14hs 321a is to tight

[RAllison]

I've recently rebuilt the 321 out of my147 and everytime I torque the rod to the crankshaft I can't turn the motor. The crank measures 1,498 and the rod has .001 to .002 clearance,is that not enough?

 

[jkoenig]

Have you checked the clearance all the way around? One or the other may be out of round.
...wow that stinks. Good luck!

Did you use Plastigage, or measure?

 

[RAllison]

I measured with a bore gauge,I don't get it

 

[RAllison]

The crankshaft I used a mic

 

[jkoenig]

In multiple places around?

No offense intended, but using and reading a mic are tricky. Are you confident? I train people frequently that struggle mightily with the technique.

And I have not read the specs in a manual for about 15 years, so I don’t remember if that is enough clearance.

 

[RAllison]

Yes,all the way around,I'm taking the piston out now to recheck it all

 

[RAllison]

There's about a half thousands out of round on the crank...but it's to the low side

 

[jkoenig]

With the piston out, it should be easy enough to bolt them back together, and see if the rod is free then. Could there be a width problem? Rod or cap wider than the crank journal surface?

 

[RAllison]

That's the funny thing,the rod is the one that came out of it and it rotated fine,I reused it cause it measured good at the crank

 

[jkoenig]

Did you have the crank turned? Maybe the shop didn’t go straight, or wide enough.

Or are you saying both the rod and crank were a matched set, and now they don’t match?

 

[RAllison]

No,I reused the crank and rod with no machining,but I did put it all in a different block so I could get back to3.5

 

[jkoenig]

Have you tried torquing the rod onto the crank outside of the block?

If the rod moves freely on the crank out of the block, I would guess you have an alignment problem with the bore.

 

[RAllison]

You're thinking like I'm thinking...but that's for tomorrow. I'll post how it goes and agree,I may have some kind of alignment problem. I did tighten it on a same size shaft at work and it rotated,but the crankshaft is next

 

[jkoenig]

Sure wish we didn’t have to think this way.
It’s time for me to go change the Hytran.

 

[RAllison]

I'll give ya an update tomorrow

 

[RayF]

not sure on the 321. but on a K241, you can reverse the rod cap, and the crank won't get oil.
Perhaps the rod cap has to be on a certain direction to work on the 321???

 

[kashaver]

I think RayF is on the right track. You can reverse the cap on the rod. Then it will bind.

There should be index marks on the rod and cap so they can be installed in the correct orientation and (Correct me if I am wrong) I am thinking you want the oil hole in the cap to be on the camshaft side of the assembly. Doesn't the piston also have to be oriented properly or else it will 'slap' as it goes up and down?

 

[jkoenig]

I questioned him on using a micrometer, but I assumed he got the rod and cap on properly. I do think the piston must be indexed correctly just like the rod and cap. I was not aware the rod might bind if installed improperly.

Robert, check the manual, and verify installation directions of rod, cap, and piston.

 

[dschwandt]

The oil hole goes towards the cam side of the block,
I assume you installed new rings, Did you check the end gap on them?

 

[mgonitzke]

I agree with the others...I think you have the rod cap on bassackwards and/or the rings have no end gap.

There are match marks on the rod and cap that need to match up, and the oil hole needs to point towards the cam.