BeerRunner

Hi all thanks for the help. This is my first engine rebuild so I may be missing something obvious.

My main bearings plastiguaged perfectly and my crank turned easily by hand with all main bearings installed.

When I installed my rod bearings I could no longer turn over the engine with anything short of a breaker bar. I then pulled them apart and measured clearances they were all on the tight side, about .025mm in one case slightly tighter. Not what I was expecting especially since the crank guaged out so nicely and uniformly. I also noticed some slight scoring on some of the rod bearings.

I verified that my torque wrench is accurate, and am almost certain (I labeled and checked discoloration scoring marks) that caps are on there perspective rods. I had .010 taken off the crank by ENGNBLDR and the bearings are brand new from him as well. the pistons seem to travel in their cylinders correctly.

On a side note I hope its ok that I have torqued and retorqed the cap nuts a bunch of times.

BeerRunner

Heres a picture of the scoring and a plastiguage reading.

Grego92

iTrader: (4)

You're good...same as me, paranoid....still running like a champ!

https://www.yotatech.com/forums/f116/rebuild-question-crank-turning-246588/

BeerRunner

Thanks for the reply Greg, Good to know. Im still a little worried since my clearances are tighter than yours and because I can not turn my crank with a 1/2 inch wrench. were all your rod clearances at .038?

Grego92

iTrader: (4)

Yes, they were all about the same.

Not too long ago (months) I worked on 5vz rebuild. Clearances were well within spec but the crank turned WAY easier than mine. The only difference between the builds was the 5vz cylinders were coated with some motor oil and put the recommended amount in the ring areas. On the 22re I used WD40 on the cylinders and the ring areas. On both engines the cylinders were only honed and new NPR piston rings (standard size)

So I guess my question is did you put some lubricant on the cylinder walls and the piston ring area per the factory manual?

BeerRunner

Yes the cylinder was lightly coated in engine oil as specified in the fsm. Im thinking that the problem may be that I used assembly lube between the rod and bearing. Maybe this effected cleances?

Grego92

iTrader: (4)

Yes, I believe the fsm says to measure clearances when dry.

I think that is why some tend to skip the plastigage step, it's "extra" work to them rather than a "necessary" step. You have to do a complete install dry, then take it all apart, lube it up and install again. If you ever visit Japan and/or have relatives or friends who work over there, you'll come to understand why the stuff they produce is usually right the first time when it comes to market. They take so much pride in their work no matter the job, whether a janitor or doctor, they rather check twice and do it once to help prevent the shame of a failure.

vital22re

iTrader: (2)

It should not take a breaker bar to turn the motor over by hand. remove the pistons from the rotation and see if it free's up. If not then you have a bearing thats too tight somewhere. Call up engine builder and see what he says.

BeerRunner

I removed the pistons and rods last night. The pistons move in their cylinders easily, So the problem is defiantly the bearings. I have been emailing tod at engnblder. Im going to try mocking it up again without assembly lube between the rods and rod bearings and see if that helps.

BeerRunner

I got in touch with Tod at ENGNBLDR I will be assembling again without the grease under the bearings. He also said that the torque specs for the rods are not 51 ft lbs as the fsm specifies so i will be torqing to 41 under his recomendation.

vital22re

iTrader: (2)

Grease UNDER the bearings? you mean between the crank and bearing?

osv

don't ever build a motor with wd40 on the cylinder walls! or grease on the bearings, for that matter, because it doesn't flush out very fast with the oil... some people will mix assembly lube with oil, for the bearing/crank surfaces.

never force a motor to turn over with a breaker bar! if it doesn't go over fairly easily with a socket and ratchet(plugs out), something is wrong, and the problem needs to sussed out... that said, four cylinders should turn over easier than six cylinders, etc... this testing gets done before the head is on the motor.

the way to test the rod fit is to torque the rods/bearings down on the crank, with the bare crank/rod assembly sitting on the bench, not on the motor... at that point, the rods should fall from vertical, under their own weight, it should be an easy 360 degree turn... any kind of hangup at that point needs to be investigated.

