Any tips on cutting weight off the flywheel? Im turning mine tomorrow and would love to hear any tips you all might have for me.
Im also pulling the gears I can get at with the left side cover off and putting holes in them to cut down on rotating mass.
Anyone ever do that? Personally? Ive seen pics, so i know it's been done. . .
[evil]
4-jaw chuck on the lathe and align it perfectly. Never a problem with balance afterwards. 3-jaw chuck -- always a bit off.
Gears? Use lots of lubricant and don't let them get too hot while machining.
None of the gears on the left side of the motor, other than the cam drive gears, spin while the engine's running.
The ones that are easy to remove are starter gears.
You'll only save weight.
Good point. Ill do the cam drive gear. . .
How about gears on the right side?
There's a really big one there, but im not sure how it comes off. . .
I doubt this machine will have a 4 jaw chuck, so Ill just indicate and shim as necessary.
Cam drive gear is small and runs at half of crank rpm, so the benefit is small.
Primary gear on the right hand side is large, and would be some benefit even though it runs at roughly half of crank speed.
I suspect it's going to be tough drilling/milling on that one.
It'd be a good plan to remove the right side cover anyway, just to look around and make sure all is OK, as you did have a bunch of crap on the drainplug magnet.
Watch out for the O-rings when replacing the cover.
I hope you have a LOT of good tooling to burn up. Those gears are VERY hard indeed :)
If you are interested in doing a few from a testa motor, please let me know [thumbsup]
Quote from: TAftonomos on December 18, 2008, 01:15:54 PM
I hope you have a LOT of good tooling to burn up. Those gears are VERY hard indeed :)
If you are interested in doing a few from a testa motor, please let me know [thumbsup]
+1 Most machnine shops don't want to touch them.
I have the primary exposed. How does it come off?
Quote from: tSpeeddog on December 18, 2008, 11:32:07 AM
Cam drive gear is small and runs at half of crank rpm, so the benefit is small.
Primary gear on the right hand side is large, and would be some benefit even though it runs at roughly half of crank speed.
I suspect it's going to be tough drilling/milling on that one.
It'd be a good plan to remove the right side cover anyway, just to look around and make sure all is OK, as you did have a bunch of crap on the drainplug magnet.
Watch out for the O-rings when replacing the cover.
Should just pull straight off.
Quote from: ducpainter on December 18, 2008, 04:26:06 PM
Just?
I'm assuming he means the driven gear behind the clutch basket.
If he means the drive gear on the crank, well.... that requires a hella stout puller, preferably the OE Ducati unit, and a beefy impact driver.
Helmet and flak jacket optional. ;D
If he does mean the crank gear, that's not worth drilling, it ain't that big.
Quote from: Speeddog on December 18, 2008, 04:30:52 PM
I'm assuming he means the driven gear behind the clutch basket.
If he means the drive gear on the crank, well.... that requires a hella stout puller, preferably the OE Ducati unit, and a beefy impact driver.
Helmet and flak jacket optional. ;D
If he does mean the crank gear, that's not worth drilling, it ain't that big.
Ya never know with ML. ;D
2 seconds after I posted that I put more ass into it and it pulled off. I figure I might as well port that clutch basket while I'm at it ;D
I also set aside the cam drive gear off the left side.
For the record I doubt a drill would even touch these gears. They're likely heat treated to 60rc or more. Generally you need at least 30 points more on the hardness scale to cut something. I can tell you that no hss or hssco drill is in the 90's.
Carbide on the other hand definitely is
Years ago I put an lsd diff from an integra type r into an 88 prelude. I had to bore the ring gear to fit. That wasn't a big deal. I also had to machine a new bolt circle. I tried a cobalt drill and it died instantly. I ended up endmilling all the holes.
It worked ;). The car was much improved!
As for the flywheel... I'm going to turn off every last free gram of material from it [evil]
I thought I read somewhere about running no fw at all but I don't see how that can be done. If someone knows let me know cause I wanna do that!!!
The primary objective of lightening the fly wheel is to reduce inertia of the rotating mass. For a flywheel or gear Inertia = Mass x Radius^2 x 0.5 Here you can the the inertia varies by the product of the mass and radius squared. In other words reducing the diameter of a rotating mass will reduce its inertia much more (squared) than simply reducing its thickness by the same percentage. On that same thought lightening the flywheel or gears by drilling holes in it, especially near the center will have very little impact on inertia, but it will be lighter. Because these type changes (engine) only effect acceleration by reducing rotating inertia it has diminishing returns as compared to the rest of the bike. Remember inertia is inertia, regardless if its going in a straight path or rotating. Substantial reductions in total mass e.g. bike weight will have a bigger bang for the buck after you've picked the low hanging fruit like the fly wheel. Wheels are also a big candidate for inertia reduction because they have a big R and are a substantial fraction of bike weight, you get two bangs for your buck, reduced rotating inertia and reduced straight path inertia.
