RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   Ray's Nut-Be-Gone flywheel nut removal Tool (https://www.rx7club.com/1st-generation-specific-1979-1985-18/rays-nut-gone-flywheel-nut-removal-tool-1058973/)

DivinDriver 03-11-14 12:18 PM


Originally Posted by ray green (Post 11695760)
I really think the eshafts with the ground threads would be fine in a rebuild, you guys worrying about things blowing up are obviously not engineers, more likely fear mongering Republicans.

Hate to have to say it, Ray... but I am an engineer, and I would never use that e-shaft.

Not because I'm a fear-mongering republican (I'm not), but because like all good engineers, I'm lazy and I know that the universe is my enemy, and will side violently with any hidden flaw or sub-par component that I choose to use.

This inexpensive solution has always worked for me:
https://img.photobucket.com/albums/v...4.jpg~original

$70 from Mazdatrix for both, and between work I've done and people I've loaned it to over the years, it's probably got about a dozen tear-downs to it's credit

RotaryEvolution 03-11-14 12:25 PM

i try not to be too anal about minor flaws but the threads missing will relieve pressure on the ability of the nut to torque properly and possibly remain torqued, a bit of red loctite would probably let it work but i'm with DD, murphy's law. a little more care in only nicking into the threads would have worked, once you start removing 30+ degrees of friction binding surface then problems are most likely to arise.

i've cut bolts off in a similar manner before, just not as aggressively and let the results fly.

NCross 03-11-14 02:59 PM

I use a piece of chain bolted from a clutch bolt to the upper right ear of the engine as a stopper.Just make sure you have washers to spread out the force to prevent sheering. I bought my 54mm socket at sears for $50. I bought my 3/4" drive breaker at TSC for $30. I use a 4 foot metal fencing pipe for added leverage.

If your engine rolls around on the ground or engine stand I find that chaining the engine to some 2x4s kind of like your giving it skis gives added stability for no tourque loss while heave hoeing on the nut.

ray green 03-11-14 03:41 PM

"Hate to have to say it, Ray... but I am an engineer, and I would never use that e-shaft.

Not because I'm a fear-mongering republican (I'm not), but because like all good engineers, I'm lazy and I know that the universe is my enemy, and will side violently with any hidden flaw or sub-par component that I choose to use."

I totally agree DD, that's why I've got 6 other eshafts extracted the "right" way stored for my first 6 rebuilds (recognizing, of course, that we all have our favorite methods).

I'd only use those shaved eshafts if I was down to my last two. (And, being a biologist and, at one with Nature, I'm sure it would work).

Also, I'm about to tear down another 12A from an '83 GSL, only 125,000 miles, on a beautiful Georgia spring day afternoon.

I'm betting at least one good rotor housing and a pair of nice rotors, if the Rotary Gods approve.

And if James stops by, maybe more 12As.

PS, what's that lumpy thing hanging off the right side of your 12A?

https://img.photobucket.com/albums/v...4.jpg~original

Qingdao 03-11-14 07:33 PM

Thermal reactor \m/

DivinDriver 03-12-14 09:58 AM

Yup.

RotaryEvolution 03-12-14 11:05 AM

dead weight is what i'd call it

ray green 03-12-14 12:58 PM

Ray's Nut-Be-Gone flywheel removal tool would probably work pretty well on that thermal restrictor too.

KansasCityREPU 03-12-14 01:06 PM


Originally Posted by NCross (Post 11696305)
I use a piece of chain bolted from a clutch bolt to the upper right ear of the engine as a stopper.Just make sure you have washers to spread out the force to prevent sheering. I bought my 54mm socket at sears for $50. I bought my 3/4" drive breaker at TSC for $30. I use a 4 foot metal fencing pipe for added leverage.

If your engine rolls around on the ground or engine stand I find that chaining the engine to some 2x4s kind of like your giving it skis gives added stability for no tourque loss while heave hoeing on the nut.

I've used the single bolt method and cracked the rear iron. I now own a factory flywheel stop.

NCross 03-12-14 01:22 PM

Has anyone ever broken the front iron while mounted on an engine stand? Seems like it could snap while torquing it down.

RotaryEvolution 03-12-14 04:41 PM


Originally Posted by ray green (Post 11697020)
Ray's Nut-Be-Gone flywheel removal tool would probably work pretty well on that thermal restrictor too.

i'm thinking a pool of molten hot metal to turn it back into what it started out life as would be best.

recycling and all. ;)


Originally Posted by NCross (Post 11697035)
Has anyone ever broken the front iron while mounted on an engine stand? Seems like it could snap while torquing it down.

nope, it would take a lot of work to break that casting. look at the 2 bosses on the 20B center thick iron and those can easily carry the side loaded weight of the whole engine even while dicking around with it.

ray green 03-15-14 03:35 PM

1 Attachment(s)
I can just see DD now, imagining his thermal reactor being converted to a molten mass. Only in California.

Back to the friggin' flywheel.

