hastily repaired rods and bolts.

[Stoffregen Motorsports]

I'm not the one who brought it up. I'm just saying that if you install new bolts with a higher clamping torque, get the rods resized.

My point is changing something important like the bolts and the torque that involves several other steps (resizing the bearing) to "fix" something that is not broken. That is just not good practice.

It sounds like the clearances in this engine are off. Changing the bolts and the torque do not fix that root issue. My guess is ( as others have stated) proper assembly techniques were not followed. Instead of changing the bolts and the torque, disassembly and assemble the engine following the service manual instructions.

And I wouldn't have gone to all that trouble either, but his machinist did, so I'm trying to save him some more headache by offering what I think is valuable advice.

[SamsFarm]

I am still wondering what necessitated a change of the rod bearing cap bolts!

Old rod bolts stripped? Cracked? Broken in two? Engine machinist wanting a filet mignon dinner for his family that day?

What is so special with the new bolts?
Thread pitch different?
Increase in diameter for some odd reason?
Bolt company recommendation for use in a different application non Cub related?

I'm not the one who brought it up. I'm just saying that if you install new bolts with a higher clamping torque, get the rods resized.

My point is changing something important like the bolts and the torque that involves several other steps (resizing the bearing) to "fix" something that is not broken. That is just not good practice.

It sounds like the clearances in this engine are off. Changing the bolts and the torque do not fix that root issue. My guess is ( as others have stated) proper assembly techniques were not followed. Instead of changing the bolts and the torque, disassembly and assemble the engine following the service manual instructions.

Amen

[SamsFarm]

Is anyone with engine experience close to pett3227b that they could have a look on what he has if he would be willing?

Carthage, NC 28327

I know sometimes the experienced folk can overlook something that a fresh set of eyes sees!

I am starting to wonder whether something might be bent, and binding up as assembled

[inairam]

Is anyone with engine experience close to pett3227b that they could have a look on what he has if he would be willing?

Carthage, NC 28327

I know sometimes the experienced folk can overlook something that a fresh set of eyes sees!

I am starting to wonder whether something might be bent, and binding up as assembled

I have used to find engine machine shops in my area. https://www.aera.org/member-locator.html

[ricky racer]

Instead of confusing the the poor guy, I suggest he install the bearings, insert a piece of plasti-gage, torque the bearing caps down to the specified torque for the fasteners he's using and see what the clearance measures. Once he does that, intelligent decisions can be made. Maybe it will go together just fine and all will be good...

[Matt Kirsch]

Okay on looking at the other thread I see that it doesn't get hard to turn until the pistons and rods are connected. The machine shop still needs the entire engine to diagnose the issue. I know it's a lot of work and a pain to take it all back apart again but it's either that or use it as a lawn ornament

[Stoffregen Motorsports]

Instead of confusing the the poor guy, I suggest he install the bearings, insert a piece of plasti-gage, torque the bearing caps down to the specified torque for the fasteners he's using and see what the clearance measures. Once he does that, intelligent decisions can be made. Maybe it will go together just fine and all will be good...

That's the most logical course of action.

[Stoffregen Motorsports]

Okay on looking at the other thread I see that it doesn't get hard to turn until the pistons and rods are connected. The machine shop still needs the entire engine to diagnose the issue. I know it's a lot of work and a pain to take it all back apart again but it's either that or use it as a lawn ornament

I wish I were closer to him to lend a hand. Seeing that I am not there, his machinist is his only fallback. I wonder, would it be easier to trailer the whole tractor to the machine shop for the machinist to see?

[pett3227b]

I'm not understanding exactly which way to go here. I am planning on plastigauging both the main bearings and the rod bearings. Should I measure the clearance of the rod bearings at the 35 pounds that my machinist says is best for the bolts he put in or should I check the clearance at the 16 pounds that is reccomended for the original bolts?

[pett3227b]

I'm not understanding what was recommended here. Should I plastigauge the rod bearings at 16 pounds or should I plastigauge them at 35 pounds at the amount for the new bolts? I also am wondering where to get the green plastigauge? I was told to get the green one for the mains and rod bearings.

[ricky racer]

You should be able to get green plasti-gage at any automotive parts store. You have nothing to lose by checking the bearing clearance using the bolts the machine shop suggested and/also the original bolts and see if there's any difference. I doubt you'll see any. If there's no difference, choose a bolt and move forward.
Your original problem was difficulty turning over the engine. If your bearing clearances are within spec and crankshaft end play is good, you've eliminated the most likely cause of a tight engine. There will be drag created by the piston assemblies but your starter should easily turn the engine over.

[Jim Becker]

I have mostly avoided commenting in this thread or the other threads on this same problem. The lack of solid information makes it nearly impossible to provide any solid advise. For a start, I don't know what "too tight to turn over easily" means. I do know that a freshly rebuilt engine that has not been run will turn pretty hard just because you have a full set of new piston rings trying to slide across cylinders that have been cross-hatched so the rings will seat when it is run. That is the reason for my one previous comment on October 5: "However, I suspect you are chasing a non-problem."

The truth is that none of us except the OP have talked to the machine shop or looked at the engine. We know that the OP is a novice and everything we have heard from the shop has been filtered by him. It seems to me that we should be a little more trusting of the machine shop. Unfortunately, the OP has done so much DIY mucking around that the shop now has plenty of wiggle room if something does go wrong once the engine is started up.

The OP's best option at this point may be to remove the engine, take it to the shop, and have them finish the assembly. Then they may be willing to stand behind the job.

[Eugene]

pett3227b: There is a service manual for the C60/Cub engine on this site. Upper left, Quick Links.

There is a lot of small/different steps to take to assemble an engine. It would be worth while reading and understanding the service manual.

That's my opinion and suggestion based upon the questions you have posted.

[pett3227b]

One thing I did not mention about the new bolts is that the machinist even installed them in the rods with some kind of locktite. Should I just replace the rods and bolts? I have plastigauged the main bearings and they are all three at 2 thousands of clearance. I also confirmed that the end play is within spec. Thanks for the advice. I am still waiting to test the clearance in the rod bearings if they need replacing anyway

[Stoffregen Motorsports]

If the machinist installed them properly, there is no reason to replace the rods. Have you asked him if he re-sized the rods with the new rod bolts? Either way, go ahead and check the rod bearing clearances and determine for yourself if the clearance is good.

If you want to use a lower torque value on the rod bolts, be sure to use red loctite on the nuts.