As some may know, I am a bit in the middle of a car change, but my question is actually the same. My car will have a SB engine and run on LPG true a standard IMPCO system. It will still have the old carb as well, for running on petrol as well. I was thinking of converting to a FI system, like an Edelbrock Pro-Flo system and convert this LPG. I will loose the petrol option, but that will be ok. Does anybody have experience with such a conversion?
Looks like you'll have to wait for a member with Taxi-cab experience. Most parts of Canada concentrated LPG and LNG in the cities for heavy-mileage vehicles. I'd think the US would be the same. All I've ever seen is the dual-fuel systems.
Which Impco do you now have? 300A ....425... Why should you change to FI? Got a 300A (on a Q-jet) for the 455/4 Buick engine: for performance the 425 maybe is a better choice, but for cruising only a 300A is the best choice IMHO
Rob, I now have a 300A and is, as you said, enough in terms of performance. Either another engine in this car, or the new engine in the new car will have more power then this 307, but I can upgrade to a 425. Point is that I would really like a dedicated system for LPG, so no carb, fuel pump and tank anymore. I can always buy an IMPCO carb or maybe a OHG 450. As I think that EFI can optimize the engine further, I was thinking about the combination. I think it would give me the most power out of the engine and be the most fuel efficient at the same time. Besides that, I have a ton of possibilities to tweak the engine, but that is just a nicety. I could always install a EFI and then convert to LPG, but I guessed that that would not be so efficient as I would probably buy to many parts (I don't need any fuel parts, of course). But after some googling, I have not found anyone who has done this kind of conversion. It is still thinking out loud....
You might search for Police cars or Checker Cab sites, and find alternatives. Most of them were dedicated to one of the two (LPG/LNG).
I never knew that. There must be a lot of knowledge about this then. I mean, those guys do drive a lot! With the normal systems, the efficiency is about 10% lower, as thhe volumetric enrgy of LPG is 10-% lower then that of petrol. If you vapourize the LPG in the right way, you can cool the incoming air, so more mixture fits in the engine. This could even give more the 10% efficiency increase, so netto LPG would be more efficient (not to talk about emmisions, they are way better!).
The (standard) LPG installation will be added before the throttle body. The installation that I know of has a Lambda simulator and a Timing relay in the (ECM) electronics of the car (Superfix) to avoid the "check engine soon" warning light will be red all the time (better than to take the light bulb out):
I have non of these electronic devices. My Check engine light is always on! This time delay device, is that changing the ignition curve as well? With my new engine I will probably have either a dual curve system, or a free to change curve system, if I go for a dedicated LPG car. But the system you pictured is also an "added" system. I know experience has proven time after time, that this is the most robust system, but to trow away the cold made by the evaporazion of the LPG, instead of putting it in decreasing the temp of the air, is such a shame. If I can't find a good system, I just have to make something myself, don't I???
hmm I'm pretty sure I added a few photos in my latest reply (although the ïmage button didn't worked while doing that...???? ....in stead I just typed the [img/] etc code) Here they are (again):
Is the Superfix not from Dualcurve? I just saw on their website that all products are discontinued....
I found this info with special LNG/LPG controls. Don't know a thing about it, so you'll have to check it out. Its a translation from Spanish to English with some errors, but it's not way off. http://www.galileoar.com/2005/00_ingles/conversion_kits/electronic.htm
