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Fri May 13, 2011 10:00 am

I'm looking at a few logistics with alternate fuel systems. Does anyone have an idea if the oil pump would be generating enough pressure if the vehicle idled @ 5-700 rpms?

Fri May 13, 2011 10:01 am

5rpm?

Even 500rpm would be difficult to keep the engine running.

Fri May 13, 2011 10:05 am

tdonaldson wrote: I'm looking at a few logistics with alternate fuel systems. Does anyone have an idea if the oil pump would be generating enough pressure if the vehicle idled @ 5-700 rpms? Probably not at 5 RPM.......

Really, just a few PSI is all that's required at idle if you don't have hydraulic lifters.

RC

Fri May 13, 2011 10:12 am

Sorry I meant 500 to 700 rpms. From what I've been reading real low idles are common with propane fuel systems. I know in some applications if you idle too low you end up not circulating enough oil.

Propane might make this worse since it's already gonna run the heads hot, then a low idle spinning the fan slow, if it was compounded by not getting any oil to the heads it would be doomed almost immediately.

Fri May 13, 2011 10:33 am

this thing about lpg its been tryed in my country for years, i have seen a few aircooled vws, but not one with good results, they idle really low, runs hot, and the lpg corrodes everything inside the engine. this only what i saw , never tryed myself, the people doing that are concerned about the gas prices but they end up having to rebuild the entire engine and usually sells the car first...
BTW: over here people use the converter from those litle lift trucks, and take the heat from the muffler...

Fri May 13, 2011 10:44 am

Thanks for the recommendations. I love the idea of switching over to propane, but the facts of it aren't working out real well. There's one guy on here that is posting about a conversion he did, but that's about all I've heard about it.

Right now I'm just trying to approach it from every angle. The guy posting on here about his LPG Beetle got the parts cheap. I just don't know if I can justify spending a chunk of cash on something that might even be harmful.

Fri May 13, 2011 11:37 am

On propane conversions on lifttrucks here, they use the heat from the radiator hoses for it

Fri May 13, 2011 12:03 pm

Yes, coolant is the only way to stop the Vaporizor from freezing up.

My dad has been doing LPG conversions on truck since the 80's. As soon as Chevy came out with Aluminum heads, shit hit the proverbial fan. Seats started dropping, heads warped blah blah blah.

I don't see it being worth your time. especially over $4 gallons of gas. You think you have it rough :roll: move over to the Civilized world (Europe) and then you can complain.

It's up to $5.20 a gallon here in canada now too

Fri May 13, 2011 12:59 pm

Part of it is the gas, mostly I'm just interested in doing it 'to do it'. The economics of spending $500 on the convserion might pay off eventually, but I mostly don't want to pay $500 to burn up some heads, p/c, and then switch back.

I've read about some people heating the regulator with exhaust, which prob wouldn't be too hard to work off the preheat tubes since the manifold wouldn't need them. One of the smaller converters is has a sealed passage that I've heard can be oil warmed, and I've even read one mention of an electrically heated converter. I haven't contacted any distributors for definite answers because I don't want to waste their time until I figure out if I can even run the fuel without needing a new engine by next year.

If I do switch it over I'd probably like to get a higher flow oil pump, an external oil cooler, maybe get a heat dispersing ceramic coating on the cylinder and head fins, and seal up the tins real well.