Piston pin size?

[Saint aka ML]

So I found fast by ferraci pistins, 96mm.

They are 12:1 compression, 19mm pin.

Few questions.

1. I assume 19mm pin is stock size pin (no need to mod/change con-rods)?
2. What alterations if any I need to do to the head to make them fit?
3. What squish I should be aiming at and how to do it?
- Is it done with some kind of spacer gaskets? If so what size do I need, where to get them from and how to measure what size I need?

[Saint aka ML]

One more what are the sizes of the bigger valves for m900? I want to measure the sizes I have now to see what is in there.

What is the best modification for those valves ie best size without going crazy.
Where could one buy such valves or stock size but lighter valves?

[Dukedesmo]

So I found fast by ferraci pistins, 96mm.

They are 12:1 compression, 19mm pin.

Few questions.

1. I assume 19mm pin is stock size pin (no need to mod/change con-rods)?
2. What alterations if any I need to do to the head to make them fit?
3. What squish I should be aiming at and how to do it?
- Is it done with some kind of spacer gaskets? If so what size do I need, where to get them from and how to measure what size I need?

Assuming M900?

1. Yes 19mm is correct (at least on older models) so should be straight fit.
2. Probably none but not sure?
3. I would look for 1mm squish, do this by altering thickness of base gasket or, if necessary machining material from the bottom of the cylinder. To measure you need to assemble and use something that will 'squash' between piston & head - I use solder but there are specialist materials you can buy. Fix around the piston using grease at 90 degree spacings and turn the engine by hand to squash the solder, then disassemble and measure the squashed thickness of the solder - looking for 1mm.

I used standard Ducati base shim/gaskets that I had in both 0.3 & 0.4mm and it turned out that I needed the thinner gasket on one cylinder and thicker on the other to get it right - 1mm squish (actually around 0.95mm).

When I set the squish on my 916 I needed a 0.8mm gasket (standard is 1mm) and I couldn't, at that time, locate them so I had 0.2mm machined off the base of the cylinder (don't machine from the top!) as this means I can now use standard (easily available) shim/gaskets.

Ducati make (made) different thickness shims (same as used on 916 models) although they may be tricky to locate now but if you need a custom thickness try Louigimoto in Bristol.

As for 96mm pistons, I'm not sure how much material that will leave between cylinder wall and studs - probably OK but you may want to check as the reason Ducati homologated the 996 for racing was that overboring the 916 engine caused reliability issues due to the thin walls remaining (916 has same bottom end and therefore stud spacings as M900) although I believe that 96mm = 955cc and it was the 98mm (996cc) that had the issues?

[Dukedesmo]

As for bigger valves (in fact any specialist tuning), talk to Chris at CJS racing... :thumbsup:

[Saint aka ML]

Yes pistons to over-bopre 916 are 98mm hence me stopping at 96mm. I know off a kit that goes 98mm and even more from NCR but hey I am not made of cash sadly :(

Uh yes 96mm kit I will use gives 960cc BTW how do you calculate that?

CJS is great but in long term to expensive for me due to UK labour prices.
I can have the same done at half the price or less in Poland so looking for all the info I need to get it done there.
Guy on that end is X mechainc for one of the German teams that raced 888/851's in WSBK. The ZZtop guy not unlike Slob :)

[Saint aka ML]

I was also thinking I am going to use 900SSie injectors assmelby and injectors.

Was thinking would something like one from 996 or 916 sps be better or the same?

I know 900SS ie uses IW031 injectors while monster 750/900/1000 injected use IWP043 injectors which flow a bit more.

Would the difference be worth looking for a new loom, ecu and injectors as I have full setup of 900SSie.

[Saint aka ML]

Final question I guess no air-box but bellmouth filters he :)

[Dukedesmo]

Uh yes 96mm kit I will use gives 960cc BTW how do you calculate that?




http://www.mathwarehouse.com/solid-geometry/cylinder/images/volume/picture-formula-volume-of-cylinder.png

Where; r = radius (half of bore), h = stroke.

So for a 96mm piston, radius = 48
Stroke = 68
pi = 3.142

3.142 x (48x48) x 68 = 492263 sqmm = 492 cc per cylinder so 984cc

Or use; http://www.online-calculators.co.uk/volumetric/cylindervolume.php

[pompone]

How much are the FbyF pistons then?

[Saint aka ML]

If I were to pay all fees including stung by customs then 230 delivered. Not bad at all.
He has few sets if you interested just add is bit confusing. On photos it is full set with rings and all on description he says full set so pistons, pins, circlips no word of rings. Fallowed by full set wording.

Waiting for confirmation from him.

[Kato]

A word off warning mate 96mm is a very big bore, FBF developed the kit for racing not for street use, no reason why it can't be used in a street bike BUT....... it will get very hot very quickly, if you ever get stuck in traffic start praying that the cylinders don't crack and no two oil coolers will not sort that out.

[Saint aka ML]

A word off warning mate 96mm is a very big bore, FBF developed the kit for racing not for street use, no reason why it can't be used in a street bike BUT....... it will get very hot very quickly, if you ever get stuck in traffic start praying that the cylinders don't crack and no two oil coolers will not sort that out.

Ok and two big oil coolers?

Well it is that or you know of a 999 engine I could use for good money?

[Saint aka ML]

My main issue is I cannot find 94mm pistons with high compression. All I can find is 11:5:1 and was wantinh 12:1 if possible.

Seen any?

[Darren69]

Spotted this, pretty close and not silly money

http://www.ebay.co.uk/itm/Ducati-998s-engine-/271346930362?pt=UK_Motorcycle_Parts_13&hash=item3f2d8992ba

[Saint aka ML]

Spotted this, pretty close and not silly money

http://www.ebay.co.uk/itm/Ducati-998s-engine-/271346930362?pt=UK_Motorcycle_Parts_13&hash=item3f2d8992ba

By the time it is done auctioning it will be about 600-700 plus delivery. Then you need all the spare parts to just complete engine, another 100 the least. Then come injectors, coils that 150-200 so we at grand territory before one even starts to play around with it..... neh.

I have bit the bullet and bought 94mm pistons again so will now be building the engine again the same but this time will try to set squish bit better and play with heads.

Plus MADASL weight therapy for some engine bits as well should loose me at the end about 1.5kg from engine moving parts plus will loose bit more from static parts.

[Dirty]

I'd go for less sand this time as well :)

[Saint aka ML]

I will put woman stockings over bell-mouths or something ..... :)

[Darren69]

I will put woman stockings over bell-mouths or something ..... :)

Whatever you use make sure it won't end up being sucked into the engine! I've heard a few horror stories of people making make-shift filters to go over open bell-mouths