Total Cub Engine Rebuild (after violent death)

[krazzyman]

Due to some unfortunate circumstances our working tractor had a piston rod blow off the crankshaft while out in the Garlic. After realizing when went wrong and tearing everything down to see the damage we have decided the fastest option is to order a matching set of engine, crankshaft and pistons with all necessary parts from JP tractor Salvage. Shipping will be about 2 weeks then we are going to put it back together and do it right... the first time

Wanted to know what tips people have for doing the rebuild. We have it all taken apart and I know what goes were. Is there jigs we will need, a special tool? Parts that should be serviced before putting it all back together? what do you use for making sure gaskets are installed properly (does anyone use gasket maker?). Like I said we want to do this perfectly so our fine ol' cub can run another 70 years or more.

Thanks immensely in advance. will post pictures soon too.

[tst]

before ordering pistons bore should be measured to see if the block needs to be bored, use a good quality gasket set such as fel pro or victor brand

[krazzyman]

before ordering pistons bore should be measured to see if the block needs to be bored, use a good quality gasket set such as fel pro or victor brand

We are ordering it all together from JP tractor salvage. We will be getting a set of pistons to match the new block. Thanks for the recommendations.

[k hutchins]

There are several threads here on rebuild. I don't recall brands off the top of my head, but the experts would recommend that any bolts going into the water jacket, i.e. headbolts, manifold bolts and the like. Use a good quality, heat resitant thread compound. Also there are reference pages for specific torque and order to install headbolts.
I guess my best suggestion since you have a couple weeks, research, and make notes.

Good luck

[BigBill]

I use permatex #2 on my head bolts so the antifreeze can’t creep up the threads.
I burnish a moly engine assembly lube into the bearings, on the crank bearing journals, in the cylinder walls and piston skirts. The camshaft lobes and lifters. Prime the engine oil pump with oil before starting.

[staninlowerAL]

Check the manuals tab under Quick Links, top left corner of this page, pdf manuals. There's a GSS Engine Rebuild manual there that will give provide the engine rebuilding instructions. If you have not built an engine before it's a lot more than just putting the parts back together.
EDIT: Pay special attention to the postings here on the crankshaft pulley removal and replacement as well as the rear c/s seal retainer from tst.

[jsfarmall]

As far as parts go, jp will take care of ya.

I like using Lucas oil stabilizer for assembly lube. Reason is it will stay in place better than plain oil for your first initial start. Remember to lube cam lobes, valve stems, gears, etc.

[Glen]

Hi,
Below is the Cub service manual, it has lots of info. The engine is in section 1, I would read it before installing the replacement engine.

http://farmallcub.com/rudi_cub/www.clea ... index.html

I don't know what the engine you are buying comes with, the rear crankshaft seal was mentioned above. The new oil seals made nowadays don't fit tight in some of the rear seal retainers on Cub engines.
Member tst on here sells retainers that he bores out, and fits a new seal in.

The front crankshaft pulley should fit tight, and need a large puller to pull it off, and a long bolt tool to install it again, using the threads in the front end of the crankshaft.
There is info in the service manual.
There are posts about it on here, or do a search at the top of the page.
The How To forum on here has info also. Go to the Board Index at the top of the page to get to that.

[Bill V in Md]

I recommend using plastigauge to check clearance on the crankshaft bearings.

[Ken (48 Cub)]

I have rebuilt 3 engines using JP's short block solution. The block will come bored .40 over with matching pistons and rings. I didn't have need to get a crank from him. Just make sure it has been machined and comes with matching bearings. You will have no trouble putting it back together. Enjoy your project.

[Glen]

Hi,
Before putting the front cover on the engine, be sure the oil passage plug is in place.
Below is a pic from TM Tractor of the front of the block. The plug is to the upper left of the camshaft hole, left in the pic.
There are more plugs on the engine,
1 behind the valve cover, in the valve area,
and several more on the outside of the block.
If any of the plugs are left out, the engine will probably have no oil pressure.
I would check the tightness of all of them too.

[krazzyman]

Thanks everybody for the advice, I appreciate the help immensely. Here is some pictures from the engine. After digging into the engine I think what happened was a set of rings failed and started losing or burning oil (didn't check the oil that particular morning) and the piston seized and broke off. A disaster that could have been averted at a much lower cost but I know what to listen and look for now. also a picture of my pulley removing jig is there too. Made real rustically from railroad footings cut with a torch.

More pictures to come once the parts come in.