F20 failure update

Dropped the oil pan and loosened the connecting rods. Sure enough it turned easy. Tightened them up and still turns nice. Guess I cranked them too tight. Still feels plenty tight without changing any spacers. Now I'll have to get ahold of Frank at Rice Equipment and get a new pan gasket. Sure hopes this solves my problem. Thanks everyone for all the info.

You might still need to add shims,if all you did to free it up is loosen rod bolts,you may have the bolts loose enough they no longer have a clamping force on the rods.The bolts will start to flex and fail.

Yep. I was wondering that. I basically backed the castle nuts one notch

I would add one shim to each side then. A tad loose on those is better than too tight at least in my experiences.I don't use plastic guage I set them up the old fashioned way described in the old manuals so far no problems.

Loose rod bolts, loose rods will beat up a bearing in no time. Moreover, if you use the tractor and you heat it up, the tolerances will close and can pinch the bearings causing friction and possibly melting the babbitt.

I agree with the other posts. Find some material that is .003-.005 thick and put it in on one side only. Tighten the castle nuts up and make sure you put in the cotter pins.

Now, an old geezer taught me to help the break in process by pulling the spark plugs and pulling the tractor around for a bit. By doing so, there isn't any pressure in the cylinders (plugs removed) and the engine pumps up the oil (verify by gage), splashes it around, and gets everything moving without power going through the engine. I would say pull it a couple hundred feet and you are good. Check things out, if good, put in plugs and start it up!

u must have the rods torqued to spec. i have even switched castle nuts around so that the cotter pins go into the nearest hole. the best thing to do is use plastiguage to find the clearance. i do not believe in the guessing game. .003-.004 is a nice spec for those. then you know what you have. not guessing and feeling. you must have the same amount of shims on both halves of the rod. the reason they did it by feel back then is that that was the thing to do. everybody has a different feel.

Be sure to oil the crank and the babbit bearings when reassembling the motor - dry bearings are hard to turn.

True everyones feel may be different but if you have ever read the procedure for setting rod bearings it is not by feel. I agree you must balance the shim pack so both sides have the same thickness of shims. That is always my first step , because it seems like most of them have been done in the past by someone who just adds or removes from one side. The reason I don't like plasticguage is because the journals are usually not true and the old fashioned way seems to compensate for that better. And now the "professional engine builders" can tell us how it will fail immediately if we don't machine the crank. The fail to realize the non availability of undersize bearings , plus the fact that the engine has been running fine for 75 years with out of round journals . Bottom line whatever procedure you feel most comfortable with will work. These are very simple forgiving engines designed to be operated and maintained by men with very little mechanical experience. If you fixed everything the way it should be done you would have 10-15 thousand dollars in a tractor worth a thousand bucks.......

Keep in mind these engines run at speeds lower than 1600 rpm. They are not high performance engines. They are crude, inefficient, yet very durable and can take alot and still do the job well. I have seen engines with cranks egg shaped, tapered, out of round, and yet it purrs like a kitten and pulls a double bottom plow without a complaint.

Using plastigage should only be used as a reference at best, since the crank will probably be egg shaped. I was taught to use blueing compound to find the high and low spots and go from there in taking measurements. After working on many of these engines, I found that best is to set them by feel. Run it for a while, then pull the hand hole covers and feel the temp of each bearing. A very hot bearing )in comparison to the others) means it's dragging and too tight.

Now keep in mind we are only talking about the regular, f-20, f-30, 10-20, 15-30, 22-36 type engines; the ones with ball bearing mains and hand hole covers. An F-12/14& wk-40 is a newer style and you must treat it as such.

As said before, it is true you want the shims to be balanced and the same on both sides of the rod bolts. I find it hard to get .002 thick shims to go in well so that is why I suggested putting in a single .005 shim on one side. Chances are you will remove that shim in the future atmost (that is if you work the tractor - most will never be used enough to need shims taken out again).

(quoted from post at 15:30:19 08/14/16) True everyones feel may be different but if you have ever read the procedure for setting rod bearings it is not by feel. I agree you must balance the shim pack so both sides have the same thickness of shims. That is always my first step , because it seems like most of them have been done in the past by someone who just adds or removes from one side. The reason I don't like plasticguage is because the journals are usually not true and the old fashioned way seems to compensate for that better. And now the "professional engine builders" can tell us how it will fail immediately if we don't machine the crank. The fail to realize the non availability of undersize bearings , plus the fact that the engine has been running fine for 75 years with out of round journals . Bottom line whatever procedure you feel most comfortable with will work. These are very simple forgiving engines designed to be operated and maintained by men with very little mechanical experience. If you fixed everything the way it should be done you would have 10-15 thousand dollars in a tractor worth a thousand bucks.......

Click to expand...

Id love to hear just how that was done always willing to learn something.

Thanks for all the info guys. When I have the opportunity I will be back in the shop working on the project. Was just relieved when I was able to turn that motor over. One gets so much invested in these projects that you want them to work out.

1070BK,
when you put your new oil pan gasket on only permatex the pans side not block side. this will allow you to remove the pan many times if needed. oldiron29

Thanks for the info. Will do.

(quoted from post at 00:53:41 08/14/16) u must have the rods torqued to spec. i have even switched castle nuts around so that the cotter pins go into the nearest hole. the best thing to do is use plastiguage to find the clearance. i do not believe in the guessing game. .003-.004 is a nice spec for those. then you know what you have. not guessing and feeling. you must have the same amount of shims on both halves of the rod. the reason they did it by feel back then is that that was the thing to do. everybody has a different feel.

Click to expand...

Can you show us the torque specs on the rod bolts from a period IH source?

guess i should have said i put the plastigage on three sides of the brg. bottom and both sides. it does show the different clearances when out of round.