Main Bearing Caps

[Ianashdown]

My engine project has aftermarket steel main bearing caps and the markings on then is quite ambiguous, there is no Front Arrow. It had been previously disassembled and the caps had been replaced inconsistently.

My question is: Should the main bearing tangs be on the same side or on opposite side of the crank? It seems there is no consistent practice manufacturer to manufacturer, or so I’ve read. There are no obvious witness marks on the block or cap, but these will have been line bored in a specific location so it important to get them back correctly.

I’d appreciate any guidance from those that know! Failing that, I do have a stock 120E engine that I could pul a main cap to observe the tang setup. I’d rather not though.

Thanks,

Ian

[2cams70]

The tang cutouts sit opposite either side of the centre line of the block. That's only part of the puzzle though as you'll still have to determine which cap belongs to which bearing in the block

[nmauduit]

Sounds like you're going to spend an afternoon with plastigauge to sort out how best to install the caps back...

[Ianashdown]

That you for confirming what I previously believed. It seems logical, but I saw that other manufacturers specified both on the same side. Strangely I have not found any reference in any book or manual I have, only to put the arrow forward on the standard caps. Fortunately the caps and block are numbered, so their location is clear. Both the block and the caps are stamped with Q and the number. Anyone know a shop who uses the letter Q?

Back to the garage!

Ian

[pharriso]

Anyone know a shop who uses the letter Q?

Back to the garage!

Ian

QED?

[rgh0]

All the Ford 1500 blocks I have, come with the cutouts for the bearing tangs for both block and cap on the same side of the block ( the right hand side)

cheers
Rohan

[2cams70]

Thinking about it Rohan could be correct. It was late at night when I went into the shed after having a few wines and with the engine lying on it’s side I may have mistaken the rear of the engine for the front when I was looking at it. I’m out today and can’t have another look until tomorrow. At least it might become two things Rohan and I can agree on - that is main bearing cap orientation and original Bosch inertia starter motors being better than the rubbish you get nowadays. See 512BB you are wrong - us Australians can agree on some things.

[Phil.C60]

Rohan is, as ever, correct. Both cutouts for bearing tangs are on the same side. As for
R which cap goes where….centre and rear are obvious, the others it’s trial and measure….

[Ianashdown]

I’m heading out to the garage to see if I can see witness marks to confirm this conclusion. If all else fails, I’ll pull the sump and one bearing cap of my un-molested 120E.

Photos to follow.

Ian

[512BB]

'See 512BB you are wrong - us Australians can agree on some things'

Yes, keep it up lads. Your mental ages could soon match you're shoes sizes & boom boom, then

L

L means leave off, I am enjoying myself

[rgh0]

One potential issue is that whoever machined the steel caps might have got it wrong

I would check clearances and alignment very carefully

cheers
Rohan

[Ianashdown]

My faith in engineers is restored. Oh, wait . . I am one. Never mind.

The caps are stamped in a correct and logical way. I was just confused because I did not expect the tangs to be on the same side.

Once the tangs are all correct the stampings on the caps are on the same side as the stamping on the block.

Ian

[2cams70]

'See 512BB you are wrong - us Australians can agree on some things'

Yes, keep it up lads. Your mental ages could soon match you're shoes sizes & boom boom, then

L

L means leave off, I am enjoying myself

Rohan is, as ever, correct. Both cutouts for bearing tangs are on the same side. As for
R which cap goes where….centre and rear are obvious, the others it’s trial and measure….

Not amused

[512BB]

Neither am I.