Installing an Onan 4K genny in a 1998 Vista

[RolesvilleMarina]

I thought I would start a new thread here in case anyone wants to follow the Genny Install.

In October of 2019 I bought a short yellow school bus with seats off the FB marketplace and literally just went to town on it. It went too slow, so while I was building the inside I bought another schoolbus and swapped the transmissions so it would tool down the motorway.

this thread though is the genny install

We have a 1998 THomas 7 Window Vista
T444E engine and an Allison 2000 transmission

[/url]

and of course the inside for those curious




I picked up this 1996 Onan Emerald Plus 4k for $100 on FB last thursday.



It's missing the muffler, and the remote start panel. However I DO luckily have the wires and plug to the control board to fab up my own remote start panel.


The guy wanted $450, I offered $200 and a week later he said ok. Drove 1 hour to see it, and the starter bendix wouldn't engage. He agreed to take $100 since he couldn't demonstrate it would even move.

I got it home, stripped off and cleaned the carby, pulled the starter and greased it up. She turns over and I verified 120 PSI in both cylinders, so I don't think it has a lot of hours on it. Also cleaned the slip rings and the brushes are still very long, another indicator of lower hours.



She fired right up and made power that evening. However the next morning she wouldn't stay running and was blowing the fuel pump fuse.
Broke it down, did a LOT of maintenance items anyway (slip ring cleaning and other bits) and became very familiar with its internals as I have never seen one before.



In the end it was learned that too many pints in me was the issue and that the night before when I was messing and cleaning after test I had incorrectly wired the relay. So I was the duffer, and all is now well.

Next on was to fabricate a new down tube. Looking online this part is $50, and being a tight bastard I used one of the Bus seat brackets left over (I save most metal) and made my own. The Previous owner had left the bolts, and the gasket... just no muffler. So I had the gasket to make the pattern.

the gasket



The Bus seat scrap thingy



I filled in the hole that was kinda in the way of making the piece and then traced it out and drilled the holes




using regular hand drill, and a vise... my drill press broke and I have not gotten another...



Then cut and shaped it with a harbor freight grinder and a flap wheel

and ended up with this



which I welded a chunk of leftover gas pipe from some other project.


I was telling the missus I can't even remember what the gas pipe was bought for or what I used the rest on.

Then bolted my new flanged down pipe on






Next I built a "Fake Genny" to use when mocking up and deciding where to put the genny, as the real one weighs around 175 lbs.

So far the stern under the rear of the bus where the motorcycle is stored is the best location... Width wise the genny was too low



Lengthwise however it tucks up nice and tidy.



Yes, I said under the Motorcycle



All for now... headed to the coast to see how the summer house fared during hurricane Isiases or whatever it was called

I'll be back onto the project Sunday on return

Cheers

[Meathead]

I’m currently doing the same thing. I hope you continue with this thread.

Peace

[Booyah45828]

Looking good. Those onan are pretty compact and reliable units. Good to see you got a deal on it too.

What's the fuel source going to be? Is it a dual fuel unit or gasoline only? Where are you going to mount the tank? You should also consider installing a muffler and piping to get the exhaust out from under the bus, but I imagine you already know that.

[RolesvilleMarina]

Originally Posted by Booyah45828

Looking good. Those onan are pretty compact and reliable units. Good to see you got a deal on it too.

What's the fuel source going to be? Is it a dual fuel unit or gasoline only? Where are you going to mount the tank? You should also consider installing a muffler and piping to get the exhaust out from under the bus, but I imagine you already know that.

Sadly it is petrol only so I will have to come up with a separate tank of at least 12 gallons to make it worthwhile. Petrol Burn is supposedly 1/2 gal per hour.

Onan mufflers are $100 and up. Agri supply provided this nice Allis Chalmers for $26, and the cool flapper was only $6 so I grabbed it too. Doubtful I will run the exahaust up and use it, but was too cool not to grab the flappity flap.

So this is what I have for the moment, for testing and being able to run it longer than a minute as before I had nothing.



