ESE's works engine tuner

[husaberg]

Just an RGV250 head & that was for clearance & best rectified for power.

Sorry Dave I was meaning the first suzuki Wolf T90 like the stinger only smaller bore http://www.suzukicycles.org/T-series/T125.shtml

[bucketracer]

Thomas and I have had a cylinder head copper sprayed in the combustion chamber and right across the underside. The copper is about 1.25mm thick and the objective is to have a thin combustion shell that readily sheds waste combustion heat to the furthermost fins.

As copper has nearly twice the thermal conductivity of aluminum we expect to see less localized heat build up in the combustion chamber and faster transfer of heat to the outer fins on the head.

The forth picture is the original head showing localized hot spots.

Well we have discovered one of the problems with using polished copper in the combustion chamber. That is, it discolors when heated and goes a very dark brown/black where as polished aluminum retains its polish and reflective properties after normal heating.

And lastly, the chamber only is coated with a clear ceramic heat reflective, that retains the high temp in the chamber as the combustion gases are expanding. Creating more gas expansion is the holy grail to pushing the piston down harder , with less wasted heat into the water - on the other side of the insert.

Same with the piston - only the chamber area is coated, if you coat the whole piston, the heat reflective surface becomes hotter than the raw piston underneath, again this will create deto in he squish band area.

Maybe the clear ceramic Wobbley talks about could be the answer to stopping the copper discoloring .........

[TZ350]

Some of the more technical Links and Posts from the last 10 pages swept up together so the good stuff is easier to find.

Mt Wellington track

Google map "1 Tainui Rd Mt Wellington NZ"
http://maps.google.co.nz/maps?client...ed=0CBwQ8gEwAA

Some stuff I found a while back for fork conversions
Plus some materials stuff here (if you want to build say a new frame) quite a neat site http://www.engineersedge.com/manufacturing_menu.shtml

Fork Diameters
http://www.kiwibiker.co.nz/forums/sh...post1130124931

Steering stem sizes.
http://www.kiwibiker.co.nz/forums/sh...post1130124931

Steering Head Bearings.
http://www.kiwibiker.co.nz/forums/sh...post1130124931

I now have sets of FXR 150 cam sprocket verniers adjusters for sale. I do an exchange with your sprockets as they need to be drilled and slotted for the verniers. The exchange set is $85.

Tuning wise my h100 based engine at the time up there with the fastest real legal bikes I ever encountered. The Honda xl125 bikes were the fastest then but they were ……….

Interesting background story of Buckets ……

My usual resources at Motormaster http://www.moto-master.com/productnow.php# Metal gear how some useful info but no pcd http://www.metalgear.com.au/ (JT) one useful for sprockets pcd centre hole dia teeth avail splines etc http://www.jtsprockets.com/40.0.html

There are several posts of useful gearing charts on page 307 ……….

WATER INJECTION By Randy Norian http://www.suzuki-rg500.com/water.htm

The link has more on water injection.

I was in the pit at Philip Island when Doohan tested the NSR with the water solenoids on the headers.
He did 3 laps, immediately full noise as he always did.
Came in and said it was a piece of shit till 1/2 way down the straight, but had heaps of power off the bottom and lost around 1000 rpm on top.
They plugged in the laptops, and I assume wound back the squirt volume.
Another 3 laps, and he said it now came on song much earlyer, but had lost most of the bottom end, and was still 800 rpm down on top speed..
More festering on the laptop, back out again.
This time no useable gain in bottom end,slow to come on the pipe, and still no overev power.
Mick just said - "maaaete,turn the fuckin things off and give it a go."
Went out and put it on pole,easily.
Talking to Burgess in the Cowes pub that night he said it seemed that to get enough water into the pipe to do some good for the bottom end, it took too long for the temp to rise back to "normal" again, so they had ripped the whole thing off, and binned the idea.
Adjusting the PV curve gave better, repeatable results.

I guess the dyno does not tell the whole story. If your going to try this, best read every thing you can.

I was just pointing out that the idea of using water, great as it may be in theory, and on a dyno when looking for bottom end, it "works" just fine.

But in a controlled test to see if its was usefull, it failed, as the systems effect had to be reduced so much that any gain in bottom end was still offset by a loss in the top end.

