TO20 engine rebuilt time

[FergFord]

TO20 is oil fouling the #1 plug every few hours and she is buring oil and loosing power. I have put this off long enough.

Question: Where to start and how far to go? Not sure if it is a valve guide that is letting in the oil or a ring. Last time that I checked the compression was good on all cylinders.

Should I just focus on the #1 cylinder or do a complete valve and ring job?

 

[Anonymous-0]

Ferg. Have you looked at the engine kits on this site? Very reasonably priced compared to reconditioning any other four cylinder engine!

 

[FergFord]

Bob,

I have priced these kits. I am just looking for an opinion where I should just do a complete rebuild or not. Rings and/or valves are considerably less than a full rebuild.

 

[Jerry/MT]

Generally, if valve guides are worn, you see blue smoke at the low power end of the rpm spectrum where the vacuum is very high and then the smoke will disappear at full load/WOT when the vacuum is near zero.

If the rings are worn, the blow by is highest at WOT i.e max power and accerating the engine will show blue smoke.

Stuck oil control rings smoke all the time and are quite common on these old machines when they sit for long periods without use.

If I was in your situation I would warm the tractor up, disconnect the air cleaner from the carb inlet, open the throttle plate to WOT, pull the plugs and do a dry and wet compression test. that will give you a good idea of the condition of the rings and valves. Your compression should not be below 90 psi (newly rebuilt engines are arouns 120-125 psi)and should not vary much between cylinders. After you have those numbers, get back here with the results.

 

[Chuck (CA)]

Well, one way to find out if it is rings or valves is first of all, do a compression test just like Jerry said. Then, put about a tablespoon of oil in each cylinder and do it again. If the compression stays the same, it's most likely valves. If the compression rises, it's most likely rings. The oil temporarily seals the rings and gives a better, but false reading.

 

[Chuck (CA)]

That would be the "wet" compression test that Jerry referred to.

 

[gshadel]

You really need your compression numbers to make the best decision. Speaking from experience here... A word of wisdom... try to decide up front the extent of your rebuild/replace job, rather than working into it one step at a time. There are quite a few kits available, from gasket sets, upper rebuild kits, lower rebuild kits, whole rebuild kits. The kits are all lower priced than buying the individual components. If you start out buying just a gasket set, and rings, then decide you need to rebuild the head, or replace a worn piston, you will get duplicate gaskets and pay more than getting one all inclusive kit. If you have the luxury of time, I recommend tearing into your TO to inspect the valves, guides, pull your piston(s), check for wear, then decide the extend of your repair, and order parts once. You can do ALL of that without splitting the tractor or pulling the engine. Also, if your TO was ever rebuilt before, you may have oversized pistons/sleeves. You will want to measure the piston to make sure you get the right size rings.

Step#1 though is to make sure you have a Fergy reprint shop manual. The info in there will help you decide the extent of your repair work.


George