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Discussion Starter #1
OK. Now that I have my engine out and I am awaiting my heads back, I was thinking of going up to the 95mm vs 94mm bore. As far as I know, the only pistons are the Mahle's at 600 a set. Well, that got me thinking to have some custum ones made. It seems that all of the piston companies that I called require a minimum of 4 pistons. The company I am thinking of going with is either Arias Pistons or diamond racing pistons. They charge about 155 a piston, so about 630 total with tax (315 for 2). This includes everything. I asked about group buys and it looks like the number would be 12-14 pistons total. I would be using the specs from my pistal pistons (94mm) from ducati as the mold/blank. Anyone interested? Thanks

In addition, I called a local place (millenium technologies) in regards to bore and plating. With a group discount (12 cylinders) and using my tax id, I can get the price of the cylinder bore/plating to about 130.00 a piece. So 260 + 315 = about 600 dollars. We could end up saying cost + 10% in the end.

In addition, if anyone just wants to get their cylinders plated and/or bored/plated, let me know. The more done at one time, the better discount I can get. I am short 4 cylinders from the minimum 12.

Thanks

Mike
 

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The Ducati pistons are most likely not Pistals. I would recommend you consider CP for your pistons. Experienced with motorcycle work and easy to work with their technical department. And be sure to use nitrided rings. Also, before you send your cylinders out for bore, measure the thickness of the bottom of the flange that sticks into the crankcase. This area is thinner than the upper part. Under 2 mm is too thin to go 95 mm. Some cylinders you just can't use - they are all just a little different.
 

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Discussion Starter #3
Thanks for the info. I knew that cylinder skirt was thin, but did not realize that different cylinders have different material thickness. I would assume that the older cylinders (92-96) are probably more susceptible to this b/c of quality controll.

The pistons that I have are pistals. I had a 944 kit installed in my bike about 8 years ago. As for CP, I contacted them (Arias,Diamond,Ross,CP). I then contacted total seal and talked to a guy that I have been working with. He said that CP do make a nice piston, though they can be fairly light and that longevity might be an issue with them. Not to mention they were the most expensive. My goal is to have a piston made that is bullet proof. I do not want 5 yrs to go by and have to have something go wrong my pistons.

Any piston manufacture I have found out can make an exact copy of the piston you supply them. They all seem to use 2618 material and all are ISO certified. I think it comes down to 1) word of mouth 2) talking to them to get a feel of knowledge 3) desired result 4) price.

If anyone can chime in one here and help me out, let me know. This endeavor of mine is to help people out and in the process make a little jack. We pay enough in maintenence in regards to our Ducati's. I think that certain people ( I can go into a long rant about a night and day situation in regards to two dealerships) think that since we own a motorcycle and a ducati, that we will be willing to bend over and take it any way they can give it to us. It is just a fact of life....demand vs supply. I am blessed to be in a situation where I do not need to charge a high price to support my life.

Thanks again for the information. I do appreciate it.


Mike
 

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When the ST2 came out in 1998, a factory 944, I was the first person to develop a big bore kit (966) for that bike. After a couple of years, people started wanting to use that kit on their 900 and 944 bikes. In my personal opinion, it is really not that much more power than the 944, especially not on the thinner cylinders coming from the 900s. It worked great on the ST2 because the cylinders were thicker to start with. The 966 gives a little more mid-range torque but not more on the top end. Sometimes due to piston ring sealing issues, the whole result is less than what would have come from a 944. I know that doesn't sound logical but I have done many of these installations and speak from experience.

In addition, the 944 is fairly straight forward for a home technician but the 966 requires significant care to ensure that the head seals to the cylinder properly. Also, if you have Pistals (which that long ago would have been purchased by whomever did the job from either myself or Nash as we were the only people importing Pistals at that time and in fact, the Pistal is my design) the dome shape would result in too much compression for a 966. It would move to 12:1 which is too much for that air cooled engine on pump gas. So you can't just have them copy it anyway.

On another note, I'm curious why you are taking out the Pistals. The 944s that I have installed or have been done in my old shop, used to last 40-50,000 miles.

Bruce
 

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Discussion Starter #6
OK. After talking with both Guy and Bruce Meyers, I am going to go with CP pistons. These pistons will be a little bit more to make, about 220. In addition, due to Bruce's relevation/suggestion that some of the older cylinder can be of different thickness in the skirt, I am going to make this a 94.5 mm bore (954ish). This will give about 2.2-2.5 mm thickness of material. The design of the piston should put compression about 11-11.5:1. I am trying to incorporate longevity and ease of use for this endeavor.

I will keep in touch with both Guy and Bruce in regards to this endeavor (thank you both for setting me straight!).

So 220x2 + 260 = 700 cost. I would then say 750 + shipping, though tips would be appreciated :)

I believe that I have enough cylinders if the two who had interest are still interested.


Thanks again Guy and Bruce. Your reputations really do proceed you.


Mike
 

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966 kit on 900 Supersport

OK. After talking with both Guy and Bruce Meyers, I am going to go with CP pistons. These pistons will be a little bit more to make, about 220. In addition, due to Bruce's relevation/suggestion that some of the older cylinder can be of different thickness in the skirt, I am going to make this a 94.5 mm bore (954ish). This will give about 2.2-2.5 mm thickness of material. The design of the piston should put compression about 11-11.5:1. I am trying to incorporate longevity and ease of use for this endeavor.


Mike
Hi Mike, I just stumbled across this post.

I raced my 900 Supersport with Guy's heads and Mahle 966 pistons all season last year. The engine performed great until the last couple of races where the power started dropping off and had some overheating issues. Marty at Seattle Ducati is freshening up the engine and found that the side of the front piston has some white residue just above the rings on about one third of the piston; it almost looks as if the piston coating/finish is coming off. He recommends going to Pistal but from what I am reading here Pistal does not make replacements for the 966 bore. What do you guys recommend?

Thanks!

Thanks for your help!
 
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