92 Caddy with WK gasifier trailer

Projects
#1

Hi all,

I’ve finally got back into gasser mode after a long hiatus. I started this project 2 years ago but basically did nothing with it last year despite being mostly retired. Funny how it seems like I have less time than ever. It does feel great to be tinkering with woodgas again!

Anyways, I started out building a LaRosifier on the back of the Caddy on a platform like Herb did with his Caddy but it became too unwieldy so I decided to go with a trailer ala Mike but with a WK gasifier. I found a great SS barrel to use for the filter and used bits and pieces from the '69 GMC project, may it RIP. I drove the GMC down to our winter place near Asheville where it suffered a few mishaps like jumping out of gear, rolling down a hill and hitting a tree. Finally the trailing arms broke again and, not having my welding equipment with me, I sold it without the gasification system which I had left in NY and later cannibalized for the new Caddy project.

Here are some pictures of the Caddy and trailer:

cadillac 6-11-16 under hood.jpg956×717 81.9 KB

gasifier trailer1 6-11-16.jpg868×651 79.8 KB

gasifier trailer2 6-11-16.jpg868×651 65.2 KB

gasifier trailer3 6-11-16.jpg868×651 70.2 KB

Under the hood I have two blowers to suck the wood gas up to the engine in addition to the vertical stack of 5 blowers (4 forward 1 reverse) on the trailer. Past the blowers underneath and out of view I have a T going to an air filter and just an open leg to vent gas while the blowers are on. On the trailer I have the heat exchanger towards the car followed by the hopper/firetube section and finally the SS filter section. The trailer is kinda low so I didn’t use a condensate tank but have drain valves on the vertical legs of the radiator and filter. I have a car battery under the exchanger to power the blowers plus a standard ash dump under the firetube/ hopper section. The blower switches are in the back under the filter.

I used a well aged bag of wood chunks to make charcoal and put another bag of chunks in the hopper on top of the charcoal filled firetube.

I fired it up the day before yesterday with mixed results. I was able to flare the gas within minutes of lighting and then tried to move the car. The car didn’t drive well with the lit gasifier on gasoline, probably because I currently have no provision for closing (even partially) the woodgas line to the engine from within the car. All I have is my air valve right now.

After a few minutes of fooling around with the air valve I was able to run the engine on woodgas alone. It would even idle well! However, when I put the car in gear I could not make the hill in the driveway despite the engine running great at very low rpm. Some of this is because I currently have no provision for mechanically advancing the distributor, I read how Herb added this later to his but even before he did he was able to go 65 mph on woodgas. There is another possibility, the car had been running rough for a while on gasoline, the plugs were fine, I figure it has a bad injector but that isn’t easy to change, I had been trying to clean it out with Lucas fuel injector cleaner but so far it hasn’t worked. However, it might have a bad valve instead of injector which of course would hurt the engine’s performance on woodgas as well as gasoline. With the plugs as hard to get to as they are a compression test would not be easy but I might have to do it (sigh).
Also, the “engine overheating” light came on while I was trying to go up the hill so I backed back down and shut it off.

So, some of the things I will try to get the Caddy going down the road include:

  1. Add provision for mechanically advancing the distributor.
  2. Add a valve for at least partially closing the woodgas line to the engine from inside the car.
  3. Add a rheostat to the power to the injectors so I can run in a hybrid gasoline/woodgas mode, currently its either all woodgas or all gasoline. Maybe if I do this I won’t need to do #2. above.

If I still can’t get it to run right I will have to try to rule out a bad valve. I certainly miss the easy access to everything the old GMC had.

If anyone sees something I missed I would appreciate any suggestions.

Thanks,

Rick

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#2

Hey Rick glad you are playing with wood gas again I too took a break and trying to get going again. You can check for a bad valve easy enough with just a vacuum gauge. If vacuum gauge flutters and unsteady you have a valve not sealing. If it is steady valves are sealing fine. If you can get under the car the rear plugs are easily accessible from underneath. I sure miss driving my Caddy. I parked it due to the electric brake booster motor going south. It is an obsolete part and not all used them so even hard to find in the salvage yards. Since it has been sitting the fuel lines have rusted through. Keep at it you get it going well.

#3

Thanks, Jim for the vacuum gauge suggestion. I’d forgotten that trick. I’ll see if I can find mine and try it tomorrow.

#4

glad to see your back at it rick its funny seeing you posted because I made it to argos this year and mentioned to someone I haven’t seen anything on you lately . I was hoping to meet maybe this summer.
there is a couple of people local that picked up plans but so far just talk but there is still hope .
back to your problem running weak and overheating could lean towards a head or headgasket problem kinda a cady problem good luck. paul

#5

Paul, it would be great to see you anytime. Hope it’s nothing too serious with the Caddy as it’s probably not worth putting too much work and/or money into.

#6

Hey Rick. I too thought we had lost you. Taking the entire winter off from woodgas, I thought you had lost interest. And then to have you post, and you have a WK completely built. How great is that.

I don’t understand why you are going to put in a valve / restriction of the woodgas going to the motor. Get all the woodgas up there that you can and dilute it with air from your air mixer.

To check for a blown head gasket, take the radiator cap off when it is cold and run the engine looking for bubbles or pulsation in the radiator. Not sure if this can be done with the new radiators with the resivore separate from the radiator. Good luck. You have gone to all the trouble to build the WK don’t let a factory built Cadillac stop you now. TomC

2 Likes
#7

Hi Tom,

Great to hear from you, too. I have always appreciated your interest and support. I’ll have to peruse the thread on your truck and catch up. I had the WK mostly built more than a year ago and then was distracted by family, work and other life issues. Finally got it operational and tried it out.

