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Engine transplants


Ronald Hribar

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Ronald Hribar

Sitting in my chair day dreaming

was thinking about the problems when putting in a different engine in an old tractor.

it usually involves raising new engine up an inch or more.

Would it work to raise the front of the tractor with taller tires or wheels?

would seem to me you would also gain more mower height

Whatvam I thinking wrong?

 

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Hi Ronald,

Yes you can put larger front tires on. But keep in mind the height you gain will be half the height difference between the new and old tires.  If the new tires are two inches in diameter larger, the front end of the tractor will only be raised up one inch. Remember one inch of new tire height is below the front spindle and one inch is above the spindle, hence the new tires only raise the front end up one inch in my example. 

Rick

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The extra inch or so must be added between the frame and the engine block.  The objective is to properly align the new engine crankshaft with the tractor's driveshaft.  You don't want a lot of wobble between the engine and driveshaft connection or you will blow out the fiber coupler.  It is designed to absorb some of the wobble, like a universal joint, but an engine swap can easily exceed normal limits.  Having performed several engine transplants, I don't see how larger wheels will do anything but raise the front end.

 

Edited by wwbragg
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You can buy mounting plates from gopowersport.com or studzracing.com but you will probably have to modify it.

I built mine from bedframe angle iron, steel plate and sloppy welding. 

Here is the plate I built to put a Predator 670 into a 9020 Powermax.  

Another major modification is the engine to driveshaft coupler.

Small engine warehouse has repower kits that include the mounting plate and coupler but they are pretty pricy.

What are you going to build?

DSCF3245.JPG

DSCF3246.JPG

Edited by wwbragg
add pics
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Was my solution to the fibre disc, just realized I have joints mismatched

it wouldn't let me paste the picture and do the dialogue  too

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It is my understanding comes from reading about Jeep builders. U-joints or flex plates will only absorb a small amount of driveline mis-alignment. So I think that using the right engine riser is the key to preventing unwanted vibrations! 

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U-joints are built to take extreme alignment issues.  @720nut's solution looks perfect.  They use u-joints on heavy trucks and NASCAR racers but a fiberglass disk will only take so much.  When I bought my 725, I found this:  A love-joy knuckle in back and a piece of old tire in front.

 

love joy.jpg

tire.jpg

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Some PO put this on one end of my 7016 driveshaft - 3/16" steel, mis-drilled and mis-aligned. Lucky it didn't ruin bearings or something.

 

shaft coupler.jpg

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1 hour ago, AC710 said:

mis-drilled and mis-aligned

We hate PO's don't we, @AC710?  Here's the driveshaft from a Landlord I found out n a field.  Looks like some kind of home-made u-joint.  I hope someday some restorationist doesn't have problems with some of my workarounds. 

I'll bet the fiber disk exploded and, with the motor still running, the driveshaft was left to flail around and destroyed the connector.  This one actually looks like an acceptable fix.

DSCF3260.JPG

DSCF3261.JPG

Edited by wwbragg
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17 hours ago, wwbragg said:

I'll bet the fiber disk exploded and, with the motor still running, the driveshaft was left to flail around and destroyed the connector. 

No doubt true!

I'm guessing the fiber disc got wallered out and the driveshaft had a war with the rockshaft before it all went south, judging by this photo. The wear pattern seems excessive, but confined, for an explosive, one-time failure.

 

driveshaft 7016.jpg

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6 hours ago, 720nut said:

Incase anyone is interested I have the plate and couplings to put a Honda in a Sov.

I was going to say "what?! a Japanese engine in a truly USA made tractor" until I thought further and checked - Honda manufactures small engines in the USA.

Oh, and I drive a Honda CRV.

Edited by AC710
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11 hours ago, AC710 said:

I was going to say "what?! a Japanese engine in a truly USA made tractor" until I thought further and checked - Honda manufactures small engines in the USA.

Still ain't right.  Kinda like Toyota in NASCAR.  666    But, in all fairness, they have been putting Kawasaki liquid cooled engines in the Legacy's, and Lombardi comes from over the pond in a different direction.  And we all have discussed the Predator numerous times.  Depends I guess if it's a worker or an anatomically correct, restored Garage Queen.  (and your wallet)

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1 hour ago, Brettw said:

Depends I guess if it's a worker or an anatomically correct, restored Garage Queen.

Truth be told, I just like to see them keep running and not go to the scrap yard. The only ones I object to are the hack jobs like the guy who took a sovereign and used the electric lift actuator as an outside lift for a snowplow. Y'all probably have seen this joker before.

 

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  • 3 weeks later...
On 3/16/2023 at 7:44 PM, Brettw said:

Depends I guess if it's a worker or an anatomically correct, restored Garage Queen.  (and your wallet)

Mine are workers, I have several brands of toys, all anatomically, sort of, correct. I try to put them back as original or improved, but, they still look like they should. I have said several times that I restore or improve mechanically, rarely touch the paint, since they are only original, once. I guess that is why I have a several Briggs and a few Kohler spare engines. No predatory junk around here, besides coyotes and hawks!

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On 3/16/2023 at 9:51 PM, AC710 said:

Truth be told, I just like to see them keep running and not go to the scrap yard. The only ones I object to are the hack jobs like the guy who took a sovereign and used the electric lift actuator as an outside lift for a snowplow. Y'all probably have seen this joker before.

 

I saw that years ago. If only he had read the operator’s manual. He spent all that time re-engineering the tractor to do what it did from factory but now in a less efficient manner. 

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10 hours ago, Chris727 said:

I saw that years ago. If only he had read the operator’s manual. He spent all that time re-engineering the tractor to do what it did from factory but now in a less efficient manner. 

Tragedy was, he had all the parts on hand but didn't know it. Added to that he's a terrible videographer - the videos are nearly unwatchable due to his lack of technical skill and planning.

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  • 1 month later...

Mmmm, I did a repower of a 7117 replacing a Kohler Kt17....  I used a very old piece of oak plank from a very old barn and as I keep my tractors inside I have not had and problems.

I also repower a sunstar with kohler m20 with predator 23hp and I again used a piece of old oak. (And again no problems) 

 

Remember lots of old cars had wooden chassis 

 

I find it easier to work with wood. 

 

 

Edited by colincox1
I forgot something
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