Need advice on a 520H re-power

[Wheel-N-It 2,969]

Hello everybody. Just joined, posted in the "Meet and Greet", and now seeking some advice from the 520 experts. I recently finished front to back maintenance of a 1991 312-8 that I have owned since new, and now the WheelHorse bug has bitten me, I'm infected and I need another one. One of my Allis / Case collector friends has a mid 1990's 520H with a crack in the Onan block. Probably replacing the Onan with another Onan is not going to happen, so I am seeking advice as to whether or not I can replace the Onan with a single cylinder .flathead Kohler 16hp engine (K341). I think the 520 was built for a couple of years with the 16 Kohler. Not that I have a problem turninng wrenches but for me this needs to be a direct bolt in replacement or I had rather get another/different Horse. I have surfed all over this site to find an answer to my question but with no success, so i will have to ask the question. Thank you all very much for any help you can give me. By the way I have a K341 in a 1975 Cub Cadet 1650 Hydro so I am a little familiar with that motor too, but I'd rather not take it out of the Cub and install it in the 520 just to see if it would work (HA)

Van

[Rollerman 290]

The 520's all used the Onans.

One of our members "zieg" a few years back did a 520H/Kohler K341 conversion.

I believe he was happy with the outcome.

[HorseFixer 2,012]

What all is wrong with that 520 Onan Engine? what cracked the block? A 16 should bolt in there maybe not directly without drilling nut it should go. Its still going to require some wireing changes and some of the stuff on the dash vaccume for example, ect will not work so just keep that in mind. The 520-H to my knowledge never had anything but an ONAN 20HP installed in them. How much are you picking this tractor up for? You say your not a wrench So you would be better off waiting and buy a Tractor that is all together trust me I know from experience!!

Cheers ~Duke

:beer:

[Wheel-N-It 2,969]

What all is wrong with that 520 Onan Engine? what cracked the block? A 16 should bolt in there maybe not directly without drilling nut it should go. Its still going to require some wireing changes and some of the stuff on the dash vaccume for example, ect will not work so just keep that in mind. The 520-H to my knowledge never had anything but an ONAN 20HP installed in them. How much are you picking this tractor up for? You say your not a wrench So you would be better off waiting and buy a Tractor that is all together trust me I know from experience!!

Cheers ~Duke

Duke, don't know what cracked the block, but according to my friend the tractor started losing power, the shop adjusted the valves, everything worked ok for a short while then the engine lost power again, and that is when he discovered the block was cracked. I have not looked at the 520 yet. It was was raining here Monday evening when I was scheduled to go there (the 520 is sitting outside), so we have rescheduled for Thursday or Friday evening. We have not talked any money yet, so that is still up in the air. As far as my wrench turning skills go, I am certainly not a master mechanic, but know myself well enough to know if this not a direct bolt in replacement then I will be better off with another project. Been down that road too a few times

Thank you Duke. I need your input and expertise.

[CRE1992 135]

Wheel n it, get some pictures of it, if your not interested in the project, some members on here might. Heck I might even be interested in it!

-Charles

[zieg72 209]

Very happy with the K341 on the 520. I completely replaced the wiring harness with one from the donor C165 that I got the K341 from. I deleted the amp gauge circuit but retained the hour meter, volt meter and gas gauge. I removed the 520H wiring harness and Tach for future use. I was very impressed with the power and because engine was a lot lighter than the Onan twin the gear reduction steering was really easy. Operator bought it from me and has since sold it to another member on here.

[sorekiwi 761]

I havent actually done it, but I did look at doing it a couple of years ago. And I have a 516H here that is probably going to have that swap done to it when I find my round-tuit.

It should be a relatively easy swap.

I am not sure if all K341's are the same, the one I had here was a Wheelhorse spec one from a C160, and had the solid mount, cast iron oil pan and the 1 1/8" shaft so the Onan pulley and PTO assembly would swap right over.

I seem to remember that the crank on the Kohler sits a little lower than the Onan, so I was going to put a spacer under the engine to raise it up - I'm thinking 1/2" or 5/8", This would put the pulley in the same place as the Onan, so your belt guard will fit as well as the belts to drive a mower deck etc. If you did bolt the engine directly to the frame (without a spacer) you would probably need a belt guard of a Kohler powered tractor for example your 312.

Wiring has been mentioned, and you''re tach and vacuum guages wont work anymore. Probably an exhaust from something like your 312? You'll have to mount a voltage regulator for the Kohler somewhere.

I am not sure that I agree with Carl on the engine weight thing. I havent actually weighed either of them, but going by the hernia-o-meter I would bet on the Kohler being heavier. I've carried my Onan from the workbench to the tractor, I really dislike picking up a Kohler by myself.

Good luck and :text-welcomewave:

[SAM58 30]

This is an option...

http://smallenginewa...520H%20tractors

Click on Link.

And another one...

http://www.ebay.com/itm/STEINER-WHEEL-HORSE-ONAN-P220-20HP-ENGINE-REMANUFACTURE-/300645704351?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%252BC%26itu%3DUA%26otn%3D5%26pmod%3D300566748023%26ps%3D63%26clkid%3D5534756529148117546

[Wheel-N-It 2,969]

Thank you everyone for jumping in to help me with this decision. One thing is for sure, the 520 has been sitting outside for only four months so there would be no weathering damage done to it. So if it is not the project tractor I am looking for then I will plead with my friend to let me take it home and put it in the tractor shed to keep it out of the weather. In that case I will ask him if he is willing to sell it to someone else and I will get back to whoever is interested and text you some pics and a price. Sorry but one thing i cannot do on the computor yet is post pics. I use a computr quite a bit for my job but I never have to post pics. Thank you SAM58 for the link to small engine warehouse. I check thm out already and I think I will be money and frustration ahead to buy a running 520 over the V-twin convsion. Good idea though! To Rollerman, HorseFixer, zieg72, and sorekiwi, thank you for your experience input. It adds value to my WheelHorse life.

