GT14 Repower

[dells68 7,498]

Ok guys.  I posted a little in another thread about working on repowering my parts GT14 with a 13 hp harbour freight engine.  Well, it's an engine bay full.  I had to slide it far enough to the left to get the pulley to line up, well that caused issues with the grille brace on that side.  I also had to raise it 1" to get the belt to line up in the guard.  I used 1" square tubing to lift and mount the engine.  I struggled with what to do with the gas tank and air filter.  I ended up making bracket to lift the tank about 1 1/4" and moved it 1 1/2" to the right.  I then decided to make an elbow out of pvc pipe to turn the air cleaner to the side like on the original Kohler.  I used a spare filter and rigged that up.  Fired right up and drives good.  Still gotta mount the switch and belt guard, but I'm more than satisfied for now.  Almost forgot, she'll be getting a cub muffler soon since the stock muffler blows right into the grille!

[Aldon 4,826]

Looks great! I like that the hood lines were kept original!

 

Let us know how it compares to the kohler for fuel consumption and power....

[dells68 7,498]

I may be wrong, but I'll bet it will beat my other thirsty Kohler on fuel consumption.  Started on second pull, tried on first.  As far as power, time will tell, but it seems to do ok on a pull.  I tried starting and stopping on a steep hill and it didn't flinch.  One real difference is weight.  When you go to turn on a hill, she seems a little light in the front and wants to slide some.  The predator isn't nearly as heavy as the Kohler.  Oh well, at least I feel like I can use it and not beat up on my all original one so much.  I really like the other one and want to take care of it!

[953 nut 55,297]

Very clever air filter mounting, hope the PVC holds up well. Didn't notice any choke or throttle cable hook ups, with a hydro I guess it is just fine to set it near wide open anyway.  

[Tankman 3,518]

Looks good! Ready...........work! 

[ztnoo 2,298]

dells68,

You've got a very interesting, well thought out, repower project there.

Its very informative to see your progress.

Keep up the good work!

My GT 14 was repowered, but merely switched over to a 16 hp Kohler K341 and was an easy swap. I agree Kohlers are very thirsty.... mine using 3-4 gallons in about an hour's worth of mowing at my residence! Even a simplistic chore like mowing the yard is becoming becoming expensive.

 

If memory serves me right, don't you have two GT 14s? Doesn't the other have a Kohler, I assume a K321?

Could you please tell us what the model numbers of both tractors are?

I've seen specs on the weight of the Kohler engines, but I can't put my finger on them this morning. My guess is you are probably sacrificing somewhere between 50 to 75 pounds using the Predator. That can make a big difference in handling. You may have to add weight to the front end for better control and tracking.

The spec for my GT 14 says it weighs 840 pounds, so if you have access to a scales close by, you could calculate the weight difference from standard stock weight. It will be significant I imagine. Cast Kohlers are boat anchors.

 

On another note, Aldon and I have been regularly comparing notes on our GT 14s. His resto-mod is a 1971 Model 1-0500. Mine is a first year,1969 Model 1-7441.

We are finding some rather subtle differences between the two model years while he is in the middle of his rebuild.

Of course, the difference is he's rebuilding his tractor, while I'm just trying to keep my functioning dependably for its one intended purpose......mowing.

One difference I discovered from his excellent pics is in the idler pulley set up. After some winter work on the tractor, I've recently had some belt derailment problems occurring with the hydro drive pulley as of late, of which the idler pulley/parking lever assembly is a part of the driveline/propulsion part of the tractor.

I discovered Aldon's idler pulley is surrounded by U shape bracket which my tractor doesn't have. We postulated perhaps that is likely an update from my first year production model. The lack of that bracket, 47 years after the tractor was made, maybe accounting for some of my problems now, because of wear and increasing tolerances in the idler pulley/parking brake assembly.

Aldon tells me all 4 GT 14s he has had have this idler U bracket. Here's a cropped pic of Aldon's idler.

 

Neither of your tractors appears to have this idler bracket. See below.

 

If its not too inconvenient, could you please take some close up shots of the idler pulley/parking brake area of both your tractors for us to examine and study?

If you could, please take a few shots with the lever in the up, parking brake position too.

Have you have any problems with belt derailment on either tractor?
Are you still using a stock 85" length belt on your repower?

Anything you can show us might further enlighten us about this critical area of the tractor.

