Convert GAS Briggs V-Twin to DIESEL?

[Cfs]

I am impressed how politely answered this question was. It is very very impractical if not totally impossible to convert economically from gasoline to diesel fuel. Like someone said if you have an unlimited budget…have at it

 

[max_satoh]

go ahead and listen to guys that want to prove they're smarter about diesel than the next guy - but you need to ask yourself why do you really want to convert. evaluate the cost of what you think you need vs just build a basic adapter for an existing 20hp diesel that you could pick up for $500-$1000, I've even seen some pull-outs going for $250 locally.

fyi I've run both gas and diesel zero turn mowers on my accounts, I have both gas and diesel ag tractors, and both gas and diesel pickups to haul this stuff around. some turbo, some not. I'm happy to talk pros and cons if anyone cares but I won't argue which is better.

 

[Shady oak]

I have a 2013 Mercedes 3500 Unity 23’ motor home. I get a consistent 16-17 mpg with it. My friends think I am lying, but I have the receipts to prove it.

Owning and driving a small diesel is like owning a HD ElctroGlide! If you wanted something quick and fast, you shouldn’t have bought a Harley! If you own a vehicle larger than a car, acceleration should not be a concern. If it is, the problem is not the vehicle, it’s the owner.

I love the Mercedes, it just quietly rolls along. And I have never had to "look" for diesel. The large majority of stations now carry it.

 

[biggertv]

Screw Diesel. Go with Propane. Plugs will last 4ever and you'll have to stick to strict runtime oil changes because oil always looks new as the day you changed it. Conversion kits are out there and reasonably priced.

 

[Skippydiesel]

I am a diesel lover stuck in an anti-diesel country....LOL. My boat has a wonderful 54hp Yanmar (that uses 5 quarts of oil, BTW). I had two diesel VW wagons -- yes, they had a turbo, but WOW would they accelerate! My top MPG trip was 50MPG over a 200mile trip. Yes, really! To be fair, I was "trying" and so did the entire trip at the posted speed limit -- doing the normal 10-15 MPH over the speed limit kills fuel economy.
I do find it interesting that the US is considered an environmentally irresponsible country, with Europe much more progressive. But, diesel is ubiquitous in Europe, and can't get through the US environmental regulations (putting aside issues like cost and customer preference). It's always struck me as an odd situation.

Enjoyed your response.
I would speculate that the reason why most of the World uses diesel extensively, while the US not so much, is that you have always had relativly cheap petrol, making the acquisition of a diesel car/ small commercial, questionable economics.
My wife's Hyundai i30, 1.6L, turbo diesel delivers a consistent 5L/100km (51.5mpg?) no matter how hard you drive it.
My Ford Ranger, 3.2L, turbo diesel, delivers 7L/100 km on a long trip at 110 kph. Towing a large two horse float (trailer) it goes down to 14L/100 km.
While a small turbo petrol may equal, even better my wifes mpg, there is no way a petrol will deliver the economical towing capacity of a diesel.

 

[Skippydiesel]

Simple answer is no.
The compression is too high for a standard gas engine to be converted to diesel then there is the following.
You will need a custom cylinder head with precombustion chamber, glow plugs, fuel injectors with heat shields and an injection pump that is able to properly supply adequate high fuel pressure to the injector of several thousand psi and then time it all to work with either gear drive to the crank or roller chain.
Diesel engines do not use carburetors they use a high pressure injection pump, the good diesels like cummins use mechanical pumps.
Then the internals, beefed up crank shaft, bearings, rods, piston and rings.
Look back to GM's flop of the early diesel conversions, bent connecting rods, broken rings, blown head gaskets. Not that the duratrash from Isuzu is much better.

FYI - From my limited understanding. There have been two main types of diesel cylinder heads;
Precombustion (PC). An excellent but expensive system. Tolerant of fuel quality & to a small extent contaminants. Does not lend itself to fast exceleration. I have never seen a cross flow pre combustion head engine.
Direct injection (DI). Came into its own when cross flow combustion systems became more common. Piston has a "swirl chamber" cast/machined into top for better air/fuel mixing. Injectors less tolerant of low quality fuel and contaminants. Potential for more rapid exceleration. Less costly to manufacture.
Non turboed diesel usually run 20-22:1 compression ratios
Both systems can be turbocharged. Speculation; DI lends itself to lower compression engines, which reduces cost & weight.
Very early diesels did not use injectors - I had a diesel model aircraft engine, it did not use an injector.
Older diesel engines all used mechanical pressure pumps of one sort or another to supply high pressure fuel to the injectors. The most common were inline and rotary.
Not sure but think the current very high pressure, Common Rail diesel, will still use a mechanical pump to deliver the pressure to the Rail. Timing is now done electronically (computer) opening/closing the injectors.