But now I can start and let it run. We've tested the rooftop AC unit off her and she does great. So the decision was made to go ahead with the install... they have a good reputation, and parts aren't bad on this as long as the alternator side stays good. Seems the control board, and the rectifier are its two main trouble spots should one have issues.

I randomly start it, let it run, all the time now kinda daring it to act up and she runs like new. Doesn't hunt either which my 3500 house back up does slightly no matter what I have done to stop it.




So here it will sit until I fab up the cage/mount under the stern of the bus. It has been daily over 33C+ so not getting a lot done outside.

I wired in the 1000 watt inverter as well. We can roll down the road and keep the mini fridge cold for now.

Currently my plan was just shore power, and two deep cell leisure batteries.

However the inverter and the Genny have complicated things and now I have to put in a transfer switch (I have) and etc now. I have 3 sources of power now.
1. shore
2. Genny
3. Inverter whilst truck running. I do not have solar, nor a large leisure bank... We do not "live" in the bus, and do not plan too.. However small solar to top off the two leisure batteries we do have might come later. But no plans to be uber green with a roof full of solar here. And the missus won't do without the air con, so shore or genny will be 99% of it.


For the exhaust piping I am using gas pipe for the elbows and I will likely end up using conduit as well as part of the piping.. A friend says to def point down to ground to help muffle. I was however thinking a 2nd muffler, and then piping it up the stern to the roof (outside) steam punk style and using flappity flap. Cause I am weird

In the end its just metal and welding. I used a $3 gas threaded fitting and just welded that to the AC muffler... now I can screw it on or off if I need and as I fabricate.

I will build my own remote panel vs buying one... it's just an hour meter and the start button, as well as a volt meter but I have USB chargers in the bus with built in LCD volt meters so I don't need yet another lol

So we will be able to just wake up and have power at the push of a button if we need.

[RolesvilleMarina]

Originally Posted by Meathead

I’m currently doing the same thing. I hope you continue with this thread.

Peace

I am not sure if you followed my transmission swap thread, but I will totally complete this

I also have an Air con thread that prob some think is dead... but engine driven AC has taken a back burner for a bit... too hot to work outside so will be a fall project

and ask questions if you need anything... I learned a lot about these little petrol gennys when I messed up the relay

cheers

[Booyah45828]

Originally Posted by RolesvilleMarina

For the exhaust piping I am using gas pipe for the elbows and I will likely end up using conduit as well as part of the piping.. A friend says to def point down to ground to help muffle. I was however thinking a 2nd muffler, and then piping it up the stern to the roof (outside) steam punk style and using flappity flap. Cause I am weird

In the end its just metal and welding. I used a $3 gas threaded fitting and just welded that to the AC muffler... now I can screw it on or off if I need and as I fabricate.

I will build my own remote panel vs buying one...

Gas piping is fine, your emt conduit is galvanized, so be careful welding that or getting it hot.

Pointing exhaust down only works if the earth surface is grass or something soft, if it's gravel/concrete it won't make much of a difference down vs out. I'd put it out, and then use you're flapper to keep out bugs and rodents. Just make sure it's going out, with gas engines, there is a very real possibility of producing carbon monoxide, you don't want it sitting under your floor.

I built/bought my own panel. Nothing really to it but creating and following wiring diagrams to get it to work. You can make it as simple or complicated as you desire.

You don't necessarily need an auto transfer switch, you can run the generator wires to an outlet near your RV cord, and then either plug into the generator or a shore pedestal. Fairly easy IMO, bus some prefer the automatic feature of a transfer switch.

[Booyah45828]

Oh, and sometimes with gas piping and engine vibrations you might occasionally crack where the threads are. It all depends on the design really, but it wouldn't hurt to install a flex pipe of some sort with it.

[RolesvilleMarina]

Originally Posted by Booyah45828

Oh, and sometimes with gas piping and engine vibrations you might occasionally crack where the threads are. It all depends on the design really, but it wouldn't hurt to install a flex pipe of some sort with it.

yes def a flex pipe between the genny and the rest..

unsure how to pipe it yet, until I get it mounted.

I like the idea of piped up and out the roof like a crooked stack lol, but M will like veto this idea