 

Regards,

Steve

Edited April 11, 2016 by ztnoo

[Aldon 4,826]

I would be tempted to add a concrete or lead or ?? weight inside the empty nose space to regain handling similarities. Maybe relocate the battery to the nose section.

z

[953 nut 55,297]

1 hour ago, Aldon said:

tempted to add a concrete

Down and dirty way to do that would be to remove the grill, lay it flat on the ground, form the top near the lights and bottom where the bolts are and fill the rest with concrete. Probably add a couple of anchors to each side to hold it in.

[ztnoo 2,298]

dells68,

If I were in your situation, I'd want to know about how much weight you've lost pulling out the Kohler (or not having the Kohler originally) and replacing it with a Predator.

I'm sure you're going to need to add weight up front, but if it were me, I'd want to keep it as low as possible to the frame rails.

I would focus on maintaining a low center of gravity.

If you fill the grill frame with concrete, you'll be raising the center of gravity considerably over the weight of a full gas tank, let alone the engine weight differential.

Weight of One Gallon (U.S.) of Water, Gasoline, and Ethanol

• 1 gallon of water equals 8.33 lbs.
• 1 gallon of gasoline equals 5.8 to 6.5 lbs.
• 1 gallon of ethanol equals 6.59 lbs.

*     http://scplweb.santacruzpl.org/readyref/files/g-l/gasoline.shtml

      Source: U.S. Dept. of Energy. Fuel From Farms: a Guide to Small Scale Ethanol Production. May 1980. Page D-3.

 

So you've additionally lost + or- 39 lbs. from not having a filled stock tank  (6.5 lbs. x 6 gal.)

If someone here who knows or has a K321 on the bench they can weigh for us, we'll know reasonably accurately what you've lost in weight up front in the engine swap.

I'm guessing now its at least 100 pounds when fuel is included.

 

Looking at your pics, I'd say it looks like you might be able to slide a couple of weight lifting cast iron plates under the engine cylinder.

I'm pretty sure typical 25 # plates would sneak in there.....2-3 of them, and you might even luck out with a least one 50 # plate. Bolt them down through the center hole to a bracket on the underside of the frame rails.

I've got some plates in storage and I'll go measure diameters this afternoon. You could then cut some cardboard patterns based on my dimensions and see if they might fit before buying anything.

That would still leave space above them for other possible uses and keep all the weight very low. The less top heavy you can make the weigh adding, the better, IMO

Just some ideas.......

Edited April 11, 2016 by ztnoo

[dells68 7,498]

Hey guys, I agree about the weight.  Still no where near as light as my son's suburbans, but enough to notice!  I like the idea of hiding some weights in the grille shell!  I tried my best when I made the mods to the motor to do so in a way that would avoid damaging the tractor in a way that couldn't be easily repaired.  Ztnoo, I've noticed that there seem to be some differences in the way the brake lever operates on both tractors.  Perhaps this is different from year to year?  Neither have the bracket you were referring to.  I'll try to get some pics later this week.  I'm at work, but am running a temp of almost 100 with tylenol, so I doubt I'll be doing too much for the next couple of days.  My son started this junk on Friday night and I woke up with it this morning!  Thanks for all of your comments and suggestions, that is why this is a great place to be.  We all help each other out in sourcing ways to rehabilitate our machines.  My all original GT with the K321 is much heavier in the front, so I'm sure I've lost a good amount of weight, but to make a parts tractor a functioning worker, I'm still pretty happy

[dells68 7,498]

Sorry guys, forgot to mention - I plan on putting the throttle cable on within the next week.  Choke will probably stay as it is.  I plan on mounting the ignition setup near where the old rectifier was on the side panel.  This way I don't have to cut any wires that might void my warranty.

 

Dell

[ztnoo 2,298]

Just came back from storage and have the weight plate dimensions.

25 lbs. = 11 1/4" diameter, 1 1/16" hole (for bar mounting)

50 lbs. = 14 1/2" diameter, 1 1/16" hole (for bar mounting)       

 

Every plate you locate may vary slightly from these dimensions, but generally speaking, I think these specs will be pretty universal with plates with 1 1/16" holes.

At least it would allow the cardboard template to be cut to either prove or disprove the fit theory.

My plates were + or - 1" in thickness.    

Edited April 13, 2016 by ztnoo

[ztnoo 2,298]

Dell,

I think we've got an answer to the weight question.

Review the entire following thread:

118 + 39 = 157 lbs.

