Alternative Fuels

Hello, folks. Just finished my second conversion. The car is a 1968 Volvo 144S with a B20 motor and a 4sp. I used a weber manifold and CA100/Cobra/VFF30 propane package. The CA100->manifold adapter is the only custom piece required. The tank is a 10-gal forklift unit, mounted right behind the passenger seat. No performance or mileage stats yet, should have these in a couple of weeks.


Under the hood: mixer, converter & lockoff. Weber intake manifold, "custom" linkage.










10-gal LPG forklift tank.

Nice workmanship. There is a discussion about the use of a non-conforming DOT tank on another thread.

It looks to me like you've connected manifold vacuum to the VFF30 fuel lockoff. You might have more reliable lockoff operation you connect the VFF30 to a mixer vacuum tap. It will probably work just fine the way you have it hooked up though.

I have upgraded the car to a set of twin CA-100 mixers on 1-1/2" TBs. The original configuration used a single 1-1/4" TB. The 2X manifold is a factory unit intended for twin SUs or Strombergs.

The result is a loss of idle quality & low end torque, hard starting with a considerable gain in top end. The manifold vacuum now seems to be barely sufficient to keep the lock-off from closing.

In short, the car seems under-carbed with a single CA100 and over- with two. A progressive setup would be a better solution, it seems, with the secondary carb on a larger TB and valved rich.

Here's a link to an .AVI video of the car running - the loud intermittent rattle is the mixture control solenoid. The rest of the rattles are from the motor...http://c-5.org/Storage/Twin_CA100/MVI_0741.avi













PS: My water pump pulley exploded! I'm sure it's not LPG-related. Does anyone have a good idea of the cause?

You need to get to smaller mixers for that size of engine. I'm not surprised about the weak bottom end. Take a look at the IMPCO CT60 or CA55 series mixers. It should improve the bottom end and idle dramatically.

I ran a post before going to twin CA-100s, first proposing to use CA-55s. Franz suggested that I use 100s instead, so I did. Twin 55s would likely have little advantage over a single 100 in terms of net flow. If I were to do yet another carb-based set-up (I'm not), I would go with a progressive twin 100 setup, on a different manifold, of course. I think a primary 100 with a small TB and a lean valve, and a secondary 100 on a large tb and a rich valve would be a good compromise.

That would also be a good method. It wold give you the best of both worlds. Good lower end and excellent flow at higher revs.

I just got my hands on a positive-pressure Voltran vaporizer and a set of injectors with nozzles. The next conversion will be a MegaSquirt-driven EFI one. Cheers, -Alex

Sorry to bump an old thread but i had a few questions about this car. It has been up on craigslist around here 3 times in less then a year. I am wondering what it would cost me to put a safe tank in it and how liable the builder would be for this car. I was considering it until i saw the discussion on the fuel tank. I am just trying to figure out if i could put a proper tank in for a 250 or so (i am a college student)