RHD light flywheel - review and question re noise when starting

[Poorhouse]

From RHD Facebook page:








Rama Rhd

June 20 at 9:59 AM ·

...

IMPORTANT FACTS ABOUT m20 STARTERS & FLYWHEELS

Towards the end of e30 production there was a significant change to the ring gear tooth profile

WE HAVE BOTH TYPES AVAILABLE!!

Different countries got the upgrade at different times but generally around 1988-89. Some countries possibly didnt get the change at all. (If someone has more accurate information on this please let me know!)

Also many cars have since been fitted the wrong replacement starters. (cheap aftermarket (flea-bay!) starters are generally late model version) Using the wrong starter causes a lot of very harsh noise, excessive tooth wear and eventual stripping of the ring gear teeth. There is only one way to tell the difference and that is to count the teeth.

Early version FW has 137t
Late version FW has 116t.

This change is ONLY relevant to the STARTER!!... ALL other fitment and clutch details are exactly the same, so please choose the correct one in the options if you purchase one from us.

DONT WORRY if you have the wrong one, changing to the correct starter will fix the issue... (easier than changing the FW) But be aware of this in the future!

I will offer big discount to anyone who has damaged their RHD one with the wrong starter and needs a replacement.

[jeffnhiscars]

I haven't driven my car much recently but have tried to take stock of the starting sound and honestly, I don't think I know what a stock m20 starter sounds like anymore. My RHD has become the new normal. Drive and enjoy

[r-mm]

I am not really concerned with the starting noise any more. The noise when the starter is engaged and cranking is tinnier than before but not an ‘uh oh’ noise. I can’t give an explanation but without a doubt my ‘technique’ of releasing the key from start sooner than I think is needed is helping/eliminates the grunchy disengage noise. In summary I have no evidence as I havent removed parts or had parts break but my spider sense tells me nothing is untoward.

After about a thousand miles my obersvation is that the number one sound I hear is a ringing when on throttle.

[Poorhouse]

Curious about this as well.

R-mm is yours quieting down with use?

[gilber33]

Any update on this? I just sent Rama a follow-up email. I'm going to be pulling the engine to check some clutch chatter and will be putting the OEM flywheel back in the car.

[jeffnhiscars]

I am certainly not trying to play down the problem and plan on pursuing it with the manufacturer but I will say that releasing the Key much much earlier than my past experience and intuition tells me is necessary has reduced the sound.

Is it absolutely the case that the flywheel on a running motor pushes the pinion back? I have not looked into this in much detail I was under the impression that releasing the key from start de energizes the solenoid and allows the pinion to retract but I could be wrong.

"The Bendix system places the starter drive pinion on a helical drive spring. When the starter motor begins turning, the inertia of the drive pinion assembly causes it to wind the spring forcing the length of the spring to change, and allowing the pinion to engage with the ring gear. When the engine starts, backdrive from the ring gear causes the drive pinion to exceed the rotative speed of the starter, at which point the drive pinion is forced back and out of mesh with the ring gear."

In other words...yes :)

[r-mm]

I am certainly not trying to play down the problem and plan on pursuing it with the manufacturer but I will say that releasing the Key much much earlier than my past experience and intuition tells me is necessary has reduced the sound.

Is it absolutely the case that the flywheel on a running motor pushes the pinion back? I have not looked into this in much detail I was under the impression that releasing the key from start de energizes the solenoid and allows the pinion to retract but I could be wrong.

[jeffnhiscars]

Gilber can you try and experiment. Get your car warmed up or to wherever it is in its happy place for starting. Then try starting it and release the key a lot sooner than you think you need to in order to get it to catch. I am wondering if I’m not hearing an improvement and whether technique may have something to do with the sound. Let me know what you find

Trying to think why this may be. All I can think is the different rotational physics of the lighter wheel makes the retraction of the pinion harder to execute ?


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The pinion retracts when it becomes driven by the flywheel rather than driving it. I can't see that mass would have a bearing on that especially given that it takes place at idle

[Poorhouse]

Pitch is the same.

Can't check distance to ring gear without pulling the RHD flywheel.

[r-mm]

Checking that the gear pitch is the same

Checking that the depth from mating surface to ring gear is the same.

[Poorhouse]

I installed mine last night.

Engine is out of the car, trans not attached.

I can compare to the stock dual mass flywheel.

What are we looking for?

[hasa]

Steel flywheels with machined starter rings are always noisy

[pazi88]

We have had the m50 RHD flywheel for m5 pressure assembly in use for one summer. No problems with starter, no strange noises or other stuff. Works great. But maybe bit too light for daily driver. Getting car moving from standstill is tricky because thorttle is very touchy with that.

http://racehead.com.au/products-page/engine-components/bmw-lightweight-performance-flywheel-m50-m52-m54-s50-s52-s54-heavy-duty/

[gilber33]

Gilber can you try and experiment. Get your car warmed up or to wherever it is in its happy place for starting. Then try starting it and release the key a lot sooner than you think you need to in order to get it to catch. I am wondering if I’m not hearing an improvement and whether technique may have something to do with the sound. Let me know what you find

Trying to think why this may be. All I can think is the different rotational physics of the lighter wheel makes the retraction of the pinion harder to execute ?


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My car takes maybe 2 seconds if cranking to start and it makes that sound for the duration of it. Hot, cold, start it, turn it off and start it again. It doesn't matter. Always makes the sound. Being that you're having this issue and another person local to me experiencing the same thing, I don't think it's technique, I think there is something wrong with the flywheel.


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[r-mm]

RHD light flywheel - review and question re noise when starting

Gilber can you try and experiment. Get your car warmed up or to wherever it is in its happy place for starting. Then try starting it and release the key a lot sooner than you think you need to in order to get it to catch. I am wondering if I’m not hearing an improvement and whether technique may have something to do with the sound. Let me know what you find

Trying to think why this may be. All I can think is the different rotational physics of the lighter wheel makes the retraction of the pinion harder to execute ?


Sent from my iPhone using Tapatalk