P220

[Oak]

Thanks guys! Sam & J-Mech, nope as per the manual, the cam bearing away from the flywheel is splash lubed. Wow, I thought about drilling and running an external lube line but there are probably a million of these out there that run fine.



If you see something I'm doing wrong let me know. I'm still learning.


Started assembly with the crank first.
I'm using this assembly lube. Is this stuff any good?
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This crank was from a different engine(B48G) but I used the original shim and torqued it down to spec and ended up with .009 end play. Spec was 0.006-0.012.
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Here are the new style rods. They don't have the oil hole that points up towards the cam and also have a solid beam. There is a little notch in the casting that points up at the cam. You can see the notch at about the 4oclock position.
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Got the rods & pistons in and torqued to spec. I used red Loctite on the nuts.
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[Oak]

Time to install the crankshaft gear. It needs to be heated to around 450* to slide on the crank. Too hot and you mess it up, not hot enough and it won't go on. I used my Mapp gas tourch and a Fluke IR thermometer.
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That didn't work. Went to Walley World and picked up this finely built bearing oven for $18.
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I didn't let it in long enough but the bearing went on about 3/4 of the way and then I just used the hammer/socket method.
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Time to install the cam.

Houston, we have a problem!
This is where the cam enters the block on the flywheel side of the engine. These bearings where the aftermarket type and my machinist got them switched around. This bearing should be the thin one that is now installed on the opposite side. The thin bearing allows the cam to be angled around so that the lobes will clear it. The original and Onan replacements are notched so the lobes will clear. $50 wasted there.

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Here are 3 sets of cam bearings. The original are on the left, aftermarket replacements in the middle and the Onan replacements on the right.
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The new set on the right has the notch for installing the cam on the front bearing and the hole in the back bearing is for the points push rod that this engine doesn't have.

I used a threaded rod to pull the bearings into place along with some red Loctite.
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[J-Mech]

That "oven" is what I use to heat gears. If you leave it in there it will work fine.


I am not sure that red loctite on the cam bearing was a good idea. (I also wouldn't use it on the rod bolt/nuts.) Unless Onan specifies something like that (I'm doubting) they are to be installed dry. Hope you don't have to remove it. Installing it that way was a good idea. Cam bearing installation tools are expensive. I would have made the machinist who f***** it up install it.


That assembly lube is good stuff. As long as you have the oil pressure to clear it out. Don't use it on splash lube motors. It has to heat up to "melt" it out and let oil in. I shy away from it on all small engines. I use it on all other engines. Honestly, I'd recommend wiping it out and putting some gear on the journal.

[Oak]

Thanks J-Mech. I'm using the JD/Onan manual and it said to heat the gear for 30 minutes but I'm thinking that little oven may take longer, I'll know better next time. Didn't know that on the rod bolts either but then again it didn't say to do it in the manual.
I thought about taking it back to the machine shop for the cam bearings but that would have been another week I would have to wait....probably. When I was reading through the different manuals the Onan one calls the flywheel the front of the engine(because it is) but the JD calls the pto end the front of the engine, kind of confusing, maybe that is where he screwed up.

I do have another issue. I got all the valves in and adjusted but I noticed that the exhaust valves rotate fine but one of the intake rotates a little and the other intake does not rotate at all. I've also read that the P series(what this engine is) never had valve rotators. Why do the exhaust rotate and the others don't? They seem to rotate when in the lifted position if I turn them by hand. I pulled it apart and looked at the keepers, retainers and caps but don't really see anything strange but then again I don't what the he%$ to look for.
TIA

[J-Mech]

According to the P220G parts book, that engine does not have rotators. Rotating them by hand is not a good check. Sure they move some, maybe even spin but it really is irrelevant. Not sure why one intake doesn't turn. Is it tight in the guide? I never really tried to spin a valve once installed than I can remember....

A rotator goes on the end of the spring instead of the bell shaped cup that the keepers fit into on that engine. A rotator is thicker. It has a mechanism inside that rotates the valve when under pressure from the cam. Even if it had rotators and you rolled the engine by hand, you can seldom rotate it fast enough to get a valve to spin. Some will, some wont.

According to the parts book, the B48G had rotators.


I hope you didn't think I was being smart about the homemade tool for the cam bearing install. I really did think that was a good idea.

[Oak]

J-Mech, thanks for the help so far, I really appreciate it and no I didn't think it was a smart comment on the homemade dohicky. That is why I posted early that if you see me messing something up to let me know. I read that also about the rotators in the P series but what is strange is that the exhaust turn 90* on every rotation(lifter only). Maybe I'm over thinking but then the more I think about it on an engine with rotators I bet the complete valve turns and not just the lifter. Is that correct?

[J-Mech]

The lifters should spin a little because of how the cam drives them. If a lobe is wore funny, or the same lifter didn't go back on the same lobe, it may spin, but should wear back in.

Yes, the whole valve will rotate with a valve rotator.

The purpose of the rotator is to set the valve into the seat differently each time. Helps the valve and seat wear more evenly, not just on one side. Valves tend to cock to one side because of spring force which makes it sit into the seat at an angle, wearing the valve head on one side. Then it doesn't seal as good. Rotators help it wear the head even. Also helps with carbon build up on the sealing surface, and valve head temp. The side of the head closest to the flame will tend to get hotter. Intake valves always have cool air flowing across them and they don't tend to get hot, or wear as fast as an exhaust valve. (Because they stay cooler.)

[jaynjeep]

Originally Posted by Oak

J-Mech, thanks for the help so far, I really appreciate it and no I didn't think it was a smart comment on the homemade dohicky. That is why I posted early that if you see me messing something up to let me know. I read that also about the rotators in the P series but what is strange is that the exhaust turn 90* on every rotation(lifter only). Maybe I'm over thinking but then the more I think about it on an engine with rotators I bet the complete valve turns and not just the lifter. Is that correct?

Todd,

the rotator is designed to rotate the entire valve.. that way it seats in a different spot every time it comes down on the seat.. A lot of times you only see rotators on the exhaust valve. I don't know enough about the Onans to say if it should have them or not. Even if they aren't rotating correctly it should work just fine in a light duty application.. something that isn't being run hard all day every day.

Looks like you are doing a fine job to me!

I like the custom tools!! or doohickey!!

[Oak]

Okay guys, what do I do for head bolts? Reuse what came out, get grade 8 bolts or something else?

[J-Mech]

New grade 8 bolts. I have used bolts over, but prefer new because, hey, they're cheap.