As Burgess said, when the effect was useful, it took too long to reheat the pipes.
My thoughts,from the testing I did with a PV and ATAC operated separately ( instead of combined together as many MX engines have now) is that this works real well with no down sides at all,and is easy to implement.

If someone can refine the original idea - then great.

I am going to try water injection at some point as I have already got the gear made up for it.

The plan was to get a good dyno run without and a run with water injection and then turn the injector off at the point the two graphs cross over.

At first it seemed simple to me, if I could get a power extension at the bottom, the two graphs joining together nicely with the top end revving out like before then the thing should work.

But of course a full on dyno run is not like picking your way through the twisties where you are on part throttle a lot of the time using that low end grunt. Not a lot of people apex a slow corner using full throttle.

The powerjet switched with a solenoid is done just after peak power, as the engine is most efficient at peak torque, where it needs the most fuel.

But the carb doesn’t know about efficiency, only bulk flow past the main jet - and the flow keeps rising as do the revs, so the mixture goes rich over the pipe ( thus reducing the temp).

By switching off some of the orifice area ( PWM is way better) we can lean down the fuel curve into the overev and heat the pipe up way more than is possible at peak torque.

On a HRC - RS250 for example the solenoids are activated at 12200 to 12800 ( adjustable plugs in the loom) and it will rev hard to 14000.
Without the powerjets it falls dead just past peak power at 12000.

STA or Specific Time Area, (Port Time Area) is at the heart of 2-Stroke port timing design.

Click the link to read the whole post.

To get around 38 crank Hp from an RGV100 ( to create mid 30RWHp) the T port needs to be up at 198 duration. This is governed entirely by the blowdown available when the transfers are in the right place as well. Having the T port as well as the aux ports may allow the exhaust port to be dropped a few degrees in duration, this then increases the range where the pipe is in resonance, giving a wider spread and no drop in peak power.

"MSV is high at 25M/Sec", forget all that old shit - here is the go with squish. In any race engine the squish height should be set at the minimum achievable,just shy of the piston tapping the head when overeved.

Wobblys view on MSV and Squish, its worth reading the whole post.

TeeZees piston/head photos, he was doing this close clearance thing way back, when others were championing something else ...... so its satisfying to see the concept validated by Wobbly

Air Cooled 125cc 24mm carb 28.9 PS and 17.9Nm measured at the rear wheel on a DynoJet. The graphs are TeeZees tests of the Soft vs Hard closing rotary valve and extra crank clearance and case volume.

The case com being bigger works better and better as the inlet is optimised to fill that volume to the same pressure ratio, and subsequently the ducts/transfers are able to move the extra vol available into the cylinder. This then increases the delivery ratio and ultimately the dynamic com. I don’t really see much gain from reducing the cranks effect on intake streams - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.

Here is a gearing chart with rev drops I did.

To see the chart you need to follow the link.

2-stroke crank mods http://vincentcrabtree.co.uk/RGV250CrankStroking.aspx

Some RS125 info http://www.bonavolta.ch/hobby/en/moto/rs125r.htm

Some practical carb setup stuff http://www.bonavolta.ch/hobby/en/moto/mainjets.htm

The one piece insert is far stronger than plain aluminium in such a big bore, thus the water can be run much closer to the places its needed, in the squish area , and around the plug threads, reducing thermal hysteresis.

And lastly, the chamber only is coated with a clear ceramic heat reflective, that retains the high temp in the chamber as the combustion gases are expanding.

Creating more gas expansion is the holy grail to pushing the piston down harder , with less wasted heat into the water - on the other side of the insert.

Same with the piston - only the chamber area is coated, if you coat the whole piston, the heat reflective surface becomes hotter than the raw piston underneath, again this will create deto in he squish band area.

Other collections can be found on the decade Pages .........

[husaberg]

I will be back .......

Got any 10kg blocks of Bronze TZ?

Ps I looked through the race video way back page 130 ish.
I can see why the wide spead of power is what you are chasing.
It looks like a series of corners, conected by well, more corners.
I think what you really need is a minimoto and a 40kg psycho
or a bigger track

[Buckets4Me]

I think what you really need is a minimoto and a 40kg psycho

Jo Mead on his streat magic use to do pritty well (but he wasent 40 kg)

[F5 Dave]

heck he was more like 3 times that. But he was a psycho.