that said, there are issues with rod bolt stretch, and gauges that measure that... depending on the rod bolts involved, there is probably a limit to how much the bolt can be stretched before it has to be tossed, which means that there could be a limit to how often the bolt can be torqued down.

if the crank is hanging up when turned in the block, it'll make troubleshooting a lot easier, since you have already eliminated the rods as a source of the problem.

those rod bearing pics look like there was grit in between the bearings and the rod mains, is the crank scored in any way?... btw, did you remove the allen wrench plugs in the crank, and blow out the crank journals with carb cleaner and compressed air? and/or brush them out with pipe cleaners?

how well the piston moves in the bore isn't the best indicator of how well it fits... the bare rings should have been put in the bore, and the ring gap measured... as well as the gap between the piston and the piston wall.

pretty involved stuff, yet simple tests like how the bare crank/rods rotate tells you more than you'll ever get with just using plastigage... for instance, there are a lot of remachined rods out there that don't have caps sitting perfectly square on the rod, so the side of the cap is brushing up against the wall of the crank... there is a factory clearance for it, that should be measured.

BeerRunner

Thanks for the reply guys

@Vital22re Yes I put assembly lube under the bearings I now realize this is wrong and cleaned all the grease from under bearings.

@OSV
1 There was no wd40 on the cylinder walls just engine oil
2 Im using a molly assembly Lube I have heard using stp would be better it will be a while before I fire the engine so I dont want to use oil
3 Nice trick I will pull the crank (one last time hopefully) after work tonight and give that a try.
4 I was told by a mechanic the 22re rod bolts should still be good for many more retorqings are you thinking that having them torqued top spec 4 or 5 times would be a problem?
5 The cranks turns easily when the rods are noty connected.
6 the crank was just resurfaced all bearings were meticulously cleaned before assembly/No I did not I would hope that this was done at the machine shop but is there a write up for this or do you know hoew tight to retorque the allen plugs?
7 The pistons are brand new ring gap was measured and all were within spec.
8 Thanks for the detailed reply man I really appreciate it

I also talked with my friends uncle who is a head nissan mechanic last night. He said that the rods being twisted could also cause a hang up.

kornhuskerwizard

After i rebuilt mine i could grab the crank pulley and turn it by hand. It wasnt easy but i could do it.

osv

if the crank mains/rod bearing areas were turned or even just polished, there could be residue still left over inside the oil passageways, leading to the bearing surfaces... you can see the potential for a problem there, I think, but most people don't bother with it.

you could ask the machine shop if they pulled the allen plugs, and flushed those areas out, but I doubt that they did... typically you run the allen screws down fairly hard, it's steel against steel, using a good grade of locktite, something that will stand up to heat... it sounds like a potential disaster, lol, but the locktite keeps 'em from coming loose, and the threads actually deform under the torque... I would not overtorque 'em, if that is what you are asking, just a pretty tight snug.

was the block machined? I believe that there are oil passageway plugs in it as well... what I used to do for the vw motors was to blow all the oil galleys out at the car wash, using high pressure rinse, then flush 'em out with a hose at home, followed by compressed air... if this motor was never blown up, just being rebuilt with no issues, and no machining on the block, you may not have to hassle with that.

hopefully the rod bolts are new? afaik, the only way to tell if they are stretched to the fatigue point for sure is to measure the length when new, then measure the length after they are torqued down, there is going to be a rod bolt length spec for it... maybe try torqueing 'em down at less than max, for the testing.

crank end play... there is going to be a factory spec for it, so I imagine that you'll want to check that with the bare crank in the block, main bearing saddles torqued down to some extent, bearings in of course... I think that the 22re uses shims, hopefully you have the original shims that came with the block, and that there won't be much wear in that area.

I never built a 22re short block, but all of those things are pretty universal, you might run 'em by the Nissan guy, if there are any questions about it.

JSteenaert

All good info on experiences, I can surely use on my 1981 HiLux with 22R engine.
No3 rod bearing cap came loose, piston rod stuck in the cylinder, crank only turns some 200 degrees, did not completely took the oil pan off yet (steering rack in the way), I can see one undamaged rod cap stud, as if the nut came undone. Top end is still on, I fear some damage there as well.
Hopefully the crank can be saved.