 

[TobyU]

Had a W123 240D, 3 x W123 300D's and a W116 240D - LOOOVE diesel.
While the naturally aspirated variants are very sloooow to accelerate - man do they just keep going! 160 kph, noooo problemo! and as solid on the road at that speed, as they are at 60 kph. One of my 300Ds was a station wagon 5 speed factory manual. Fully laden (adults & gear for a weak on the road), high speed cruising, 7 L/100 kilometres ( 33 miles /gal?) - this in a 1985 built vehicle!!!!

• Your generalisations on oil capacity/filters is BS.
• Your statement on turbo charging is also BS - while a turbo will generally improve a diesels performance (just like a petrol) is not actually required.
• Diesel engines, of the same swept capacity, will in general outperform & use less fuel than a petrol when it comes to work (torque) - not many petrol trucks & tractors around these days.
• Car (petrol) drivers do not, in general, like the lower acceleration of diesels, the smell of the fuel & exhaust and the usually higher purchase price.
• Diesel engines will usually outlast their petrol equivalent - the exception being where the manufacture tries to achieve petrol type exceleration/weight /cost. These engines have a troubled history & are most often rubbish. Dont purchase a diesel if you \want to get burning rubber at the traffic lights.
• For a diesel powered vehicle variant to be cost effective, you must be doing high mileage or towing/carrying (working)
• Industrial equipment (large mowers, etc) are usually diesel due to the better torque characteristics of the engine & the lower fuel consumption.
• In service time, injectors/turbos will wear out, no matter petrol or diesel.
• What the uneducated /fashion/market driven public do/purchase is little indication of any products actual worth.

In short you don't actually know what you are talking about

But you took the topic away from where the question was asked and took it into tractor trailers, and automobile engines of the diesel variety.
Some of the things you said that are absolute fact like diesels almost always outlive their gasoline counterparts, wow true, that is because these diesel engines were designed from the ground up to be diesel engines.

No one here was having a discussion about whether a twin gasoline engine or a 3 cylinder yanmar diesel as to which one was better than the other.
They were only asking if you convert a Briggs & Stratton engine over to run on diesel.
The quickest and best answer is that it wouldn't be worth your time.

Like one of the other answers stated, while it is technically possible to do, it still wouldn't work well and it would have no longevity.
In fact, just to get it to function at all you probably couldn't even use the original block so would it still be a Briggs & Stratton engine?

You could build or buy a custom block and use some of the Briggs & Stratton parts but that goes back to the original best answer... It wouldn't be worth your time, or money.

Diesels can certainly be great when done right but there is nothing going to be done right about trying to convert a 44XXXX series Briggs to run on diesel.
Propane or natural gas is quite simple and will work just fine.

Propane's probably the easiest because you can have little tanks like the little green ones or you can run it off a torch bottle but actually I'm thinking push mowers here and you could take you a barbecue grill 20 pounder and put a hanging bracket right between the handles of your lawn mower or even a little platform there about 8 in off the ground and run your lawn mower for a long time on propane.

I will say that while propane and natural gas both burn cleaner, you are likely to have more problems if you put a lot of hours on one of these engines with propane or natural gas then if you just use gasoline like they were designed.
More likely to have valve problems using propane than gasoline BUT sometimes this is a moot point because most of these engines never get enough hours on them and their lifetime to ever come close to wearing anything out.
They simply have some needed repair at one time or another and they're replaced or junked because of that.

I can't tell you how many 17 to 24 year old riding lawn mowers I have serviced and how many I have seen replaced that were only maybe 15 to 22 years old because they needed some repair and mainly because most shops are so expensive it just wasn't worth putting that kind of money into it.

Not a single one of these engines was ever worn out and they probably could have easily gone another 10 plus years had they have had a simple repair.

In my area the average person with a 42-in rider plus between 25 and 35 hours per year maximum.
Some people in some areas don't put that many hours on them and of course some do more but unless you're cutting more than one lot or trying to cut commercially, people in my area do 25 to 35 a year.

You can do the math but I see so many lawn mowers disposed of and replaced when they don't even have 225- 275 hours on them.

In fact, in the 10k+ of mowers that I have serviced over the past 14 years really do I see any above 325.

This is simply because by that point they have had the mower so long that it's really old to them and it's getting pretty janky and probably has really floppy steering and the seats all chewed up and all that so they're ready for a new one.

Only occasionally will I see one in the 400s and that's been twice.
I keep track of all these numbers quite religiously.
The highest hour engines I have had come in were 879 on a John Deere commercial that was a private owner for five or six years and was about 11 years old when I saw it.
Had another Husqvarna zero turn with a twin Briggs 44xxxxx that to my amazement had over 1200 hours on it.
A lawn tractor style with 742,
And only one or two up there above 425.
99% of the ones that have come in have had under 375 on them and the majority of them have been in the low to mid 200s.

Anyways, converting a Briggs or any other gasoline engine for a lawn mower over to diesel is going to make its life expectancy under 1 hour.

