Engine upgrade on Judson TNT

After musing over the information in Davey's tm restoration, I am seriously thinking about ditching my factory 20 hp Kohler for a 27 horse on my tnt so that I can take advantage of a kunkle valve. Basically, I am looking to turn the tnt into a simplified El Diablo with the benefits of both machines.

They both use the 45 blower, but that El Diablo really holds excellent vacuum power thanks to the kunkle valve, but I prefer the ease of maint. of the tnt. It has been noted on this board that to spin the 45 into the 15 hg range takes most of the motor's power (18.5 hp) and will bog down on cgd carpets.

My business is heavily biased towards commercial, so it looks like the kunkle is not an option with the smaller 20 hp engine. I am thinking therefore of going to the same 27 hp that is found on the El Diablo to get my blower to work towards its full potential.

I see that Les had a "Super TNT" at the recent ICE expo running a 27 hp engine, but I wonder if this would be a direct bolt-in replacement or would the alignment be off with the blower? Anyone go to ICE and see this tnt up close?

My 20 hp engine only has 400 hours on it, so I could probably recover at least half of the upgrade cost, but I don't want to run into alignment issues down the road. After-all, the best part of this machine is the inherent reliability and I don't want to screw that up in the process.

El Diablo is a good machine and has pretty decent access to the components, but trouble-shooting and getting parts for the heater isn't so great. I also don't care for the weak tanks. By upgrading the tnt to a 27 hp with kunkle valve, I should have the best of what the El Diablo offers with all the benefits of what the tnt offers.

At least, I hope it works in that fashion.

Why don't you try your TNT first. I have a TNT with an 18hp Briggs and 45 blower and it performs great. I have not experienced any issues with it bogging down and my relief pops open around 18-19hg. This is where it was factory set. We can get into a whole other discussion about relief settings, but I think Les knows his stuff, so I don't monkey with it. The point being is that even at those settings it doesn't bog down. Just try it, you might like it and save yourself some time and money.

Thanks for the kick in the pants Pro Touch, I was starting to calm down over it driving home today. I should give it a shot first.

I think part of my concern was that my step valve was missing when I received the mount and had to mod one from the local hardware store, but I still don't think it pulls correctly. The idea of having a factory set valve at the ready appealed to me, especially if it can improve the vacuum.

Once I get it into the truck, I will have to talk Les into a chat about all this stuff. I guess I am just so anxious for Spring and being able to finish this project that has been staring at me since October....driving me crazy.

My TNT doesn't bogg down either the foot valve is set at 16 HG. Pick up a foot valve at Tractor Supply if the one you have doesn't work. But Im sure theres a good reason the new TNT dont come with the old 18 HP briggs

Mo wrote:My TNT doesn't bogg down either the foot valve is set at 16 HG. Pick up a foot valve at Tractor Supply if the one you have doesn't work. But Im sure theres a good reason the new TNT dont come with the old 18 HP briggs

Did you modify the foot valve or is it off the shelf at 16 HG?

It's the one that came with the machine it the same one at the tractor supply store double check the ID

http://www.tractorsupply.com/en/store/water-source-1-1-2-in-brass-foot-valve

I picked up a couple of them actually, but was never really happy with changing out the springs and trying to dial them in for the right setting. The closest I got was about 13 Hg and even then it was a little sporadic.

Seems weird..

I bought one, and found a much heavier spring at ACE, cut it to length, and then used my TM vac gauge to adjust the tension until it would only pull 15" max shown on gauge with the hose 100% blocked off. It was easy, and has been reliable, and hasn't changed in the almost a year since I set it. I check it once in awhile to make sure and it's always been spot on.

BTW your eng upgrade sounds interesting, Rob.

But like others have said, I'd prob run it first with what you have before you upgrade it......test it, and see how it performs, then make a decision.

engine upgrade is probably the best thing you can do for this truckmount a 27hp engine is what a 45 needs to perform best
you can use a smaller angine but is not the same El Diablo use a 24hp before and switched to a 27hp
I have a 47 roots blower and a 31hp EFI water cooled engine remember you are not spinning just the blower the pump can take up to 4hp to perform

Thanks gtech.....I was hoping someone had a photo.

