520h Engine swap Idea

[6wheeler 669]

So here I am thinking of an engine swap on my 520. I peened and glued the valve seat in once already. I don't know if I can do it again. And, I can't get T-Mo's post opened to see if there is something else I can do. So, with that being said? I came across a T260G (Onan). I got it with some other parts I aquired. I know it is a 24hp. I got it to spin over. It has good compression. So, I am thinking? Why can't I drop this in.The crank is the right size. It doesn't have the coil or wires on it. I haven't pulled the fan cover off yet. I don't know if it is a points engine. Anyone see a problem with this? I know JD (wash my mouth out with soap) used them on the front deck machines. Thoughts????  Thanks  Pat

[lynnmor 7,787]

I am not a fan of relying on peen and glue repairs.  Take the engine to a knowledgeable automotive machine shop and fit a custom valve seat with .005" to .006"  press fit.  Then you can peen a slight rim around the seat.  If you or the shop does the install of such a tight press fit, heat the block with a heat gun for an hour, while cooling the new seat in alcohol and dry ice.  Work fast, the seat will grow and the block will shrink in seconds as they transfer heat.  I made custom install and peening tools for my custom installation, but your final size will be different.  I cooled the install tool as well to maintain the low temperature longer.

[Shynon 7,479]

37 minutes ago, lynnmor said:

Take the engine to a knowledgeable automotive machine shop

Take it to Randy at Napa in Northfield, he can fix it and it will last.

[6wheeler 669]

Thanks lynnmoor. Done a few of these with limited success. This one is a bit tired. And, so am I. Shynon. I talked to Randy. We are kind of on the same mindset. Is it worth it? You know what I mean. I am thinking re-power. I have never been a big Onan fan. I had a feed trailer with a 220 as well and it was a PIA. Past memories are coming back. I know the 260 was a better( sort of, engine) I really want to put in a 224. But, it has an 1 1/2" shaft. Again, better engine. But, I think this T series engine might work. They logged alot of hours on Gen sets and welders w/o alot of grief. Maybe a tractor app. may be too much. I don't know. If I can't make it work? I am going to shoehorn a diesel into it. On a side note? Did you guys go to the Pioneer Power swap meet?

[ericj 1,579]

I've been told that the 24 hp Onan's were to big to physically fit into the 520 frame the 24's have longer jugs and a deeper oil pan to aid in cooling the big monster. I bought a 724 wheel horse Z turn mower just to get a hold of the 24 hp motor. If the trans die in the z turn then that motor is going in a wheel horse tractor. I will follow along to see how you make out. If you are going to make it to the big show I'll have 2 onan P220 motors for sale. good luck

 

 

 

 

eric j  

[Shynon 7,479]

22 hours ago, 6wheeler said:

Did you guys go to the Pioneer Power swap meet?

Yep wouldn't miss it

[ZXT 2,401]

On 6/5/2019 at 5:53 PM, 6wheeler said:

So here I am thinking of an engine swap on my 520. I peened and glued the valve seat in once already. I don't know if I can do it again. And, I can't get T-Mo's post opened to see if there is something else I can do. So, with that being said? I came across a T260G (Onan). I got it with some other parts I aquired. I know it is a 24hp. I got it to spin over. It has good compression. So, I am thinking? Why can't I drop this in.The crank is the right size. It doesn't have the coil or wires on it. I haven't pulled the fan cover off yet. I don't know if it is a points engine. Anyone see a problem with this? I know JD (wash my mouth out with soap) used them on the front deck machines. Thoughts????  Thanks  Pat

I think that a T260g is the same size as the N52M that's on my Sears. If that's the case, it's roughly 4" longer than the P220 in your Horse. I've read somewhere before that they will not fit due to this. Just food for thought.