T500 porting

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tz375
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Re: T500 porting

Post by tz375 »

Thanks for the link Ian.

I had not seen the last 2 pages before. Not sure I would recommend that particular set of changes but that was 1969 or so and a lot has been learned since then. And that was for Daytona racing too.
Zunspec4
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Re: T500 porting

Post by Zunspec4 »

One other point to take in is that all these modifications specified on the Suzuki data sheet were for good'ol leaded 100 octane fuel. The use of modern premium unleaded would require the ignition to be retarded (2.9mm BTDC is the Odell std. for pump fuel) at the very least.

Cheers Geoff
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Re: T500 porting

Post by ConnerVT »

A good article on today's fuels, octane, and vintage two-strokes:

http://www.klemmvintage.com/gasolines.htm
Zunspec4
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Re: T500 porting

Post by Zunspec4 »

Thanks ConnerVT ,

Interesting reading and food for thought.

Cheers Geoff
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Re: T500 porting

Post by Vintageman »

http://www.klemmvintage.com" onclick="window.open(this.href);return false;" ; has other good tech articles

Have been here before and just here for would like to get a Kawasaki Big Horn and make it a street only bike
tz375 wrote: Not sure I would recommend that particular set of changes but that was 1969 or so and a lot has been learned since then. And that was for Daytona racing too.
What's wrong with those changes for the HP numbers you were quoting?

For me (exiting street ride tune) I think 2-3mm vs 5mm port change would be better and still take off the 1.5mm from head. What I liked for this specific tune only need to match the ends of the transfer but not change its timing.

As far as TS250 savage carbs I think the later T500 without homo bowl venting (what was in 1969) is what the Ts250 gives
Zunspec4 wrote:The use of modern premium unleaded would require the ignition to be retarded (2.9mm BTDC is the Odell std. for pump fuel) at the very least.
I agree, pump gas use, anything else is a hassle. Timing, It all depends how you ride. If you mainly like midrange rpms go more advanced if not the power there is far poor compared to retarded setting.
But then if you like to run max rpms for more than brief moments yes retard timing to avoid excess heat and then detonation and then broken. Variable timing would be nice.
If you are worried about timing you should not rely on stock oil injection ration either. I add a little oil in the tank just in case I like to run upper midrange rpms or hold peak a tad longer than I should.
I have another complete low mile T500 engine and every time this T500 hop comes along it sure make we want to try some of this myself

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tz375
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Re: T500 porting

Post by tz375 »

It's all in the numbers and in what are the targets or goals.

If you want a little more, change it a little bit and hope that it works. Want a lot more, then the port time areas have to be appropriate and that's a combination of height and width and timing has to work with the exhaust and sometimes you need to raise the exhaust a lot to get the blowdown the engine needs. And modern engines are so highly tuned that most changes would be a retrograde step.

What worked in 1969 is not always the best way to go because a lot has been learned since then about 2 strokes.
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Re: T500 porting

Post by Vintageman »

tz375 wrote:What worked in 1969 is not always the best way to go because a lot has been learned since then about 2 strokes.
By 1969 they knew quite a bit and years of empirical data and research behind them by now. There are articles through 1966,67,68,69 (some I posted) that show they well understood intake timing, transfer timing (how to avoid peaky engines) and exhaust port timing, effects intake length, expansion chamber, crank case volume ... reeds still new.

What you don't have yet is variable exhaust timing multi petal case reed valve for example. The final key to allowing this power is you simply have to be liquid cooled.

Maybe I don't understand . these are old engines to start what else can you do different? I am sure the simulation software allows you to design what you want but old piston ported engine has trade off. And, you need to test it to prove simulation is accurate.

Want does “Daytona: mean to you. A top end only road racer? Or something that can still pull out corner with midrange torque?
What you never see here is “modern” porting data for these old girls (be it t500, gt550, gt380, etc… And if the factory tested and published something I am sure you can do a lot worse too.
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tz375
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Re: T500 porting

Post by tz375 »

Daytona has always been about mondo top end and never mind the low to mid range. It's that sort of a track.


For sure a lot was known about 2 strokes by 69 but top end on a TR500 was still about 60 or so HP and the last of the 500 GP bikes were making closer to 200. 250s were making around 100 at the rear wheel, or the same as a TR750 in 72 or an early TZ750.

Water cooling helps and so do variable exhaust valves and reed valves but they don't make more power - they just make that power more accessible.

