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Discussion Starter #1
Thought I would ask the question that bug me most and see what those who are smarter than I say.

How does one go about running their engine on propane and how does this play into performance engines?

Has anyone ever heard of 'cheap' octane boosters that actually work? I built my motor back when gas was about $1.50/gal and I have to run at least 100 octane to keep from detonation.

Just a few things to ponder.

Thanks for your time,
Jay Josey
 

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Power will be down about 20% going from gasoline to propane due to less BTU's in the fuel. You can gain some of the power back by raising the static compression ratio. Each point is worth about 4%, for instance 300 hp at 9:1, 312 hp at 10:1, 324 at 11:1. Slickest way to use propane is with a blow-thru turbo installation. Propane has an octane of 110. Ak Miller was the guru of doing it. I used to have all his manuals and instructions, but they have been misplaced. I know because I looked for them the other day. You might advertise for them. Put a wanted ad on ebay and post a wanted ad on all the forums. Maybe someone has a copy they will give or sell you.
 

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Hates: Liver. Loves: Diesel
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The main difference in older propane cars was the carburetor. Propane doesn't really need a carb since it exists as a gas as soon as it leaves the tank, but you might be able to find a fleet van in a junkyard with a propane carb. I think timing requirements are different, but the actual swap should be very straightforward once you have the tech info.
 

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A long time ago I used to work for So. Cal Gas Co. We had Dodge pickups with the slant six engine which was'nt too bad until they switched over to a dual fuel setup. When you ran them on LNG (liquified natural gas) they were actually dangerous to drive on the street they were so slow.
 

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You got a leaky spark tube...
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My grandfather had a '73 Chevy C20 pickup that he installed a propane system on. Between the dual gasoline tanks and the large propane tank in the bed he could drive from here to Los Angeles. without refueling. (that's about 1100 miles) He kept the factory Quadrajet in place installed an injection "hat" over the top of the carburetor. He had what was basically a choke cable hooked to a valve that would switch between the propane and the gas. He had the system on the pickup for probably 15 years.
 

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Buick Hybrid Guy.
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www.impcotechnologies.com has carbs for any vapor style fuel. You can choose the size for the power you'll be making.

Octane and the fact that it's already a vapor and burns better in the combustion chamber than a wet fuel (like gas) is a advantage. It burns cleaner too.

There was a nice article in car craft or hot rod many years ago about a twin turbo small block on Propane or LP.. Can't remeber which... Might want to do a search on those sites for the article. It'd take me awhile to find it in my stack.. Lol..

Good luck.. it is a neat setup but it requires alot different thinking than a "Gas" engine.
~Scott
 

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Discussion Starter #7
I appreciate the thoughts......

So no thoughts on the octane booster?


Thanks for the reply. techinspector1, I already run 11.89:1 compression ratio. I don't know if I want to lose 20% of my hp. How would it effect torque output? I need all the torque I can get I drive a full size 81 chev long bed.


Jay
 

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I think you should turbo it.

Flip some cast iron manifolds around and point them forward... Make your own pipes from both to mount turbo and use a blow through carb.

That'd be cheap and effective. You'd still need a wideband to tune it right and someone at the carb building place to give you tips on how to get it fuel'd right. You'd still make 5-700hp on pump gas...
Gail banks has been doing that since before the 80's
His small blocks go from 500-over 1300hp depending on boost and fuel.

Do a search on google for Gail Banks... ;)
Scott~
 

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Posted by jayjosey:
"So no thoughts on the octane booster?"

They are just hype. They say for instance that they "will raise octane 3 points". Well, to you and me, that would mean an increase from 87 octane to 90 octane, right? BZZZZT!! wrong. Pick up a can and read on the back. They interpret a 3 point increase as going from 87.0 to 87.3 :eek:
 

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UR50SLO said:
I think you should turbo it.

Flip some cast iron manifolds around and point them forward... Make your own pipes from both to mount turbo and use a blow through carb.

That'd be cheap and effective. You'd still need a wideband to tune it right and someone at the carb building place to give you tips on how to get it fuel'd right. You'd still make 5-700hp on pump gas...
Gail banks has been doing that since before the 80's
His small blocks go from 500-over 1300hp depending on boost and fuel.


Do a search on google for Gail Banks... ;)
Scott~
Except he spells his name Gale.
 

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Discussion Starter #12
Quote from techinspector1
They are just hype. They say for instance that they "will raise octane 3 points". Well, to you and me, that would mean an increase from 87 octane to 90 octane, right? BZZZZT!! wrong. Pick up a can and read on the back. They interpret a 3 point increase as going from 87.0 to 87.3

I guess this is why I have never trusted them.

Qoute from Matt167
laquer thinner is a cheap octane booster, it contains toulene, the main ingrediant in most octane boosters.

Any Idea how much to go from say 93 to 100? If it's like 2 or 3 gallons then it's not worth it.

Quote from UR50SLO
Flip some cast iron manifolds around and point them forward... Make your own pipes from both to mount turbo and use a blow through carb.

That'd be cheap and effective. You'd still need a wideband to tune it right and someone at the carb building place to give you tips on how to get it fuel'd right. You'd still make 5-700hp on pump gas...
Gail banks has been doing that since before the 80's
His small blocks go from 500-over 1300hp depending on boost and fuel.

Bad idea, My engine is already at 11.89:1 compression ratio. But, good idea for another engine.

Jay
 
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