NCross, those end irons will take a lot of stress, plenty for dogging. Here's how I do it:

Attachment 649284

woodmv 03-15-14 05:09 PM


Originally Posted by ray green (Post 11699248)
I can just see DD now, imagining his thermal reactor being converted to a molten mass. Only in California.

Back to the friggin' flywheel.

NCross, those end irons will take a lot of stress, plenty for dogging. Here's how I do it:

http://i764.photobucket.com/albums/x...ps550ebda9.jpg

The ONLY way to do it! With Sam Adams... Love it!

ray green 03-29-14 06:58 PM

8 Attachment(s)
OK, for you dudes who are too squeamish to try Ray's Nut-Be-Gone flywheel removal technique, I've developed yet another original method for taking the flywheel nut off.

First, get yourself a BFMW. I borrowed this one from Robert:

Attachment 648393

Then secure the 12A with a 2x4 wedged between your steps and the foundation:

Attachment 648394

Then install the MSCVJ on the FWN:

Attachment 648395

Put a dog in between the FW and engine block to lock the FW and connect the BFMW to the MSCVJ such that you get good leverage on the FWN:

Attachment 648396

Now go up to the third step on your back porch and trounce smartly on the handle of the BFMW to break loose the FWN:

Attachment 648397

Attachment 648398

Now back off the FWN until it's about 1/8" proud of the E-shaft and install some dogs to keep the flywheel tight against the engine block:

Attachment 648399

Then give the FWN a couple whacks with a 3-lb hammer and the flywheel will pop loose from the E-shaft:

Attachment 648400

Bing Bang, you're done!

Qingdao 03-29-14 07:09 PM

Much better :D

NCross 03-29-14 07:27 PM

Plasma torch...

Jeff20B 03-29-14 09:12 PM

Why did you have a GSL-SE flywheel on your 12A?

MazdaMike02 03-29-14 10:38 PM

Lmao that was awesome. I'm gonna do it that way next time lol

ray green 03-30-14 09:27 AM

3 Attachment(s)
By gummers Jeff, that IS an SE flywheel. Good eye!

I have no idea why it's there, I picked up the car, a white 83 GSL, a few weeks ago because the price was right. The engine has a coolant problem (white smoke in the exhaust) which is why I'm tearing it down.

But it also had an odd vibration even when idling in neutral, which I figured at the time was a misfiring rear rotor. It'd been sitting for 3 years, so who knows why it got parked.

The clutch that came out of it looks practically new, so I'll bet that's when the SE flywheel got subbed in. I don't see how the SE flywheel could've caused the vibration however, since except for the number stamped on the "engine side" ("31" on the 12A unit, "304" on the SE unit; see Flywheels for reference) the flywheels appear to be identical.

Which makes me think maybe the clutch wasn't installed right (or maybe just a misfiring rear rotor). Here's a photo of the clutch and the flywheels (SE on the right). If anybody else sees anything suspicious please let me know.

Attachment 648367

Attachment 648368


Attachment 648369

Thanks for the feedback dudes, even you guys who take life to seriously. And while the purpose of this post is to offer some alternatives for the backyard mechanic struggling to get the FW nut off late on a Sunday afternoon, I hope all will remember that SAFETY IS JOB ONE anytime you're doing your own automotive work.


ray green 03-30-14 11:31 AM

1 Attachment(s)
So, it turns out the 83-85 12A and SE flywheels are NOT the same, even though they look very similar and weigh the same.

A closer look and measurement of the built-in counterweight at the bottom of the flywheels shows that the SE is thicker and wider than the 12A unit and the open part of the rim on the SE is a longer. Therefore the SE FW has more counterweight than an 83-85 FW.

The counterweight on the front of this engine is from an 83-85 12A, not an SE, so it seems likely the SE flywheel was the source of the engine vibration.

Thanks Jeff!

Attachment 648366

NCross 03-30-14 07:41 PM

You have to remember its meant for heavier, larger 13b rotors. Wonder what would happen if it was revved to 8000rpm on a 12a...

ray green 03-30-14 08:01 PM

Yep, that's what I was thinking. Good thing I don't do that kind of stuff.

I can't believe the PO drove the car like that for 25,000 miles without complaining to the shop that installed the clutch and SE flywheel.

glewsRx 04-02-14 11:24 AM

Good looking stuff ray. Saw the ogta meet on reddit today. Lots of nice stuff there

ray green 08-11-14 07:50 PM

Here's a recent update on the research being done at the Rotary Institute to determine the most effective way to remove flywheel nuts from rotary engines:

https://www.youtube.com/watch?v=hYCP...ature=youtu.be

I'm pretty much convinced the BMFMW coupled with the modified Subaru CV joint is the way to go.

Siraniko 08-11-14 08:07 PM

No disrespect but a cold chisel and a hammer work very well at bone yard trips or when a 3/4 impact gun or rb flywheel socket are not available. Chisel must be grounded down to avoid slicing the flywheel nut.


All times are GMT -5. The time now is 12:41 PM.


© 2024 MH Sub I, LLC dba Internet Brands