2c
It's done.
I weighed it before I started (postal scale) and it was about 4.5 pounds.
2 pounds now ;D
I reduced the OD big time, cut the rear face down by .200, and cut a big chamfer on the back side/od to get just that last little bit.
I did not get a chance to work on the gears, but Im going to.
The box I used to carry parts in weight a *ton* (Primary, flywheel and the gear behind it, cam drive gear) Discounting that it's rotating mass that I'm reducing, the static weight reduction should also be in the neighborhood of pounds. How can this be bad?
[evil]
I love cutting metal :D
Quote from: Monsterlover on December 21, 2008, 05:10:42 PM
It's done.
I weighed it before I started (postal scale) and it was about 4.5 pounds.
2 pounds now ;D
I reduced the OD big time, cut the rear face down by .200, and cut a big chamfer on the back side/od to get just that last little bit.
I did not get a chance to work on the gears, but Im going to.
The box I used to carry parts in weight a *ton* (Primary, flywheel and the gear behind it, cam drive gear) Discounting that it's rotating mass that I'm reducing, the static weight reduction should also be in the neighborhood of pounds. How can this be bad?
[evil]
I love cutting metal :D
My imagination is pretty good and all, but I am craving visual evidence......always makes a project more interesting 8)
Maybe this will give you some more ideas
(http://i290.photobucket.com/albums/ll274/motox79/IMG_6386.jpg)
As another asked previously, are you interested in doing others/more?
Quote from: Ducnial on December 19, 2008, 06:21:06 PM
Wheels are also a big candidate for inertia reduction because they have a big R and are a substantial fraction of bike weight, you get two bangs for your buck, reduced rotating inertia and reduced straight path inertia.
2c
Oh yes, I loves me the light (CF) wheels!! [thumbsup] [thumbsup]
I can only imagine how much bigger the effect (and it was huge ;D) would have been had I not started with the fairly light Marchesini's that came on the bike. Makes me think about those "HEAVY" wheels on all my jap bikes....and the diff that would have been made had I done the switch!
Quote from: 2001cromo on December 26, 2008, 09:45:27 AM
Maybe this will give you some more ideas
As another asked previously, are you interested in doing others/more?
cromo, where did you get the pic and who did the work?
Quote from: BastrdHK on December 26, 2008, 02:27:13 PM
cromo, where did you get the pic and who did the work?
http://www.speedzilla.com/forums/ducati-classifieds/46923-lightened-gears.html (http://www.speedzilla.com/forums/ducati-classifieds/46923-lightened-gears.html)
That is Garrick Opie's work (or at least his picture). Guy is a machining genius. Made a fender for a 999 bike out of a solid chunk of billet. #1 of 1, for MJ (Jordan) himself. HAD to have been a 6 figure bike, probably at least 2 times over.
Those gears, as discussed, are hella hard to cut. I believe the cost was ~$750 to do all the machine work, but it was a while ago I looked into that, so I could be wrong.
If the time ever comes to split the cases on my monster, you can rest assured everything will be shaved down (including the shift drum, and other internal bits).
Google Garrick Opie for some kick ass pictures of the 999 build.
Quote from: 2001cromo on December 26, 2008, 09:45:27 AM
Maybe this will give you some more ideas
(http://i290.photobucket.com/albums/ll274/motox79/IMG_6386.jpg)
As another asked previously, are you interested in doing others/more?
Yeah, I guess I should post a picture of it, huh?
That picture. . . perfect. I think I just messed myself [laugh]
I am interested in doing more, but I don't think I have enough access to a mill to do more than the few gears I have for myself.
That may change soon though, so stay tuned. . .
Ok, got them done today.
As mentioned before, most machine shops wouldn't touch this project.
But I would ;D I did lots of touching.
I even have some pics for your viewing enjoyment.
[ENJOY]
(http://i2.photobucket.com/albums/y25/900rider/Gears001.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears002.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears004.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears006.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears007.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears008.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears009.jpg)
(http://i2.photobucket.com/albums/y25/900rider/Gears010.jpg)
[/ENJOY]
There is a downside to negating the flywheel of course; compression braking... Without flywheel inertia the engine compression will massively increase rear wheel lock on engine decellaration. And of course, the fix for this is a slipper clutch, which weighs more than a stock clutch. Sooo....... Would you really want to nix the flywheel and replace that weight with a slipper clutch?
BTW, this is.... truely..... motoporn!
W
Any before/after weights?
The lightweight flywheel is easily purchased, more interested in the basket and primary gear....
Quote from: Smokescreen on January 03, 2009, 08:41:44 PM
There is a downside to negating the flywheel of course; compression braking... Without flywheel inertia the engine compression will massively increase rear wheel lock on engine decellaration. And of course, the fix for this is a slipper clutch, which weighs more than a stock clutch. Sooo....... Would you really want to nix the flywheel and replace that weight with a slipper clutch?
