LP Propane Conversion for Diesel Engines (1 Viewer)
- Thread starter xenophon1
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It was all the rage a few years back. It has its good and not so good points.
Some engines work better on LPG than others.
In Australia they would want it fitted and/or inspected by a lic person to make it legal, so maybe the same for you.
A few people have been burnt to death in Australia from home made or badly maintained gas conversions.
You are also adding another level of complexity
Unless everything was in your favour, I would be looking at other turbos and/or fueling.
Some engines work better on LPG than others.
In Australia they would want it fitted and/or inspected by a lic person to make it legal, so maybe the same for you.
A few people have been burnt to death in Australia from home made or badly maintained gas conversions.
You are also adding another level of complexity
Unless everything was in your favour, I would be looking at other turbos and/or fueling.
Some good discussion here. The proper name is "diesel fumigation" because the gas enters via the air intake.
4x4earth.com
Diesel LPG injection
Wanting to get some info on the diesel LPG injection. I have read some things online and have asked my mechanic and he said it's great to get more power. If anyone has done it to there 4wd it would be great to hear your opinion on it.
4x4earth.com
I used propane injection systems for many years with great success. The only problem that I ever had was that the added power proved to be too much for my Torqueshift tranny on two different trucks...
I prefer using methanol injection now. It drops EGTs while boosting power. Propane does not do much for lowering EGT. Modern methanol injection systems can be programmed to come on in stages and can be a lot easier on the tranny...
I prefer using methanol injection now. It drops EGTs while boosting power. Propane does not do much for lowering EGT. Modern methanol injection systems can be programmed to come on in stages and can be a lot easier on the tranny...
Don't do it. LPG can autoignite at the temperature diesel engines reach before injection. So you get a big spike in internal pressure and stress with every combustion event.
Diesel and boost is much better and safer for your engine.
The reason these systems proliferated in Australia was due to very low pricing of LPG there and govt rebates for those fitting them. Both factors that don't apply in the rest of the world.
Diesel and boost is much better and safer for your engine.
The reason these systems proliferated in Australia was due to very low pricing of LPG there and govt rebates for those fitting them. Both factors that don't apply in the rest of the world.
As do I, I wished I started using it years ago! The bang for buck instant power increase this provides is seriously underrated within the diesel/4wd world. I can drop my EGT 200 degrees near instantly when I activate it and the added performance increase is great.
GTSSportCoupe
2LTE abuser
I use methanol/water injection too, and have mixed feelings about it. I think it might be better suited to DI than IDI. If I run 50/50 mix, it pre-ignites in my engine causing pinging (the methanol pre-ignites before TDC, or diesel injection). I think this might be an IDI specific problem because of the high compression ratio and hot pre-cup temps. If ambient temps are below 5C, I can get away with 50/50 mix ok. To stop this, I have to run more than 70% water in summer.
The other problem I've found, is if you don't have good nozzle placement, it can cause cylinder wash, resulting in part of the cylinder bore lacking oil lubrication and being exposed to damage. This happened to me with my first short block. I had the nozzle placed right before a 90 degree bend before the intake manifold. I did not know until too late, but the water/meth mix spray is heavier than air, so was hitting the far side of the 90 and then dripping down into the intake manifold and flooding one cylinder (#3 in my case) more than the others. I tried a different brand and lighter viscosity engine oil at one point. I also heavily used the meth injection around the same time. This caused rings to come in contact with the cylinder wall in #3 and ruin it. Had to replace the whole short block. When I took it all apart to figure out what happened, I could clearly see the path the meth/water was taking.
Another problem I've had is the check valve I was using wore out or failed. My reservoir was higher than the new nozzle location and I had the truck parked for a week. Filled one cylinder with meth/water and hydro locked the motor when I went to start it. Fortunately did not appear to cause any damage. Pulled glow plugs and turned over motor till it all blew out. May have rusted that bore a bit unfortunately, but a compression test showed things were ok stil.
So, I'm quite wary about how things can go wrong.
All that said, it does have potential for a lot of power. Under ideal circumstances, it seems to add about 20hp to my motor. I run a Devil's own setup. 250psi progressive pump with an electronic controller. I use a single D04 nozzle which is now placed where the EGR normally comes into the 2LTE intake manifold. Comes on at about 15psi. This location is still not ideal, but is much better than the original location. I think installing a D01 nozzle at each intake runner would be better; but obviously a lot of work.
I'd be interested to hear what pumps/nozzles you guys use, and where you've placed them. What mix do you run and any problems with pre-ignition?
