Ducati Monster Forum

Moto Board => Tech => Topic started by: xcaptainxbloodx on October 31, 2010, 11:39:23 AM

Title: light engine building
Post by: xcaptainxbloodx on October 31, 2010, 11:39:23 AM
im starting to put together plans for the winter mods and im worried I may be making a big mistake.

I definetly plan on doing a TPO intake kit, PCIII and dyno tune.

Im thinking about throwing a lightend flywheel into the mix as the case covers will be removed for PC anyway.

my question is;  I do most riding  (even spirited riding) betweek 3-6k. This leads me to believe I should look at the Beast (not the beast R) and that a lightweight flywheel is more of an added bonus than anything else. But im concerned that with the lightend flywheel and 14t front sprocket it will be so easy to spin up rpms that I may benefit more from the beast R. basically, am I building this bike for too much bottom end?

the bike is an S2R800, the mods that affect the bikes ability to make power are the electraeon quick throttle, dropped tooth front cog and arrow exhaust (full system).

also, anyone with advice on buying vs machining on the flywheel?

Title: Re: light engine building
Post by: xcaptainxbloodx on November 01, 2010, 12:37:43 PM
ruling out lightend flywheel now.

think im going with the beast R  to give me the peak rpm gains im missing out on.

unless anyone can convince me otherwise.
Title: Re: light engine building
Post by: ducatiz on November 01, 2010, 01:36:29 PM
i put a lightened flywheel on my SS and the difference is noticeable -- with the FCRs, it wheelies in 2nd gear.  very quick acceleration, engine spins up faster than the original flywheel.
Title: Re: light engine building
Post by: junior varsity on November 01, 2010, 04:40:06 PM
Quote from: ducatiz on November 01, 2010, 01:36:29 PM
i put a lightened flywheel on my SS and the difference is noticeable -- with the FCRs, it wheelies in 2nd gear.  very quick acceleration, engine spins up faster than the original flywheel.

+1 experience on my M900. Was a great addition (Nichols Flywheel with 2 jamb nuts). Very happy with motor after doing lightweight clutch (99 had steel basket, lots of weight to lose) and flywheel. i have lightened primary set to put in next to turn it up to 11.
Title: Re: light engine building
Post by: greenmonster on November 01, 2010, 05:23:58 PM
+1 on lighter fw, engine feels livelier.
Title: Re: light engine building
Post by: xcaptainxbloodx on November 01, 2010, 05:55:33 PM
my only reason for ditching the FW idea is engine life. racing buddies telling me im going to eat clutches.


I figure theyre  thinking more along the lines of crazy race flywheels than where my heads at. anyone have a refferal for built lightend flywheels or shops with good reps for machining down my stock one?
Title: Re: light engine building
Post by: ducatiz on November 01, 2010, 06:36:40 PM
http://motorcycle.nicholsmfg.com/ (http://motorcycle.nicholsmfg.com/)

I could see you burning out clutches faster, but it will depend on how good you are at adapting to the engine's new performance curve. 

My neighbor bought a 911 GT a few years ago and burned the clutch out within a month.  Of course, he is a dumbass and that was his first non-automatic tranny car. 
Title: Re: light engine building
Post by: mattc7 on November 01, 2010, 07:12:56 PM
For street riding, around 1.5 - 2 lbs is as light as needed.

keep away from aluminum, as they can break splines easily, and occasionally have starting trouble when batteries aren't kept at full power.

Ducshop, or Ben Fox both lighten flys.  I believe AMS does their own as well.  I'm sure other sponsors do to.

I like the nichols flywheels on race builds, but on a street bike, I think it's often too light.
Title: Re: light engine building
Post by: greenmonster on November 02, 2010, 04:02:47 AM
Quoteracing buddies telling me im going to eat clutches.

Dunno about wet clutches but simply not true on dry.
Never heard of lw fw eating clutches.


Quotekeep away from aluminum, as they can break splines easily, and occasionally have starting trouble when batteries aren't kept at full power.

