ESE's works engine tuner

[adegnes]

Me too. Good stuff Alex.
It looks like you don't have a clutch on the variator or the driven pulley. Are you using the engine movement to act as a clutch?

Thanks!
Actually there is a centrifugal clutch on the driven pulley, I'll make shure to include it in the next video.

[TZ350]

If you are only permitted to use fuel commercially available at the pumps does Gull Force Pro E85 fit this definition ?? 85% Ethanol / 15% Petrol

This is available at the Gull Forrest Hill direct from their forecourt fuel pumps as advertised on the Gull website and the roadside signage .

Also available from other Gull service stations as well.

Looks good.

I would be pretty interested in what others think. This type of fuel will be more and more available at the pump everywhere in time. Metholated spirits is available at hardware stores everywhere now and 8.5 L of metholated spirits and 1.5L of 96 is the same thing as Gull pro. So should fuels becoming available to the public at the petrol station pump be allowed for general use in Buckets?

There has been a thread started over here by Fastfred:- http://www.kiwibiker.co.nz/forums/sh...post1131007011

[Hemi Makutu]

Looks good, there has been a thread started over here by Fastfred:- http://www.kiwibiker.co.nz/forums/sh...post1131007011

I would be pretty interested in what others think, should any general pump fuel available to the public allowed in Buckets?

No, OH&S/material safety regulations state that gas containers must be of approved type, not allowed to pour in a bloody bucket.

( heheheh...)

& since racebikes are 'not for highway use' then avgas ( it is pump gas at aero-clubs) oughta still be ok..
2T's like a bit of TEL, & it is still available as an additive 'Kemco Octane Supreme 130' if you want to do a bit of blending.

www.hi-flow.com/hp016aOS.html

When was the last time anyone's bucket race-gas was protested/analysed?

[Grumph]

If you are only permitted to use fuel commercially available at the pumps does Gull Force Pro E85 fit this definition ?? 85% Ethanol / 15% Petrol

This is available at the Gull Forrest Hill direct from their forecourt fuel pumps as advertised on the Gull website and the roadside signage .

Also available from other Gull service stations as well.

Yeah, but only where Gull has outlets - which at the moment AFAIK is limited to the Auckland area. Certainly only in the NI anyway.

Remember that it was a couple of National racers bringing their own Gull fuel South to the Southern national meetings that caused the shitfight over fuel a season or so back. Personally I'd like to see open fuel come back but that won't happen....But I'm sure that if guys bring this fuel South there will be protests. Missing from the definition is "available nation wide"
As an amusing aside, 98 is not available in Invercargill to my knowledge at present - but LL100 is.

[Frits Overmars]

I have a TZ250G with the inlet port about the same size as the bore. My solution was to weld a 6mm wide vertical bridge in the inlet port which was then shaped into an old cylinder that needed to be re-plated. Early days but this seems to give better support to the rear face of the piston to guide it down the correct hole .l My reasoning also included that since it was in direct line of the conrod there was little reduction in effective port area.
Reversing the cylinder would mean new pipes etc so this solution have the least effect on the rest of the bike. Also wanted the bike to look "original". Also managed to find a stash of 30 "G" pistons which are 54.25 mm rather than 54.00mm !! And no - I do not want to sell any. Comments anyone ? ( Especially Frits Overmars )

Welding a bridge in the G's inlet port will certainly improve piston life, but it will also cause extra turbulence, reducing the effective flow area. The con rod is directly behind that bridge alright, but the inlet flow has already expanded by the time it encounters the rod, so the rod is less of an obstacle.

We wanted to avoid welding and the according cylinder distortion, and we wanted to make our own pipes, which became a lot simpler with the reversed cylinder block.
We had to make an airbox for the carbs sitting directly behind the front wheel, but that was no extra work because even if we hadn't reversed the cylinder we would have made an airbox in order to keep the engine from inhaling hot air from the radiator.
And we didn't care about the bike looking original because it wasn't a classic back then. It should win races, never mind the looks. And the best combination proved to be a reversed G cylinder block with 38 mm carbs on RD400 crankcases with their extra case volume. That bike really flew.

[jasonu]

And the best combination proved to be a reversed G cylinder block with 38 mm carbs on RD400 crankcases with their extra case volume. That bike really flew.

Buggar. Now I wish I had kept my RD400...