[F5 Dave]

Sorry Dave I was meaning the first suzuki Wolf T90 like the stinger only smaller bore http://www.suzukicycles.org/T-series/T125.shtml

Is that an old family snap? You're quite a handsome lad, bet the gurls came running.

So the T90 is still in a shed? I need a headlight surround & the chrome strip for the seat of my stinger resto that I'm quietly collecting bits for

[wobbly]

My take on the copper in the head would be to have it extend only to the edge of the bowl.
Then have the alloy bowl ceramic sprayed.
This pulls heat out of the squish, but keeps the heat in the combustion area to do some work.
Only issue is the same as bronze inserts, there is still a joint face that will dramatically slow thermal conduction between the copper and the alloy.

[marsheng]

I had one of these as a kid. Very fast at the time, when it ran, kept blowing up. I it would go to 10500 RPM but I eventually just dumped it.

[husaberg]

Is that an old family snap? You're quite a handsome lad, bet the gurls came running.

So the T90 is still in a shed? I need a headlight surround & the chrome strip for the seat of my stinger resto that I'm quietly collecting bits for

Nope its defiantly not a family snap as I am true blue feral inbred, red necked yokel. Sorry to disappoint you. The wolf is complete and off limits for raiding, but I do have a parts Stinger. I can have a look for you but it is a bit of a turd I doubt it has any decent chrome sorry.
At one time a Suzuki stinger (not mine) held the NZ speed records must have been little competition at that time as it was something like 78mph for the flying quarter I think.

I will say this though, they certainly did have real downdraft carbs.

[TZ350]

My take on the copper in the head would be to have it extend only to the edge of the bowl.

Then have the alloy bowl ceramic sprayed.
This pulls heat out of the squish, but keeps the heat in the combustion area to do some work.

Only issue is the same as bronze inserts, there is still a joint face that will dramatically slow thermal conduction between the copper and the alloy.

Speedpro suggested much the same and its what I have been using.

The joint face may be a thermal barrior but there is a lot of contact area so intuativly I expect there is still a resonable amount of thermal transmission.

The copper outer fins get hot enough, so its doing its share of shedding waste heat from the combustion chamber area and cylinder top. Certainly a whole lot more than if it was not there.

With a composit gasket between the cylinder and copper head fin, the head runs much cooler than the cylinder, without the gasket the inner head area is much the same temp as the top cylinder fins. I have spent a bit of time looking at these things with a lazer temp gun.

The copper under cylinder fins in the exhaust area run the hottest, suggesting that is heat from the exhaust duct that is not finding its way into the original alloy finned cooling system.

I would like to know more about the clear ceramic coating.

[bucketracer]

.

The 1987 Honda RS250R had the ATAC system ........... its got to be worth a try in a Bucket

[wobbly]

Fast Freddies 500 tripple had them on 2 cylinders as well, but I found that the combo of independent atac and PV was the shit.
Adding them to a non PV cylinder is an easy way to gain a heap of free bottom though.
The clear ceramic coating I have NOT being using for years on KT100 pistons and chambers where its illegal, nor in World Champ winning stock class jet skis at Lake Havasu.
Several tech inspecting teams have commented about how lean the middle of our pistons run in comparison to the squish band,I told them that was all in the jetting of course.

[husaberg]

My take on the copper in the head would be to have it extend only to the edge of the bowl.
Then have the alloy bowl ceramic sprayed.
This pulls heat out of the squish, but keeps the heat in the combustion area to do some work.
Only issue is the same as bronze inserts, there is still a joint face that will dramatically slow thermal conduction between the copper and the alloy.

I must admit I could never get my head around the ceramic coating and here Wobbly cleared it up in one paragrath.If only someone could achieve the same with my spelling.

Two questions though.

1 Bronze or copper which would be better?

2 Does copper or Bronze get on better with Aluminium ?

[wobbly]

The material depends upon the application.
Bronze is quite "strong" and can be used to create a complete insert, or just bands pressed in.
Copper is softer than poo so wont hold its shape, but has better thermal conduction.
I believe the best setup would be a combination, but always keep in mind about boundary joints forming a big barrier to heat transmission.