Diesel Tiger and other Diesel stuff here

[coachgeo]

...
consume is beetween 2-2,7 liter diesel on 100km....l

gulp.. according to this that's

87-117mpg (us)  WOW

on a bike that can cruise the highway..

topspeed ca 140 and with charger 155

thats *MPH top speed 87 naturally Asperated or 96 with charger.  Definately a bike and not a moped on city streets. Not  Audubon speeds either but regular highway. granted you dont crusie at top speed

Heiko- in the powerband of the lombardini what do you find to be an efficent cruise speed?  Where in the RPM/powerband is that ?


*according to this

[REGULATOR]

Welkommen

     If I try to speak German, forgive me,..   your Enlish is better then my German.

    I like the bike.   want to do somethign similar some day,  good to have options.

[coachgeo]

Some of you may recall that Im eventually putting a 3cyl turbo diesel into a Steamer.  Project is moving closer to starting though it could still well be a year away but..... its moving.

This has been done VERY successfully with a steamer a few times. Engine mounted simular to OEM but with ultima harley trany and belt drive.

Anyway....... bikes rattle and vibrate.... but w/a diesel probably more. Have talked to one of the owners of a diesel tiger. His previous experience is with a diesel Royal Enfield so he was not able to judge much on vibration etc. since that was a rattle box.  ON his diesel tiger the mirror immages are fuzzyfrom vibration is the only imperical data he could give me.

Im wondering if I used engine mounts simular to concept and location as on the frame as OEM but set them up with rubber isolaters if that would negate too much of the intent of steamers engine as a stress member.  Thought is with belt drive mounted solid and engine on rubber I could elemintate a lot of the vibes thru the bike that way.

So you bikers in here with engineering backgrounds... what do you think?  Rubber isolators in a simar locations as oem mounts.. will it weaken the frame to much by reducing the engines ability to be a stress member?

I've thought about adding a craddle to be the stress member thus  removeing that task from the engine. This way I coult total mount engine to isolate its vibes from everything but I would hate to add more weight to a steamer. The diesel itself is already heavier as it is.

one of the other diesel tigers

[Sin_Tiger]

It really depends on the frequency of the vibaration and any harmonics that stem from it. I hate to say this but your probably not going to know until you get it running, which would mean ripping it apart again to experiment.

Most diesel "noise" comes from the combustion process, i.e. it's much more of an explosion than with petrol, as the speed increases and the temperature of the air at the combustion point gets hotter at the combustion point and the fuel is injected earlier in the cycle the detonation is not as marked. What I'm getting at is that you will notice it more at or near idle or very light loads.

You can still have isolastic bushes that will support stressed members but will detune certain frequencies.

In short you will have two choices, build it and get very technical with measurements and sourcing the correct materials to make bushes or trial and error.

[2004Tiger]

...Im wondering if I used engine mounts simular to concept and location as on the frame as OEM but set them up with rubber isolaters if that would negate too much of the intent of steamers engine as a stress member.  Thought is with belt drive mounted solid and engine on rubber I could elemintate a lot of the vibes thru the bike that way...

I can not advise rubber isolators. The rubber would allow such frame flex that metal fatigue would result.

...I've thought about adding a craddle to be the stress member thus  removeing that task from the engine. This way I coult total mount engine to isolate its vibes from everything but I would hate to add more weight to a steamer. The diesel itself is already heavier as it is...

A cradle would be ugly and heavy. On such a prototype I think you should accept the increased vibrations as the inevitable result of shade tree fabrication.

[coachgeo]

...

[coachgeo]

...I can not advise rubber isolators. The rubber would allow such frame flex that metal fatigue would result.

I thought it would reduce vibes thus lesson metal fatique.. least that which comes with vibration.  Are you thinking it will lesson the intent of the engine as a stress member in the Tiger frame design enough to cause flex fatique in the Tigers Back Bone frame?  Though I guess some of this would be determined where the rubber mounts were used.  On engine mounts, on frame mounts... or both??...

A cradle would be ugly and heavy. On such a prototype I think you should accept the increased vibrations as the inevitable result of shade tree fabrication.

The other two Tigers bikes diesel swaps (Heiko) are fare less of shade tree as mine; though I am doing my best to put together a build team of various indivuduals from this area that has shiat load more experience than I have. Doing this to lesson its "shade tree" factor in the build.  

Hieko's Tigers as far as I know are complete solid mounts like OEM.  Not enough time on them yet to see if typical vibration stress causing breaks will show its uggly head or not.

[coachgeo]

BTW... thanks everyone that has repsonded so far. Look forward to continued discussion on this.  We ALL learn from discussions like this

[Nick Calne]

I think Sin makes the best point here.  You are going to have to be prepared to experiment a bit.  Have you prepared or obtained any drawings of the frame or engine?  That might allow people to give you a bit more advice.  8)

[coachgeo]

Drawing and pics of frame

[Mustang]

ooohhhhh looky ...............I know the idiot who put that sprint motor in there ...........oh wait it was me

[coachgeo]

drawing. I removed some drawings that were added to this but it should be pretty accurate for this discussion

[coachgeo]

my tiger is half hour north of me and not just outside.

are these four the main engine mounts?

Those back two look small for holding an engine and tranny

Any others?

[2004Tiger]

...I can not advise rubber isolators. The rubber would allow such frame flex that metal fatigue would result.

I thought it would reduce vibes thus lesson metal fatique.. least that which comes with vibration.  Are you thinking it will lesson the intent of the engine as a stress member in the Tiger frame design enough to cause flex fatique in the Tigers Back Bone frame?  Though I guess some of this would be determined where the rubber mounts were used.  On engine mounts, on frame mounts... or both??....

I wrote that without any knowledge of the Steamer frame. Seeing your photo, I confirm my statement. I am not addressing metal fatigue as a result of vibrations, a subject with so many unknowns in your project so as to be simply a guessing game. As a general explanation, I can see that the stressed engine completes the third side of a load-bearing triangle (not vibration loads, just the weight of the bike and multiples of that weight caused by road and suspension dynamics). Assuming that the Triumph design team knew what they were doing (?), I cannot imagine they would build a backbone capable of 100% support, and then throw in a stressed engine "just because." The engine side of the triangle prevents the other two sides from flexing, and resultant metal fatigue. Rubber bushes are not rigid, thus they allow flex. You have only two choices here, flex or no flex. The backbone was probably designed for no flex, and the intent of the stressed engine was to eliminate all flex. I can guess that you are thinking that the rubber bushes will allow "only a little flex," but that is still enough to cause metal fatigue. Of course, so will the wildly vibrating diesel engine, but the gas engine also vibrates, so you will depend on the inherent capacity of steel to absorb some shock.

I do not discourage this project, as I too am interested in diesel powered MCs. Carry on, live with vibrations, or reinforce the backbone to carry the loads.

(NB for the nihilists who tend to quibble: Of course all frames flex, even a "rigid" triangle. When I say "no flex" I mean nothing beyond the original designers' intended stress which we hope has been calculated to reduce metal fatigue to a "never fail" level.)

[coachgeo]

.... Seeing your photo, I confirm my statement....

Thank you for that info.  To help me take into account the various educated opinions I will get in here..... what in general is your background that you pull from to derive at your opinioun.

Mine is in Biomechanics, Motor Learning & Education (human mechanics/movement via systems of muscle, bones, joints etc. as well as the study of learning movements and knowledge).

Thanx again

Yes I agree Sin.  Much experementation will take place.  Figured starting with an educated guess by getting your fine folks opinioun would be a good starting point though.