Best way to be sure middle splayed main caps are on correct!

[NXBOY]

Got a DOVE block that I had 4 bolt splayed caps put on about ten yrs. ago and there numbered but no arrows and the numbers faces different direction then front cap letter. I'm hoping that the first cap has the taps on same sides and thats how theses are suppose to be. Will have to check the parting line if can't tell will get a dial bore gauge. Does it even matter if shop put bearings tabs together?? Hate calling and asking since its been this long, ran great but set apart to long lol. Maybe there is a method shops use that I'm not sure of. There definatetly getting arrows.

[SupStk]

I would hope a shop competent enough to install caps would install the tang notches on the same side. But then I would assume they would of marked them too. Since the middle cap has the thrust bearing that just leaves two. If you look closely the honing marks are unique on each position, sort of like finger prints. Match them up and you should be good. The final word is what the dial bore gage says.

[NXBOY]

Their numbered but face different direction then front cap number, also arrow points forward but numbers reads to the back on center three back. I would of numbered them the same direction as to read as factory or put a dot towards the front. But Sounds like the tabs together is the main thing. Will look at hone marks tomarrow. Thanks

[Frankshaft]

In theory, it shouldn't matter. If it was done well. The line bore and then line hone, should have all the mains in alignment, and the same size, so, they should be able to be anywhere. But, tang to tang. You should be able to feel, and then measure, to tell where they go.

[Walter R. Malik]

Measure the main bores.

[Cubic_Cleveland]

Their numbered but face different direction then front cap number, also arrow points forward but numbers reads to the back on center three back. I would of numbered them the same direction as to read as factory or put a dot towards the front. But Sounds like the tabs together is the main thing. Will look at hone marks tomarrow. Thanks

Am I reading this correct? The caps are numbered and there’s a arrow on them?

What’s the confusion????

[Dave Koehler]

In theory, it shouldn't matter. If it was done well. The line bore and then line hone, should have all the mains in alignment, and the same size, so, they should be able to be anywhere. But, tang to tang. You should be able to feel, and then measure, to tell where they go.

Sorry Bud, it does not work that way, especially if it is an oem block.

Arrows go forward. Can't say I have ever seen a case in automotive or otherwise where they point to the rear.

[peejay]

In theory, it shouldn't matter. If it was done well. The line bore and then line hone, should have all the mains in alignment, and the same size, so, they should be able to be anywhere. But, tang to tang. You should be able to feel, and then measure, to tell where they go.

Sorry Bud, it does not work that way, especially if it is an oem block.

Arrows go forward. Can't say I have ever seen a case in automotive or otherwise where they point to the rear.

I disassembled an Audi cylinder head that had a couple of the cam caps installed backwards on the machining line. The bolts are offset enough relative to the cam bore that there was no way you could put it on "correctly", and the oil staining witness marks agreed that the head spent its whole life with some of its cam caps pointing the wrong way. I knew it was supposed to be like that but I cringed every time I looked at that head!

Speaking of which. Some engines have what looks to be an arrow but is actually supposed to be a crankshaft with a flywheel on it. If you interpret that as an arrow, then it means that end goes towards the flywheel. (And on old ACVW engines, then that would coincidentally enough be the front of the engine)

As far as THIS engine goes. I have never seen a block with "PERFECT" main cap registers. If you put a cap on backwards the bore mismatch should be plain to see with the naked eye. At the very least you could feel it with your finger. And if you can't feel it with your finger... does it matter? IIRC one's fingertips can feel a step height change of .0002". Two ten-thousandths.

[NXBOY]

The original cap still being used have a arrow. The Milodon center three only have numbers. Best to be safe then sorry , thanks.

[Cubic_Cleveland]

The original cap still being used have a arrow. The Milodon center three only have numbers. Best to be safe then sorry , thanks.

Ahh that make more sense!

[Dan Timberlake]

A bunch of years ago BMW cars and cycles were unusual, in that they had the bearing tangs opposite sides of the bore, like was common in aircraft, at least on the con rods.

Ses fif 13. on page 6 here -
https://www.lycoming.com/sites/default/ ... cation.pdf

I have no clue what they do these days.

[modok]

They go on whatever way they were on there when it was machined.

Usually, bearing tangs on the same side, but that isn't an absolute rule.

If in doubt, bolt them on and measure.

[pdq67]

In theory, it shouldn't matter. If it was done well. The line bore and then line hone, should have all the mains in alignment, and the same size, so, they should be able to be anywhere. But, tang to tang. You should be able to feel, and then measure, to tell where they go.

Sorry Bud, it does not work that way, especially if it is an oem block.

Arrows go forward. Can't say I have ever seen a case in automotive or otherwise where they point to the rear.

I disassembled an Audi cylinder head that had a couple of the cam caps installed backwards on the machining line. The bolts are offset enough relative to the cam bore that there was no way you could put it on "correctly", and the oil staining witness marks agreed that the head spent its whole life with some of its cam caps pointing the wrong way. I knew it was supposed to be like that but I cringed every time I looked at that head!

Speaking of which. Some engines have what looks to be an arrow but is actually supposed to be a crankshaft with a flywheel on it. If you interpret that as an arrow, then it means that end goes towards the flywheel. (And on old ACVW engines, then that would coincidentally enough be the front of the engine)

As far as THIS engine goes. I have never seen a block with "PERFECT" main cap registers. If you put a cap on backwards the bore mismatch should be plain to see with the naked eye. At the very least you could feel it with your finger. And if you can't feel it with your finger... does it matter? IIRC one's fingertips can feel a step height change of .0002". Two ten-thousandths.

Years ago at W.A. Shaeffer Pen, Ft. Madison, IA, an old Master Machinist told me this and then showed it to me!!

pdq67

[modok]

Your finger cannot feel the difference between a step and a burr. If the corners are chamfered, as many believe they should be, makes it difficult to feel also.

But PROBABLY, if it backward you would notice by feel, yes, and probably the crank not turning too.

[Dave Koehler]

I don't know about that Glen. A burr has at least 2 sides and a step has 1.