T 3-15 engine swap

[Alexhasson]

well Maryland had a bad winter plus i didn't give the loader proper attention during the winter. the tarp blew off and the loader was covered with snow multiple times. some how water got in the hydraulic tank and not just the normal amount from building up over time, something like 2-3 quarts of water was drained out. heres a pic. there's some oil on top, also a small amount of oil water mixed (grey)


so on a warmer day i pulled that out of the tank. I got to the engine a couple days later and it was low temps again. I couldn't get teh carb to play nice so i pulled it apart to clean it and it was a frozen block of ice.


I was already unhappy with this old worn out engine (k321) last year that i didn't hesitate to start shopping for a new engine. honestly if i had the cash i would have bought a better engine. but if the harbor freight 420cc last a few years it wil have done it's job.

any way i'll be pulling every hose the main pump and the drive motor apart in the coming weeks to clear them of any water and then put it all back together with the new motor.
gonna be fun.

 

[Terrasteve]

Looks like the old girl has been thru a flood. Was the cap missing from the hydraulic tank? I can't imagine that much water getting into the tank with the cap on. You will always have some condensation, but 2 or 3 quarts is a lot of water. I hope you can get her back up and operating again without to much trouble. Let us know how the engine swap go's.

 

[Alexhasson]

Well i only have some working theories on has that much water got in. now it did snow a lot in Maryland and it was uncovered so that might be some. but the upright arms that the loader attaches to the tractor doubles as a reservoir and the tubing is open at the top to receive the arms. so i thought maybe a cracked weld may allow water to enter. just a theory , i'll pressure test it in the future but for now on with the motor swap.

Alrighty so here's the main event, pull out the K321 from 1975 and install the Harbor freight predator 420cc (chonda motor).

Primary hurdles.
- motor mount to the frame is different.
- existing bell housing for the hydraulic motor doesn't match anything on the new engine.
- overall size and shape of the new engine is different.
- does the new engine have to torque to start against the hydraulic load from the trans pump

so on with the pictures.

Here is the bell housing adapter. It takes the trapezoid bolt patter and marries the square bolt patter on the new motor.




here's the motor frame mount adapter.




had to cut out part of the frame due to the shape change, carb and air intake stuck out a bit. i'll weld some metal back in once the engine is done.


all bolted up. but it was 10pm and i couldn't test it out. until the next day.


TESTED. It all worked except my love joy walked. upon removal i noticed the set screw wasn't hard to back ut on the pump side so i'm thinking this was my fault. I'll be buying 2 shaft clamp collars to assist.


HILL BILLY BONUS
I made this adapter to run on a corded drill so i could run the loader and backhoe. the drill didn't have enough power to handle the drive needs though.


I'll update after i get to tinker again.

 

[Terrasteve]

The shaft clamps should do the trick to help keep the coupler together. I would use Loctite on all of the set screws for the clamps and coupler to keep them from backing out.

 

[Alexhasson]

well i found the right pump adapter after a couple weeks of hunting. it will be here before next weekend so i'll have time to rework the body of the tractor to better accommodate the new engine also i need to build a wire harness to extend the ignition switch to the operator dash. My plate worked but I'm happier with the right part.

 

[2manyrocks]

My question is how well this chonda is going to power this unit. All the old kohlers had some pretty heavy flywheels that made torque. On my T5c with the newer Kohler engine style, it seems to me that it would have been much better to have had a diesel engine both from the viewpoint of fuel use and from the standpoint of having enough power to really run the machine.

 

[Alexhasson]

My question is how well this chonda is going to power this unit. All the old kohlers had some pretty heavy flywheels that made torque. On my T5c with the newer Kohler engine style, it seems to me that it would have been much better to have had a diesel engine both from the viewpoint of fuel use and from the standpoint of having enough power to really run the machine.

Fair question, based on the existing limitations of the t3-15 I doubt it will be noticeable. I think it's too small of a tractor to really worry about. I also would prefer a diesel for this application.

 

[Alexhasson]

The new adater delivered yesterday afternoon. it was test fitted and everything was perfect.


engine is all tightened down and ready to go. New adapter had access on both top and bottom and that was a welcome upgrade.


my breif use of it the other day using the first bracket proved that the engine worked fine at half idle just driving around so i think it will do well.
FYI to the other t3-15 owners, the pump installed in these units can handle up to a 40 horse power (1975) engine. So if you're in the works for an upgrade that could be a factor.