This is the only time I`ve heard of that:
http://www.bikeboy.org/flywheelducati.html (http://www.bikeboy.org/flywheelducati.html)
Starting issues due to low inertia, not material.
Title: Re: light engine building
Post by: junior varsity on November 02, 2010, 05:28:47 AM
No spline problems on the Nichols, the old DP ones had some issues.


Jeff @ AMS prefers lightened crank over lightened flywheel on full builds
Title: Re: light engine building
Post by: mattc7 on November 02, 2010, 05:40:21 AM
Quote from: greenmonster on November 02, 2010, 04:02:47 AM
This is the only time I`ve heard of that:
http://www.bikeboy.org/flywheelducati.html (http://www.bikeboy.org/flywheelducati.html)
Starting issues due to low inertia, not material.


The aluminum ones are lighter, typically. I haven't seen an alu FW that was meaty enough to provide easy starting on low battery.  I meant to say, when you go below the 1.5 LB mark, it can become a problem.   I've seen the nichols, combined with a low battery, crank over, spark, and since blow a starter motor from the piston not passing TDC after the spark, but stopping and kicking back. I've also seen this on a stock flywheel turned down to nichols weight

I've also seen a nichols with no splines at all, the old DP too.  It's not a common issue, and having not done the install, I cannot say they were properly torqued which could lead to extra vibrations, and assistance with these issues. But i have seen it. 

the new DP is a 2 lb hardened steel option, which I do like. otherwise, turning the stock down is just as nice.
Title: Re: light engine building
Post by: Porsche Monkey on November 02, 2010, 06:43:59 AM
Hmmmm. I have access to a lathe, balancing would be an issue though.  Hmmmm.
Title: Re: light engine building
Post by: Monsterlover on November 03, 2010, 07:15:20 AM
^

Don't even worry about it.

I took a stock M900 FW and weighed it.  4.5 pounds.  I turned it down to 2 and could have gone a lot more.

If it's out of balance, there's no way to tell.  I also punched a bunch of holes in my clutch basket and primary gear (on a bridgeport, all precision like ) and the bike spins up like nothing.

The OP is over thinking things.

I had a 2000 M900ie with the flywheel, cut air box, pipes and a power commander.  With clipons (remember they get more weight over the front) it would wheely in 2nd gear with throttle only (14/41 gearing)

You won't eat clutches, or wear out your engine.  Aluminum flywheels don't break splines unless they're defective.

Just get it and you'll love it.  Your bike will still be easy to ride, it's not like the aluminum flywheel makes it like riding a 2stroke. . .
Title: Re: light engine building
Post by: junior varsity on November 03, 2010, 04:18:36 PM
Quote from: Monsterlover on November 03, 2010, 07:15:20 AM
You won't eat clutches, or wear out your engine.  Aluminum flywheels don't break splines unless they're defective.

Just get it and you'll love it.  Your bike will still be easy to ride, it's not like the aluminum flywheel makes it like riding a 2stroke. . .

+1

They run great - makes it behave much like a current gen bike, not like an un-street-able racebike
Title: Re: light engine building
Post by: greenmonster on November 03, 2010, 07:25:02 PM
& if any regrets,easily reversed & sold part.
Try It! [thumbsup]
Title: Re: light engine building
Post by: koko64 on November 04, 2010, 08:39:10 PM
Quote from: ducatiz on November 01, 2010, 01:36:29 PM
i put a lightened flywheel on my SS and the difference is noticeable -- with the FCRs, it wheelies in 2nd gear.  very quick acceleration, engine spins up faster than the original flywheel.