More than I thought!

No wonder your front end seems light.

[ztnoo 2,298]

I better complete my homework assignment and finish the equation, or I might have to stay after school in study hall or have to erase the backboards in the entire school for a month.   

118 + 39 = 157 lbs.

157 rounded to 160 - 73 lbs. (Predator weight) = 87 lbs. + or -  (weight to be added to repowered GT 14 to approximate stock weight with full tank of six gallons of gas)

Stock tractor weight: 840 lbs.

 

http://www.harborfreight.com/engines-generators/gas-engines/13-hp-420cc-ohv-horizontal-shaft-gas-engine-epa-60340.html

Edited April 11, 2016 by ztnoo

[dells68 7,498]

Don't worry, this teacher won't get you.  I'm still at school leaving plans for the next 3 days.  I was just diagnosed with the flu Type B.  Wanted some down time, but certainly not like this!!

 

Dell

[953 nut 55,297]

  Get well Dell.

[ztnoo 2,298]

The actual weight differential between the engine weights is not as great as it would seem on the surface, but, not insignificant either.

118 - 73 = 45 lbs.

73 / 118 = .6186

The Predator engine weighs roughly 3/8 less than the OEM Kohler K 321 installed engine.

 

I'll be interested in the performance aspect of this swap because this is a OHV engine, as opposed to a flat head Kohler 14hp K321.

It will be more efficient fuel wise no doubt, the question is will it have the same sort of "torque power" of a cast iron Kohler engine?

Beyond that question, is the ultimate measure of its service life.

Lots of Kohler K engines 45 to 60 years old, are still out there doing work for their owners. Tens of thousands, most likely. Who knows?

How long will the Predator hold up?

I'll probably be dead and 6 feet in the ground before that question can be answered.

You younger enthusiasts can argue that long after I have ceased to walk on this earth.

It should be an interesting discussion.....maybe technology will figure out a way to message me in the afterlife. 

 

The Predator's price is a very attractive price option and it is readily available all over the US @ Harbor Freight stores.

But, the displacement differential is not insignificant in small air cooled engines.

Generally speaking, displacement is king......that's old school stuff.....but we're not talking F1 engines here in this scenario.

A Kohler K 321 is 31.27 cu. in. =  512.42 cubic centimeters

The 13 hp Predator is 420 cc's.

A differential of almost 100cc's

Basically giving away about 1/5 volume of displacement. Not insignificant.

Dell, we'll expect a full report once you get well from your current affliction & have the time to perfect your swap.

Time to think is never a bad thing.........

 

Regards,

Steve

Edited April 12, 2016 by ztnoo

[Aldon 4,826]

1 hour ago, 953 nut said:

  Get well Dell.

[dells68 7,498]

Thanks guys-this is the first time since I was a teenager that I've had the flu!  Man do feel rough.  Saying some strange things too.  Forgive me if  I'll blame it on the 102.2 fever!

[ztnoo 2,298]

Very understandable, no apologies needed.

Get well, man......you have work to do......professionally and personally.

But let that thought coast until you improve medically.

That's Numero Uno.

Regards,

Steve

[dells68 7,498]

Thanks guys.  I'm laying here in a sweat trolling the parts for sale or trade at the big show.  Looks like I will have to come this year to pick up some goodies for our tractors - I hope!!!!

[dells68 7,498]

Just worked out a deal with Redhorse54 for a front blade for my GT.. Think that Emory's suburban had all the snow it wanted this last year!  Now I can beat up on my own tractor!

[dells68 7,498]

Thinking about weights.  I like the idea of making a weight for inside the grille she'll, but would have to find a way to hold it in.  Also considered putting some suitcase weights on the front or making a similar weight for the front, but that wouldn't work with my new to me blade when I get it.  Just laying here feeling green and thinking. I think I found a pic of how I'm feeling right now - . Only instead of flies, I think the buzzards have already picked up on my scent!

[Aldon 4,826]

If you find a money tree and tractor spends have less justification pain, you could procure a Spare GT14 cast nose section and fill with concreteband keep a spare if you ever decide to revert it back to original.

 

Or...if the original tank will still fit, use it and fill it with play sand.

 

 

[WHX?? 48,828]

I assume you consider looking for a set of front wheel weights to help out??

 

Nice thing about being sick is you get to lay in bed with the wife and kids waitng on you hand and foot...all while you get caught up on your on the laptop...

Get well soon