Knee down on an RE5? Racing rotary from Switzerland.

[wayne]

A new member who tells me he's been stalking the board for many years joined recently. Hans is from Switzerland and has owned an RE5 since 1985.

They have done some serious work on the bikes and raced them extensively.

Hans has given me permission to post these pics of his friend Kevin Manz riding (one of) his RE5s. Note the remarkably long (and well made) exhaust).

Rather than reinterpret Han's emails, I include his recent to me. He speaks way better English than I do Swiss and it's clear what's been done.

He also refers to chatter and oil consumption. These are specific answers to questions I asked as Suzuki apparently had or were concerned about chatter at high rpms and held redline to 7000 rpm as oil use became excessive above this. How much contribution ceramic seals made to remedying chatter would be interesting (note his comment about the weight of the ceramics vs original).

Thank you Hans and welcome to the board. Over to you:

Since more as 20 Years I make vintage racing with a second RE5. Over all this years we have tuned the engine in different stages.
In the last stage we had 89 HP at 9800PMM on the wheel and a torque of 71 NM at 7200 RPM.

On the engine we have made the inlet port so big as it is possible concerning the cooling water canals. Also the exhaust port we have make a little more dimension.
The apex seals are from ceramic. We have this from Dr. Fabrizius at Bad Soden Germany, he make this also for the NSU Wankel spider Racer. They have only the half
of the weight from the original. Also we have a long exhaust pipe and a 44mm Mikuni Carburator.

We have never had problems with chatter. The Oil consume is ca. 0.2l for a turn of 20 Minuten. For the apex seal we have mixed a two stroke oil in the fuel in the ratio 1:100.

The only problems, that we had. was two time a chackes Trochoide by the spark plug (EDIT: I think Hans is referring to a "crack"). But I think, we have raced 120 to 150 times.

The tuning I have make together with my friend Hanspeter Günthart. Hanspeter is a Rotary Specialist and is the owner of different Russian Wankel bikes and engines.

Best regards
Hans

[Framitron]

Wow. Almost 90 horsepower. These ceramic seals are intriguing. Norton also ran a very long curled exhaust. But I cant say that I understand how one tunes a Wankel exhaust.
Some questions: What is the front wheel and fork arrangement? Looks like the original swingarm. I dont see any bracing which is presumably per the racing rules. Probably running metallic bushings. Shocks might be Ohlins. Not sure about the rear wheel...
Still the same duplex primary chain?

Very cool!

Al

[timpa136]

Welcome Hans,

Thanks for sharing.

Tim

[hausi1957]

Hello everyone and thank you for allowing me to join in the forum.

After a fall on the track last year,i decid not to race anymore, because i am to old.

But it was been more than twenty interesting years with tuning the engine, travel to the tracks and race the bike.

Now i have sold the bike to England.

To the questions from Framintron:

The wheels are original, but with wider rims, 3" x 18" in the front and 3,5" x 18" in the rear.

The front fork is 37mm from the Suzuki GSX 1100E.

The swingarm is original with bronce bushings.

The rear shocks are from Wilbers

The primary chain is original and make no problems.

Best regards from Switzerland

Hans

[motomartin]

Hello Hans,
I think this is my favorite RE5 of all time. Do you have more pictures of it?
I would love to hear what it sounds like with the single exhaust and 44mm carb.
Was the 44mm carb just tuned for high revs or did it work throughout the powerband?

Thank you for sharing your awesome creation.

Martin

[Framitron]

I agree with Martin! It's exciting to know that the RE5 can be much more capable than what we are used to. And it's great that the primary chain handles the power without problems.

A few more questions for Hans:
-Are the power readings at the back wheel or at the crank?
-Were the inlet and exhaust tracts smoothed and widened (aka "ported")?
-Are you using the stock ignition?

Thanks!
Al

[Framitron]

[Ok, Reading Wayne/Hans' March 25th note a little more closely, it actually answers two of my questions from yesterday:
-Yes, the power is measured at the rear wheel and
-yes it has been heavily ported on both intake and exhaust. Not sure how I missed both of those tidbits of information].

I'm very impressed at 89 rear wheel horsepower. Wow. Mine made 48 rear wheel hp when I dynoed it last. Basically double the power with the stock cooling system and many other stock parts.

Al

[hausi1957]

Hello from Switzerland
sorry for my late answer and i can give you the follow informations:
- Yes, the power is on the rear wheel
- the exhoust port is only a little bit bigger, because we have not more room between the engine bolts and the cooling water canals.
- the inlet port is ca. 44mm outside and more or les rectangulate on the inside of the trochoide. We are verry closed on the cooling water canals. The two small holes we have closed.
- the first ignition was a Dyna S, insted the breaker points with the original centrifugal adjustement.
- later after a crash and the damadged centrifugal adjustement we have take a DYNA 2000S from a 4 cylinder four stroke bike,(i think Kawasaki Z1)mounted in the place of charging Rotor and stator. we have need ony one canal of this Dyna and only one coil.
- with this Mikuni VM 44 Carb, the engine run well in the idle and also up to 10000 rpm.

After a crash and problems with my shoulder i have sold the bike to UK and i think, the new owner is happy and this year raced on two track days and one race.
Besr regards Hans

[Framitron]

Hello Hans:
Thank you very much for your detailed response! I am sorry about your crash and I hope that your shoulder heals soon.

That much power at the rear wheel sounds great considering that it is a very smooth and linear power curve. It is good to hear that you have had very good luck with the VM44 carb.

-Did you close the two small primary holes because your Mikuni carburetor is using the large passage only? Or for timing/overlap reasons?
-Is the original inlet manifold still being used?
-The exhaust pipe is interesting, I presume that its length being used as a tuned pressure wave system to suck fuel in/extract remaining exhaust during the overlap?

Very nice work and I am happy that the bike is still getting raced at its new home in the UK.

Al