Propane Power

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Jun 21, 2003 | 05:59 AM

Craigwell

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More Turbo

Joined: Dec 2002

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From: Halifax, NS

Propane Power

Wondering what you folks have to say about Propane conversions. As far as I understand things, a dedicated propane conversion is better than the dual fuel setups. I also understand that propane has a lower BTU level than gasoline, and that an RV cam is a good idea to compensate for any power loss.

The application i'm looking at is for my highboy, with a 429 4 BBl from a 1970 Thunderbird. This engine still has "lead heads", and I'm wondering if it will be necessary to do the valve seat work usually reserved for unleaded gasoline. Also, will the 4 barrel intake manifold prove to be suitable, or should I find a 2 barrel intake.

Any insight would be most appreciated.

Jun 21, 2003 | 08:11 AM

73Custom

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From: SD

Propane Power

A friend did a propane conversion to a '72 F250 390 and wasn't very happy with it. It ran good and was as dependable as gas, but propane isn't as readily available as gas, he lost a substantial amount of power and the fuel cost savings was marginal - and it always stinks. So he ended up switching back to gas.

Marty

Jun 21, 2003 | 10:11 AM

F150daniel

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From: spartanburg, SC

Propane Power

propane loves compression, about 12:1

Jun 21, 2003 | 11:05 AM

Mil1ion

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Propane Power

Yes, the changing valve seats was also meant for LP powered engine's.

Jun 21, 2003 | 01:20 PM

Craigwell

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Joined: Dec 2002

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From: Halifax, NS

Propane Power

Thanks for your insight folks. I'll run the casting numbers on the heads and block before i go too far.. if the heads are nothing special, i will look at getting different ones as opposed to changing the valve seats. that may be simpler and as cost effective.

Jun 22, 2003 | 09:10 PM

hartmark

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Joined: Nov 2001

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From: Virginia

Propane Power

I've been researching propane too. High compression and a good electronic ignition, with a dizzy curved for propane is important. I once saw a turboed jeep that burned propane and got huge HP... I guess it's like anything else, you spend more, you get more...

Get the hardened seats! Propane is much harder on 'em.

Good luck!

Mark

Jun 23, 2003 | 03:37 PM

RockinWagin

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Joined: Jun 2003

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Propane Power

Here are a couple of helpful sites:

http://www.propaneguy.com/

and

http://franzh.home.texas.net/engine.html

I am putting a 390 in my latest project and will go propane. Limited fuel is not a concern b/c this will be offroad only and I can take extra bbq tanks on the hauler to refuel. I am surprized at the post above in which a performance loss was noted. Should get a performance improvement with increased octane on an otherwise healthy engine. You can put a propane carb. on a 2bbl manifold with an adapter, but would be better to change to a 4bbl manifold.

Good luck and let us know how it progresses.