8N engine rebuild

Lostforty

New User
Ok so I dis assembled this engine block and ordered a complete rebuild kit. The new sleeves fit inside the old sleeves witch is not good, so them didn't work, now I can't find the correct ones. The top of the old pistons are stamped X695 and .083 Also not sure about the valves. Four of the valve guides are split guides and those valve stems are kinda like mushroom shaped on the stem. I do think these valves are the rotating ones.
The engine block serial number is 8N43512. Any help where I can get the complete engine rebuild kit for this tractor would be greatly appreciated.
 
(quoted from post at 22:05:20 10/21/20) Ok so I dis assembled this engine block and ordered a complete rebuild kit. The new sleeves fit inside the old sleeves witch is not good, so them didn't work, now I can't find the correct ones. The top of the old pistons are stamped X695 and .083 Also not sure about the valves. Four of the valve guides are split guides and those valve stems are kinda like mushroom shaped on the stem. I do think these valves are the rotating ones.
The engine block serial number is 8N43512. Any help where I can get the complete engine rebuild kit for this tractor would be greatly appreciated.

Something is very wrong here. Start by getting some basic measurements. What is the diameter of the bore in the block. You need to be able to measure ID and OD to within .001 to do a reliable job fitting sleeves and pistons.

TOH
 
.083 pistons were installed in blocks without having sleeves installed. When you add the wear to the block from running without sleeves the bore is now oversized. You can have it bored to install .090 sleeves or have custom made sleeves installed.

Mark
 
(quoted from post at 07:37:21 10/22/20) .083 pistons were installed in blocks without having sleeves installed. When you add the wear to the block from running without sleeves the bore is now oversized. You can have it bored to install .090 sleeves or have custom made sleeves installed.

Mark

He says the new sleeves fit inside the old sleeves. That is bizarre if true.

TOH
 
It may have thick sleeves that have been bored for the .083 pistons or he is sliding the sleeves in the block. Without knowing if he has removed sleeves there is no way to tell.

Mark
 
Both sleeves measure .040 but the inside diameter of the old sleeves are bigger, hence the .083 on the old pistons.
 
The old sleeves have been removed from the block. The new sleeves slide in and out of the block. Both the old and new sleeves are .040 thick but the old sleeves are bigger in diameter, hence the .083 on the top of the old pistons. I have not been able to find replacement sleeves or pistons for that matter. Any constuctive help would be appreciated
 
(quoted from post at 08:42:37 10/23/20) The old sleeves have been removed from the block. The new sleeves slide in and out of the block. Both the old and new sleeves are .040 thick but the old sleeves are bigger in diameter, hence the .083 on the top of the old pistons. I have not been able to find replacement sleeves or pistons for that matter. Any constuctive help would be appreciated
Ave a set of sleeves made for original pistons. Might be cheaper to find a different engine to work with. here is one of many places to check: https://dartonsleeves.com/custom_sl.html
 
It either had .090 sleeves that were bored for the .083 pistons or it had custom made sleeves installed. If it had .090 sleeves you can just replace them with new .090 sleeves and standard pistons. If they were custom made sleeves they will need to be replaced with custom sleeves which can be sized to standard or .083 pistons.

Mark
 
(quoted from post at 22:05:20 10/21/20) .....Also not sure about the valves. Four of the valve guides are split guides and those valve stems are kinda like mushroom shaped on the stem. I do think these valves are the rotating ones.
No, split guide mushroom type are not Rotating valves. There are small caps that go on the ends of the straight stem valves with one piece guides to make them rotate.

The engine block serial number is 8N43512
Either somebody swapped out solid guides for the earlier split type or your block is earlier than 8N43512. The change to solid guides and straight stems happened at 8N42162


(quoted from post at 10:38:07 10/23/20) Both sleeves measure .040 but the inside diameter of the old sleeves are bigger, hence the .083 on the old pistons.
Many many things have been done in the past to these engines regarding pistons & sleeves. We can't go by serial numbers for that. That being said I have seen more than a few engines where .040 sleeves were removed and .083 over pistons run directly in the bore. Cheaper way out back in the day for a farmer rebuild. For somebody to install sleeves that would accept .083 over pistons is a new one on me, and a long way around to use those pistons. I suppose though it's better than running directly in the bore, as in that case the next rebuild would definitely require a boring rather than just a re-sleeve. But if the sleeves are custom bored for the .083 pistons, I guess either way would requires re-boring.


(quoted from post at 10:42:37 10/23/20) The old sleeves have been removed from the block. The new sleeves slide in and out of the block. Both the old and new sleeves are .040 thick but the old sleeves are bigger in diameter, hence the .083 on the top of the old pistons ......


(quoted from post at 11:16:15 10/23/20) It either had .090 sleeves that were bored for the .083 pistons or it had custom made sleeves installed. If it had .090 sleeves you can just replace them with new .090 sleeves and standard pistons. If they were custom made sleeves they will need to be replaced with custom sleeves which can be sized to standard or .083 pistons.

Mark

Sounds like (as mark said) somebody may have installed 090 sleeves and bored them out. If so, that will save you the cost of boring for .090 sleeves. That is a two step process. First bore for the diameter of the .090 sleeve, and a second bore as the .090 sleeves have a different top lip than the .040's.

I have not been able to find replacement sleeves or pistons for that matter. Any constuctive help would be appreciated
It requires an accurate bore gauge and skilled machinist to determine the bore of your block and to evaluate the condition of the bores.
Probably best left to an engine rebuild machine shop. Those guys could then get you what you need for sleeves & pistons.
 
(quoted from post at 10:42:37 10/23/20) The old sleeves have been removed from the block. The new sleeves slide in and out of the block. Both the old and new sleeves are .040 thick but the old sleeves are bigger in diameter, hence the .083 on the top of the old pistons. I have not been able to find replacement sleeves or pistons for that matter. Any constuctive help would be appreciated

A stock .090 wall sleeve bored .083 over will have a nominal wall thickness of .049. Are you SURE the wall thickness of the old sleeves is EXACTLY .040?

Bottom line is you need to measure the bore in the block to know what is going on. That is what you have to match with new sleeves and you need to know that dimension to +/- .001 or better.

TOH
 

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