Hi folks, some questions of a general nature as I'm contemplating building a historic "junior", IE under 500cc.

I have been a Ducati owner in the past, SS Darmah (caught fire and melted the wheels off it) and a late model Multistrada, (sold and replaced with a Z1000), and I currently race a period 6 CBR250. So the desire for racing historics and the lovely look of the tt2 has me hankering for a project. At this point I will say I am not right up to speed with the belt drive variants hence my questions.

At 498 cc the 500 pantah engine will be the engine of choice, am I correct in saying the cylinder heads on the 500 have an inferior valve geometry to the 600?

If so do the 600 heads fit the 500 barrels?

Are the cases the same for both engines, ie will the 500 bolt to the Verlicci frame?

What is the wheel diameter of choice for competitive purposes?

Generally speaking is this a viable project or am I barking right up the wrong tree?

All answers, comments and suggestions will be appreciated,

Ian Mac.

This is a very broad topic. I really would recommend buying Ian Falloon's new version of DUCATI Belt-Drive Two-Valve Twins as a starting guide. Many/most things are interchangeable between the 500-650 engines, less so with the 750. The 500s engine and some of those parts are getting old, well worn, and scarce. And they use the smallest pistons (74mm) of all versions. The 600 and 650cc version are, generally, superior, and the 750cc engines even better. Yes, there are some generalized comments here. It is also not clear if you thought about using a TT race frame (600 to 750cc) or a stock Pantah/Alazurra street frame (500 to 650cc); the first are expensive, the latter are still cheap. MikeV

well said, Mike.
  I have a friend who is building a 500cc, with the crankshaft of the 350! He wants to make a short stroke! In my opinion, I think it will explode!

The Ducati 500 is a beautiful motorcycle, if you use the frame pantah, you can stay in the costs, you can 'use his original rims, they are light and tires are wide enough to use them in competition.

So let's get to work!

I think as Mike...would opt for higher displacements.
Although the chassis is not so beautiful as one tt...can do big things with this.
I remember much fun with a 500 pantah .

Racing a Pantah has been done before, with a bit of succes
Behold : the original TT2

Bellissima Foto!!!

500 pantah, interresting topic.

As you said you want to built a "historic junior 500cc", to answer your questions you shall know the regulation for this class because probably you are not allowed to use a TT frame and the tire dimension should be 18" ....etc...

Have look to this one: viewtopic.php?f=21&t=10108 it's a 500, Short stroke, 125kg and within the French regulation for Classic class.

Regards.

12 hours of Jarama 1981

Angel Nieto(12+1 world champion )

Sito Pons (2 world champion)

Another one!

Well thank you all very much gentlemen for your inputs and insights.

I had forgotten that Ian Falloon had published the belt drive twins book, I have his bevel drive publications, so now I have that on the way.

Yes the intention is to stay within the 'historic junior' class, ie under 500cc, as it is referred to here and I am now attempting to decipher the regulations though there will be consultation with Motorcycling Australia to confirm what can and cannot be done. It does appear that newly manufactured components that are identical to OEM parts can certainly be used.

Bernard, thanks so much for your insight, particularly the Hall effect ignition system , the 125Kg weight of that lovely machine of yours will also be a challenging target.

Thanks also to those of you who have dug up the photos of the original Pantah race bikes.

Together you have all given me a great deal of encouragement to take this a step further.

Thanks, Ian Mac.