Oddball engines and prototypes

[malcy25]

Hilariously uniformed blather ( that's being kind, more like being arrogant to the point of wilful stupidity) from Marcy..

I do hope Frits will be gentle..

I'm well aware of Fritz's knowledge. But I will argue the point with him about cranks and it's not just a simple rejig of ignition.....

As for you...whatever.

[Frits Overmars]

why did Yamaha, Honda, Suzuki, Cagiva... a Big bang set up which closed up (not evened out) the firing order at the expense of a more even crank shaft speed/inertia?
The short answer was giving the tyre a "rest period".

May I suggest some more reading on the subject, Malcy? http://www.pit-lane.biz/t1461p32-tec...moteurs-motogp

I do hope Frits will be gentle..

I try to be; I'm not here to take part in a mud-slinging contest. I don't even understand why it is going this way, but I seriously consider giving this thread a rest for a couple of weeks, hoping that peace will have returned by then.

[husaberg]

May I suggest some more reading on the subject, Malcy? http://www.pit-lane.biz/t1461p32-tec...moteurs-motogp

I try to be; I'm not here to take part in a mud-slinging contest. I don't even understand why it is going this way, but I seriously consider giving this thread a rest for a couple of weeks, hoping that peace will have returned by then.

Hence my polite request
Don't go though Frits I have asked for this thread to be moved to the seniors section I am waiting to hear back.
My own thought would be the R1 has much closer centers and has a proper balance shaft for the rocking.

What was the 125 I posted Frits can you recognise it?

[malcy25]

I try to be; I'm not here to take part in a mud-slinging contest. I don't even understand why it is going this way, but I seriously consider giving this thread a rest for a couple of weeks, hoping that peace will have returned by then.

Frits, don't worry, I'm with you on that one. Dunno what JAW's plan is as he's the source of most of it here and a number of posts elsewhere.

Would love to chew the fat with you and understand the differences of what you say about rear tyre vs what Masao Furusawa says as you seem to have opposing views. I'll have a read soon, when I get a chance and come back once I have read wghat you say. I guess the nagging question in my mind is why do Motogp etc still use an odd firing order if there is no perceived benefit (or in your view an actual detriment) to traction and tyre life?

So excuse my overly long post prior - was not aimed at you - more for JAW who seems most interested in how I should operate my motorcycle, at my expense, than worrying about his own.

Cheers

Malcy

[Frits Overmars]

What was the 125 I posted Frits can you recognise it?

I think I've seen a picture of it before but I do not know anything about it.
Let's do some guessing: I see two Dellorto carbs feeding through a single belt-driven rotary disc. The cylinders seem to be italian Morbidelli items, but the exhaust pipes are thinner than the Morbidelli's which strikes me as funny: if you have access to Morbidelli cylinders, you will also have access to the corresponding pipe dimensions, so why not use them? They were pretty good at the time.
Both front and rear suspension are Marzocchi products. And the partially visible number plate on the right could be italian as well, so I would gamble on a spaghetti bike.

[husaberg]

I think I've seen a picture of it before but I do not know anything about it.
Let's do some guessing: I see two Dellorto carbs feeding through a single belt-driven rotary disc. The cylinders seem to be italian Morbidelli items, but the exhaust pipes are thinner than the Morbidelli's which strikes me as funny: if you have access to Morbidelli cylinders, you will also have access to the corresponding pipe dimensions, so why not use them? They were pretty good at the time.
Both front and rear suspension are Marzocchi products. And the partially visible number plate on the right could be italian as well, so I would gamble on a spaghetti bike.

I guess if i can find it on my computer i can do a reverse look with the image code.
I like the layout.

[Mental Trousers]

I don't even understand why it is going this way, but I seriously consider giving this thread a rest for a couple of weeks, hoping that peace will have returned by then.

Just put the idiot on ignore like everyone else is.

[husaberg]

Just put the idiot on ignore like everyone else is.

