1938 allis WC engine rebuild

Hi have been on this site several times in the past and enjoy the information available Thanks to all!
I have an AC tractor that has been sitting idle for about 25 years, my dad did some work to it...(new rings on pistons , I was told, he had bought a head gasket that was the wrong one and tried some other alternative but at this point his cancer got the best of him and it was left "as was" my brother looked at it and saw that the sleeves on 2 cylinders were badly gouged on the lower half of the sleeve but doesn't seem to be in the compression area. So my philosophy with something like this is just to redo everything. I am a retired guy on a fixed income, money is important to all of us...but I want to do this right! I have the engine block on a stand in the garage.

I am about to buy a rebuild kit for my dad's old WC and I believe it has the 201cc engine but first question how do I D it to make sure that this is the correct size motor, or is this the only engine that came with this tractor? all the info I have points to the fact I am assuming correctly.. but you know what happens when you assume!

the next question, do these engines originally come with 4" sleeves at then you rebuild them to a 41/8 sleeve, with appropriate rings? It seems all the rebuild kits mention the 4 to 41/8 sleeves.
I have found rebuild kits around the $600 range that contains sleeves ,pistons, rings, a complete gasket set, and bearings which brings up the next questions!
I have vaguely been told about making sure that I measure the crank for the right size rod bearings...this is the part that has me scratching my head it is very simple to do the measurements , but what exactly am I measuring for wear on the crank. so that if the crank is worn I order smaller bearings? or am I looking to make sure my "new" bearings fit in the rods correctly?

I don't think there is anything wrong with the head and it is another $150 for a rebuild kit for the head, new valves, guides springs, keepers...should I go with the kit or just have the valves ground and/or maybe replace the guides? Can I buy guides separately?
 
First, I have never bought a rebuild kit. Simple reason, there is no way to know what you need until it is dissembled, inspected, and measured.

Do your tear down, clean everything up, sort it out. If you have access to precision measuring equipment, as in micrometers and dial bore gauges, you can check each component, compare the results to the wear tolerances (you'll need a manual!). If you don't have the equipment, find a reputable machine shop that does engine work, take the clean parts (unless you want them to chemically clean everything), let them measure everything and make a recommendation.

Once you have their recommendations and prices, then sort out the "must do" from the "can probably get by" list. Remember, these are slow turning, forgiving, low performance engines. Most likely it's working days are over or very limited, you're basically building a museum piece that will get very little real work.

About the crank... The wear needs to be measured, both wear tolerance and out of round. Also the numbers need to be checked against the original size to see if it has been ground undersize. You must match the replacement bearings to the crank size. (Not sure, but that old might have babbit bearings, whole different can of worms!)

The head... You can check the valve seat seal by laying the head on it's side and filling the intake and exhaust ports with solvent, watch for it to leak around the seats and stems. Still be a good idea to tear it down, check the guides, maybe just lap the valves and seats if they're not too bad.

You'll learn this as you go, just get a shop manual, don't be afraid to ask first!
 
Sounds like a 201 Allis, stock was 4" bore, 4" stroke. Might want to ask on the Allis board.
Now for the crank. No. The crank will not wear to an undersize that you fit bearings to. It would need to be cut at the machine shop before fitting new size bearings. Often times, the bearing shells will have the size marked on the backside, .002, .010, .020, etc. If you are really good with a caliper, you can tell if the crank has been cut. But, to measure a crank for service requires a micrometer, and some skill. Each journal needs to be measured for size, taper, and out of round. In addition, the overall straightness of the crank should be checked. These measurements are best done by a machine shop. Should have the connecting rods sized as well. That said, many ignore that advice with mixed results.
When going back together you can use Plasti-Gauge to check the bearing clearances. Plasti-Gauge is a wax thread that you place across a journal, then torque the cap. Without turning the crank, remove the cap and measure the crush of the wax. You need to know the Allis' specs for bearing clearance( i.e. .0015 to .0035) and buy the right size Plasti-Gauge, comes in colors, green and red usually gets the job done. Make sure you mark all the rod and main journal caps and put them back exactly how they came off.
Any questions, ask 'em.
 
I&T manual AC 11 for specs and details on assembly. Yes, it would be the 201 "square" engine.....WC, WF, WD.
 
I just wanted to say thanks for the input. maybe as I learn more I can save myself some money in the process with you guys help! As far as the parts I need for the rebuild it seems to me to be all or nothing when I look at parts, Example I cant find sleeves without buying a kit with everything else... or should I just stick with the E-bay method, seems to be lots of parts out there.

thanks again!
 
It has bearing inserts; but unless it has been
'updated' at a machine shop to newer specs, final
clearance is set with shims and plastigage.
 

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