Putting the 9 back together

[William S]

Hello,
I finally rec'd my engine back from the machine shop and have a few questions before I start bolting it back on:
behind the timing gear cover I can see the 'Gear Assy. (cam shaft) part# 6256 and I don't see the Ring (camshaft gear locking) part# 91A 6258, all I see are the four bolts holding the gear on. Also I don't see Spring (camshaft thrust) part# 8n-6276. Are these needed?

I am replacing the throw-out bearing and the new one is about a half thousands (.00005)thicker than the old one. Is this critical? Also I am looking to replace the bearing (clutch pilot) part# 7600 , the book show is being installed on the engine side of the flywheel and it looks like the pocket is on the other side of the flywheel. (No the shop didn't press it in for me) The flywheel has been resurfaced on one side and I believe it should face the rear or throw out bearing is this correct?

and from what I see there is a shim installed on the flywheel between the Part# 7609 flywheel and the bolt (flywheel to crankshaft) part# 350816-S. ???? Is this the proper place for the shim?

At present I have the clutch rod, that is connected to the clutch shaft part# 7510 and the left brake pedal at the axle, extended out as far as it can go, being that I have replaced it and other connected parts should I disconnect it, and reconnect it after I have put the tractor back together? Any previous setting is no longer valid.

The engine seems overly tight as I cannot move the pistons or valves via the ratchet (crankshaft) part# 6319 and a screwdriver. The machinist said this was due to the new rope seals and other parts he installed. Being that this my first machine shop rebuild I am not sure what to think on this. I thought that I would be able to move the crankshaft pulley with some drag, but not this amount of effort.

I had to remove 6 head studs to move some of the brackets to the correct place (IE: governor linkage mount, spark plug wire tube) Is there a method sequence for re-torquing these studs I should be aware of? I would think I would spread the torque as much as possible over the valve cover and slowly increase the torque over multiple passes.

After spending the time and money having the engine rebuilt and buying various parts, I don't want to create more work by not asking.
Thank You all for the help over the years, I'm glad to have the forum and it's members when I need help.

Happy Thanksgiving to All.

William

 

[soaked]

Hi William S,
If mine, would call the machine shop and ask if they used locktite on the cam bolts.

Many front mounts dont have the thrust spring. The helical gear thrust wants to push the cam into the engine. ( unless decelerating )

Half a tho thicker on the throw out bearing seems ok.

My 8n flywheel has opening on each side to drive the pilot bearing.
FO-4 manual says the thickness of the flywheel, measured between friction surface and mounting flange surface is not to be less than 0.855 inch.

Mount the flywheel, with the pilot bearing installed, then the ~ 4 inch shim disk, then the 4 bolts go in. Yes the new resurfaced side faces the clutch. The 6 pressure plate bolt holes are not drilled all the way through...

Not sure on your replaced clutch shaft question.

Good practice in my opinion is to rotate the crank after each piston goes in. Expect more effort to turn with each piston. Once the oil pan with its rope seals are bolted on, it can take 60 ft lbs or more to turn. I like to turn it a few hundred times by hand--- with 5 quarts of oil in the pan. Oil should come out the brass t fitting showing its oil pump is primed.

Not sure on head studs, believe they should thread in all the way to the shoulder with finger pressure, and then only torque the nuts.
Happy Thanksgiving to all!
John

 

[Bruce(OR)]

You didn't take pics upon disassembly.

The fibrous clutch disc is located between the machined surface of the flywheel and the steel clutch plate. It should be placed so the taller side of the fibrous clutch disc extends into the steel clutch plate and NOT towards the flywheel.

The clutch pilot bushing or bearing, in some cases, should be installed into the back of the crankshaft. I have installed those with large diameter sockets on the outer edge and driven into place.

Engine oil pump should be packed with Vaseline before the pan is installed. I have also placed a slight amount of Vaseline into the pick up tube.
I do not desire the oil pump to become air locked and have cavitation on a new engine.

As far as the engine being hard to turn, that is normal and is due to the bearing crush load being applied on the crankshaft upon initial assembly.
No, not the flat surface of the bearing but rather the edges where the bearing cap is bolted to the block.

Rotating a new engine without proper lubrication might damage the engine.

New cam and lifters? Break in oil is 30W? Run for 30 minutes with varying RPM to splash lube the cam?
Change oil and filter after the first 30 minutes? Refill with 30W oil to seat the rings long term?
Or going to what oil?

Others, far smarter than I, should be along shortly.

Happy Thanksgiving!!!

 

[William S]

Bruce & John

Thanks for your reply, the replies have cleared most of my questions leaving 1 or 2 for me to research further.
To recap:

I took some pictures of the disassembly, just not enough clear pictures.

A tight engine is normal. I only moved the crankshaft pulley 2 or 3 inches at the most as I realize a dry rotation can be harmful. I am going to use a 30w oil and change it and the filter after 30 mins of initial start up . Thanks for the heads up on rotating the motor w/5qts of oil to check oil flow and get some oil in various locations in the motor.

The shop replaced the everything but the valve lifters, he also replaced the valve seats as well. He said the lifters looked good and unless I wanted adjustable type lifters he would install the original ones. They also installed the valve train and pistons

The original sleeves were .090" type and they were replaced using the original pistons and connected hardware. he did acquire new main bearings

I'm glad to hear the thickness of the throw-out bearing is OK.

the nuts on the valve cover bolt,,I made 3 passes increasing the torque until I arrived at 50-55lbs.

As For the oil pump I'll ask when the shop opens next. The same for the freeze plugs, lock-tight on the cam bolts, soaking of the rope seals, what lube was used when he was putting the engine together.

