New Muffler Preheater for 92 Dakotazag

I am placing this new project here in (Projects) because of the new design concept I have come up with that can be used on any wood gasifier. This design will be all metal, with may be silcone couplers to seal the pipes.
It will no longer have a check valve and two pusher blowers that can push cold air into the preheat muffler box. Instead it will rely on vaccum of the engine to move the air through the system and vaccum/pusher blower to move the air along. This pusher blower will be on the down stream side off the Preheater Muffler Box.
I am planing on using a older all metal Kirby Vaccum Cleaner if I can find one.
It will have a fabricated all metal flapper check valve insalled and a gate valve for long distance running that can isolate the Muffler Preheater from the gasifier Drop Box Preheater by closing the valve. This will prevent moisture from entering the gasifier durning very wet flooding driving conditions, like I experienced this last Argos trip across the USA. Boy I had a lot of moisture in my gasifier system, wet char bed the works. It ran well once I got it to dry out some.
The WK Gasifier Designs and workings of it will not be discussed here on this thread. Go to The 92 Dodge Dakota (from the book) thread, if you have and questions on Wayne’s Gasifier Design.
Here is a free hand drawing of what I am planing on building, to replace the old Muffler Preheater that developed a muffler leak on the trip to Argos. Your input and is welcome. Please stay on the threads topic. Thank you.

This new Muffler Preheater will have Quick release muffler couplings so maintenance and or muffler replacement can be done more easily.
I am sure I am going to fine stuff inside the old muffer preheater box once I get it removed.
I am still driving the truck and it would be a little loud with no mufflers on it. @Wayne This truck doesn’t need a second ticket.
So I will build the new (PMB) and then remove the old one and put the new one in.
The ideal I came up with is to clamp the split box or clam box around the muffler. When removing or placing the muffler there is no welding. It has couplings that holds the pipes on.
Also the muffler I am buying has a life time warranty on it , will see if this stainless steel muffler will last. (The Muffler Shop) my Friend Jerry owns has had some muffler wear outs, with this muffler and the people got new ones at no price charge for the muffler. But there was was a removal and installing charge. This will not happen with my muffler. I will remove it, if needed and replace it and put it back in place, with the couplings claps. Quick and easy. I am sure you all have had the fun of trying to get pipes a part and welding under the vehicle with muffler repair. Not fun at all.
I am waiting for the muffler to come in and then this project can get started.
Should I build the PMB out of stainless steel or metal, the old box that Wayne built is still in good shape. Heavy duty holds heat.
The only problem I think was in the mounting it directly to the frame, this might be where some of the mufflers resonating frequencies are coming from when driving in the 75 to 80 mph zone. I know it got a lot louder when the muffler develop a hole inside the Preheater Muffler Box. I like the sound of pipes but when it rattles the brain with the wrong and loud frequencies thats not good. Even the metal pipe going up to the Drop Box Preheater will have a silcone isolater between the pipes, and the pipe will not touch any part of the gasifier or truck using muffler hangers.


Between lighting, thunderstorms, and heavy rain with hail mixed in. I found a sunny day to take the old muffler Preheater out. I had to cut the exhaust pipes to get it down and out.

The wood gas 2" line that crosses over from the hay filter is to long to get it out.

With the exhaust leak that developed in the heatexchanger box you can see how hot it all got. This pipe needs to be replaced.

This truck is out of order for gasification at the moment. It is sure going to be loud driving it down the road now.


Hi, Bob!

One item you described driving in the heavy rain: The frontwheel shower is making the intake air “oversatturated” !

So to avoid that: Make an air-intake “snorkel” tube from abowe the load-plain, using a rain cover at the intake.

The chassis is perhaps not outliving the next muffler, unless you have it
sandblasted and “icebreaker”-painted and bitumen covered… this summer.



Hi Max, yes a snorkel is a great idea. Some where it could pick up drier air. There is still a lot of heat that comes off of the lower part of the gasifier above the bed. As Wayne would say you can hold you hand on it for about Three Mississippi counts. If I built a mantel around the lower part, and brought air into that and piped straight down to the muffler heatexchanger intake, I would think that would be a win, win. It is already just wasted heat coming off the gasifier. It might mean pulling the gasifier unit out to do it. Not thrilled about doing that at this time.


A little more work done on the new muffler heatexchanger. I have this old metal glad for electrical components so I took on side a cut out the Pieces for the box. 12 1/2" W x 31 1/2" L x 7 1/2" H the exhaust intake of the box is going to have finned tubing go in. So air can circulate around the hot tubes and pass back down the one side of the muffler and out and head up to the drop box heatexchanger. This time my pipe going up to the drop box will have insulation around it to help prevent any heat loss. Here’s some pictures.

The box is not being built according to my drawing I presented above. Just figured a better way to build it in my head.


I like it Bob. I was just laughing a little…I was back in 2012 reading old threads. I just read one that I think was Wayne building that muffler heat exchanger on your truck. Then I looked over here and you are osting about it again…I might be mistaken, but I think that was it, with La Rosa arguing with him that it would not last due to salt corosion…Thought it was ironic that you are workign on it now. Was the failure on the road this year the first replacement/problem of the unit that you know of?


Yes it is the same preheater muffler box with the same mufflers inside built in 2012 no modification have been done to the box. Chris built a new intake pipe going in to the box from the blowers. I modified the pipe coming out the the prehearter box.
With the new Muffler being stainless steel, I think this new preheater box will last a long time. The old box is still good and has many more miles of use, but the new Muffler is just to big for the box and I wanted it to fit in with more ground clearance this time. I might cut it open and pull the old mufflers out and reused it for something else.