All that Simulation software does is to predict HP and torque based on wave analysis and the results provide quite a good correlation to dyno results so far. Not the same numbers but they track well. Software can't tell me how a different head shape will perform in transient conditions for example, so we work with what we have an make the most of it.

None of that was possible until relatively powerful computers became available. Much of this is well understood but not all of it and relatively few people know how to interpret the data.

Just to put it into perspective an RS250 Aprillia street bike makes more HP than an RZ350 and that makes the same power at the rear wheel as a GT750 :shock:
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Re: T500 porting

Post by Vintageman »

screw the old T500. Get something a little more modern

http://thekneeslider.com/kr800-kawasaki ... reet-bike/" onclick="window.open(this.href);return false;
It has gears! Albeit a Harley

Even that engine 13 years old and rotax 800 have come a long way since (direct injection... another 15%-20% hp, etc)

I love this comment at that link

"Awesome, I bet he turns some heads even before he starts yankiing on the rope to start it"

And, he learned technique from his grandfather father

https://www.youtube.com/watch?v=CZgx_6XaEkg" onclick="window.open(this.href);return false;

But, he later improved the technique

https://www.youtube.com/watch?v=nQiHWtoBYFM" onclick="window.open(this.href);return false;

Still no gears though. :cry:

2010 this was promissing... CA must have said we still won't allow it... never seen a modern 2 stroke production street bike

http://www.motorcycle.com/news/motus-bu ... 89129.html" onclick="window.open(this.href);return false;

I give up. I'll have one modern 2 stroke toy that handles all my seasonal needs

http://www.muskegon.com/muskegon-bike-t ... l/_mg_8917" onclick="window.open(this.href);return false;
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tz375
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Re: T500 porting

Post by tz375 »

Pipe and port and reed designs have come a long way for sure.

If you like interesting two strokes, check out Dr Rob Tuluie's Tularis road racer. 180hp 800cc twin.
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Re: T500 porting

Post by Zunspec4 »

I'll maybe put in an order for a couple of these:

http://www.ronax500.com/en/ronax500.php
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Re: T500 porting

Post by Zunspec4 »

Back on topic:

I believe the limits of tuning the compromised barrels of the T500 come down to heat generation and it's dispersion. Unfortunately that killer T500 engine can't just be treated to a bigger/more efficient radiator to take away the heat. Pete O'dell told me about a T500 drag engine he was involved with that would make 100+ bhp, but it didn't need to make it for very long :D .

The tuner doing work on my engine is renown for the usability of his engines not a peaky power band with a brief 500 rpm at high bhp figures. Proof will be getting it out on the track and seeing how it goes around a full lap not just how fast it is at the end of the straight (fingers crossed)

Cheers Geoff
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Re: T500 porting

Post by Vintageman »

Zunspec4 wrote:The tuner doing work on my engine is renown for the usability of his engines not a peaky power band with a brief 500 rpm at high bhp figures.

Simliar to the Suz bulletin would you share your port changes?

Ronax :up:

Any relationship with Rotax?
Wonder if engine is direct or semi direct injection?

I think if Aprilia adopted direct injection they would be able to have an emissions legal bike?
I wonder if Rotax for example has some hind of patent on this technolgy
How strict are Europeans on emissions?

I think I saw this bike before but, it was track only... did not realize it was street legal or at least it may be in Germany. Also I think they reduced the price significantly even if it is still 100,000 Euro :shock: Low volume manufacturing
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Re: T500 porting

Post by Zunspec4 »

Hello Vintageman,

When I have the chance to actually measure the basic porting parameters on Engine #1 I will post them in the thread. As you know though those baseline numbers are just the start. How the port is shaped, flowing of the transfers, matching the barrels to the cases, setting the C/R, squish band clearance, pipes, ignition timing/curve, carburation etc. etc. In short getting everything to work together at their optimum is the clever part and why really good engine men can make a living from it.

Have to wait for some Dyno time (hopefully in the next few weeks :D ) to see what I have.

Yep, a UK road legal Ronax would certainly have a space in my dream garage 8) Shame I'm now too old and fat to make proper use of it though :lol: .

Cheers Geoff
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Re: T500 porting

Post by ja-moo »

I wish i had time, I would like to do a 500 top end with one of my reed conversions and porting.
Visiting from the "K" camp...........
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