Can bad lifter(s) cause low oil pressure?

x2 while the crank and rods are at the machine shop, check cam bearings and galley oil plugs....

 

I think the plan right now will be to do the best I can with the engine in the car, emery cloth on the crank and change out all the bearings... If that will buy me some time I'll have the car back in service while I start fresh on another block that's not bored to the limit, maybe a roller, and I won't be under any constraints as far as schedule. I can put it all together from bare bones as time and money permits, then I'll have a fresh new bottom end waiting for whenever I have a chance to swap it out.

...or if new bearings doesn't do the trick then I'll just have to park the car and start on that new bottom end much sooner. I just don't want to be taking a .060" over block to a machine shop. If I'm going to invest in a full rebuild I would rather start with more metal, wouldn't y'all agree?

The difference is going to be, if I can give myself the time then I'll have a lot more options on the new build. But if I have to do it any time soon I'll be doing it as cheap as I can, and that's what got me into this mess in the first place.

This is the price (well one of them) of using your hotrod for a daily driver...

 

your plan should give you your oil pressure back. i would definity mike the crank and rod jounals and the rod bores incase they have been resized. then you will be able to get the right bearings.
the one other possibilty but i doubt its the problem is that the cam plate is put on backwards. it has an ear on it that blocks off an oil passage and routs oil up to the cam. it will result in about 15 psi of oil pressure. i know this because that was the problem in the motor that came in my maverick when i bought it.

 

Yes, I agree, for what it's worth.
I use mine for a daily driver as well and that was the deciding factor on the front end rebuild or M2, or strut susp. I am rebuilding because I don't have the down time to cut out the front end.

 

Hm. About that cam plate... I remember putting that on. You say if that's on wrong "it will result in about 15 psi of oil pressure." If I have 65 pounds of pressure at cold start, does that pretty much rule that out? I'm guessing that condition would gush oil and wipe the cam bearings pretty fast, right? Even when my oil pressure is at its worst, it never goes below 10 PSI for every 1k RPM. Should I be concerned about the cam plate?

 

the colder oil would create a higher pressrue. i never saw beter than 25-30 out of that motor. the pressure would drop as it warmed up. it never made any ticking or knocking noises. you would need to pull the timing cover off to check. i would get the new bearings in and if that doesnt fix the problem (you needed bearings anyways) then pull the cover and see if the plate is on correctly.
the oiling system is pretty simple. the last thing i would look at is the cam bearings. you might be able to see them from under the car while you have the pan off. well you should not be able to see them. take a flash light and shine it up into the motor. you should able to see the cam. look at the bearing journals and see if any of the bearings have been pushed out of the block.

 

The cam spins at half the speed the crank does. I doubt the cam bearings being worn out caused the wear to the rods and mains. As I stated before, cam bearings very seldom (if ever) wear out in normal service. If and when they do, you can bet something other than them caused it to happen.

 

im not implying the cam bearings are worn. im saying one or more may have been pushed out when the cam was being put in the block. its a long shot but a possibility.

 

I still haven't had time to do anything more with this, but I'm ready to buy my bearings at least. I sent the following email to Mahle/Clevite:

And this was the response:

So I'm gonna go see if I can find a micrometer at Harbor Freight or Northern Tool. Just need to determine the stock journal size and compare I guess.

 

A decent micrometer is a good tool to have anyway, then at least you'll know what you have.

 

I agree. Went and got one during my lunch break, but unfortunately the 4" caliper I bought isn't quite deep enough. Need to swap it out for a bigger one...

 

When I do this, is there an advantage in using bimetal/aluminum bearings vs. traditional trimetal like the Clevite 77's that came out of it? Is one or the other any more or less tolerant of surface imperfections in the journals? Is one or the other any easier to install by "turning in" or less likely to get messed up in the process?

 

The center bearing with the flange on it is called the thrust bearing...The flanged surfaces limit the cranks back and forth movement in the saddles. This has a specific dimension also...Referred to end play/crank thrust, a good dimension is between 5 and 8 thousanths. Any less is too tight and more than 8 is too loose. Keep this in mind when you re-assemble.

 

My neighbor is a machinist, I'm lucky.

 

Alright, so I can't measure the journals yet, but I can measure the bearings I took out.

The thrust bearing is right at 3.00" and that's the one where I still can see some plating, so I'm pretty confident that's going to be stock sized.

The other main bearing I pulled is 3.001" give or take a thou. That one has plenty of wear on it, but not at the edges where I measured.

So I can assume (although I'll measure the journals when I get the right tool) that this was a stock sized main bearing set and the .020" stamped in the thrust bearing was in reference to the thrust surfaces, not the main bearing. But this confuses me... The width of the thrust surfaces, which don't seem to have much wear compared to the main bearing surfaces, is 1.130." I see that stock size is 1.133" right? So why is that bearing marked .020"?


Now the rods... Stock rod journal is 2.311, right?

Here's what I've measured on my rod bearings. (I've only pulled 7 halves)

2.331" (This is the cleanest looking one I have)
2.330" (Also a pretty clean one; no copper showing where I measured)
2.331"
2.304"
2.304"
2.302"
2.302"

This confuses me. There's as much as .030" difference between some of these, but the ones that show the most copper are the ones that measure a smaller inside diameter. Is it possible that the "clean" ones have actually just worn all the way through the copper?


...Nevermind. I think the "bigger" ones must have flexed out some. Or the "smaller" ones bent in. Who knows. I guess measuring these rod bearings is actually pretty useless.