4 stroke diesel bike???

The_Aleman said:

I'm a big fan of diesels, but I don't think they are practical in any way for MaBs:

1) They are heavy for their power output
2) They can be difficult to start when cold
3) They vibrate much more than non-diesels
4) They have a much lower RPM redline
5) They have a much narrower powerband
6) They have a higher initial cost

Click to expand...

Heres my Diesel list:

1)They produce more torque per displacement than gas
2) They start just fine in freezing temps with a grid heater or glow plugs.
3)Nothing vibrates and is more poorly balanced than a China Motor.
4) They have a much broader usable TORQUE band, and dont have to be wound out to make power.
5)Diesels are typically built WAY more robust so they usually have three times the lifespan of its gas counterparts.
6) Diesels make power at half the RPM so there is less wear on parts than a higher spinning engine at 2-3 times as high rpm. Diesel are also to MOST thermal efficient internal combustion engines in the world. Diesel engine - Wikipedia, the free encyclopedia
7) Diesels can run on waste vegetable oil or waste motor oil.
Imagine driving around your MB on last months oil change.

Just as suspected it is a pull start, with a compression release that would make it VERY easy to pull start.

Doesn't look like it vibrates much at all

‪Diesel ready (6hp) Compares to Yanmar L70 HD300D 4 - 4.4 kW diesel engine‬‏ - YouTube

‪Diesel ready (6hp) Compares to Yanmar L70 HD300D 4 - 4.4 kW diesel engine‬‏ - YouTube

Check this little guy out

‪Changfa Chinese Diesel 5 Horsepower‬‏ - YouTube

We get eight people together we can go in on these for like $315 per engine (plus shipping)

http://cgi.ebay.com/LOT-8-CHANGFA-R...ltDomain_0&hash=item35b3c822e0#ht_2748wt_1189

Diesels can run on most anything that's oily. As long as it's been filtered very well. Some things i've used have been hydraulic fluid, transmission fluid, used motor oil, corn oil, etc. Good idea to stay away from anything that has animal fat or fish oils as this clogs the injection system and makes things run very badly. Used oils also do not give as good fuel mileage. Expect a 30% drop using waste products. But hey you usually can get this stuff free so who cares if you can't go as far. Also The exhaust runs much blacker and there is much more soot. Making a lot more mess.

306cc @ 72.7lbs & 216cc @ 73lbs?

Cool as diesels are, these wouldn't be viable engines for motorized bicycles... home built motorcycles maybe, but the unavailability of any true diesel even remotely close to the average requirements for a motorized bicycle is what forced me to go w/a 49cc gasoline four stroke for my tribrid taddy project...

I did really want a diesel/electric... but the closest I ever found were "diesel" giant scale 50cc model airplane motors which are not true diesels (mixed fuel) and are two stroke (bye bye efficiency) and seem to be somewhat... short lived anyway

Well here you go, they do make them 3hp small diesel engine products, buy 3hp small diesel engine products from alibaba.com just can't get them here...yet...

Not to be too much of a damper, but that's still 211cc @ 57.2lbs...

I think the snag here is looking for roughly equivalent horsepower ratings when a diesel's strong point is torque.

Torque does the work. The fuel consumption is considerably less also. But you have got to address the vibes. I can only think a practical use would be if one lived in a area where long distances had to be traveled. Once you got the thing to speed and rode 50-100mi might be ok. I think it would suck major in traffic, they rev in a leisurely fashion. Remember these little ones were made to start the run a load at a given rpm like a generator, or pump. Not trying to dampen the idea, but throw out the facts.

Heres a good home for a diesel, guys gotta be ok he has a Subaru.

From living and working on diesel ships, the vibes and sound really get to me. But been half looking for a good deal on one for a while for a pusher. With space, vibes and being able to use a CVT with ease, think it would be perfect.

Really would enjoy seeing one built in any fashion.

Hmmm, That 3hp has a pto on the cam also, that would be 1/2 speed of the crank. Might give better options for a manual friction clutch system, Maybe even use both pto's alternatly for low and high speed .

