Engine bearings.

[Smallfry]

Something interesting for all you mechanics regarding an MGB engine I have just bought, and am refreshing.

Looking from the rear main. You will notice that bearing shell does not have a hole to line up with the main oil feed, only one hole that aligns with the feed to the camshaft bearing, so the oil for the rear crank journal will have to feed along the groove in the block, then through the hole in the shell. I think the shell should have two holes.

The front and centre bearings (5 main bearings) are the same ! Notice the tags on the shell. The shells cannot be fitted any other way.

Now look at number 4 bearing. the hole in the shell aligns with nothing, and the shell actually BLOCKS the oil feed completely

Number 2 bearing is the same. Again, the shells cannot be fitted any other way. I did check the shells in all the caps, to see if they were different and have been installed incorrectly, but they are the same.

This means that number 2 and 4 have been getting NO pressure lubrication ! I did look at the crankshaft to see if the journals were fed by drillings, but NO ! It appears that these journals have been oiled by splash only ????

SURELY this is utterly wrong and the wrong bearings have been fitted, or am I missing something here ?

Curiously the crankshaft does not seem to be any worse for wear.

 

[minimutly]

Maybe someone fitted o or m or t series bearings? They are dimensionally the same, I've never compared oilway drillings though...

 

[Smallfry]

Maybe someone fitted o or m or t series bearings? They are dimensionally the same, I've never compared oilway drillings though...

Thats interesting, and probably what has happened. I can't believe that someone would put it together with the oil feed blocked though

 

[jo1010]

Are all the King brand bearings wrong......just had a quick look to see what they had and they do indeed have single holes. The old AE bearings have two holes of course as below
Recently I've seen some modern bearings with the cam oil feed restricted (using smaller diameter bearing hole) - the logic being that a smaller hole will increase oil pressure to the cam! My thinking is that the flow might well be reduced. - and in your case non existent!

 

[dave h 2]

Having been the victim of someone increasing oil pressure by shimming the oil pump by-pass spring with a chunk of random steel sheet behind the ball -( great till it jammed open and cost me the crank.) I'd believe rebuilders capable of anything.

A smaller hole on the cam feed will increase pressure between pump and restriction, might be useful for using modern thinner oils, but the restriction might give hydraulic lifters a bad time.

Ps I once had a ford v4 with a top end knock that turned out to be a piston marked +10 measuring as standard.
Moral - don't trust anything.
In this case check the crank size matches your new bearings.
There's a suspicious rub mark on the block thrust bearing position as well as the rear shell uneven scuffing.

 

[Tinbasherdan]

Ps I once had a ford v4 with a top end knock that turned out to be a piston marked +10 measuring as standard.
Moral - don't trust anything.
In this case check the crank size matches your new bearings.
There's a suspicious rub mark on the block thrust bearing position as well as the rear shell uneven scuffing.

I can beat that, had a Daimler dingo brought to me as it had bingo oil pressure and was smoking like a train.

Rebuild plate stated +020 bores
Pistons were stamped +030
Rings were std

Took sump off (dry sump) and thought it looked a bit of a grotty casting, what it actually was was 40mm of sand lining the bottom. Oil feed and scavenge pumps were absolutely goosed, big ends looked all right but mains were a bit sus. Gave it up as a bad job after spending 2 months trying to source bits for it, won’t ever make that mistake again

 

[dave h 2]

Some national service conscript tried to kill that one back in the day.
Top trump you win

 

[Smallfry]

Some national service conscript tried to kill that one back in the day.
Top trump you win

But wait ! I have mentioned this before, but my dad bought a Ford Pilot when I was about 6 or 7.

It never ran properly, and I remember mum being called to the garage to look at what he had found. He had taken one of the heads off (V8) and found a block of wood where a piston should have been. Its conrod had been cut down to make a spacer on the crank journal.

He put it all back together and sold it.

 

[Cobbler]

I’ve heard similar tales on a 6 cylinder Ford Zodiac, running on 5 cylinders, the new owner found a wood plug stuffed into the plug hole. He removed it & fitted a spark plug & started it. It still ran on 5 cylinders ….. for a moment, a big bang & blew the sump off. There was no piston or rod in the bore!

 

[8ob]

I’ve heard similar tales on a 6 cylinder Ford Zodiac, running on 5 cylinders, the new owner found a wood plug stuffed into the plug hole. He removed it & fitted a spark plug & started it. It still ran on 5 cylinders ….. for a moment, a big bang & blew the sump off. There was no piston or rod in the bore!

A mate of mine had a slug of a v6 Capri, loads of swapping around of parts never improved it. Turned out to be running a short stroke crank out of one of the smaller v6 engines., pistons never made it anywhere near the top of the bore , must of been running about 4-1 compression ratio

Bob

 

[Bornfree]

A mate of mine had a slug of a v6 Capri, loads of swapping around of parts never improved it. Turned out to be running a short stroke crank out of one of the smaller v6 engines., pistons never made it anywhere near the top of the bore , must of been running about 4-1 compression ratio

Bob

At least it would have run on 2 star petrol

 

[jmp49]

my "engine rebuilders" story... Years ago, I got roped into helping put a engine into a old bremmen era 310d merc pickup still in commercial use daily by a pallet yard that shared part of a yard with a commercial garage attached to a transport company that I had a summer job at. It had starship miles on it and was tired to say the least, and the company paid for a remanufactured engine from a "proper" company out of the autotrader, we put it in and it was terrible, smoking, a sod to start etc, worse than the original. So we pulled the new engine, and I was to go with the owners to take the engine back.
We drove to some place near Leeds from Cheshire that turned out to be a chicken farm, knocked on the door confused, and was directed to a chicken shed.
In there we found a load of kids about 13-14 smoking fags, ankle deep in sawdust and chicken crap and a series of badly list old benches with nests dotted round randomly between lumps of dead engine and a wash area outside that was filthy too. This was the "rebuild" room apparently.
The merc owner turned to me and said "what do you think..." and I said "I think we just get your money back whatever it takes and find somewhere else" which he did & ended up putting a used motor in from a scrapyard.

The memory & smell of that workshop has never left me decades later...