I think I will be torn on this issue for awhile, but I better get the dang thing in the truck first then go from there.

I can see a bigger motor upgrade coming in the near future though, just maybe not right away.

On a design note, it is odd to see that the exhausts were combined on this design. When I was shopping for silencers, the vendors all told me that you shouldn't combine the 2 exhausts as the heat and pulses would just cause greater noise volumes....yet here it is and I do trust Les and his engineering a great deal. Not sure what to believe any more.

milspec6 wrote:
On a design note, it is odd to see that the exhausts were combined on this design.  When I was shopping for silencers, the vendors all told me that you shouldn't combine the 2 exhausts as the heat and pulses would just cause greater noise volumes....yet here it is and I do trust Les and his engineering a great deal.  Not sure what to believe any more.

He has done that on his more recent models Probably not a factor because its tapped in after the muffler, but it would be interesting to see what it would do if you were to tap in before the muffler and after blower.

the key is like Moe pointed tapped after the muffler
but many truckmounts have it this way
it can actually help with the exhaust by creating a venturi air output
as for noise as long as people keep using car mufflers and silencers for the blowers they going to fail

our TNT runs on a 25hp and never bogs down,   commercial carpet or any residential.    You can cover the end of the hose with your hand at over 200ft and it doesnt bog down.    

reaches 15hg within a few seconds of covering the end of the vac hose

I wouldnt bother switching out an engine that only has 400hrs  for a few extra HP,    sounds like a waste of money to me

If you can clean well at 250ft why spend lots of money to get more power thats just going to be wasted in an open vac relief valve, unless most all of your cleanings are well over 300ft of hose....

but what type of carpet are you most always cleaning at over 300ft of hose? commercial. anyone here ever had trouble with dry times on CGD? Stuff drys in like an hour without even doing dry passes

Im sure your TNT runs great on a 20hp, they were built with 18hp engines for like 15+ years I believe maybe 20 years

I really appreciate all the excellent advice.

I was on a job today with the El Diablo and realized that it also runs the generator off that motor, so it needs greater ponies than my tnt. I just didn't think about that point.

Most of the time I'm at about 300 feet, sometimes out 400, but I could move the van mid-cleaning to another entrance to keep things under 250 if needed. I guess this isn't really a big deal and like you point out, cgd will dry pretty quickly.

I just rebuilt the pressure release with a spring out of a brake repair kit that I had laying around....can't be a stronger spring out there than that...and will see what I get tomorrow. I may have just been working with a weak spring.

I will set it at 15 Hg and then test it on some carpet samples and see just what happens. It will not be at 300 feet, but it should answer some concerns.

What I really need is Spring!! It is dropping down to -9 again tonight, really getting sick of it.

What size of engine is on your TNT milspec6 and how many hours

gtech12v wrote:What size of engine is on your TNT milspec6 and how many hours

Kohler 20 hp....just barely over 400 hours

almost new keep that baby no need to replace for now
spin the engine at 3100 rpm's and the blower at 3600 and put a real blower silencer on it and be done

I am actually waiting for the heater to warm up the garage so that I can go out and set a new pressure relief valve and test it on some carpet samples.

The silencer will definitely be part of the design....might even be able to coat the silencer with that ceramic sound deadener as I think it is rated for the heat.

Well, I over-did the spring a little. The lowest I could dial back the vacuum setting was 16 Hg before I was out of threads...will have to tweak it some more, but it pulled strong on the carpet samples without bogging down.

My fast idle is set at 3540 rpm, which sounds a little high to me, but that will be for another day.

It felt pretty good to sit there and have this machine running after it has been sitting in storage for so long. I don't care for the Mr. Gasket pump much, but that will also be for another day. Right now, the machine is sound in performance and design....I will shelf the plans for an engine upgrade to sometime in the future.

Ron just get rid of that 20 HP engine you need the extra ponies...

Just Send it to me