[wobbly]

Yep Frits, RD400 cases are the go to get some case volume, especially with a TZ400 with reeds added ,made from a stroked Banshee crank
and 66mm Wossner pistons in a 350G cylinder, with 8 transfers.
Because they are period legal as well, 40mm flat slide Lectrons flow way more air than the old round slide Mikunis ever did
I was astounded to find that Yamaha had made the 400 with practically the same side cover fixing as the earlyer 250 based case.

[husaberg]

I was astounded to find that Yamaha had made the 400 with practically the same side cover fixing as the earlyer 250 based case.

The actual crankcase cover used from the TZ C model on up until about the H was based on the production RD400 cover pattern. According to the details i have, They previously they used a DS7 cover pattern modified for a water pump in place of the Autolube pump with other changes as required.

[ief]

Looking at this picture made me wonder again...



Placement and size of the piston windows, anyone with some ideas about the what and the why ?

(in this case they seem small, sometimes they are higher up, these are low etc.)

I've alluded to this before and if I remember correctly Wob stated they are for inlet only (I can imagine they could also be of use on the downstroke in aiding flow to the C-port.)

Ps, love the video's Adegnes!

[adegnes]

Ps, love the video's Adegnes!

Thanks! Recording E3 tonight, will be about the variator, clutch and pipe + I got a request for showing how I measure the balance factor of my crank(method learnt from TZ's great writeup starting on page 70, I'll of course credit him and leave a link in the description)

[Frits Overmars]

Looking at this picture made me wonder again... Placement and size of the piston windows, anyone with some ideas about the what and the why ? (in this case they seem small...)

They are small Ief. Compared to smaller competition two-strokes the TZ750 is not a racing engine at all; it's a tourer. But that was what was needed to do the job.
You can't beat cubes, as the merikans say, but the cubes can beat you, if you let them.
The TZ750 had to be very forgiving, so all port timings were mild and the reeds were barely big enough for a 50 cc racer. We tried to 'correct' this once, putting TZ350-stuff on the TZ750 cases.
Takazumi Katayama rode it, once. The bike had at least 30 hp more than anything else on the track, but it was unrideable. While everybody else could start opening the throttle after mid-corner, Takazumi had to wait till the bike was completely upright, and then he had to concentrate on not flipping over backward.

[husaberg]

They are small Ief. Compared to smaller competition two-strokes the TZ750 is not a racing engine at all; it's a tourer. But that was what was needed to do the job.
You can't beat cubes, as the merikans say, but the cubes can beat you, if you let them.
The TZ750 had to be very forgiving, so all port timings were mild and the reeds were barely big enough for a 50 cc racer. We tried to 'correct' this once, putting TZ350-stuff on the TZ750 cases.
Takazumi Katayama rode it, once. The bike had at least 30 hp more than anything else on the track, but it was unrideable. While everybody else could start opening the throttle after mid-corner, Takazumi had to wait till the bike was completely upright, and then he had to concentrate on not flipping over backward.

Frits a few years ago you mentioned playing with a Kawasaki KR1
Did you window the piston?
I was looking at a cylinder map picture the other day, i noticed it had a odd port arrangement?
With what is by the look of it a blind gully port?

[Frits Overmars]

Frits a few years ago you mentioned playing with a Kawasaki KR1. Did you window the piston? I was looking at a cylinder map picture the other day, i noticed it had a odd port arrangement? With what is by the look of it a blind gully port?

That port map of yours doesn't look like the KR1S I worked on. There was no blind gully port and the auxiliary exhaust ports were 2 mm higher than the central exhaust.
And I didn't window the pistons; I replaced them with Yamaha TD2B racing pistons: lighter, one ring instead of two, and 1 mm less compression height which gave me the desired transfer timing without having to do anything to the ports.
Other mods: head inserts to compensate for the lower TDC, raising the central exhaust by 2 mm (which was the maximum that was allowed under the regulations), shortening the inlet rubbers as much as possible (6 mm I think it was) while keeping the standard 28 mm carbs (regulations again) and fitting own pipes. It produced 73 rear wheel-HP; quite enough for the then standard 400-class. 400 cc four-cylinder four-strokes against 250 cc two-stroke twins; let's show them how unfair that is .

[jfn2]

adegnes:
Videos look very good. Stay with the rum. Insights come easier.

[adegnes]

adegnes:
Videos look very good. Stay with the rum. Insights come easier.

Thanks!
+1 for rum noted.