The other problem I've found, is if you don't have good nozzle placement, it can cause cylinder wash, resulting in part of the cylinder bore lacking oil lubrication and being exposed to damage. This happened to me with my first short block. I had the nozzle placed right before a 90 degree bend before the intake manifold. I did not know until too late, but the water/meth mix spray is heavier than air, so was hitting the far side of the 90 and then dripping down into the intake manifold and flooding one cylinder (#3 in my case) more than the others. I tried a different brand and lighter viscosity engine oil at one point. I also heavily used the meth injection around the same time. This caused rings to come in contact with the cylinder wall in #3 and ruin it. Had to replace the whole short block. When I took it all apart to figure out what happened, I could clearly see the path the meth/water was taking.
Another problem I've had is the check valve I was using wore out or failed. My reservoir was higher than the new nozzle location and I had the truck parked for a week. Filled one cylinder with meth/water and hydro locked the motor when I went to start it. Fortunately did not appear to cause any damage. Pulled glow plugs and turned over motor till it all blew out. May have rusted that bore a bit unfortunately, but a compression test showed things were ok stil.
So, I'm quite wary about how things can go wrong.
All that said, it does have potential for a lot of power. Under ideal circumstances, it seems to add about 20hp to my motor. I run a Devil's own setup. 250psi progressive pump with an electronic controller. I use a single D04 nozzle which is now placed where the EGR normally comes into the 2LTE intake manifold. Comes on at about 15psi. This location is still not ideal, but is much better than the original location. I think installing a D01 nozzle at each intake runner would be better; but obviously a lot of work.
I'd be interested to hear what pumps/nozzles you guys use, and where you've placed them. What mix do you run and any problems with pre-ignition?
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I'm running a Pumptec 113C positive displacement high pressure pump. It's only rated at a max continuous 1200psi but in my testing I've been well over 2000psi and it's still going strong. I have four injection nozzles and currently only inject straight water, 2 pre-turbo and 2 pre-manifold. With just the manifold injection nozzles activated my EGT drops about 150 degrees C, with pre-turbo it drops 200 degrees. Performance doesn't change with water only injection at the manifold but what it does is allow me to increase my diesel fuelling to bring EGT back up to previous levels which is where the performance comes from. The pre-turbo injection how ever is a completely different story and you can tell exactly when that activates while driving as the increase in performance even with just straight water is incredible. Basically in a nutshell it makes the turbo perform like a much bigger one increasing it efficiency and also reduces spool by a few hundred RPM. The system works so well I completely removed my massive PDI front mount cooler as this does a much better job at lowering EGT. At the very best the front mount dropped EGT by maybe 100 degrees and this was only at high speeds, the water injection drops it minimum 150 degrees instantly at any speed. Plus the difference in throttle response with the big cooler and pipework removed was very noticeable in regards to on/off throttle response and drivability.
GTSSportCoupe
2LTE abuser
Wow! That's pretty nuts! I hadn't looked into what's available out there these days. I put my system together years ago. Glad its working well for you and thanks for the pictures.
Strangely, I have not noticed my system really dropping EGT's. I think the reason I get more power from it is my fuel pump is at it's limit and my engine has pretty lean AFR's already. I think the meth makes use of the extra air. I do get a couple more psi out of the turbo with it on also.
Initially I had a small nozzle pre-compressor on my engine also. I got scared of possibly eroding the compressor so removed it. Maybe the droplet size is reduced enough with the higher pressure systems (like yours) this is not so much an issue. With the little pre-compressor nozzle, I did not notice much performance improvement on my system though... Not sure why. I do have a very efficient air/water intercooler, so maybe that takes away some of the advantage of chemical intercooling.
Strangely, I have not noticed my system really dropping EGT's. I think the reason I get more power from it is my fuel pump is at it's limit and my engine has pretty lean AFR's already. I think the meth makes use of the extra air. I do get a couple more psi out of the turbo with it on also.
Initially I had a small nozzle pre-compressor on my engine also. I got scared of possibly eroding the compressor so removed it. Maybe the droplet size is reduced enough with the higher pressure systems (like yours) this is not so much an issue. With the little pre-compressor nozzle, I did not notice much performance improvement on my system though... Not sure why. I do have a very efficient air/water intercooler, so maybe that takes away some of the advantage of chemical intercooling.
