1948 8N rebuild progress

[JJay48]

If it won't run well on a 6v system,converting to 12v won't make it magically run better. My '41 9n runs great on 6v,starts easily and performs well. As said already,check the front mount distributor's timing.

What is everyone’s deal with 12v? I am past getting it running on 6v as the engine is apart for a rebuild. I never said 12v will make it run better but I like keeping everything 12v for compatibility. The timing was off as the screw was loose.

 

[JJay48]

I took the pistons out of the motor this evening and everything is in pretty good condition. I got the exhaust valves out as well but need to make a tool to get the intake valves out. The guides were stuck pretty good but everything looks like it will clean up well and I did not see any pitting. I lightly took a wire brush to the exhaust seats and did not see any issues.

I did notice the oil pump gear is loose. Looks like the rivets are loose that attach it to the pump.

 

[Hobo,NC]

I took the pistons out of the motor this evening and everything is in pretty good condition. I got the exhaust valves out as well but need to make a tool to get the intake valves out. The guides were stuck pretty good but everything looks like it will clean up well and I did not see any pitting. I lightly took a wire brush to the exhaust seats and did not see any issues.

I did notice the oil pump gear is loose. Looks like the rivets are loose that attach it to the pump.

Valves and seats look good it would be #1 priority to have them properly machined and seated. On the valves use a automotive spring compressor to get the valve keepers out then pry the springs out. If it becomes a fight are time is an issue heat the springs with a torch they will collapses and come out easy and fast. New springs are cheap old springs are not worth fighting. If you are not pushed you can keep at it till the valve guide gives up.

 

[JJay48]

Valves and seats look good it would be #1 priority to have them properly machined and seated. On the valves use a automotive spring compressor to get the valve keepers out then pry the springs out. If it becomes a fight are time is an issue heat the springs with a torch they will collapses and come out easy and fast. New springs are cheap old springs are not worth fighting. If you are not pushed you can keep at it till the valve guide gives up.

You don't think cleaning them up and lapping them in would be good enough? I dont think there is any pitting on the seats and I think the valves will clean up good. I do want to get some adjustable lifters, springs, and new guides though. I could get new valves and have a machine shop do a valve job but not sure yet.

Do you think the rotating exhaust valves are a good idea?

 

[Hobo,NC]

You don't think cleaning them up and lapping them in would be good enough? I dont think there is any pitting on the seats and I think the valves will clean up good. I do want to get some adjustable lifters, springs, and new guides though. I could get new valves as well though and have a machine shop do a valve job.

Do you think the rotating exhaust valves are a good idea?

Do you think cleaning up and lapping the old rings will be good enoufh ? I understand the thought of slacking out on the valves, if you want to ensure 100% seal do a professional job on the valves. They play a large roll in this.

Rotating valves for a beginner is a no no you will get extremely discussed with the process of setting them up. Unless its a hard working tractor stay away from them life will be good. I know what I am doing it will add a hour plus to the job for a newby it can take all day and he will need the equipment and guidance. Don't over complicate this job, stay with the standard issue parts and install adjustable lifters. You will need to drill the block for a hole to hold the lifter for adjustment its worth the effort.

 

[JJay48]

Do you think cleaning up and lapping the old rings will be good enoufh ? I understand the thought of slacking out on the valves, if you want to ensure 100% seal do a professional job on the valves. They play a large roll in this.

Rotating valves for a beginner is a no no you will get extremely discussed with the process of setting them up. Unless its a hard working tractor stay away from them life will be good. I know what I am doing it will add a hour plus to the job for a newby it can take all day and he will need the equipment and guidance. Don't over complicate this job, stay with the standard issue parts and install adjustable lifters. You will need to drill the block for a hole to hold the lifter for adjustment its worth the effort.

Thanks. What about getting the tool that holds the lifters instead of drilling the block? Do you recommend all new valve train if I am getting a valve job?

My only issue with the valve job is having to trust someone else to work on it not having good experiences with machine shops.

 

[Btzj02]

Thanks. What about getting the tool that holds the lifters....

Adjusting the lifters with these was fairly easy.

 

[JJay48]

Looking at these tractor parts websites is a bit overwhelming. I dont even know all the parts I am going to need. Tons of small little items like the rubber grommet for the starter button wire and the rubber elbow that covers the wire on the starter. I want a new input shaft seal and gasket while I am in there and new axle seals and almost every gasket there is. Maybe I can call one of these part sites and have them help me put together a list.

Adjusting the lifters with these was fairly easy. View attachment 67432

Yeah, that's the ones. I figured if they work good I wont have to drill holes in my block.

