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Are crooked main crank caps normal?

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So my 1999 V8 engine is being worked on and we noticed that the main caps that hold the crankshaft in place are somewhat crooked:

post-13129-0-08728100-1344107219.jpg

Meaning each has a bit more block showing on one side versus the other.

They each have 6 large bolts holding them in place, so it seems impossible that they could have been installed crooked, meaning they must have always been that way. Maybe from how the block was cast.

Currently the main and rod bearings look ok, though I've gone through 2 sets of rod bearings in the past seemingly due to debris. See threads:

http://www.thelotusf...fix-from-below/

http://www.thelotusf...il-passageways/

Has anyone else noticed this? Is it a problem?

I noticed Mike Sekinger had posted something similar in one of his rebuilds...

http://www.lotusespr...ineRebuild.html

Mike, you out there? Or anyone else noticed this (either bad or "normal")?

Thanks,

- Kent

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Hi Kent. I'm pretty sure you will find this is just the block casting and nothing to worry about.

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Hi Kent. I'm pretty sure you will find this is just the block casting and nothing to worry about.

Thanks, that's what I'm hoping. Though if it is indeed a problem I would rather know about it now while things are still apart!

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Kent, In light of all the problems you have had I would have the line bore checked on the crankshaft and have the big rod ends checked and re-sized if required. This is not a mechanic operation but a competent race prep machine shop task. Last I checked oversized main bearings were non existant. Mike Sekinger, I think, had some made up a couple of years ago.

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As you say you have seperated it all down there :

does the orientation from 'front to rear' of the main-bearing caps fit in order to the assembly sequence .. ?

..is every mainbearing cap fitted right way round?

#

..that's right -Mike sourced out a full set of 'first oversize' for my DIY rebuild too, just as in order to the factory numbers/requirements.

so if you have problems with your crank -first check that noone mixed up something there on the bearings/caps (caps are marked!)

Edited by Günter

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Thanks for the input all.

The assembley is definitely correct - all of the marked numbers are correct and the caps themselves are identical. They only fit one way. He actually replaced them all as well. So nothing wrong with the caps.

The machine shop did check out the rod ends, and all of the bearings right now are fine (both con-rod and mains).

The block is not out of the car so I dont think the machine shop can do a full line bore check. Everything should be going back together today, but if for some reason any problem comes up (and we have to take the block out) this will definitely be something to check again.

Thanks all.

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Well If I understand you correctly, the mechanic replaced all the main bearing caps? You have to line bore any time you replace the main caps.

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I just found out today that only one of the main caps was swapped (see oil passage thread), not all of them. Yes, it seems that line boring would be ideal, but not possible at the moment with the engine in the car.

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Very risky to replace the main cap wothout a line bore, especially in a high rpm, turbocharged engine. Cast some doubt on your mechanic.

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!

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Yes, I am going to talk to him today and ask that my original cap go back.

The noise is still there (after changing the cap), so obviously that didn't work. If the end float play is so bad that the cap does need to be changed then I will see if we can do a line bore (since the engine is now out of the car).

Thanks for the input.

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When the original engine was assembled the whole lot was line bored so even if crooked for some reason it'll not matter.

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that's why we say he should get his original main bearing cap ..

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Ok confirmed... My original cap will be going back in. So at least I won't have to worry about misalignment.

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