Hi, Bob!
…if the box too is stainless…

The old box is still in good shape. I am just going to prep the new box and use high temp paint on the inside and out. The box if I figured it out right will be in 4 pieces and will screw together with high temperature sealant. Hoping to have water proof insulation wrap around it also. We will just have to see if there will be room between the truck frame and the drive line.


Hi all, some more up dating. I added some baffling to guide the cold air next to the muffler on the out side of the baffling there will be some insulation, not much but some.

I also extended the the stainless steel piping. The front of the box which will have the hottest exhaust gas coming will have fins to pull heat away from the pipes.

The cold air will enter the box not sure where yet, and exit out the other end.

Then the warm air will travel up to the drop box heatexchanger inside a insulated pipe. The pipe I used before was not insulated, lots of heat escaping though the pipe, even with the drier vent hose around it half way up the pipe. I am going to try to bring the intake fresh air pipe up to the Kirby blower so it can be routed to push air into the muffler Preheater Box. Max G. idea, is to Snorkel it, to get the in coming air away from the wet road conditions. I have not quite figured the pipe routing part out yet.


Looking good Bob, and the recent cooler weather has probably helped the fabrication


The box is no longer rectangular in shape. I had to shape it according to the frame of the truck. Wayne’s old preheaterbox was 11" wide.
My new Muffler was 12" wide making the box 12 1/2 " wide it touch the drive line when putting it back in the same place. So a slight modification was needed. Now it fits with just less then 1" from touching the drive line.

The top of the box is held on with screws.

Break time for me.


Life with a dakota. Jakob thinks he has graduated now that he’s working on a 2 wheel drive dakota. The 4x4 had no room at all. He says, “this thing has lots of room.”

pretty, Bob.


What is the little bird house for?


To keep humming birds warm in the winter?


Hi Don, Bird House I’m thinking as I look through the pictures. Lol okay now I see it. It is a rubber isolater muffler hanger. All the points where the muffler preheater box will be fasten to the frame has these isolater hangers. Wayne bolted the old one just to the frame. I’m thinking that there might have been some resonating sounds going into the frame at certain RPM, exhaust frequency from the engine. It was really loud even with the old mufflers.
We will just have to see if the sounds changes with the new muffler isolation mounts and new muffler. The old box was touching the frame also, so this has been changed. With the muffler Preheater box in place the front universal joint misses rubbing on the box by less then a 1/2". The rest of the drive line is 3/4".


looks good Bob that preheater should last long time while adding some preheat burner intake air, hopefully there is enough space for air travel, happy independence 4th of july. I here some fire works now 9 : 50 pm. Im with mike gib and don if there room for a winter humming bird.


A little up date on the muffler Preheater Box.

Put the ceramic blanket in side the box today and installed roofing pieces and muffler. Closed it up. Surpised it fix together great.

Now I just need to finish welding the box up and get it installed. The next thing will be to hook up the new Kirby vacuum blower, and one way flapper intake air valve all made of metal, no more plastic for me. Lots of projects planned before the snow flies.


Better hurry! The predictions are for much cooler evenings a no more muggy’s. Sign winter is coming. TomC


Here is a up date from September 8th, I did not realize I had not posted them.

Not shown are the other 3 muffler connections that were installed later at the Jerrys Muffler Shop my friend run. Jerry and Steve were a big help in getting this preheater muffler installed and connected.

On the September 9th muffler connections are welded on, and installation begins.

It was extremely hard to get everything line up and welded so this Preheater muffler could be removed if need in the future for other truck work. The clearance along the drive line is 1/2 to 3/4 of a inch. 3/8 of inch from touching the frame or foor bed of the truck. The mounting points are all rubber insulated.
With my injured shoulder I know I would not have been able to do this. Thank God for friends when you need help.
The sound of the truck is now quiet inside the cab, but out the back of tail pipe it has a great sound. @mggibb you are going to love sitting in the truck now going down the road now, we will be able to hear each other talk. Lol. The muffler is a Mega Flow muffler stainless steel, no back pressure except for the friction going down the tail pipe. Noticeable increase in power then what it had before. Hope higher fuel mileage too. On wood or gas would be nice.
Now more up dates

Insulated with ceramic wool and aluminum tape on the hot air return all metal pipe going to the gasifier Preheater. After what happen to my blowers and check valve melting down when it developed a exhaust leak in the Preheater box when traveling to Argos on gasoline last May, my intake pipe is also all metal. The check valve will also be made of metal.

This connection came off my old muffler pipe, it worked great for connecting the pipes together.

Now for today’s test. I have always wondered how hot the air gets coming from the Preheater muffler so I thought I would run the truck down the road with the 2 wood gas valves open and my air intake valve closed and see what temperatures I could develop through the gasifier to the hopper and grate temperature read outs. The air temperature was 35* f this morning before starting the truck and both gauges read 35 * f. After starting the truck up and idling for a few minutes.

The temperature at the grate was 37 *f and in the hopper it was 58 *f. Took the truck out for a drive and the hopper temperature dropped back down 40 *f and slowly came back up.
Cold air traveling around the hopper barrel and cooling tubes showed they are working good.
When I got back home after traveling around 15 miles, the temps had leveled out.

52 *f at the grate and 50 in the hopper. This was done with a cold gasifier and all the steel in it was at 35 *f. The temperature was still climbing with every 3 to 4 miles when I got home. But it showed the preheated air over came the cold gasifier steel and maintain the temperatures at the grate and hopper going down the road. Conclusion is the air is pretty hot coming out of the exhaust muffler preheater and best of all this part of the rebuild is done.

Now to work on the rebuilt Kirby vacuum blower, valving and compartment box.