Propane injection idea
Thread Starter
|
Post Fiend
Joined: Jan 2003
Posts: 8,600
Likes: 4
From: Iowa
Propane injection idea
Now admittedly this idea will sound a bit crazy:
We know that propane can act as a refrigerant in automotive AC systems. Safe, maybe not, but it does work.
Now here's my idea:
Direct cylinder injection, of LIQUID propane, in a 4 cycle internal combustion engine, when the piston is at or a little after BDC, starting the compression stroke, right after the intake valve closes. The propane would cool the air in the cylinder as it transformed from a liquid to a gas, lowering the amount of force needed to compress the mixture, thereby increasing engine output and efficiency. Then it would be ignited conventionally by a spark plug slightly before TDC.
Thoughts? Just something that popped into my head this morning.
We know that propane can act as a refrigerant in automotive AC systems. Safe, maybe not, but it does work.
Now here's my idea:
Direct cylinder injection, of LIQUID propane, in a 4 cycle internal combustion engine, when the piston is at or a little after BDC, starting the compression stroke, right after the intake valve closes. The propane would cool the air in the cylinder as it transformed from a liquid to a gas, lowering the amount of force needed to compress the mixture, thereby increasing engine output and efficiency. Then it would be ignited conventionally by a spark plug slightly before TDC.
Thoughts? Just something that popped into my head this morning.
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
In short: silly.
When a liquid turns into gas, that will increase the pressure, so even if your mixture nay become a few degrees cooler there will be more gas which will more than make up for that little drop in temperature.
When a liquid turns into gas, that will increase the pressure, so even if your mixture nay become a few degrees cooler there will be more gas which will more than make up for that little drop in temperature.
Postmaster
Joined: Feb 2003
Posts: 4,043
Likes: 4
Although if you could properly meter it, you could inject liquid propane to the intake manifold, let the expansion of the fuel cool the intake charge and pack a denser air/fuel mix into the cylinder. IF you could properly meter it.
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
At least you admit that you made a mistake and won't argue about it! 
Intercoolers do make sense with turbo or superchargers where the air heats up somewhat. You can get more power out by using a cooler mixture, but how would that effect efficiency, I do not know. More power doesn't necessarily mean more efficient operation.
Intercoolers do make sense with turbo or superchargers where the air heats up somewhat. You can get more power out by using a cooler mixture, but how would that effect efficiency, I do not know. More power doesn't necessarily mean more efficient operation.
Elder User
Joined: May 2006
Posts: 586
Likes: 1
From: Billings Mo
Originally Posted by rusty70f100
Now admittedly this idea will sound a bit crazy:
We know that propane can act as a refrigerant in automotive AC systems. Safe, maybe not, but it does work.
Now here's my idea:
Direct cylinder injection, of LIQUID propane, in a 4 cycle internal combustion engine, when the piston is at or a little after BDC, starting the compression stroke, right after the intake valve closes. The propane would cool the air in the cylinder as it transformed from a liquid to a gas, lowering the amount of force needed to compress the mixture, thereby increasing engine output and efficiency. Then it would be ignited conventionally by a spark plug slightly before TDC.
Thoughts? Just something that popped into my head this morning.
We know that propane can act as a refrigerant in automotive AC systems. Safe, maybe not, but it does work.
Now here's my idea:
Direct cylinder injection, of LIQUID propane, in a 4 cycle internal combustion engine, when the piston is at or a little after BDC, starting the compression stroke, right after the intake valve closes. The propane would cool the air in the cylinder as it transformed from a liquid to a gas, lowering the amount of force needed to compress the mixture, thereby increasing engine output and efficiency. Then it would be ignited conventionally by a spark plug slightly before TDC.
Thoughts? Just something that popped into my head this morning.
Gunner15a
Postmaster
Joined: Jul 2003
Posts: 2,628
Likes: 0
From: Calgary, Canada
I believe Chrysler played around with liquid propane injection. Don't know what came of it, but I don't think it's in wide use anywhere.
Trending Topics
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
If something is good and useful, or at least with some 'perceived benefits' usually make it to market in some way. Things with no benefits or marginal benefits usually do not, unless mandated. Of course, this doesn't include smaller entities or people peddling 'snake-oil' type items.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Senior User
Joined: Apr 2006
Posts: 154
Likes: 2
From: Fort Erie, ON
Liquid propane injection is already commercially available both in the USA and in Europe. The only way for automotive LPG conversions to meet current EPA regulations is with port injection and vapor injection is more commonly used than liquid injection.
Generally, conversions are done for economic reasons rather than for 1/4 mile drag racing performance. Actually, it is not the fuel that governs the performance of an engine but rather the amount of air that it can ingest. Propane's effect on full-throttle performance is that the propane vapor displaces more air in the intake manifold than atomized liquid gasoline. Once in the combustion chamber, all fuels must be vaporized before they can burn.
Generally, conversions are done for economic reasons rather than for 1/4 mile drag racing performance. Actually, it is not the fuel that governs the performance of an engine but rather the amount of air that it can ingest. Propane's effect on full-throttle performance is that the propane vapor displaces more air in the intake manifold than atomized liquid gasoline. Once in the combustion chamber, all fuels must be vaporized before they can burn.
!["Beemer Nut"'s Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%23bc5285' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>"</text></svg>)
