520h getting its balls back

[Wheelbearing 49]

After much debate over honda Vs. Onan. I'm going to do my first engine rebuild. starting with an Onan.

Here we go....

Oh look its not the Fricken fuel system its the intake valve seat......

[Brrly1 1,146]

Are you going to do a complete teardown? Just out of curiousity. You have already done a fabulous job on that tractor. Or are you just going to have the head redone?

:thumbs:

[Wheelbearing 49]

Are you going to do a complete teardown? Just out of curiousity. You have already done a fabulous job on that tractor. Or are you just going to have the head redone?

Yup.

after looking at the cylinder bores on the bottom side the motor had sat for a while, and ther is some water damge in the bores. and the motor does smoke when you start it slightly.

[truckin88 104]

AWESOME!!!!! will you be machining it yourself?

[Shuboxlover 478]

oh boy oh boy oh boy....

After seeing what you did to your tractor, I expect to see a tiny blower, or nitrous system on this bad boy now.

GOOD LUCK WITH THE REBUILD!!!!!!!!!!!!!!

please keep the pictures coming. :thumbs:

[sorekiwi 761]

Big pile of pieces!

I see tou havent attacked the cam drive gear on the crank yet, they're tight (shrunk onto the crank).

Here is a couple of pictures of how I have got them off. Its a thick aluminum plate bolted onto the gear with two long 10-32 cap screws, and then a harmonic balancer puller pulling on the aluminum plate.

There's a thread on MTF written by the guy at Onanparts.com with a lot of pictures and info on rebuilding Onans.

http://www.mytractorforum.com/showthread.php?t=91204.

[dgjks6 6]

Good choice. With the engine rebuild and everything you have done to that tractor, and with the proper mainainence it will last forever. I wil be watching this just I watched the rebuild of your 520.

Can you use any of the old pieces or are you going to get new pistons, rods, etc?

[squonk 40,913]

Get rid of that Fram filter while your at it. Go to a nearby Napa that has the cut open filter display. You'll see why.

http://people.msoe.edu/~yoderw/oilfilterst...ilterstudy.html

[Pollack Pete 2,273]

Lots of work.Good luck with your rebuild.In that one pic....what was in the drinking glass???? Parts cleaner???? Ha,ha.....

[Wheelbearing 49]

Lots of work.Good luck with your rebuild.In that one pic....what was in the drinking glass???? Parts cleaner???? Ha,ha.....

that was my buddies wisky glass.

Sorekiwi: Yup I'm at work right now with a piece of paper in my pocket with plans for a puller plate I'm going to make today.

As far as whats good and whats bad, when I opened the motor up it started to show some history. It was 757 hours on and remember picked this machine up about 15 months ago. No spark because of coil. when I did replace the coil if fired up and ran, tried blowing snow with it and it died first pass. Thought it was a fuel problem. That valve seat has made me replace the entire fuel system. Anyways I found inside on the bottom of the cylinder wall evidence of water sitting. And the oil pump gear had some rust on it. So this machine sat for a while before I rescued it. As for parts. Looks like new pistons. I didn't check the rods yet. I'm hoping I won't have to replace. them.

[WH Raider10 17]

QUOTE (Pollack Pete @ January 21, 2011 07:02 am)

Lots of work.Good luck with your rebuild.In that one pic....what was in the drinking glass???? Parts cleaner???? Ha,ha.....

that was my buddies wisky glass.

That sure looks like a Hoegaarden glass! Some great Belgian beer!!!

I'll be watching this thread,I'm sure the end result will be as good like the resto on your 520! Great work! :hide:

[Operator 7]

Your loves you for this

I'll be watching too.

Randy

[can whlvr 993]

it will be fun to watch this build,i would think that u can rebuild it cheaper than a 24 hp honda

[VinsRJ 721]

I'm looking forward to the progress made on this..... and the continuation of this thread. Keep us up-dated!

The only thing I know about Onans is you need to knock off a bank to cover the parts prices :banghead:

[AMC RULES 37,117]

All your 520 brothers thank you so much. :ROTF:

[Brrly1 1,146]

I got a better idea instead of going to NAPA just go to your dealer and get the correct filter for the application. That is just like the trans filter save yourself some money in the long run. Yea sure it might cost a few more dollars now but where will you end up. I doubt this next statement is true but do you have any idea that that filter could have, I say could have been part of the problem. Something to think about especially since you are going to be putting in the Big Bucks. Go OEM.

Love that tractor especially the forward controls.

:ROTF:

[Wheelbearing 49]

Timing gear removal. Cut a piece of 1/4 304 stainless steel plate at work to pull the timing gear off. I cut it on the laser, took 5 seconds. Can't believe how fast these machines are. 6000watts of power. even put the key hole clearance in.

[Confused99 2]

Looks great. I used to work on lasers. My college degree is in Laser Electro Optics.

[Wheelbearing 49]

Ok so this is how the motor stands.

valve seat is being replaced with there own design seat..

cylinders from bottom to top out .005

So I said do the seat and bore both holes over .01

I next day air sent them them the parts yesturday.

I'm picking up the block tomorrow (thursday)

fresh bore new seat. and two new pistons. boooooo. yaaa

[Brrly1 1,146]

Wheelbearing, after all the work you have done to this machine It will take care of you for a very long time. Take care of it and it will take care of you. Them forward controls are fantastic. Get some of the OEM filters. They have to be the best design for this application. Great work. You definitely have something to be proud of.

:thumbs:

[Wheelbearing 49]

Wheelbearing, afetr all the work you have done to this machine It will take care of you for a very long time. Take care of it and it will take care of you. Them forward controls are fantastic. Get some of the OEM filters. They have to be the best design for this application. Great work. You definitely have something to be proud of.

I did take a look at those filter posts man fram is got to be the worst filter as far as filter length . I was using napa gold. that filet was only on there for 7 days.

when I changed the oil.

[just me 0]

If I remember correctly NAPA filters are made by the WIX company and I my opinion WIX are the best in filter market. I'm glad the Onan is staying and you'll be happy with it now, Especially that you'll know it inside and out.

[Wheelbearing 49]

Just m: thats the filter I had in it all summer was the napa gold wix filter.

here are some pics of resealing my intake manifold. I had some problems when mowing the law. when the motor got hot the motor would start to over rev.

Motor is almost done they just have to hone the cylinders tomorrow. I need this machine back up and running its bad here in Ct. my driveway and street are like a cow path. I"m going to break her in sat. and do some clean up with this big baby. and maybe do some of the road. there is 4ft of of the road on each side with snow on it. Time for the Horse to work like she loves it. Gonna a be a lot of running break in before blowing.

[stevebo-(Moderator) 8,326]

I have to say that was fast work !! Your work is always over the top !! Great job. now you just need to load that bad boy on the trailer and get it to the show this year :banghead:

[MalMac 1,331]

When putting the cam gear back on, is it a shrink fit or press on how did you go about it?