New adapter courtesy of P&J commercial products
Log Splitter | Hydraulic Cylinders | Hydraulic Wood Splitters
Hydraulic pump mounting bracket to small engines for log splitters
for reference my adapter is #9.

new engine uses the 6.5" bolt circle and the pump uses the SAE "B" 2 bolt 5.75" bolt circle.

I'll update with a review later, i'll likely be doing yard work this weekend so i'll have some real data.

 

[Terrasteve]

Lookin Good!

 

[2manyrocks]

I think you deserve some applause for figuring out how to adapt this engine to work.

 

[Alexhasson]

thanks for the kind words.

so an update.

I have some gardening to do but the topsoil doesn't deliver until Monday so i just went and ran it through the motions. used to loader on teh dirt and rocks and used the backhoe on some firewood bucks i haven't split yet.

everything worked great. I'm very happy. If there is any power loss then i couldn't notice it. maybe my worn out Kohler in it's hay day had more power but i'm pretty happy with this replacement engine. if I get 5 years out of it i'll be happy, that's cause I now day dream of finding a diesel that will fit.

couple pictures here, I relocated the key switch to wear i could reach it from the seat. I just made the cable extra long so i could move it anywhere. I thought about making it a magnetic mount. I also haven't hooked up the throttle cable yet, but the engine is equipped with the brackets for a cable so that should be easy. I also cut out the head light upright. the upright is on an angle the straightens out. I plan on reversing the angle so the engien doesn't hit the upright. the headlights will be in roughly the same place when finished.





one last note: I thought i had serious issues when I first got on it and drove it around, it stalled and i couldn't restart it.... out of gas. no kidding, I thought of everything except gas. easy fix though. I was smiling like an idiot.

 

[pontiac58]

one last note: I thought i had serious issues when I first got on it and drove it around, it stalled and i couldn't restart it.... out of gas. no kidding, I thought of everything except gas. easy fix though. I was smiling like an idiot.

Im glad im not the only one that does that.:drink:

 

[Alexhasson]

finally got my top soil delivery and got to test out teh new engine. everything went great it is at least equal to the old engine and certainly better that it starts up in 1 second as compared to the old kohler that needed too much help.

 

[Terrasteve]

A Job well done Sir! Glad everything worked out for you. How many horsepower is the new motor?

 

[Alexhasson]

well Predator engines don't advertise horse power, it's 420cc. safely between 13-14hp. certainly not weaker then the old 14hp kohler. and the main difference with the lack of engine mass and no heavy fly wheel is the low idle operation. It appears that the old kohler had one advantage. if you put it in low idle it wouldn't stall if you tried to drive it or move the bucket. this engine doesn't have the mass for low idle operation. medium or high speed however theres no stopping it. I currently only ruin low idle when it's sitting waiting on me. which is also kind of a poor mans parknig brake, put it on low idle and if it tries to drive off it can't

although there are some dune buggy go cart sites that sell all kinds of upgrades for the engine claiming they can make it 20hp. I quick google search brings up lots of web traffic on upgrading these engines.

 

[Buggs67]

FWIW.
Ii just put a Predator engine on my snowthrower to replace the old Tecumseh. Friends who had the generator with the same engine had instructions to run at part throttle for 3 hrs, then change the oil. SO I followed that procedure with my engine. The oil looked like metal flake paint. I also used full synthetic to refill. Cheap insurance.

In my research for the HF engine it appears that the common failures might be due to lubrication and poor brake-in.
Good luck.

 

[Alexhasson]

FWIW.
Ii just put a Predator engine on my snowthrower to replace the old Tecumseh. Friends who had the generator with the same engine had instructions to run at part throttle for 3 hrs, then change the oil. SO I followed that procedure with my engine. The oil looked like metal flake paint. I also used full synthetic to refill. Cheap insurance.

In my research for the HF engine it appears that the common failures might be due to lubrication and poor brake-in.
Good luck.

hey , thanks a lot.

i did a 20 minute low idle break in and only ran it for about an hour the other day. I'll change the oil before next use and see what it looks like. I do have the 1 year warranty so lets hope that covers for me for my mistakes on the break in.

 

[Alexhasson]

ok so i made a semi important discovery. the exhaust from the new engine blows on the passenger side lift cylinder when the bucket is at a certain height. so it's not hitting it all the time but i didn't like it either way. so i relocated the muffler.

built the manifold adapter from some scrap.


it raises and rotates the muffler. so now it blows out the front into open space.

 

[parluskq]

Awesome thread! i am getting ready to do the exact same thing and this will save me a ton of time. I am just deciding on which engine first

 

[parluskq]

does this engine run counter clockwise or clockwise?