HP Limits

[matt_lamb_160 252]

What would the HP limits of this LPG setup be:

 

Old single outlet tank (no lock off at the tank) Twin 1/4" (pretty sure, but have not measured) copper lines running from a tee piece at the tank to two separate electric lock offs under the bonnet. Each lock off is connected to a model L Impco.

[bear351c 10,270]

what's it running in...a golf cart, lawnmower, 460 big block,??

 

Depends on what your engine is set up for. LPG 'can' be set up to go as hard as pump fuel, but, it has to have everything set for gas only.

351 on dual fuel for example, timing is about 6-8 deg, but straight gas, no carb, 13-15 degs. Depends on cam, extractors, ignition sytem, etc etc etc..

[PSI_LTD 37]

for your turbo build?

 

you need twin 3/8" lines mate. lockoffs should be fine, what's the tank outlet dia?

[FALCONSTIEN 32]

I run twin gas research on my 351c with centrifugal blower. max boost 9 psi. single lockoff, single line to 't' piece spit to each side. I was worried it would run way too lean. took it to a gas tuner with experience performance gas tuning. they dyno tuned it, check the mixtures adjusted the timing abit and said it was fine. i said are you sure? they said i could boost it more and it was very confortable. made just over 300hp at the wheels.

[gerg 10,871]

I run twin gas research on my 351c with centrifugal blower. max boost 9 psi. single lockoff, single line to 't' piece spit to each side. I was worried it would run way too lean. took it to a gas tuner with experience performance gas tuning. they dyno tuned it, check the mixtures adjusted the timing abit and said it was fine. i said are you sure? they said i could boost it more and it was very confortable. made just over 300hp at the wheels.

Nice! I could live with that. You'd get 13's with that combo all day.

 

If you consider that LPG is stored at between 120-160 psi, the flow rate out of even a small hose would be more than enough to feed a big engine, particularly if the gas is still liquid. And even if you did briefly run out of flow from your tank outlet size, the lines themselves would have enough volume to keep the engine going for minutes. Remember pressure is the same from tank to converter inlet.

 

The reason why people go bigger with petrol lines is that mechanical fuel pumps have to suck from a very long distance. As you know, gas needs no pump at all. I could run my Cortina tank completely dry, running on vapours only, and that gave me around 5 k's before it stopped. I could tell because the tank would give a whistling sound and I could play tunes with the accelerator pedal.

[PSI_LTD 37]

a single 3/8" line will support around the 220 rwkw mark (so 300hp). incidentally, that's the flow limit of many standard type gas tanks.

[Wes 214]

Standard gas tanks can flow a lot more with full lock offs installed. Granted you need more than one line. Minimum 3/8 inch lines and the sky is the limit with flow. The main restriction is at the carby. I won't go into details as they are reserved but here is a fully LPG system using a standard tank and you can see what it is pulling at the wheels. Near 600 rwkw. It actually made quite more after this video before switching to E85. Again, you have to know what you're doing to get this result.

 

That's over 770 hp at the wheels.

 

[bear351c 10,270]

Man, they held that WOT for a few seconds............

[Wes 214]

Can you say revs? 40-45 psi of boost when it later made more power.

[matt_lamb_160 252]

Somehow I have forgotten about this thread. I was asking for my turbo'ed 250. I am now running 3/8 flex line (one) and two electric lockoffs in the enginebay. The fitting in the tank has a ~5/16" minor diameter (much bigger than any lockoff), but I do not know if there is any internal restriction behind that.

 

I am looking for 200-230rwkw, no more.

[Wes 214]

Hang on a second.

Why are you running two lock offs in the engine bay?

One line is fine for that power but you better have a tuner that knows what they're doing and have it tuned to Lambda otherwise you're going to find out that 1 line is going to be your worse nightmare.

 

Problem with people is they think they can do it themselves with Gas. I've spent the last 6 months doing nothing but repairing faults on my old car. I sold it running like a dream after I drove it for 2 years without one hiccup in tune because I had it tuned by the best in Oz. This guy I sold the car to is a tinkerer, not unlike most on here who literally thinks he 'get's it' and has done nothing but bugger the car up from day one. 3-4 thousands dollars later, the car is still not right because he just refuses to learn and acknowledge he doesn't get it. Gas is not like fuel, it's not like running a NA motor with a carb, throw a little fuel at it and she'll be right won't work, especially with turbos and Gas.

 

Like I have said from day one to anyone that asks, take it to a pro and there is only one pro worth his weight in salt in the Lpg industry. That's Jason Ghiller and not a person who has ACTUALLY used him has had a regret.

[matt_lamb_160 252]

One per converter. The line is split in the engine bay for two converters and each converter has its own lockoff.

[Wes 214]

Ok. So you have two coverters, two lines, two lock offs at the tank and two lock offs at the converters all with 3/8 line? If so. 600 hp support at the wheels is easy