 

[Skippydiesel]

Don't think it is possible. Not enough compression, the block is not strong enough to handle the compression increase, the rods are too weak, no way to put injectors in the head.
As for a turbo many farm tractors have not used a turbo the AC D19 was the first, then other manufacturers started using them. There was a company M&W that made kits to put them on nonturbo engines. Some successful and some not. If memory is right the 4320 was JD first attempt. Many early farm tractors were not turboed and ran and worked just fine. That said some farmers installed turbos and turned down the fuel to get original HP they did it for better fuek efficency.
If you wanted to try anything it would be easier to convert it to ALL FUEL. These used "tractor fuel often refered to as distolate" You need two fuel tanks a small tank for gasoline for starting and a large tank for fuel. Start on gas warm up switch to fuel, to shut off switch back to gas so it will start next time. The problem with tractor fuel is there is a substantial power loss.

Forgot Briggs did has a three cylinder diesel made by Dihatsu and Toyota They have been out of production for many years because of many issues.

I think you may be a little confused.
Turbo diesel have been around since 1925. In serial production since 1951.
Most smaller (sub 150 hp?) tractors were naturally aspirated until about 2000?
Turbo charging can confer more efficient/complet fuel burn = better engine efficiency/power output and lower emissions. In turn smaller, lighter/cheaper/lower fuel consumption, engine can be used to do the same work of a larger. In road use you may see a small capacity turbo diesel engine being used, as an alternative to a much larger petrol engine , in the same chassis.The small diesel preserving the handling characteristics, delivering much greater fuel economy, at the same speeds while sacrificing exceleration. In recent times there has been a lot of effort put into cars/small commercials to improve the acceleration. The main thrust being twin turbos. Unfortunatly this is a much more complex innovation, greater cost and may also diminish (to some extent) one of diesels greatest feature, fuel economy. It doesn't make a lot of practical sense, as diesel car buyers usually accepting the lower acceleration.
Petroleum Distillate is" a liquid mixture of hydrocarbons obtained from crude oil through a distillation process". Examples include gasoline, kerosene, and mineral spirits, etc
Distolate (not much used) has come to mean diesel.
Gas (USA) is just another name for petrol.
Gas (the rest of the World) is usually Liquid Petroleum Gas (LPG) although Hydrogen gas as fuel is in development.
Fuel is a generic term, means any burnable material used to power/heat
Some counties have agricultural (tractor?) diesel, the only difference being the lower/nil fuel tax regime and in some cases a die that can be detected in low concentration, if used in a road vehicle - big fines ensue.
Well before my time, there were engines that could be run on petrol and or kerosene (kero burners). As you say; start/finish on petrol, run on kero. I stand to be correct - these are not diesels (compression ignition) being spark or glow plug ignition.

The problem with tractor fuel is there is a substantial power loss.

I am not sure what you mean by this.
Diesel fuel containers more energy /L than petrol.
Does not burn as fast as petrol, so does not easily lend itself to the acceleration much prized by most car/motorbike users.
Diesel engines are typically significantly heavier (more robust construction) than petrol, resulting in a lower power: weight ratio. This impacts on acceleration and road handling (cars).
Diesel engined usually deliver significantly more torque (the ability to do work) than an equivalent capacity petrol engine and for less fuel consumed. Thus they are preferred by industry (inc agriculture).
Diesel fuel, designated for agricultural use, does not differ, in performance, from road use diesel - this is usually a fuel tax arrangement.

 

[Skippydiesel]

Screw Diesel. Go with Propane. Plugs will last 4ever and you'll have to stick to strict runtime oil changes because oil always looks new as the day you changed it. Conversion kits are out there and reasonably priced.

Propane has significantly lower energy/L than either petrol or diesel. The effect is lower power, more gas consumed /hr/kilometer than a liquid fuel.
Can be attractive as often much cheaper than liquid fuels.
Does not have the "lubricity" of liquid fuels so may cause accelerated wear of valves, etc
Must be transported within a pressure vessel - weight/complexity.
Can not be successfully used without some form of conversion kit.
It has been used in a "shandy" with diesel - don't know much, supposed to deliver significantly more power/lower emission - never caught on.
The colour of sump oil is not a good indication of its condition or continued use.

 

[13brian]

Screw Diesel. Go with Propane. Plugs will last 4ever and you'll have to stick to strict runtime oil changes because oil always looks new as the day you changed it. Conversion kits are out there and reasonably priced.

I am a fan of propane as autogas fuel. Curious about your oil change interval statement, if it comes out looking clean and not smelling burnt (assumption). How are you know the oil needs changed at same intervals? Is there any data from oil sample tests (Blackstone Labs, or similar) that prove out the same oil change interval is true for gasoline and propane fuels? I am of the understanding propane burns cleaner, I would think that the oil would contaminate more slowly. Does the oil just wear out at a certain rate with no other factors?