Lightweight custom built Flywheels

[S2central.net]

Paul, you are totally right with this,

I`ll sort all the numbers and things out tomorrow or perhaps, in the beginning of next week. maybe we will have a testsetup going in the next few weeks.

But i`ve got some questions you will know. The rpm signal is comming off the teeth of the starting sprocket right?

And some pictures below will with the pins, could anybody tell me witch pinns are important ? i know offcourse the ones to bolt on the clutch but for the 0-point i guess?

one pin on the engineside of the wheel.

And 2 pins on the other side, could somebody tell me wich of those are importent ?

Cheers,

Cees

Those 2 pins are critically important as they define reference points for crankshaft position into the ECU. They must be replicated exactly. The one referred to in OFRM is at 62 degrees BTDC on cylinder #1. This pin is detected by G4 for engine POSITION. Your pic of the ABY item shows two pins which confuses me a bit - maybe the 2nd pin is less famous !

The height of this pin (or pins) is 36 +/- 0.5mm according to OFRM.

The engine SPEED is detected by G28 as it counts flywheel teeth as they spin past.

The bolt spacing where the flywheel meets the crank is asymmetrical so you must copy that accurately in order to preserve integrity with respect to cylinder timing.

Am I correct in assuming that standard flywheel BOLTS can be used or is something of a strange length required ?

May I also assume that the alloy flywheel will be machined to accept the stock needle bearing - actually suspect 3B bearing is different from DM item ?


Cheers,

Paul

[S2central.net]

Thinking this some more - and reading more details in your post Cees...

Yeah the SINGLE pin on engine side of the flywheel is the crank reference pin for G4. I had a blonde moment there. Without this, the engine will never start !

On the DM flywheel - I think maybe the two pins on gearbox side are to position the clutch cover in some way.

OK ?


Paul

[Dutch_RsBlueS2]

Thinking this some more - and reading more details in your post Cees...

Yeah the SINGLE pin on engine side of the flywheel is the crank reference pin for G4. I had a blonde moment there. Without this, the engine will never start !

On the DM flywheel - I think maybe the two pins on gearbox side are to position the clutch cover in some way.

OK ?


Paul

Yeah, the flywheel on the photo is a 3B one, so i was right i guess the 2 pinns on the gearbox side dont matter that much. But lets say the one on the engine side allong with the starting teeth are inportant ? I will measure it up on the cnc machine where the exact location is of the G4 pin. So it will come in the same place, at least within 0.005mm so i guess that will be enough

Those other two pinns i will look out for when i take my own engine out. But is the G4 sensor the same on an aby flywheel ?

Thnx for your info paul, i hope we can make something nice out off this flywheels toghether with all the forum people`s thoughts.

Cheers,

Cees

[S2central.net]

Yeah, the flywheel on the photo is a 3B one, so i was right i guess the 2 pinns on the gearbox side dont matter that much. But lets say the one on the engine side allong with the starting teeth are inportant ? I will measure it up on the cnc machine where the exact location is of the G4 pin. So it will come in the same place, at least within 0.005mm so i guess that will be enough

Those other two pinns i will look out for when i take my own engine out. But is the G4 sensor the same on an aby flywheel ?

Thnx for your info paul, i hope we can make something nice out off this flywheels toghether with all the forum people`s thoughts.

Cheers,

Cees

One final thought for now... When you measure the location for the G4 pin - make sure and note the orientation to flywheel teeth - I dunno if G4 aligns with a gap or a tooth. Actually this might not be a problem - but hey !!!



Paul

[Dutch_RsBlueS2]

One final thought for now... When you measure the location for the G4 pin - make sure and note the orientation to flywheel teeth - I dunno if G4 aligns with a gap or a tooth. Actually this might not be a problem - but hey !!!



Paul

Ok, well if its 62 degrees it will be tereffic and i will also have to place the 0-line on the outer-side to mount the timebelt. I`ve measured it and it does allign perfectly with the boltpattern in the middle. Its exactly 62 degrees from the middle of the centre, so it would make sence if i check it out on my engine to see if the 1cil is actually on TDC to confirm everything.

Well thnx for your help so far.

Cheers,

Cees

[91_S2]

Cees,

You have a message from me. Please contact me off line at:

rictan302@yahoo.com

[nos]

I am in for one !!!Send me a PM as soon you are finished with some.

[Jeffer]

This is the first one!!

Beauty isn't it.

[Jeffer]

and the other side

[porkkis]

I don't think the idle-ing will be an issue on our 5 pots. AFAIK in every cranck rotation there are 5 ignition moments (each 72 degrees). So it's likely going to stall or loose speed. I think it'll weigh 1/3 of the weight of a standard 3B wheel, maybe 1/4 th.

cheers

Whoa! A 2-stroke S2!

[Jeffer]

haha, senior moment

Whoa! A 2-stroke S2!

[91_S2]

and the other side

So how much did the new baby weigh at birth

[Jeffer]

To be honest.........I have no clue???? I'll weigh it asap. Its now at the machine shop. Their balancing it together with the cranck.

So how much did the new baby weigh at birth

[rs2 jamie]

hi guys
i was into the idea of having a alloy flywheel i saw some at autosport international .an American company called fidanza were doing them at about £350 . but i spoke to a engineer regarding the metal plate for the clutch and he said he,s seen them come apart.have you guys done your homework on this?

[AnLe]

hi guys
i was into the idea of having a alloy flywheel i saw some at autosport international .an American company called fidanza were doing them at about £350 . but i spoke to a engineer regarding the metal plate for the clutch and he said he,s seen them come apart.have you guys done your homework on this?

To avoid using multiple pieces you can make the whole wheel from chromo
dunno how its written. Same material as rollcages.

Fidanza makes only for 7a engine flywheels but I can't see any difference between s2-3b and 7a flywheel. Can someone second that siting? I don't have them side by side simce 3b one is installed in my car

What is the weight of the aluminiun wheel?