So anyway, my plans are to see the 520 in person before weeks end,then sleep on it and go from there. Don't worry though guys, there is a WheelHorse project for me just over horizon, and I will keep you all informed and included in the process and progress.

Van

[Forest Road 594]

The 520 trans is identical to the other hydrostatic of the same years. They used 12 and14hp kohlers and all 16, 18, 20 hp onans. The chassis are also nearly identical. So dropping just about any hp motor will work. It really depends on what you're going to use the tractor for. Cutting grass and blowing now require the most power. Just plowing dirt and snow a 12hp is plentiful. Make no mistake more power is always prfered. Just not necessary. Let us know how you fare.

[can whlvr 993]

i have a 312 -h and it has the series 11 eaton same as a 520,i would not recomend anything smaller than 16hp,i have a 14 in there now and its still under powered,at least for snow throwing it is,it will do it but slow is the word,go with a 16 or bigger jmo

[smoreau 658]

I'm re-powering a 91 520 with a 18 kohler magnum engine for my loader tractor and the left side onen bolt holes lined right up with the twin Kohler Just had to drill two holes. I plan on using the entire 520 harness and make all the gauges work as if it was a onen was in there. Still haven't finished the project yet as I'm just piecing it together and it will get done when it's done.

[Wheel-N-It 2,969]

Thank you Forest Road,, can whlvr, and smoreau for lending me some good knowledge. I am wanting to get another Horse to power the tiller I bought years ago for my 312.The 312 opereates the tiller just fine so a 16hp would of course do the job. OK so you guys are great, and feeding me the information I need. Also btw, my friend has several other WheelHorses (he's one of those guys who has some of everything), so who knows................... maybe instead I can talk him out of one of those that runs.

Keep your fingers crossed for me,

Van

[Wheel-N-It 2,969]

OK, struck a deal on the 520. I went and looked at it after work today. It has a 48inch mowing deck, the hourmeter is showing 735hours, low hours in my opinion. Tractor is a little dirty from sitting outside for a few months, but of course no permanent weather damage from that short amount of time. Everything is there and the tractor is not beat up. Actually I'm excited about it. I will be picking it up Monday. My friend who I am buying it from asked me to give him what it is worth in scrap metal and he would be happy knowing it is going to my house. I will gladly give him that, plus I am going to give him a brand new in the box 6.5horsepower Honda clone motor I bought at Harbor Freight, and this will be to replace the tired old engine on his pull behind yard leaf vacuum. I want to do something extra as he is a really good friend.

So anyway, once I get it home, it will be time for a good cleaning, removing the mowing deck and see where to go next. Any ideas where to go next with this paqrticular tractor???

[Operator 7]

I'd go with the 16 Kohler! I bought the one from Zieg and it was a great tractor, mowed with it and a snowblower tractor. Really hated to sell it but needed to make the wife happy [she thinks I have toooo many] tractors and I had a chance to get my dream tractor a 1984 C-195.

[sorekiwi 761]

Any ideas where to go next with this paqrticular tractor???

First thing I would do is to find out what is actually wrong with the Onan. They are a sweet motor when they are running right.

[Shuboxlover 479]

Any ideas where to go next with this paqrticular tractor???

First thing I would do is to find out what is actually wrong with the Onan. They are a sweet motor when they are running right.

I'll second that!!!!!!!!!!!!!!!!

[Kelly 1,030]

I Third that, I have 3 nice running 520's they are smooth power houses.

[AMC RULES 37,141]

Any ideas where to go next with this paqrticular tractor???

First thing I would do is to find out what is actually wrong with the Onan. They are a sweet motor when they are running right.

Ditto what the Kiwi said, love my big V-twin too. :thumbs:

[CRE1992 135]

Ditto what the Kiwi said, love my big V-twin too.

Its actually an opposed twin ! :ychain:

[Wheel-N-It 2,969]

Great responses ya'll, Thank you! Now I'm really excited. OK, if I have to replace the Onan with a K341, is there a particular K341 for the WheelHorse, such as crankshaft diameter, crankshaft length for the drive pully, or are they pretty much universal? I have to be away from my computer till about 2pm but will check back asap. Have a good morning:)

[CTPATRIOT 12]

Can't wait to see pics!

[HorseFixer 2,012]

I am not sure that I agree with Carl on the engine weight thing. I havent actually weighed either of them, but going by the hernia-o-meter I would bet on the Kohler being heavier. I've carried my Onan from the workbench to the tractor, I really dislike picking up a Kohler by myself.

Good luck and

I agree with Mike on this one! I have lifted some Twin Kohlers this year on the (417A) essentially same engine as 20 magnum and now this Onan off the 520 And I like Mike said on the HERINIA "O" METER The Kohler is way heavier!

~Duke

[zieg72 209]

Nothing special but here are a few pictures of the outcome. I didn't actually weigh the K341 and the P220 but the Kohler did seem lighter both in wrestling them around and how much easier it steered when I drove it around. As stated earlier I had a complete great running C165 to harvest from. My thoughts were to make it as simple of a tractor as possible but retain some of the creature comforts that a 520H has. I used the wiring harness from the C165 but wired it as such to use the 520H voltage gauge, gas gauge and hour meter. No holes were needed to be drilled. I used the shacker engine plate and with the excepting of changing out the engine drive pulley to the bigger, hydro one it was an easy transplant.

[zieg72 209]

This was one that I wished I had kept but anyone knowing my space situation 2 is my limit as I will not store anything in the weather.