 

[JJay48]

Got the intake valves out this evening. Didnt take a picture but I modified a valve tool and now it looks just like a flathead valve lifter tool. Was able to get the keepers out and then pull out the valves and removed the spring. Then I could pound out the guide.

I also took out the axle on the right side. Going to need a new hub I think as this one is worn. I made sure to note how many shims and where they went.

 

[Btzj02]

There is a process in the shop manual for setting the axle bearing preload by adding or removing shims. I would still recommend taking the time to do that. On my 8N51 I ended up having to add a few additional shims to get it right.

 

[JJay48]

There is a process in the shop manual for setting the axle bearing preload by adding or removing shims. I would still recommend taking the time to do that. On my 8N51 I ended up having to add a few additional shims to get it right.

Thanks. I will look into that for sure and planned to check it. I watched a Claremont garage video where he goes over it.

 

[JJay48]

Got my socket to fit the crank pulley bolt today and got that off. Came right off without much effort. Removed the crank and cam and measured the crank journals. Barely any wear at all on the crank. Smallest measurement I got on the throws was 2.0934 and the mains were almost dead on factory spec.

My oil pump gear is a bit loose where the rivets attach the gear to the shaft? Is this a common issue?

The photo of the transmission shows a piece of metal I found in the clutch area of the transmission. Is that plug suppose to go in front of the shifter rod? Maybe why it was leaking a little.

 

[Hobo,NC]

You don't think cleaning them up and lapping them in would be good enough? I dont think there is any pitting on the seats and I think the valves will clean up good. I do want to get some adjustable lifters, springs, and new guides though. I could get new valves and have a machine shop do a valve job but not sure yet.

Do you think the rotating exhaust valves are a good idea?

If it makes you happy lap'em. There is nuttin wrong by learning the hard way. BTW that cast iron block drills like butter its gonna be a little to late once you get it together and find out those wrenches break.

 

[JJay48]

If it makes you happy lap'em. There is nuttin wrong by learning the hard way. BTW that cast iron block drills like butter its gonna be a little to late once you get it together and find out those wrenches break.

I did hear the cheap wrenches can break. I dont see having to adjust the valves often as it wont get used a lot. I know it would be easy to drill but I wanted to avoid it.

I am sure I could get a seat grinder and do the valves myself unless you know of a reputable machine shop in SW Ohio. All the videos I watched online of 8N rebuilds they just used a seat grinder and lapped them if even that. Mine are also in better shape than most I had seen.
I guess the Claremont garage guy and the Gingells did it the hard way? I may still have the machine shop do it if I find one but I think my tractor will still run fine if I do it.

 

[soaked]

I did hear the cheap wrenches can break.

Hi JJay48,
Mine broke years ago on the first one. Welded it up. Still no good. Sacrificed a cheap screwdriver. It bent. Welded on the bend to thicken, and got it to kinda work.

Drilled blocks worked 100% in my experience. That tappet bolt can take some torque to turn.

If wrenches bend, then what?
Drill with tappets in?

 

[JJay48]

Hi JJay48,
Mine broke years ago on the first one. Welded it up. Still no good. Sacrificed a cheap screwdriver. It bent. Welded on the bend to thicken, and got it to kinda work.
View attachment 67786
Drilled blocks worked 100% in my experience. That tappet bolt can take some torque to turn.

If wrenches bend, then what?
Drill with tappets in?

I may still do that but not sure. Just have to make sure there are no rough spots left inside the lifter bore. Even thinking about having it machined for .090 sleeves and the 3/4" oil pump. It all depends on finding a good machine shop.

 

[soaked]

There is a lot to learn/ get right, and tools to buy, if only planning on doing this one rebuild....

 

[HFJ]

.

Question 1: Who makes the best 12v conversion kit?
I watched a YT video about the conversion and the guy mentioned another site had a nice kit and he liked how their adjusting bracket was curved. I have not noticed this though looking at the parts photos.


Thanks

if u like the look of the curved piece, cool. but i'll add that my straight one holds my alternator just fine

 

[HFJ]

What is everyone’s deal with 12v? I am past getting it running on 6v as the engine is apart for a rebuild. I never said 12v will make it run better but I like keeping everything 12v for compatibility. The timing was off as the screw was loose.

all of my vehicles are 12 volts too, including my tractors. it's not all of us, just some. many here are 12 volt people too, they just tend to be less militant about the voltage

 

[JJay48]

There is a lot to learn/ get right, and tools to buy, if only planning on doing this one rebuild....

I am thinking about buying a second one soon.