I need someone to give me the exact flywheel dimensions. I need all of them, but if you only know some of them that's okay too.

If you can't do that, pointing me in the right direction is a good start. (FSM doesn't seem to have anything other than clutch dimensions)

I'm looking into have one/some fabricated.

Thanks.

 

I could measure my RB flywheel

 

Try the Mazdatrix website. I think they have SOME of that on there.

Brad

 

If you can that would be great, but I think I need things to be pretty exact. I've marked with red lines measurements that I think I'll need. I'm not exactly sure how critical the depth changes are. I'm also not sure if I need to maintain the same curve that occurs before and after the depth changes.

 

And what's with those hunks of metal comming out from the rear of the flywheel?

The "clutch diameter" is 240mm on a turbo, where is this radius measured from?

 

Here's a picture of a 12a flywheel, note the hump in the middle. What's with that?

 

Snrub,

I've had a couple custom flywheels made in the past, although not for rotaries. I'd recommend finding a machinist who is capable and interested first. Go with the stock flywheel in hand, so he can understand the scope of the job. Rather than providing a full engineering drawing, you may be able to simply leave the flywheel with the machinist along with a sketch detailing the differences for your new version.

Keep in mind locating diameter, ring gear, and clutch pressure plate attach points are critical. If you leave the OEM flywheel with the machinist, then he can take these critical dimensions, and duplicate them on your new design. If someone else less familiar with measuring to .001's of an inch takes the numbers, you may very well end up with an expensive doorstop.

If you are still at UWO, you could try the student shop. They may be able to help, or at least point you in the right direction.

Another issue to look at here is engine balance. Does the flywheel on your engine incorporate offset weights to dynamically balance the system? If so that's another added complication to a diy flywheel project.

Roger

 

Thanks for the advice Roger. I COMPLETELY forgot about the UWO shop!

The method I was going to use was to make one in the style of all of the aftermarket flywheels by having it externally balanced and use the auto tranny rear counterweight. This makes it much simplier for the machinist.

I was going to worry about first being able to reproduce a near stock flywheel and then worry about the weight reduction. It's been suggested to me that it could be made thinner, any ideas on that? I've seen some with holes above where the clutch makes contact with the flywheel.

 

Holes could be used, but that is lots of work compared to sticking the thing in the lathe and removing some material. The lightened unit I have on my old 13B has metal removed in the thick outer section. I have no idea on dimensions, though. Surely someone on the forum has a lightened RB flywheel they can pull a few numbers from.