He might not know who it is as he only sees a few threads Mental.

[Mental Trousers]

He might not know who it is as he only sees a few threads Mental.

It's pretty obvious who should be ignored heh. But the way things are going he'll be crossing the threshold to every post gets automatically put in the moderators queue soon.

[WilDun]

It's pretty obvious who should be ignored heh. But the way things are going he'll be crossing the threshold to every post gets automatically put in the moderators queue soon.

Good, that's sorted then.

Getting back to the contra-rotating thing eg. Rotax Kart engines etc. but more specifically the Kawasaki road going version of the racer which really didn't seem to sell - I was always very keen on that concept.
Did the 'hunting tooth" effect (or lack of) figure in their failure to become popular road bikes, or was there some other reason they didn't catch on?

[J.A.W.]

Good, that's sorted then.

Well, I sure hope the pontification & one-eyed focus on perceived personality issues are.. ( notwithstanding M-25's utterly disingenuous back-pedalling)

Now..

If we could get back to a proper, cooly stated technical discussion based on mechanical matters, that would be welcome.

Manolis has an exellent program on his site - which allows the combination of crank throws,harmonics, power impulses & inertia torque to be analysed..

www.pattakon.com/pattakonEduc.htm

[J.A.W.]

It's pretty obvious who should be ignored heh. But the way things are going he'll be crossing the threshold to every post gets automatically put in the moderators queue soon.

Heh?

Way to blunder about like a bull in a china shop M-T.. for shame..

Why did you cut my invitation to Wobbly to discuss the 90`2T crank issue..
He has done work on adapting RZ 350 mills to run like this, so why not a double crank inline 4 2T (TZ 750) - as well?

& of course, 90`V twins run a 360`crank pin - to give that same firing order..

[Frits Overmars]

building NEW crankshafts at 1100 euro or a 1000 pounds each (and there are 2 remember on top of the ignition costs).

I initially overlooked this remark, Malcy. But why would you need to build new crankshafts at all when you want to change your TZ750's firing order from 2x0°-2x180° to 0°-90°-180°-270° ? All you need to do is rotate one crankshaft 90° from its original position. And it need not even be exactly 90° in order to convert you engine to Big Bang. So, irrespective of the number of teeth on the coupling gears, you can have your Big Bang without any mechanical changes to the cranks; you only need to upgrade the ignition.

[malcy25]

I initially overlooked this remark, Malcy. But why would you need to build new crankshafts at all when you want to change your TZ750's firing order from 2x0°-2x180° to 0°-90°-180°-270° ? All you need to do is rotate one crankshaft 90° from its original position.

Frits, good question. My view would be balance would go to the pack across the engine. While the individual canks would be okay still, one side against the other would be dire I'd say. That and the TZ750 cases are notoriously weak - high milage ones crack between the banks due to the way they flap.

Would need to check phasing of crank gears, if you wanted to turn one 90 may just need to create one gear with the key way 90 degrees from original.

But I'd still be concerned about the left vs right aspect. If I was going down that track I'd still want to look at the interaction of all 4 with 2 x 90 degree cranks. But call me a heretic, I'm still not convinced on the 90 degree evening firing ((as I said last night, I need to read your link closer when I have more time).

[J.A.W.]

Dogmatic.. is 'stick in the mud' M-25, - not "heretic", which indicates ( an unwelcome to dogma) readiness to consider change.

Anyhow, if the TZ inline 4 is ordinarily capable of hacking a double firing impulse - crank & trans-wise..
It surely, stands to reason - that dividing those by 1/2 - is going to even out/reduce those extant force-node peaks.. & this carries across the board to rideability.

Yamaha uses the 90`configuration in its current inline R1/M1 4s - as a way of emulating the natural V4 architecture - dynamic recip - process outcomes..

AFAIR, Harry Bartol's G.P. KTM - in its final 250cc iteration - was also doing this ( vertical twin emulating V-twin firing), so there had to be real value in it..