Kawi J engine squish clearance?

I could use some help on something that's been bothering me since I put the case together...

When I first laid the crank in the upper half and lined up the dowels with the outer races, I noticed #5 (thrust bearing) outer race moved when I pushed the crank side to side. I should only be getting the thrust clearance, but I could see that the #5 outer race was also moving a little. Like it wasn’t a perfect fit on the dowel like the rest of the bearings.

After bolting on the lower half I noticed #5 still moves with the crank. It’s not held tight by the case halves’ torque.

I’ve been having nightmares that the dowel fell out somehow and I didn’t see it. I know they were all there, and tight in the upper half. So I poured oil in at the pressure switch hole and can see the oil coming out from gravity at #5 just like the rest. Telling me the oil holes are lined up so the dowel must be there.

The manual only shows checking endplay clearance at this bearing on the bench. No installed endplay spec. But this bearing not being tight definitely increases the installed endplay.

Is that race being loose normal???

Anybody got a J engine with the block off to compare?

You might try this.
Steve

Thanks Steve. That's a good idea. There were no signs of scoring on the journals. Wondering if that dowel is loose, maybe sitting too low and not all the way up into the race (the dowel hole is tapered). Hate to split the case again, but that race moving is giving me another .010" endplay putting thrust clearance out of specs.

Wish I had another one to look at to be sure they're not all like that.

I can't help with your thrust play question, but have this to offer to your solder question. I would recommend solid solder to prevent the possibility of rosin or acid getting into the cylinders.

The bearing should be snug in the journals. The pins I thought were cast in. Almost lost one. They shouldn't be loose.
Steve

The pins were tight in the case. But if they are sitting too low (deep) in the case they won't go high enough into the bearing to keep it positioned. There's a taper in the bearing's dowel holes to make the crank easier to install.

Here's a video of what I'm seeing: www.realworldautomotive.com/kz-images/bearing.mp4

If i am understanding right, if your cam bearing is moving in the cam journal i would use a little drop of
LOCTITE 620 for joining bearings to shafts (>200 °C).

Loctite Retaining Compound 620 (Automotive Aftermarket Only)

Loctite® Retaining Compound 620™ is a high temperature (450°F/232°C), high viscosity liquid retaining compound. Provides a shear strength of over 3,800 psi on steel. Locks and secures metal cylindrical assemblies up to 0.015" (0.381 mm) diameter clearance. Prevents metal fretting and corrosion. Seals against leakage.

tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web...857/$File/620-EN.pdf

Michael

Scirocco wrote: If i am understanding right, if your cam bearing is moving in the cam journal i would use a little drop of
LOCTITE 620 for joining bearings to shafts (200 °C).

Michael

That would be a fix depending on the actual cause. I'm wondering if the light torque on the bearing is normal, but I'm getting the movement due to a loose dowel. That could be caused by the dowel too low in the case, or the dowel and/or dowel hole in the bearing race being worn. Either way I gotta split the case to find out.

putting in the pin I drilled for was very tight. I had to wiggle and twist it to raise it up so the bearing wouldn't move from side to side. The others were just as tight. It could be it is too low but I suspect it's sloppy in it's hole Licktight might help there but not on the bearing itself. I can see in your clip the race is moving about 1/8". I'd like to see the journals as well.
Steve

Dowels are there mainly for bearing location and oil gallery alignment on assembly .
A missing or low dowel will not affect bearing fit in the cases.
The bearing should not move once the cases are bolted up but I have seen them loose like this before with no ill effects.
Maybe the cases were not bored to the correct tolerance at the factory.
You could either use some bearing fit but be careful not to get it near the bearing oil feed or use the old method of centre punching the cases multiple times over the surface of the alloy bearing housing which will raise the alloy enough to grip the bearing or a combination of the two.
A bit like knurling a worn shaft to increase its diameter.

Hey Zed,

I first noticed the same side to side bearing movement before bolting on the case, meaning the movement was at the dowel. And I remember putting a trans bearing outer race on it's dowel, and there was zero play. I believe it's the same situation with the crank dowels.

Maybe the loose dowel permitted some bearing movement and loosened it up in the journal, but regardless of how tight the bearing is in the journal, the .010" sided to side is at the dowel. See what I mean? And any other bearing would probably have no ill effects, but this is the thrust bearing and the extra movement puts thrust clearance out of specs.

Hey, if you have an upper case and an outer race laying around please put it on the dowel and tell me what you see? Also, have you ever replaced a crank bearing dowel? Curious if they bottom out or have to be tapped in to a specific height?

Thanks...