800 diesel overhaul

Case8940

Member
I have a 800 that has been on the farm since I was a kid. The problem is it is getting very tired. It is now time for an overhaul and some other needed repairs. It does not get used nearly as much as it used to but it was the first tractor I drove so it holds a speacial place in my heart. I would like to use it for a few plow days and maybe the occasional antique tractor pull. I'm planing on installing a new set of 4 1/4" sleeves and piston and then doing a little pump work. I was wondering if anyone had any other suggestions for adding a little power. I want to keep it reliable and I do not want to install a turbo. Any help would be great. I'm sure there are a few old tricks floating around out there. Thank You.
 
When I overhauled my 800 with 4 1/4 piston and sleeves I could pull 8500 in 2nd with 18.4-38s and all the power I needed in 1st in the 9500 lb class.
caseman-d
 
Make sure you do the head right and get the protrusion where it needs to be. The valve that is down in the hole can have a thicker seat installed to push the valve down into the cyl farther and raise the compression. Starts much better and pulls much better. Make sure there are no sharp outside diameter corners that will develop hot spots on the thick seat.
 
DKase, it sounds like you have a lot of experience with working on Case heads. How much thicker can you go with the valve seat? I assume you by sharp corners on the outside diameter of the valve seat you are referring to making sure the valve seat is not protruding out of the head? I"m not totally sure but my guess is the heads will be milled some when worked over to make sure they are totally true. By lowering the valve into combustion chamber does that have any adverse affects on valve spring or seat pressure? Thank you for your help.
 
If I remember right on my 930 we dropped it in somewhere around .075". The seat does protrude that much so we cut a nice round radious to the seat. That 930 is completely stock other than the seats. It will pull right with our 2090. We were disgusted with the 2090 so we had it dynoed and it came out 110 HP. Not sure if you have an 800 or an 800B, but you will need a German pump to make it run really good. Post again if you have more questions. DK
 
Case8940,Also a often overlooked item in the heads is the power cells.Remove them,clean carbon well and check for burnt spots/wear in them.
 
Dkase, I assume the German pump is the inline model? I have two 801B's and both have the rotary pump. One is a 59 model, the one I'm going to overhaul, the other is a 58. I have another one spotted for a parts donor but I'm not sure what pump it has, I will have to look that over. It does not seem like putting a .075" thicker seat in would make a big difference but obviously it make a big differece. It always amazes me how a few small tweaks can make all of the difference in the world. Do you remember if it was the intake or exhaust seat you replaced. Thank you.
 

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