Crank Bearings

[Blownb18c]

Ok i have a B20a that needs looser bearings the ones in there now are to tight causing the crank to not spin very well but i found a place to get new bearings but not sure what size to get, right now they are factory specs but i need some help before i buy ones that wont work. any help will be appreciated

[khailon]

somebody help this man

[Blownb18c]

anyone?

[B96v6]

Well, bearings will come in stock sizes or under/oversize in .05mm increments. So, try ordering .05mm undersize bearings. Be sure to plastigauge everything until you get the right clearances. You can mix different size bearings to get the right clearance. So, if .05mm undersize bearings are too loose, use one stock size bearing half and one .05mm undersize bearing half and you should split the difference between the clearance when using all stock size or all undersize bearings. I used ACL main and rod bearings in my D16Y8 rebuild and they've been living happily for 18k miles. Just double/triple/quadruple check your clearances with plastigauge. Good luck.

Brandon

[BABY J]

Take the crank to the machine shop to have it turned - they will put the bearing sizes on your customer card as STD or give you the correct size, + or -.

[vtecgsrguy]

Take the crank to the machine shop to have it turned - they will put the bearing sizes on your customer card as STD or give you the correct size, + or -.
YEAH WHAT HE SAID....LOL.... :goodjob:

[AnthonyF]

is the motor apart or are you taking a guess that the crank is too tight? if the motor has never been touched before...its not too tight.

[BABY J]

is the motor apart or are you taking a guess that the crank is too tight? if the motor has never been touched before...its not too tight.

Not true. The crank could have been slightly bent - the bearings could be worn, etc. On a B - u shold be able to hang 3 pistons and still turn the block over relatively easy. But do NOT eyeball the crank - get it turned, it's just good business - the motor is broken down WAY too far to guess.

[AnthonyF]

Not true. The crank could have been slightly bent - the bearings could be worn, etc. On a B - u shold be able to hang 3 pistons and still turn the block over relatively easy. But do NOT eyeball the crank - get it turned, it's just good business - the motor is broken down WAY too far to guess.

you know what i meant. if the bearings are worn, the'd be loose, not tight. there would be a partial gap. if the crank got bent the motor would have sustained substantial damage (dropped, wrecked, something noticeable).

[Blownb18c]

motor has been rebuilt, no electrical problems thus far but the motor wont fire up--i think its the bearing clearance because the motor spins slowly

[AnthonyF]

^^get a new builder

[BABY J]

^^ What he said.

[SiRed94]

well... an engine can be rotating slowly for a number of reasons other than bearing clearances but if you have narrowed it down to that... i would suggest that you find another engine builder since they apparently didn't check the clearances (aka plastigage) before they put it back together... but definitely do not try to guess that you need .010 undersized bearings and shove them in there and expect that fix the problem... because the shop has to machine the crank to be able to use the undersized bearings...

[SiRed94]

just break it all back down and take it all to the machine shop and have it all checked out... because if you added anything like ARP rod bolts etc and didn't have the rod ends trued or anything of that nature... that could cause rotating issues as well...

[SiRed94]

but g/l with it man... hope you don't have to spend too much to figure it out...

[Blownb18c]

it was bearings, the crank was out of round so i got it reground and installed oversized bearings and now motor spins over fine

[Tech5]

PlastiGauge....way to go if everything is standard, all you need is standard, sounds to me, they didnt tork it to spec in order,
Ok i have a B20a that needs looser bearings the ones in there now are to tight causing the crank to not spin very well but i found a place to get new bearings but not sure what size to get, right now they are factory specs but i need some help before i buy ones that wont work. any help will be appreciated

[Init2winit]

Well, bearings will come in stock sizes or under/oversize in .05mm increments. So, try ordering .05mm undersize bearings. Be sure to plastigauge everything until you get the right clearances. You can mix different size bearings to get the right clearance. So, if .05mm undersize bearings are too loose, use one stock size bearing half and one .05mm undersize bearing half and you should split the difference between the clearance when using all stock size or all undersize bearings. I used ACL main and rod bearings in my D16Y8 rebuild and they've been living happily for 18k miles. Just double/triple/quadruple check your clearances with plastigauge. Good luck.

BrandonI don't know where the hell you heard that you can put two different thickness bearing halves on a journal, but that is one of the dumbest things I've ever heard.

[green91]

I don't know where the hell you heard that you can put two different thickness bearing halves on a journal, but that is one of the dumbest things I've ever heard.

The honda FSM says you can. Would i? no.

[Init2winit]

Wow.
The honda FSM says you can. Would i? no.

[Init2winit]

Here is what happens when you use two different size bearing halves......



http://i32.photobucket.com/albums/d35/ERoycroft/maincap.jpg

[green91]

I guess their logic is that if the halves are only .001 different it wont make much of a difference, i dunno. i wouldnt do it, but i have seen it with my own eyes from the honda FSM.

[Init2winit]

Thats crazy!