Is this do-able if I want to go with a single fuel-propane system. Many of the problem that come with high compression will not be a factor- but am looking into the feasablility of staying with my 400 vs going with a different motor and having to do the conversion work. (id actually like to go higher than 10:1). Are the parts available? yada yada yada

I searched the thread but didn't find the answers- so any help would...uh...help.

 

With the Australian heads and flat tops it should not be a problem.

 

how about w/o aluminum heads? Worried propane might be too warm. thanks

 

I am talking the standard Iron heads.

 

Hello Roger.
I am currently building a 400 to run on straight propane gas. Using open chamber 2V heads with custom 400 pistons (higher compression height) from Tim Meyer. I will run roughly 10.5-11.0:1 CR.
The problem is you need to be careful about how much compression you are running Roger. You also need to know about your fuel. Is it straight propane or is it a mixture of propane and butane? You can still get detonation depending on your fuel.
It is certainly possible using iron heads. Will need hardened valve seats, bronze valve guides. Will also need to recurve your distributor to run on gas. A single plane manifold-I am using a Holley Strip Dominator-is a good choice due to the different flow characteristics of a gaseous fuel compared to gasoline. Your gas carby will most likely be an IMPCO I guess. I am using a Gas Research system that currently flows 510 cfm, although a double carby system that delivers 750 cfm will probably be a better choice once the 400 motor goes in.
It can certainly be a more economic way to run a daily driver. I bought propane gas for $1.40/ US gallon yesterday, whereas premium gasoline was $4.37/US gallon.
Cheers
Craig

 

Thanks torque- I wasn't aware that they were cast.

Kionga-

"The problem is you need to be careful about how much compression you are running Roger."

Can you expand on that a bit?? Please keep me informed as to how your project is going. I'm getting some of the dual fuel parts to play with next week and the other parts as well. I will try to run dual for the experience while I build a motor- still not sure what to build- even considered building a 'hot' 300 as they have great potential. Also considering a 351w, and 390 with 429 crank. But I can fit a 400 right in so am really tempted to see what I can get out of it.

thanks so much

 

Hello Roger.
It is hard to discuss about propane conversions in one post. Unfortunately some things get missed in the discussion. I only meant that running Aussie heads with the custom pistons from Tim could push your compression over 11:1. Now depending on your propane source, this could cause some problems. Here in Oz lpg is a blend of propane and butane. Octane rating can be anywhere from 96-114; the latter being pure propane gas, and difficult to obtain for automotive use. That is why I elected to go with the open chamber 2V heads.
I have a D7TE 400 block bored 30 thou oversize, 2V open chamber heads with 4V valves, hardened valve seats and bronze valve guides, roller rockers, hydraulic cam Adv Dur I 284, E 290, I 218, E 224 @0.050, gross valve lift I 0.489, E 0.532, lobe centre 110.
Dual fuel set ups can work well, but the problem being you are trying to tailor two fuels to deliver similar performance. Not always a satisfactory compromise, especially if you are running high compressions. Can you find gasoline suitable for such high compressions? But as a learning tool worth playing with. I had an OMVL dual fuel conversion initially. Never happy with it so had straight gas put on instead.
I am posting photos on my web site presently. The motor is almost ready to go into the car. Once I get a few more photos and more details I will try to let everyone know about the web site.
Cheers
Craig

 

Thats a good question re the type of propane- will ck into it. I will probably go propane only eventually- when I build the motor.