After talking with the machine shop about the following items, I will remove the flywheel and install the pilot bearing , remove the timing cover to put the 'locking ring' and what looks like a oil-slinger on the camshaft behind the front pulley and inside of the cover..It would be a job to haul the engine back to him.

Well, I hope you had a Great Thanksgiving, William

 

[soaked]

Hi William S,
Had a very nice Thanksgiving thanks
9n came with .040 sleeves from the factory, so its great a PO bored to .090.

Hope you arent using old rings.

Hope old pistons ring lands are in spec, and piston to sleeve fitment is proper.

Yes the Head nuts torque to 50-55 ft lbs.

Also ask if oil pump gears measured .562 - .563, (or .724 - .725 if wider pump was installed), and how thick was the gasket. Short, out of spec gears, and/or a thick gasket can lead to a pump that wont prime quickly and low pressure when hot. Some ditch the gasket and use permatex aviation gasket maker, as it seals in a very thin amount, so the cover is only a thou or two off the housing.
These are too thick and aren't going in any of my 8ns.

To prime the oil pump, need to squirt oil all the way to the plunger hole in the block, otherwise, if poured in, the oil will just drain into the notch and fall into the pan.

The oil slinger goes behind the crank pulley.
John

 

[William S]

John,

The machine shop put new rings in. I'll remember that about the slinger. I should know more about the oil pump after I get everything back in place and can hand turn the engine to verify oil movement. I'll ask about the gasket.

In the end I would rather post a result that the tractor was working at it's best than not ask a question that would have an opposite result. So far with all of your help I have gone pretty far into repairing various systems of the tractor, where I have had no experience previously, and have only produced the best of outcomes.

I appreciate all the help, William

 

[William S]

John,
If the oil pump proved to have lost it's prime and not flow while hand turning
if I was to place a small tube and use it to prime the oil pump would that be possible? From the pictures it looks like I could bridge the gap with a small tube. say 1/4" or so.

Thanks for your help. William

 

[soaked]

Yes that should do it.
Ive been using this pump, with 80-90 gear oil for years

Gear oil will start coming out the end and dripping down after 3 or 4 pumps..

 

[William S]

Thank You.

 

[William S]

"ask if they used locktite on the cam bolts." The machinist said he did use locktite on the cam bolts and admitted he did not place the oil slinger on the crank shaft and the nut retention washer on the camshaft.
As for the pistons, he said he made all the measurements and the rings were replaced with the sleeves.
the oil pump was primed, yet we had to lay the engine on it's side to get it home and in the garage.
I watched him put the valve train in and do needed measurements, while his father worked on the main bearings and finished the piston work and placement. His father was the original shop owner. Their shop builds several custom ready engines for the hot-rodders and those who want something above what they presently have.

Anyway, I have put some more back on the motor and I am awaiting a Radius cap/foot rest as I seem to have mis-placed one. I need to adjust the clutch rod/pedal today and finish some paint work

William

 

[soaked]

So gotta pull the timing cover to put the oil slinger back on, thats a bummer.
While in there, gonna put the cam bolt retainer back on too?

If the engine is too tight for the starter to spin good, the remidy is pulling the tractor to start it. If the clutch disengaging is a concern, the pull will be extra dangerous....

 

[William S]

That's what I was thinking. They didn't put those two parts for no reason, machinist said they were not important, yet I've seen several references reminding others to not forget them. The retainer is not too difficult, and I'm not sure if I have to go further into the tractor to get the slinger installed.

As for the tight engine, I was first going to rotate the engine by hand (actually socket and breaker bar) and see if it makes a difference. It's just me here working on the tractor, no one here to steer it if it's pulled. Besides the clutch has me a bit leery/cautious concerning the initial start up and getting the adjustments done correctly..........

 

[Hobo,NC]

That's what I was thinking. They didn't put those two parts for no reason, machinist said they were not important, yet I've seen several references reminding others to not forget them. The retainer is not too difficult, and I'm not sure if I have to go further into the tractor to get the slinger installed.

As for the tight engine, I was first going to rotate the engine by hand (actually socket and breaker bar) and see if it makes a difference. It's just me here working on the tractor, no one here to steer it if it's pulled. Besides the clutch has me a bit leery/cautious concerning the initial start up and getting the adjustments done correctly..........

If they had those parts in their hand while doing the work I would take the engine back to them and let them be resposable for any issues that may arise from the work. I have checked the torque required to turn a newly rebuilt engine over it took 90 ft lbs I would check that. The starter lit-it off no problem.

The pan and timing cover have to come off to replace the slinger : (

 

[soaked]

Agree with Hobo.

Adding a flatbar to an engine stand makes it easy to line up the arms to the engine so the pan can come off.

 

[William S]

OK, when I was torquing the flywheel bolts the flywheel rotated to the point I needed to place a block between the flywheel and the bell housing. With the 75-85lb torque spec the engine should fall into the correct rotation torque.
Thanks for the information.
I was thinking of getting the tractor parts all put back on and then trailer it to the shop and let him deal with the 2 items. That and a can of lard will grease the tracks!....... At present I have 75% of the tractor components re-installed. It just ...skip it.

 

[William S]

Well it's done, I cut a piece of plywood 3/4 inch and drilled a couple of holes to match the bell housing of my engine. Then to get it to rotate I used the engine. With the hoist doing the heavy work, I adapted a work table that was a bit taller than my other

I still have lots of parts to re-install , just hope I have enough hardware. Some of this work I have done before , on this tractor . I'll work on getting some photos for you all.
Merry Christmas !! William