BTW, this is.... truely..... motoporn!
W
My slipper clutch is lighter than the stock unit.
The clutch rotates at less than engine speed so more effect is gained from a lighter flywheel.
Monsterlover, what type of cutter did you use HSS or cobalt? Did you break any?
Quote from: TAftonomos on January 03, 2009, 09:31:43 PM
Any before/after weights?
The lightweight flywheel is easily purchased, more interested in the basket and primary gear....
A stock steel clutch
hub basket is 4 pounds.
A machined (like the old SBK's) steel clutch
hub basket is 2 pounds
A stock aluminum clutch
hub basket is 1 pound
No clue about the gears, would like to know about these too?
edited, to make the proper name of basket instead of the wrong name "hub".
Quote from: Smokescreen on January 03, 2009, 08:41:44 PM
There is a downside to negating the flywheel of course; compression braking... Without flywheel inertia the engine compression will massively increase rear wheel lock on engine decellaration. And of course, the fix for this is a slipper clutch, which weighs more than a stock clutch. Sooo....... Would you really want to nix the flywheel and replace that weight with a slipper clutch?
BTW, this is.... truely..... motoporn!
W
while engine braking will be (slightly) stronger once the clutch is engaged, a lighter flywheel will actually reduce wheel-hop if you botch a down shift. Lighter internal engine components allow it to rev more quickly, so if you release the clutch 1500 rpm's off, it will take less work from the rear wheel to right the situation. also i have found that the lighter flywheel makes it easier to match revs since it does rev more quickly now.
i had mine machined last winter and would never go back, in fact i was thinking about going all the way and getting a lighter aluminum flywheel.
Quote from: Capo on January 04, 2009, 01:59:01 AM
My slipper clutch is lighter than the stock unit.
The clutch rotates at less than engine speed so more effect is gained from a lighter flywheel.
Monsterlover, what type of cutter did you use HSS or cobalt? Did you break any?
Read a little further up in the thread. I made some comments about HSS or HSSCO not being hard enough to cut through the "skin" on the gears.
Carbide all the way baby!! I didn't break any cutters. . .
In fact, I could probably use them to do a second set.
I do this for a living you know ;D
Quote from: 2001cromo on January 04, 2009, 07:31:26 AM
A stock steel clutch hub is 4 pounds.
A machined (like the old SBK's) steel clutch hub is 2 pounds
A stock aluminum clutch hub is 1 pound
No clue about the gears, would like to know about these too?
Where would one find a stock aluminum clutch hub? I know veetwo sells a billet one for 3-400.
Did ML lighten the clutch hub?
Could you be meaning the clutch basket?
Here is a pic of mine
(http://i295.photobucket.com/albums/mm143/Tarugo996/P1000718.jpg)
Quote from: TAftonomos on January 04, 2009, 11:02:14 AM
Where would one find a stock aluminum clutch hub? I know veetwo sells a billet one for 3-400.
Did ML lighten the clutch hub?
Could you be meaning the clutch basket?
Fixed that to say "basket" as that's what I meant. Doh! thanks for the catch.
I coulda sworn all the hubs were aluminum and the newer SBK's like 749/999 had a lighter aluminum hub. I've heard of the V2, but never seen one in person to compare.
like a zombie, i resurrect this thread.
you wouldn't happen to want to lighten mine would you? i'm tearing an engine apart and have lightweight/straight cut primaries, and was interested in lightening things up on the alternator side... of course, i'd pay in money and your bev of choice, with goodwill moonpies thrown in.
Me?
I could probably do it.
I just kept cutting mine until it looked good. I could have gotten more off it but access to the lathe ran short.
I could also punch holes in the clutch basket and primary gear...
already got the primary taken care of, going to use a slipper on the clutch, so it'll come with basket. (the one i'm getting does - 48T).
but the sprag gear (i believe that's the one riding behind the flywheel - that's the one I want done.
thoughts?
Sprag gear doesn't spin when the engine is running, so only benefit is the weight removed.
I'm thinking of the correct one, right - the one right behind ze Flywheel?
I forgot it was only for starting the bike. As I play in the garage with my mostly disassembled motor, I see that.
Well, weight savings from a big ass gear is weight savings. At this juncture, I suppose my deciding factor to have it machined is cost.
can you machine more holes in the timing gear that's on that side?
I can put holes in pretty much anything.
Like pistons for example ;D
I put holes in my starter sprag, primary and clutch basket.
I turned the flywheel and in hindsight I feel I could have punched some holes in that thing to lighten it up more.
There's a few pics posted around here somewhere.
i spied the pics at the beginning of the thread. i'm just disassembling this here 900ie motor and looking at making it fancy when it goes back together.
I'll help :)