Inlet port size?

[speedtrifle]

Does anyone know what the standard inlet port size should be?

I think ours may have had some tuning work done because the inlet ports have clearly been machined down by the valve guides.

The ports are 32mm dia. Is this standard?

Regards,

Steve.

[Skins]

I came across a site (I think it was Australian) quite a while ago where a bloke went into some detail about the inlet port - including pics and diagrams of work needed to improve the standard port, which he reckoned was very poor as it came from the factory. I know my port could be much improved.

I have tried to find the site again, but couldn't.

[Skins]

I just had another hunt for that site, Steve, without success. It was six months ago or more that I came across it, in the early days of my computer ownership, and I didn't realise how relevant and rare the material was, and that I should make a note of it.

But the gist of it was that the shape of the ports as they come from the factory is not very good. Also, I'd say, there would be some variance from one bike to another - the finishing of the castings would not be very uniform, I think, and I doubt that the size of the port openings would be specified anyway.

There is relevant material on the net - typing 'pantah, heads, ports, inlet', etc, into Google is a start.

I've never done any porting, but I've seen it done. I think the general idea is to eliminate steps, and to try and make the passage as straight as possible.

[mike]

does it look like this?

[Paul]

Skins,

From your description I did a search on Google. This is an Australian site that may match the site you are referring to, although there are no pictures.

http://www.docv.org/articles/bench3.htm

Paul

[Skins]

Yeah, thanks Paul. I found that one again myself. I seem to remember seeing drawings or images showing modifications of the port. Perhaps that part was recalled from one of the tuning books I've read.

Have you done any more on your carbs?

[Gwenadu]

Does anyone know what the standard inlet port size should be?

I think ours may have had some tuning work done because the inlet ports have clearly been machined down by the valve guides.

The ports are 32mm dia. Is this standard?

Regards,

Steve.

Hi Steve! Mine have 31mm inlet ports. and they are rough cast. When I adapted the Mikunis, I used 26mm roughcast inlet pipes of 600 Monster . Now I have widened them to adapt to the port and the result is very very good (I have not modified the port of the head).

Alain.

[Paul]

Have you done any more on your carbs?

Skins,

I got back from leave on Friday so I had time on Sunday. I took her for a ride to warm up and then stripped the bodywork. The tick over was still high, but not as high as before, and if you blipped the throttle the revs didn't come all the way down to tickover.

The carb piston lifting was still synchronised, so I started by reseting the tickover and then setting the idle mixture (then the tickover, then the idle mixture etc.) until it seemed right. I finished this just before the Grand Prix was on so I had to stop and watch that.

When the GP was over I thought "I'll just wash the Ducati..." which ended up with me washing her and then waxing her. I had bought a new camera for my wife's birthday and given it to her early as we were going on holiday. Out came the camera and I took some pictures for the gallery (any link between my wife getting a new camera for her birthday, and me wanting to take photos for the gallery are intirely accidental...).

The tyre valves on my bike when I got it were too short to be able to inflate them at the petrol station so I sourced some angled extentions from a quad bike. These worked perfectly for the last three and a half years. When I was cleaning the bike I must have moved them slightly. When I put the bike away the front one must have touched something (I suspect the brake caliper) and it bent the valve, splitting it (not the extention) so the tyre started deflating. I quickly put the bike in the garage.

When my bike was new the centre stand was removed and a rising rate rear linkage was fitted, so I don't have a centre stand. I tried to buy a "paddock stand" for the front but nobody has stock, but they have a rear one of the correct size. They might get some in today, so I will get one of each. The tyres were getting a little ropey so I will change over to my new Metzlers that came with the bike.

So as soon as I have paddock stands, and I have replaced the valve and the tyres I will be able to go for my test ride to see how I did with the carbs.

Paul