Comp wheel erosion can be a serious concern on poor system setups with no safeguards in place. It's also one of the main reasons I went for the highest pressure pump I could source as the higher the pressure drop at the orifice the more effective the atomization nozzles are and the smaller the droplets. Most people think the damage occurs when the injection is activated and spraying water into the comp wheel but this is incorrect and if you've ever seen water injection been sprayed into a turbo which is on boost you'll notice it gets sucked in kinda like a vortex into the centre section of the wheel only. Most pre-turbo injection damage occurs when the nozzle activates/deactivates and some dripping happens which then moves along the wall of the intake and hits the blade tips on the outside edge where the tip speed is highest and as solid liquid. You can imagine that each time the nozzles activates/deactivates a few drips occur and it doesn't take long for water to start pooling in the intake elbow which eventually makes it way to the comp wheel tips causing erosion. I have solenoids directly attached to the nozzles which eliminates any chance of water still in the lines going to the nozzles from dripping out. Also even when my system activates the pre-turbo nozzles my solenoid still won't energise until I have reached a preset system water pressure which also prevents any initial dripping or poor atomization occuring due to low water pressure as the pump turns on and builds pressure.
GTSSportCoupe
2LTE abuser
Very interesting; sounds like you've got it well sorted! I suppose with some investment in similar parts I could run something pre turbo too. Not sure a 2LTE is worth it though.
FJBen
SILVER Star
so im not up on meth injection, but its very intriguing to me and my 13BT. Not a lot of room for intercoolers on the 13BT with A/C. I was thinking about A2W, but I still need a heat exchanger and then pump/coolant setup.
GTSSportCoupe
2LTE abuser
If you want to use it in place of a regular intercooler, you'll need a big reservoir. So either you try to fit an intercooler, or a reservoir.
FJBen
SILVER Star
RIght, there always is +/- to cooling.
A/A = hard to find room for piping/exchanger
A/W = easier to fit, deal with smaller exchanger/pump/hoses
Meth = need a huge tank, always need to fill it, freezing temps = more methanol
A2W maybe the best setup for size restrictions. The only real worry is internal failure of the cooler pushing coolant into the engine, not sure how probably that is? And a small barrel intercooler, not sure how well that would cool in place of crossover.
GTSSportCoupe
2LTE abuser
A/A although hard to install initially will be the most reliable and simple long term. Least failure prone.
I installed A/W for much the same reason as you are considering. I don't think the failure mode you're thinking about is very common. More likely the pump/electrical might fail and cause the system to overheat. That said, I've had no problems with mine. My pump runs 100% when the engine is on, and has done for the past 8 years. It's a Bosch pump. I checked the brushes last year and they still had 80% life left. I've been really happy with it, but if I had more room would have preferred A/A for it's simplicity.
I've always bought winter windshield washer fluid for my meth injection system. The -40C stuff is 50% methanol and 50% water. In summer I add water to reduce the methanol ratio a bit (because of the pre-ignition issue I have). Anyhow, in winter it's no more likely to freeze up than my windshield washer fluid; cause it's the same stuff! If you're concerned about detergents etc, you can always buy methyl hydrate from a paint store and mix your own ratio of water in.
One thing to consider if you go the A/A route, is most people oversize their intercooler piping. With the CFM requirements of a 13BT, you'd be fine with 2" air piping. I run 2" piping on my 2LTE, and a friend of mine with a front mount A/A on his 1HDT (17psi Supra CT26) also runs 2" piping just fine. 2" pipe might make it a lot easier to route.
Chemical cooling can achieve some crazy low IAT, below ambient even, BUT you need to inject a lot of volume. Seriously a lot! Once you've done all your calculations and worked out what size tank you think you need the next step is to then double that and you might be happy 
I'm currently running a 50L tank and I can easily empty it in less than an hour of spirited driving on an aggressive injection setting. Good thing I can just stop and fill it back up at any tap I find, water is free so I don't mind regularly filling it up.
You can't beat the simplicity and zero maintenance of an a2a system though and it's really not that hard to fit one in with appropriate sized pipework and core. You'd be surprised how small in diameter you can make the hotside pipework before it starts affecting flow, coldside needs to be larger though due to the way air flow changes with density especially for any bends/curves getting back to the manifold. Same for cores, if you look at a lot of the common sizes used with a temp gun or thermal camera when under load you'd quickly find that nearly all the cooling is done in the first 1/3 of them and the rest is just wasted volume and restriction.
I'm currently running a 50L tank and I can easily empty it in less than an hour of spirited driving on an aggressive injection setting. Good thing I can just stop and fill it back up at any tap I find, water is free so I don't mind regularly filling it up.You can't beat the simplicity and zero maintenance of an a2a system though and it's really not that hard to fit one in with appropriate sized pipework and core. You'd be surprised how small in diameter you can make the hotside pipework before it starts affecting flow, coldside needs to be larger though due to the way air flow changes with density especially for any bends/curves getting back to the manifold. Same for cores, if you look at a lot of the common sizes used with a temp gun or thermal camera when under load you'd quickly find that nearly all the cooling is done in the first 1/3 of them and the rest is just wasted volume and restriction.
