Slightly diffrent propane question

[JeepsAndGuns]

So after reading the posts on here about propane, I have been puting more thought into it. I have a 401 right now. It has the holley truck avenger on it and I am kinda getting tired of the carb thing. I have a trans,t-case, and axle swap I am gonna do next year (see signature) Once I get all that done I am gonna start working on rebuilding my caddy 500. My plans were to build a nice fuel injection for it, since I was so tired of carbs. But I am a little worried about the cost of building the system (I want a MPI system, not TB) Not to mention the possiable PITA factor of tuneing it. After all the good threads on propane I was thinking, it has a lot of the benifits of fuel injection. Pressureized line, so no fuel pump. Since its a gas, no fuel bowl, and it will run at any angle like FI. It burns cleaner, motor and oil lasts longer. From what I read, its pretty easy to tune it. So I figgured I would just build the engine for propane and run that. But then I thought, what if it doesnt work out as well as I want, or becomes too mutch of a PITA because of the dis advantages. (harder to find propane, smaller tanks, less mileage, etc..) I would then have a motor with too high a compression to run pump gas. I would prety mutch have to stay with propane, or build a new engine. I dont want to put myself in a bind.

I have been tired of the carb on my 401 for a while, and I was thinking about running a TB injection on it untill I build my 500. And I just missed a complete TB system that was for sale a few months ago. But then a few days ago, it hit me like a ton of bricks. Why waste time and money building a TB system for it if I am only gonna run the 401 for a couple more years. So I figured why not start with the 401 and convert it to propane. That way if I like it, I stick with it, if not, I go fuel injection.

My thoughts are this, If they make a propane system that can feed the 401 and the caddy 500, then get that. I guess my question is DO they make a propane system that could feed a 401 and a caddy 500. What I would do it start out with it on the 401. If I like the system, the way it runs and all that other stuff, and decide I want to keep it. I would build my 500 for propane, and then swap the system over when I swap motors. Thats why I want to know if there is a system big enough for both. It would be a good start for me. I run it on my 401 as kinda a experiment to see how it runs and how I like it. If I like it, keep it, if not, start work on fuel injection. I figure this would be the best way to start, that way I can keep myself out of a bind if I dont like it.

Thoghts? Ideas? Comments?
Please, I want them all.

[Fiodh. Argus]

sounds like a good idea to have a run at the propane for a while and see how you like it. I am quite happy running my propane around here but am still working the bugs out of the rest of the truck, so haven't been able to take long trips and source propane along the way. Currently though, the mileage seems pretty decent and it has plenty of power.

I am running a 360 with the IMPCO 425 carb. It is a 394 cfm and seems to feed the motor just fine, with an edelbrock manifold, erson performer style cam, and headers. When I ordered my carb (mixer) from Roy at www.Propaneguy.com he also offered me the next size up, a IMPCO 450 (500cfm), asking if I was building this more like a race engine. I decided to stay with the more economical 394cfm unit to save gas, but would still consider upgrading if needed. He also offers dual carb manifolds so you can have sort of dual quads on that caddy! He builds high performance motors fairly often. The compression ratio I have is not much higher than stock, maybe 9-1 with the high-temp propane pistons we installed.

as far as propane tanks go, I am running a 50 gallon tank which has about 30 gallons of useable range, and also carry a 10 gal forklift tank as a jerry can for another 50 miles. If you are just using forlift tanks then atleast get two with valving and switching.

I like the propane because it's so clean burning, smells OK (some people don't care for the smell) and also as you mentioned, good for the motor. Also supposed to be 65% cleaner than gasoline.

and if necessary the engine can be switched to natural gas or even hydrogen using the same equipment, different tanks.

I say go for it!

[hcm]

Technocarb

Another option for your 500 Caddy is a mixer/carb from a company called Technocarb. These flow around 750 CFM and would work well on a larger motor. There are a few propane mechanics around my area that have used these on DD's and Track/Trail machines. Similar in design to the Impco's, these have 4 venturis and dual inlets. A LS1 dynoed at 600H.P. using one so the power is no problem.

[Richomino]

Hey!

The short answer is YES, there are 'pane systems that can feed your 401 and 500.....if the 401 is stock or mild, you may even feed it with a single 425 or 450 mixer......and for modified, theres always dual mixer maifolds....

(I'm gonna look into that technocarb for when I build my next motor, it sounds awesome!!)

Im running propane on my 360 with edelbrock intake, MSD ignition, and dual exhaust, it is otherwise stock including compression, other than colder plugs, and advanced timing (and no vacuum to dizzy)....and it works awesome.......

...sooooo...by all means...go for it!!!!!.......

Later!

[JeepsAndGuns]

The 401 is not anything wild. I rebuilt it before I droped it in a couple years ago. Its bored 40 over and has a comp 256H cam in it. I am running a edl non egr intake, and stock exhaust manifolds, and a single 2.5 exhaust that dumps right in front of the rear axle. The pistons are stock style, but I think the machiene shop shaved a hair off the heads. I have to run mid grade to keep it from pinging.

If I decide I like propane then when I build the 500 I will do it for propane. (high compression)

Fiodh, thanks for the link. I am gonna have to make some time and call that guy up.