The Caddy has been reliable but deteriorating recently. Rust is becoming more and more of an issue, I have had to replace most of the brake lines, one of them twice. It started running unevenly last year, I checked the plugs, they all looked good but I replaced them anyway and moved to the dirty injector theory. To remove and replace them would require removing a lot of other engine components,too, Having spent most of its existence in the rust belt has made removal of nuts and bolts problematic in many cases, so I tried the chemical route, so far unsuccessfully. It never has overheated before but maybe I do have a burnt valve or head gasket problem, I will check before doing anything more with it. If there is valve or head gasket trouble I will probably junk it as it would be too much work to fix it given its condition. At least with the WK on a trailer I can move to a different vehicle with less trouble.

Rick

1 Like
#8

Hello Rick,

Real glad to hear from you :blush: Missed you at Argos ,

Hope you work out the issues with the caddy .

1 Like
#9

Hi Wayne,

Glad to hear from you. I have missed going to Argos but unfortunately the May meetup coincides with our spring migration from NC to NY. When I get the Caddy system bugs worked out and it is roadworthy on woodgas I may reschedule the migration and brave a trip with it to the meetup.

I did a vacuum check on the Caddy this morning and with a steady vacuum reading of 17" Hg at idle with a little needle shake I believe the basic engine compression is OK, the slightly low reading according to the online guide to readings I found either indicates that the engine valves have significant overlap, certainly possible, and/or that the timing is a little retarded, also possible since I burn regular gasoline in it and the knock sensor is retarding the timing. The needle shake, a steady and rapid less than 1/2 psi flutter also indicates valve overlap. Anyway, no signs of burnt valves or blown head gaskets.

Rick

2 Likes
#10

Hi Tom,

I forgot to answer your question about the valve/ restriction of the woodgas to the motor. The trouble I ran into was when the gasifier was lit with the manual valve for the line on the trailer to the engine open and I tried to operate the engine on gasoline the engine bogged down like it was getting too much fuel even with the air valve wide open. I believe the engine was still sucking a lot of woodgas from the gasifier and enriching the gasoline mixture too much. So, if I either restrict the amount of woodgas by adding a valve that I can operate from within the car or reduce the amount of gasoline with a rheostat on the injectors I should be able to provide the engine with a better air/fuel mixture when trying to run with gasoline while the gasifier is lit.

Rick

2 Likes
#11

Hey Rick,

On some of my early builds I didn’t have the woodgas shut off valves from gasifier to motor. There were times when trying to switch to gasoline the woodgas was still getting to the motor and would not start or run too rich . After the gasifier is hot it will produce a slight positive pressure when shut off , enough to through the fuel/air ratio off .

1 Like
#12

Hi Wayne,

Sounds like what I experienced the other day. Hopefully either reducing the gasoline from the injectors with the rheostat or a shutoff valve in the woodgas line that I can operate from within the car will take care of the problem. I think the rheostat will be the easier solution for me to implement as access to the woodgas line near the engine is very limited and there are two lines underneath the car that I would have to install shutoffs in if I went that way.

Thanks,

Rick

1 Like
#13

Rick, is there anyway you can have a larger air inlet to you system so that you aren’t pulling gas from the WK. I am looking for something other than a reostat. I have a TBI system and put a dash light dimmer reostat in and it is not sensitive enough. It goes from off to on with like full fuel pressure. I know theoretically, that isn’t how they should work. I believe that is maybe why the guys are going to PWM ( electric trailer brakes ) and even with those Mr. Zinn is using a series of resistors to get fin tuning. So for your “flooding” problem I would suggest a larger air inlet. TomC

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#14

Anybody ever try to reroute the fuel pressure line through the cab and put a valve to dribble fuel and also shut it off completely?

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#15

Fuel in the passenger compartment would be a bad idea Mr. Don.

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#16

Maybe a long stem on the valve then with just the handle in the cab.

2 Likes
#17

Trucks have had fuel tank in the cabs for years. Most of mine still do . Only the Dakota don’t.

3 Likes
#18

After 1973? With high pressure fuel lines?

1 Like
#19

Hi Tom and Don,

Your questions and suggestions made me question in my mind how cutting the voltage to the injectors affects how the injector works. I do not know. Does it reduce the distance the pintle (the plunger in the injector) is retracted and hence the amount of fuel? Or does it somehow reduce the length of time the pintle is retracted? I suspect the former, that the pintle is not retracted as far but am not sure. I think the duration of the pulse is solely controlled by the computer. If so, then the shape of the injector pintle point and its mating socket would affect how sensitive flow of gasoline would be to distance of pintle retraction and hence to voltage reduction. I don’t know how variable the shape of the pintle and socket are. I can see how a broad, flat pintle point and socket would result in full or no flow with very little movement, a tapered pintle point and socket would need a longer stroke to get full flow and would be more easily controlled with voltage reduction. Maybe someone has looked into this and can enlighten me. Maybe I’ll hold off on the rheostat until I know more.

As far as the air inlet is concerned, I now have a 4" opening in the T below the engine compartment blowers along with the other 4" leg of the T that goes to the air cleaner. Of course the air has to move through the stationary blower fan blades to get to the engine. I don’t see this reducing flow much but maybe I’ll add another valved opening to the system before the blowers. As Wayne mentioned above, the gasifier might be pushing wood gas into the system with a slight positive pressure. Unfortunately adding a shutoff to the woodgas line that I can control from inside the car would not be easy as space and access to do so are limited, so adding a provision for more air might help and would be a lot easier to do.

Thanks,

Rick

1 Like
#20

I think most of us are leaving the injectors alone and just cutting the voltage to the fuel pump in the tank.

2 Likes