Std size new big end bearings + std crank => can't turn over by hand *conrod bent?*

[thechuckster]

note: you have to read the 'codes' on the crank along with the block to work out factory bearing preference.

[beerhead]

On a motor that's had its bearing caps rearranged you should think about having the rods resized and the main caps done while your at it. It'll cost money, but an oblong shaped bearing tends to lead to spun bearings, just as if your factory rod bolts have stretched while the revs are too high.

They'll machine off a small amount of material from the mating surface of each bearing cap and then rebore a perfect circle for the bearing while the end cap is bolted in place to torque specification.

I've heard of standard size ACL bearings not working in the place of standard size Toyota bearings in the past, as they run different tolerances, what breed of bearing are you running?

[allencr]

WOW I'm really an ass for assuming.
The recent advances since the Industrial Revolution, and interchangeable parts, mass production, quality control and LotS of other stuff still aren't up to the 'plug & play' mentality. It's a physicial piece of the universe and it has error messages, just like Microsoft & other software's obscure misleading shit, so it is not as easy to restart as Cntl+Alt+Del.
Sorry.

[The Real Roadrunner]

So, where are we now. The plastigauge returned some very interesting results, some impossibly thin clearances (0.0007 or so) and some 0.0028 clearances too (or there abouts)

So I had some spare caps here and I just did a bunch of combinations with various caps on various pistons till I got the clearances within tolerable limits. Probably not an ideal 'engine builder' solution, but probably as good as you'll get while it's in the car. I vary now between 0.001 or a tad over (maybe 0.0015) and 0.0028 again for pistons 2 and 3.

I seriously hope that your joking and not planning on running this engine. you cant just throw in whatever caps you want and hope for the best or you may aswell just bash the crank with a hammer while your there to adjust your endfloat (same effect really)

Whatever you do DONT start this engine. fix the problem properly (im sure you know someone smart enough to help with it) otherwise you may aswell throw the parts in the bin as they won't be any good afterwards.

Oh and an aside, my torque wrench is a way old school very expensive one my Dad bought and it doesn't have an calibration fittings, but it always feels very on the mark.

Feels very on the mark? last time i check they are calibrated for a reason, to be spot-on. Not to "feel" right otherwise you may aswell just use a rachet.

Im not trying to have a go at you Rob and i understand its a learning experience but sometimes its better to double check with ppl who have alot more experience than yourself before just trying something.

RMS on here is one of the best around and has built some awesome stuff, his post above yours says it all.

If you need a hand or some advice then give me a buzz or sms and ill guide you in the right direction.

cheers
linden

[oldeskewltoy]

note: you have to read the 'codes' on the crank along with the block to work out factory bearing preference.

[RobST162]

ok well great thoughts thanks for pulling me up guys.

I find it strange that I had intolerable clearances when using original caps. That said, I did ask a mate to put the new bearings in the caps and he moved them out of my numbered boxes. To be honest, I'm surprised there's not matching stamps on the rod/caps to make this process more obvious given it's cruciality.

But it seems no matter which way I turn in this scenario i'm completely stuffed.

edit: oh, I wasn't using factory bearings, and there were no corresponding numbers I could see on the ACL items, I did look for the preference.

[RobST162]

this is clearly a whole new world for me.. and sadly

anyway out of this hole you think? or is it time to pull the engine out give up

so frustrated

edit: just to speak a little in my 'defense' here, but i think that's not really needed, and this thread is awesome for anyone doing a little bottom end work of their own, so i'm stoked about that, but the Haynes manual didn't make any specific reference to be uber careful with matching the caps, and I thought the general warning/concern in this area was to do with oil clearances, not particularly matched items/journal 'round' and so on.

if you guys can think any way out of this hole that'd be great, I didn't really have a few months to burn while I remove the engine again (third 'four' engine removed in as many months - so over it) and rebuild the thing, ah, just going to take a holiday from GT-Fours I can't take it any more damm thing in the bin

[thechuckster]

fwiw: the cam caps were identified as I or E when i pulled my motor out. Mains had no marks so I put my own punch marks on one one side of every cap (and the corresponding face on the block or head). Numbering (e.g. 1, 2, 3, 5 or 4 punch-marks) always started from the front so when shit got mixed up, i wasn't stuffed.

rob: I have noticed on some toyota motors some very subtle marks (probably an ink put there during manufacture) on the side of the caps - if you give them a healthy but non-abrasive clean, you might notice some marks that allow you to match caps to the relevant spot on the rods/block.

I'd suggest a coffee or three to wake up, some strong lighting then a very careful inspection of the sides of the caps for identifying marks.

[RobST162]

thanks mate, my motivation is so low right now

driving my brother's auto down to the F1 this weekend (urgh) rather than the hoped GT4

i'll get back on the horse on tuesday and see how we go

[thechuckster]

chin up Rob ... mine was 13 months from purchase to first time i heard it running ... and now i'm up for suspension bits, rego, my 17" 3-piece rims leak and I have no income ... but it's still fun having the white barge in the yard

[YGT04A]

yeah keep pluging awayat it you will get there, mine has been off the road for about 18months now

[RobST162]

and all this is to encourage me? lol

man I am just going to totally do everything I can to forget about it and come back hopefully with some fresh motivation

I didn't want it 'new', just 'working'.

I'll take the sump off again, and check the bearing caps and pistons very very carefully when I get back and decide what to do then. If I can't match them, is my only option to pull the motor?

[oldcorollas]

as jeffro suggested, if you can get/borrow/beg/steal an inside micrometer or whatever, you can spin it around inside the hole with the caps torqued down..

this will give you three important measurements. (assume you are looking at rod with piston at 12oclock position)

A: 6 to12oclock size, ie from bottom of cap to top of rod.
B: 2.30 to 8.30 size
C: 3.30 to 9.30 size

B and C will tell you if the cap is shifted sideways or not, relative to the rod.... and if the cap is oversize/undersize relative to the rod.
IE like
.___
|.....|
.|___|

put those numbers in a table, and it should be easier to match the caps. ie minimum difference betwee B and C for a given pair, and minimum differene in A for different pairs..

also measure the crank journals in at least 2 positions, and compare them..

edit: but looking for marks is the best first action
i usually scratch or punch the caps.. but sometimes there are assembly marks already there.

[RobST162]

ok yeah I don't have an inside micrometer, but that's great advice mate cheers

of course.. I can't do that with the engine in.. ah my life..

[jonathan yee]

hope this may help in some way with matching the bearing caps back to the rods.

now i know in these two rods have very similar markings on the join. it's either an M or W, but on the other 2 rods that i havent pulled out of my block the little M/W are orientated differently so not made by a machine.

i dont think the rods have been removed prior but i cant say for sure.

also there is a 6 on all the caps and the rods have a 7 on the same side. other side has 1 on the cap and either a B or a C on the rod. so that'll help get the cap orientated the right way.

also very informative thread. thanks for all the pro's that commented.