ESE's works engine tuner

[Kickaha]

oh come on now, be serious

yes, you mean "when"

[Grumph]

Tell you what if i beat you at Grey on the GN Bucket vs 2 stroke Bucket Challenge.
Will you then let me take it off your bike and shoot it a couple of times.
Then mount it on My wall as a trophy head next to the stags Thar horse possum and other animals i have er... Ran over in my ute?

Given that Wobbly seems to be involved hands - on in Husaberg's project, Wawick, you'd better bring the GN out here....

Bear in mind I have no computer tuning aids and my dyno is the road up to the local sawmill....sounds like just the challenge.

Can we specify rider ages are to be similar ? No young hired guns ?

[husaberg]

Given that Wobbly seems to be involved hands - on in Husaberg's project, Wawick, you'd better bring the GN out here....

Bear in mind I have no computer tuning aids and my dyno is the road up to the local sawmill....sounds like just the challenge.

Can we specify rider ages are to be similar ? No young hired guns ?

When you hired guns is it all right if the rider is er... Free

rider weight is middle aged as is the rider i will pilot the bitch myself. Chicks dig scars.


Bellow some 90's GP stuff

[Grumph]

When you hired guns is it all right if the rider is er... Free

Never had a young gun on your bike have you ? the buggers expect to be fed !!! The least they could do is starve for their sport...

[husaberg]

Never had a young gun on your bike have you ? the buggers expect to be fed !!! The least they could do is starve for their sport...

When i was first racing from 16-20 one of my fathers friends who always had a heap of spare bikes used to lend me his when mine broke.

I used to repay his generosity on most occasions, by er....crashing them repeatably. Lovely guy Bruce Wearing I miss him. Never told me off just shock his head and tut tuted a bit. He had a 175 Aermachi for a while i wonder where it went? also a Mach 2 250 and a C15. I own his old 350 Honda, I just don't know who has "borrowed it" at the moment.

[husaberg]

If I remember correctly (1926 is some time back) the Garelli 350 Competizione was a split single allright, but unlike the later DKW split-single racers it did not have forked or articulated conrods. The Garelli was a normal 360° (both pistons rising and falling simultaneously) parallel twin with three transfer ports in the left cylinder and two exhaust ports in the right cylinder. Both cylinders shared a common combustion chamber. Each piston commanded two carburetters. Also unlike the DKWs, the Garelli had no auxiliary pump cylinder or blower of any kind.
I do like the look of the Garelli's exhaust pipes. It is the oldest bike I know of with such modern-looking pipes. Using diffusers to promote suction was not yet common practice then, and adding end cones would be regarded as revolutionary 26 years later! But I suspect that neither the exhaust timing nor the blowdown time.area of the Garelli did the end cones much justice; they were probably shaped like this just to accomodate the fish-tails.

I would not bother with offsetting cylinders or piston pins to achieve asymmetrical timing. The effect is very small and who needs the complication.
The pic below shows a calculation I did on the Aprilia RSA125. I gave it an offset of no less than 10% of the stroke in order to enhance the effect.
It is obvious that the maximum conrod angles become asymmetric. What may be less obvious, is the increase in piston stroke for a given crankshaft stroke!
It is also remarkable that it takes more than 180 crank degrees from TDC to BDC, and less than 180° from BDC to TDC.

Thanks for your reply Frits and Grumph I actually thought the offsetting might decrease the stroke but i guess my cockeyed math was a little crap.

But to save me stealing my kids compass and protractor would moving the cylinder forward or backwards actually have the same effect as the offset of the pin?
No doubt fits or wob can click a few keys on the keyboard? if not i will try to draw it out to see old school style. the 12mm offset did seem to make a meaningful difference on the sim with no other changes to spec to suit. it may have been a lot less reliablw though no doubt. Slapwise


Below is the Swiss Auto/ ELF/ ROC /MZ /Pulse V4 500 GP bike Bill Bucley has a Pulse 500 don't know if that has a ROC frame but i guess ir does.

[Frits Overmars]

But to save me stealing my kids compass and protractor would moving the cylinder forward or backwards actually have the same effect as the offset of the pin?
No doubt fits or wob can click a few keys on the keyboard? if not i will try to draw it out to see old school style.

If I tell you, you'll know. If you draw it, you'll understand .

[NordieBoy]

If I tell you, you'll know. If you draw it, you'll understand .

Frits Yodamars.

Anyone else read that with Yoda's voice in their head?

[TZ350]

Got the piston off and had a look at the underside of the crown, well that looks about the right amount of stain so not excessivly hot then.



Heated the piston and carfully removed the trapped ring. If I could I was going to re cycle it and the piston.



Perfect .... good for another 100,000 km's



Chris V went to a lot of trouble and carefully measured everything up for me. It turns out that there was an excessive amount of clearance and the consensus was, that the piston slapping back and forth had hammered the ring lands trapping the ring.

[Yow Ling]

Maybe posted before, bit of a goldmine, maybe just a coalmine

http://www.mitaka.co.uk/catalogue_index.htm

[Ivan]

what happened to thomas from the first post is he still building the bikes?

[teriks]

The Roberts Aluminium bike was at Wanganui and I managed to bleg Henks camera as we were having a nosey.

Here is a pic of the dimpling I was talking about.
Again I say, I'm not sure how useful it would be; just a thought.

Attachment 253899

WOW, that's pure areodynamic perfection. You know why golf balls hav.. oh wait a minute

I'm impressed by the amount of work gone into that, but the return in reduced mass or improved heat transfer must be very very small.

[TZ350]

Had a FXR up on the dyno today, it had a bit of a hole in the 6-8,000 ish range.



Std short inlet, good up top but resonance hole down low.



I had posted before about how I thought a long inlets resonance could be changed by opening/closing holes in it like a musical instrument.

Long to get rid of the resonance hole, or improve bottom end and short (open hole) for top end.



For the test I simply Blocked the hole with my thumb and opened it about 8K. I think an inlet could be quite long with a series of holes opened in sequence.



Red line std carb, Blue line, long inlet with hole, hole closed, resonance dip disapeared, hole open, good top end.

Narr ... can't see any value in a variable tuned inlet system like this, its too simple.

[NordieBoy]

WOW, that's pure areodynamic perfection. You know why golf balls hav.. oh wait a minute

I'm impressed by the amount of work gone into that, but the return in reduced mass or improved heat transfer must be very very small.

That would be around double the surface area though?

Ever seen Tiger Woods pause play because of overheated balls?

[bucketracer]

Red line std carb, Blue line, long inlet with hole, hole closed, resonance dip disapeared, hole open, good top end. A simple variable tuned inlet system.

Stunning ... is this a first, never seen this way of tuning inlet resanance talked about in the go fast forums before.