95 mm cilinders and pistons

[antonio carroccio]

I have got the bad idea to fix new cilinders and appropiate pistons.

Change the mine from 92mm to the new one 95 mm.

 

what do you think guys?

pro/contro?

[Velf 2003]

Pro: something to look forward to (Why did I not get the the extra power I hoped for, can I tweak it to do so)

 

Contra: if you don`t do it, you never know what you`ve missed out on.

 

Summary: Just decide if you want the extra cc`s, don`t expect more.

[macguzzi]

go on do it just to see what happens I was thinking of doing this myself

[Guzzirider]

Go for it Antonio! Size matters!

[callison]

As I understand it, the 95mm bore on the new engine is accommodated with a wider stud spacing. You can take the older cylinders out to 95mm relatively safely but the very narrow metal surface areas between the bore, studs and so forth will require a solid copper gasket. According to Mike Rich, pushing anything over 100HP out of the older big block is inviting trouble because the heads can't dissipate the heat. You would probably get more for your money with a good port job and leave the bore at 92mm for reliability.

[antonio carroccio]

Carl,

 

Do you think I will go over the 100 HP?

I thought with those big bore heads, I would go over the 1200 cc and maybe with a cosmetic adaptation (twin sparks) the produced heat inside the heads should be dissolved because we will have a double combustion and detonation.

 

…or am I wrong?

Besides, what the hell does Paul have done on his Daytona?

[Paul Minnaert]

Antonio, I have 100mm, no way you can have that, other than the BigBore engine.

Power doesn't come only from big bore, but a carefull combination between bore/stroke/vale size/timing and then you also need to get gasses in and out quick.

[Pierre]

Carl,

 

Do you think I will go over the 100 HP?

I thought with those big bore heads, I would go over the 1200 cc and maybe with a cosmetic adaptation (twin sparks) the produced heat inside the heads should be dissolved because we will have a double combustion and detonation.

 

…or am I wrong?

Besides, what the hell does Paul have done on his Daytona?

Antonio, last Monday i put my sport i on the dyno to get it mapped. First ran three chips (ignition curves) back to back just to get best power curve. Best pull was 98 RWHP - just a little under Mike Rich's calculations.

 

I ran into fueling issues while mapping. Probably plugged fuel filter - but want to look at injectors again also. Bike did sit idle for over a year. It's getting the fueling issues sorted now, and will be back on dyno for final mapping early next month.

 

I'll update my hot rod 101 article on guzzitech when it's fully mapped and final results (with dyno chart) are ready. But yes, close to 100 RWHP is attainable with flowed heads, pistons and stock bore. It cost me a lot of money to get there, but a big chunk of that was due to mistake after mistake I made. If you wait a month, you can read my updated article and then build your own for a pretty reasonable amount.

 

Profit from my trial and error.

[antonio carroccio]

Pierre, now you mention it, the heads I have seen, are originally from a 1100 sport.

I have got contact with this guy, and the heads will fit on the V11.

 

What do you think?

 

Should I have to replace the valve too?

[Pierre]

Antonio, not sure I am understanding what you are telling / asking me.

 

Here's what I did.

 

I ended up working with Mike Rich to achieve a complete combustion chamber package. He installed new valves the same time he flowed the heads. He knew exactly what cam I was using (he sells same cam). So ... he did the entire combustion chamber as a package - all designed to work with his pistions and my particular cam. As I indicatd, it is a fairly radical grind so he had to recess the valves to gain piston / valve clearance.

 

He did a straight "flow equals x HP" calculation prior to beginning the work, and then gave me the actual flow numbers when he was done. He was pretty close (both on predicted flow and predicted HP), and actually I can probably get to exactly his predicted HP with a little more ignition curve and fuel map tweaking.

 

I have to believe there are European sources for this kind of thing as well. Doesn't Dynotec over there offer turn-key packages? It's really nice to let a pro who's done it before duplicate prior efforts with predictable results. I have to believe if you told Dynotec your target numbers, they'd put together a full package (head work, cam, valves etc.) for you.

 

I have various ignition maps laid out on a spread sheet as no one I could find had a a modified map for the sport i, but they are "best guess" interpretations of existing stock and after market ignition curves. Happy to share that information with you, though I think Dynotec has their own chip which probably includes a modified map. Not sure abourt that.

 

Pierre, now you mention it, the heads I have seen, are originally from a 1100 sport.

I have got contact with this guy, and the heads will fit on the V11.

 

What do you think?

 

Should I have to replace the valve too?

[dlaing]

Pierre, now you mention it, the heads I have seen, are originally from a 1100 sport.

I have got contact with this guy, and the heads will fit on the V11.

 

What do you think?

 

Should I have to replace the valve too?

Huh!?!

I thought you were talking about the 95mm pistons and cylinders from the 1200S and Norge 1200.

Who made these cylinders?

[Pierre]

Huh!?!

I thought you were talking about the 95mm pistons and cylinders from the 1200S and Norge 1200.

Who made these cylinders?

I'm so lost.

[Murray]

Agostini list a 94.6mm big bore kit for older motors who they are made by etc etc I don't know. Would be intrested in any feedback on these. Although I think they lift the capacity to aprox 1132 Significantly more expensive than the standards as well.

[luhbo]

...

I ran into fueling issues while mapping. Probably plugged fuel filter ....

 

What fueling issues did you ran into exactly? Was it at high loads/ high RPM? Probably, but then, have you already thought of rising the fuel pressure? Anyway, if you have to go this way this will not necessarily improve driveability for low load/transition conditions.

 

Hubert

[Pierre]

What fueling issues did you ran into exactly? Was it at high loads/ high RPM? Probably, but then, have you already thought of rising the fuel pressure? Anyway, if you have to go this way this will not necessarily improve driveability for low load/transition conditions.

 

Hubert

None initially. I got three full-throttle power pulls (1 for each chip I'd brought along) in, and no evidence of issues.

 

Thereafter began mapping and the injectors (both) began going into 100% duty cycle (and a/f would go to max) as RPM's increased. Thought maybe it was heat related, so let the bike cool. Tried again but the issue was still there, but at even lower RPM.

 

Concluded it was a plugged fuel filter, or that both injectors had gotten plugged. Bike did sit for a considerable period of time and I didn't flush the system before taking it to the dyno.

 

Sean at MGC is looking at it now to see what he can find. I hope the filter is filthy with crud - easy fix. If not, then will need to look at fuel pressure, dying pump or bad injectors. FWIW - the injectors are upgraded from stock so according to the supplier should handle anticipated flow no problem. That's why, when they went to 100% at modest RPM, we concluded it was fuel delivery, not undersized injectors. That, and the fact the symptom didn't show up until the bike had been run hard for several minutes.

 

Sean was racing this past weekend, so he'll be swamped with work for a few days. Hopefully he'll have an answer and a fix for it later this week. Then I''ll go run it again.