+2 [thumbsup]
Title: Re: light engine building
Post by: atomic410 on November 09, 2010, 07:11:34 AM
i would cut down the stock one, i just had mine done for $60.  there is a ducati race team that does it in CO. for $100.  here's what eats clutches on a race bike......racing.  lightened flywheels are well worth the money imho [bacon]
Title: Re: light engine building
Post by: Buckethead on November 09, 2010, 08:49:37 AM
So if someone were cutting down the stock flywheel, what, specifically, needs to stay?
Title: Re: light engine building
Post by: atomic410 on November 09, 2010, 11:19:11 AM
from what i could tell all of the weight is cut off of the outside, so it becomes smaller in diamiater.  from what the machienest told me is that it is kinda hard on bits if its not done a certain way so going though someone whos done it before seems to be the way to go.  i'll see if i can spot that teams name and post a link.  i think they wanted $100?  i'll check [bacon]
Title: Re: light engine building
Post by: junior varsity on November 09, 2010, 11:26:55 AM
don't think that's a good way to go on carbies with the ignition pickup lump on the flywheel
Title: Re: light engine building
Post by: ducatiz on November 09, 2010, 12:40:44 PM
Quote from: a m on November 09, 2010, 11:26:55 AM
don't think that's a good way to go on carbies with the ignition pickup lump on the flywheel

or the efi models with the ignition pickup lump on the flywheel.
Title: Re: light engine building
Post by: junior varsity on November 09, 2010, 12:47:43 PM
i ain't got none of them thar fancies in my g'rage.
Title: Re: light engine building
Post by: ducatiz on November 09, 2010, 12:50:23 PM
Quote from: a m on November 09, 2010, 12:47:43 PM
i ain't got none of them thar fancies in my g'rage.

yew keepin' 'em in th' shed, zeb?
Title: Re: light engine building
Post by: junior varsity on November 09, 2010, 12:52:23 PM
nah! that's where i poot me banjoz!
Title: Re: light engine building
Post by: Monsterlover on November 09, 2010, 03:56:20 PM
Quote from: ducatiz on November 09, 2010, 12:40:44 PM
or the efi models with the ignition pickup lump on the flywheel.

???

I turned more than 2 pounds off my stock flywheel.

I never noticed a pickup lump.

My bike runs just fine fwiw. 

I turned a lot of material off the od and back face. If I had to do it again I would have drilled holes through the face of it as well.

All that really matters is that the stator rotor and one way bearing still are able to mount up and locate properly.

I swear to you this is not rocket science.

Do a search for a thread of mine called "machining a stock flywheel and gears"
Title: Re: light engine building
Post by: ducpainter on November 09, 2010, 04:01:34 PM
Quote from: ducatiz on November 09, 2010, 12:40:44 PM
or the efi models with the ignition pickup lump on the flywheel.
no lump on efi models...the lump is on carbies.

it's on the idler gear on fuelies.
Title: Re: light engine building
Post by: ducatiz on November 09, 2010, 04:47:51 PM
Quote from: humorless dp on November 09, 2010, 04:01:34 PM
no lump on efi models...the lump is on carbies.

it's on the idler gear on fuelies.

yup, i knew that.  i swear i knew that esp after all the greenmonster postings on the ignitech [bang]
Title: Re: light engine building
Post by: ducpainter on November 09, 2010, 04:54:27 PM
Quote from: ducatiz on November 09, 2010, 04:47:51 PM
yup, i knew that.  i swear i knew that esp after all the greenmonster postings on the ignitech [bang]
You're either suffering from brain cramp...

or getting old.  ;D
Title: Re: light engine building
Post by: koko64 on November 09, 2010, 04:58:09 PM
Quote from: humorless dp on November 09, 2010, 04:01:34 PM
no lump on efi models...the lump is on carbies.

it's on the idler gear on fuelies.

hdp's correct.

Carb flywheels have to be machined around the ignition trigger lumps, inner face, the inside diameter and back 'shoulder' sections. Mine was also relieved wherever the machinist could do so without buggering it up. They need to be done in a way that maintains the integrity of the material and within reasonable balance.

A mate did mine for 60 bucks and removed a kilo (2.2lbs). It's nice off corners and not too snatchy like a really light one when toodling along. Wouldn't stop me shelling out for a Nichols super light one though, just to try one.

Some may not like the side effects of a very light flywheel with a hi comp motor. I had a DP alloy piece on my 900SL and I found the engine braking quite intrusive with hi comp pistons and 39 FCRs. When I lightened the clutch I swear the effect was reduced.

I have the same pistons (literally) in my Monster and the engine braking is not quite so savage nor low speed operation as snatchy. I take a pillion much of the time so I think it works well. I think a couple of pounds off a stocker is a nice compromise.