, and you have to figure out why there's such heavy contact (e.g. warped case, bent crankshaft, etc).

You're seeing copper on the intermediate shaft bearings, which seems to be pretty 'normal'.

The thrust bearing wear suggests checking the main bore for straightness (to me), but I think that's called for on just about any mag case rebuild.

[304065]

For a quantitative approach you can mic them with a ball end anvil on the mic to fit in the curve. Of course you would zero the mic on the anvil with a standard first, then measure at a few points.

[KTL]

Does the #1 bearing get more than it's fair share of abuse due to the flywheel & clutch hanging on the end of the crank, as well as seeing the shock loading from clutch work? Isn't that why it's wide, grooved and has thrust surfaces on both sides?

[Walt Fricke]

#1, like the IS thrust bearing, always seems to show some copper or whatever. But somehow that doesn't seem to lead to real problems, unlike rod bearings showing copper.

I wonder how many of us have replaced all the bearings because we were in there, the motor had run for some time, and some rod bearings were bad enough that there was no question about them? Perhaps that is why you seldom see the mains in really bad shape? Because the rods were so everything got replaced?

Glad to see Henry has thought about something which occurred to me: bearings not new, but not looking bad, so can they be coated. Sounds like the answer is yes. I've got quite a few OK looking main bearings in bags from rebuilds. I should send a set or two off to Calico.

The one bearing you should keep and shouldn't need to worry about is the #8 nose bearing. Absent running with zero oil or something equally bad, it normally doesn't wear. And costs a fortune to replace.

[marlinaness]

Well, I talked with Henry and was enlightened. I am still in discovery and discovered that I had the wrong 2.7 case. I did have a spare 2.4 7R case which I will be using. I was checking the parts out and discovered the 7R case had 2.2T pistons. When I checked the wrist pins on one of the Mahle 2.2E pistons, it was a definite way tooooo tight fight. I had hoped to use the 2.7 crank and rods with the 2.4 7R case and the 2.2E pistons. So, somethings not right with the rods or the pistons. Time to keep researching.
thanks
Marlin