Just curious about Gasoline to Diesel conversions.
Just curious about Gasoline to Diesel conversions.
(OP)
I've seen one in person, but at the time I wasn't interested enough to check it out.
I'm curious is to if anyne has any experience with this? If so was it done with the stock components or did it require extensive modifications? Basically I'm looking to convert a port injection engine into a diresct injection, but I have no idea where to even begin looking for this info... Yes I'm aware of the problems that occur from high sulfur contents of pump-gas. That's why I plan on running something like an alcohol.
I'm curious is to if anyne has any experience with this? If so was it done with the stock components or did it require extensive modifications? Basically I'm looking to convert a port injection engine into a diresct injection, but I have no idea where to even begin looking for this info... Yes I'm aware of the problems that occur from high sulfur contents of pump-gas. That's why I plan on running something like an alcohol.





RE: Just curious about Gasoline to Diesel conversions.
Franz
RE: Just curious about Gasoline to Diesel conversions.
I've seen a gasoline engine converted to a diesel with a fuel injector installed where the spark plug belongs normally. I was curious if anyone knew anything about this. I'm looking to do this conversion with a Honda engine, but instead of using diesel for fuel I will be using alcohol if at all possible. Opinion's on whether this is a accomplishable task, or not is always appreciated.
RE: Just curious about Gasoline to Diesel conversions.
Blacksmith
RE: Just curious about Gasoline to Diesel conversions.
However, where I see this modified engine fail, is in the area of mixture formation. This is of course assuming that you would be using a stratified mode of mixture generation, which would be advantageous with regard to throttling losses. To accomplish proper mixture formation, you would require extensive revamping of the piston and combustion chamber shape.
Also, alcohol would require a different fuel metering system, due to its lower calorific value. Another thing you have to keep in mind is that alcohol has poor ignition performance and you have to ignite it with a spark plug afterall. So, you will be unable to simply replace the spark plug with injector.
Therefore, though I would not recommend it if you are short on time, it would be a good acomplishment if you do manage to do it. All the best!!
RE: Just curious about Gasoline to Diesel conversions.
Uh, if he screws an injector into the spark plug hole, where does he screw in--ah, never mind.
RE: Just curious about Gasoline to Diesel conversions.
If you want to burn alcohol, just fill 'er up and adjust the current injection system (injector size and/or pressure and/or program) to inject enough alcohol to account for lower BTU value.
If you want direct injection, figure out how to fit the injector into the head along with the current intake valve, exhaust valve, and spark plug.
If you really want a diesel cycle aka compression ignition with engine power and speed controlled by the quantity and timing of fuel injected into the cylinder, I stand by my first post.
Blacksmith
RE: Just curious about Gasoline to Diesel conversions.
Blacksmith is correct in his first reply, along with Metalguy. How deep are your pockets? Its easier to use alcohol as a spark ignited fuel engine, them adapt the injection curve to suit the particular fuel. Also, alcohols are corrosive to certain engine components which is why it has not caught on in big numbers. Stainless steel pumps, lines, tanks, injector bodies, fuel rails, and so on.
Franz
RE: Just curious about Gasoline to Diesel conversions.
That is, it is very resistant to compression ignition.
The Brazilian government has sponsored a greaty deal of research into using alcohol in Diesel-cycle engines, as any web search will turn up, and they have concluded that, for straight alcohol, "Research has demonstrated that it is not possible to establish this substitution program in diesel cycle engines."
They have run blended fuels with alcohol contents as high as 11%, but they point out there are safety concerns in the storage of such blends due to their having a significantly higher vapor pressure than does straight Diesel.
Finally, no discussion of dismal failures among "converted" SI engines would be complete without mention of the VW Rabbit Diesel of the '70's.
RE: Just curious about Gasoline to Diesel conversions.
Sidenote ~ This was an effort to maximize the fueling quality entering the cylinder, and to help improve the ratios on a turbo application for highest mean output. Sorry for the confusion, but I figured that the title would be a hint at what I was trying to get at.
RE: Just curious about Gasoline to Diesel conversions.
As it stands, I will stick with Franz's first post as being the DEFINITIVE of this thread. I think in future threads a bit of forethought would be greatly appreciated by the very knowledgable engineers that have taken their time to try to decript your posts.
Rod
PS I vote to give your star, Blacksmith, to FH.
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
I ment no disrespect in my last post even though it does look rather severe when you see it in print.
Rod
RE: Just curious about Gasoline to Diesel conversions.
"Sharp rap with a hammer" - are you setting the timing on the BBC motorhome again without a distributor wrench?
RE: Just curious about Gasoline to Diesel conversions.
Rod
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
As for controlling cylinder pressure (90 bar max for engine), it is amazing what a pilot injection (a small squirt of fuel before the main injection) will do for you...
Kevin
RE: Just curious about Gasoline to Diesel conversions.
Is there ANY competition?
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
A sprint car racing class runs alky 410 cu/in engines on fuel injection in the intake feed tubes as well as injectors direct into the chambers.
In our case we make in excess of 500 hp with carburation and the FI cars are all above 800 hp. The FI 410s are well above 11 to 1 cr.
None of this comes even close to being a diesel type operation.
There are a nunber of different types of engine configurations for diesel use. All have high compression ratios.
I am most familuar with the old GM 4/71 and 6/71 industrial engines. These had blowers that forced air into the cylinders when the piston uncovered ports around the cylinder then exhausted out a standard valve like a gas engine.
RE: Just curious about Gasoline to Diesel conversions.
I planned to run this engine with as close tolerance parts as I can get, just the cylinder wall's are pretty thin. I was thinking about some liners or sleeves...
RE: Just curious about Gasoline to Diesel conversions.
Regards
pat pprimmer@acay.com.au
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RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
Rod
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
Actually the Rabbit diesel was a excellent diesel engine for the vintage, and has developed over the years (using the same basic design and architecture) into the current TDI which is probably the nicest automobile diesel in the world. The original ones were certainly not powerful, but they were reliable if maintained properly. They virtually never had bottom end problems- the block crank and rods were more than up to the task.
RE: Just curious about Gasoline to Diesel conversions.
Funny I saw an awful lot of broken cranks and bad bearings in the first incarnation of the Rabbit diesel in the U.S. It was quite common to convert them to the gasoline version at the time. If I remember correctly, the originals had the crank "snout" break off due to ???. The original engines were prone to overheat (I do not know the reason) and the cyl heads would crack. Any damage to the timing belt would result in a broken camshaft (and all that entails).
Granted the problems were solved---eventually. My son in law will have nothing to do with VW to this day, irrational as that may be. Some of the later Rabbits I have seen have accumulated some impressive mileage figures in spite of these original difficulties. At least VW , unlike some domestic auto makers of the era, did not give up on the engines and continued to fix them.
I agree the new engine is super. My son had a 6 speed diesel wagon in Europe for a spell---he ablolutely loved it.
Unfortunately, it's not imported to the U.S. !
Rod
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.
RE: Just curious about Gasoline to Diesel conversions.