I think a small diesel would work well on a recumbent trike. Extend the rear and make a sound box to put the engine in. It would make a great cross country traveler, you could pull a heavy trailer behind it! After seeing BarelyAwake's Tad Pole with the lifan in it, anything is possible. But I wouldn't stick one of these diesels in a beach cruiser, ha ha, it would shake the handlebars right off!

lol thanks Tad, but not quite "anything" - blasted laws of physics still gets me frm time to time

My initial "concept vehicle" (read daydream) was radically different then what I ended up with (isn't it always lol?) due to the lack of a suitable diesel. There are some valid concerns stated regarding the appropriateness of diesels in general - all of which are workable save one, that being the ones available are all comparatively massive, even the "little" 3hp is still over 200cc & about 60lbs, and that's not including it's drivetrain/tranny/etc or battery.

It's limited RPM range could be addressed with a pulley-based CVT for example & vibrations are comparative, I suspect it'd be no worse than an ol' Harley lol - still as these are "utility motor" setups there's some isolation potential with their large, flat mounting plates...

...but it's all a moot point given their sheer physical size & weight - and that's not just the obvious legal issues of a 200cc+ engine on a "bicycle" nor even the weight's impact on a bicycle's chassis. A 200cc diesel that's "only" 3hp isn't like any gasoline 3hp, the massive torque a diesel four stroke is known for would no doubt completely eviscerate any bicycle components it's attached to, I'd be nervous about even moped parts being able to handle it's grunt.

What I'd wanted to do was experiment with making a micro genset for a "true" hy/tribrid taddy as this would complement some of the diesel's characteristics. If I had found a suitable diesel in the approximate 30-50cc range I would have mated it to a milspec 24v DC alternator to maintain charge in a battery bank w/an electric drive - much like the diesel/electric systems commonly found in many commercial applications such as shipping, abet on a much, much smaller scale lol Naturally, it'd be far simpler to just use the diesel as a direct drive w/a CVT or w/e - but where's the fun in that heh

...but 200+cc? Even with only 3hp, with the amount of torque diesels kick you could spin a genny large enough to replenish the banks in a small electric car - the scale is all wrong for our app

LOL

...just abt lost my coffee when "Two-Speed Wayne" posted that! lol

Always thinkin!

Gears would be necessary for a diesel torque band, as CB2 said...
but belts are not going to be able to hold it for MAB use. My guess.

I love the smell of diesel in the morning!
rc

brentemmons said:

I was looking into a 4 stroke build ,I have a idea about a diesel build with a 4 stroke motor.I know the motors a a bit pricey but if your going to do a 4 stroke why not do a diesel.Has anyone tried this or even thought of it.I found a motor for around $1300 4.6 hp but just imagine the milage on a bike frame and the tork would be wild.Give me you feed back on this I have got a cvt drive for a 3/4 shaft just need a motor.My HT 2 smoker was fun but I want to go for reliabilty and milage.

Click to expand...

At 70+ pounds it's too heavy for a normal bike frame, especially one with no suspension. You hit one good size pothole at speed and your bike frame will be in pieces all over the road. I also looked into diesel torque monsters but they are just too risky. You would need a custom made reinforced frame to hold that kind of weight.

This is a crummy pic, but it came up when I ran a search on Hatz... it shows? the size mc frame that would be required? for a hatz diesel engine???

Thats what I been sayin. I would think a 350cc frame would be fine for a 6-8hp diesel, maybe a 10hp, bigger motor bigger frame. That pic I posted of the M/C was a 2cyl Hatz. You see the frame size for that. The 8hp Hatz I have sits on the same motor isolator as a 2L Volvo engine. A bicycle frame would vibe like a tuning fork until it failed, the vibes generally concentrate in the extremities, like pedals, handle bars, fork etc. The engine would have to be supremely isolated to use bicycle components even on a custom frame. Think motoecycle frame.

Yeah, a diesel engine puts out huge vibes every power cycle. The compression ratio of most diesels is double that of gasoline engines.
The power stroke peaks at very high torque for an instant and anything other than an I-6 or V-12 have little inherent balance.
Besides that, diesels truly run best with turbocharging. A really small diesel should be positively aspirated or it will be anemic - especially with a bit of altitude.

There's an easy solution here. Put pedals on a motorcycle frame, Mount a diesel of choice, go riding.