LocostUSA.com

Thanks again for the advice. I was attempting to remove material from the center mounting ring as there is a center ring opening on the adapter plate that I assumed it fit into snugly, and was therefore giving the starter more room to move away from the flywheel.

Hey I just thought of something. Do you see any issues if I remove some material from the tip of the pinion gear teeth itself to help the pinion gear slide by the flywheel teeth better?? See pic below of the concept.

I think that would be equivalent to shimming it away but you can't take out shim if it didn't work.

The gear is very hard material and would require a grinder to make the change and deburring each tooth after. It could damage the flywheel teeth if it isn't done right.

Much easier to mod the aluminum plate.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

OK Thx. I do have a grinder, and I do have extra pinion gears, but I definitely do not want to ruin the flywheel teeth by screwing up the pinion gear teeth. I'm a desperate man....

I'll continue on the starter mounting ring and/or shimming avenue at this juncture for now.

Did some additional sanding and grinding on the mounting rings and bolt holes of the starter. Measurements indicate I have removed >1mm on the bolt holes and mounting rings.
Added a second shim to the left side of the starter. Unfortunately, no success yet upon start up.

Tomorrow, I am drilling into the tranny for an observation port.

I thought we were still on step 6.

See pic for where material would be removed in orange. I have not suggested removing material from the bolt holes.

A 1mm horizontal movement of the starter body does not equal a 1mm change in gear engagement.

This didn't work again or you didn't reinstall the washer/shims with the starter swap?
viewtopic.php?f=36&t=13605&p=186254&hilit=starter#p186254

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

This thread makes my brain hurt. I read something a few posts back that confused me, something I asked about before. When you say that there is zero engagement, does that mean the starter sounds like it's spinning in the air, making zero contact with anything, or is it hitting the ring gear teeth but not engaging? One of the pics appeared to show the pinion gear teeth reaching the ring gear. I know this doesn't solve the issue but it would help to better understand what's happening.

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Ok to clear things up and summarize. I have 3 starters. All have behaved similarly. The bendix gear spins, comes out, seems to smack the flywheel tooth, but does not slip into the trough of the flywheel teeth and doesn't get the flywheel spinning (i.e., doesn't engage).

One starter (I have now labeled A) I have disassembled and have used that see the engagement with the flywheel teeth manually. Seems to mesh with the flywheel when pushing slowly. This was observed when using Play-Doh (see previous page). Note: This starter is, however, no longer functional, and i will use for parts should my mods on starter B (described below) require it.

One starter (I have now labeled B) I have been modifying to shift the starter pinon gear away from the flywheel. This concept has been suggested by Kennedy Engineering as well as MiataV8, and certainly makes sense. I have filed/sanded outer and inner rings and bolt holes to allow movement away from the flywheel. I have also created some shims to assist this. I have used paint on the flywheel and the pinion gear to see what is happening. So far results are the same as an unmodified starter (described below)

One starter (I have now labeled C) is brand new, and I don't intend to mess with the integrity of this one. I have used this new, unmodified starter without success and observed evidence of pinion gear contact against flywheel paint on one tooth. Pics on previous page.

This morning I worked on improving access to the crank bolt so that I can rotate the flywheel and avoid wearing down a flywheel tooth with all this testing. I had success (pic below).

My plan for later today was to poke a hole in the tranny bellhousing and insert a endoscope camera to observe the interaction.

Have we ruled out that the flywheel teeth may have become so damaged that they no longer accept starter teeth?

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Yes, I think so. The only real sign of any wear is on the one tooth that has been stuck in the same spot over the last 4 weeks, and is visible in the pic below.

I have subsequently rotated the flywheel to avoid further wear on that tooth.

Could the ring gear on the flywheel have been put on backwards = engagement cut on teeth away from starter???

_________________
When you're racing, it's life. Anything that happens before or after is just waiting -- Steve McQueen from LeMans

My build log viewtopic.php?f=36&t=10658&start=0 NOW NAMED =The Wycked 7

My other build log viewtopic.php?f=18&t=15162 The Skayt'R6

Great question. To answer that question and others, I poked a hole in the tranny bell housing and inserted an endoscope. Although the camera angle needs improvement to answer the starter/flywheel spacing issue, it does adequately show that the backside of the flywheel does not have engagement cuts and thus was not put on backwards. phew!

See pic below and movie: https://youtu.be/OwGyLCFqdFA

I'll try to get a better viewing angle on the starter/flywheel interaction tomorrow.

Teeth look fine. I know this is just a preliminary video, but it looks like the starter is too close but looking forward to a better angle.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Better access for endoscope viewing of the starter pinion gear/flywheel interaction, through the tranny, was successfully obtained. Below are pics of the tranny hole as viewed through the starter mounting area, as well as a pic of the interaction of gear and flywheel taken through the tranny hole. The pic suggests the clearance between Bendix tooth and flywheel tooth is close and might be insufficient. Again, the camera angle altho0ugh better is not perfect.

Additional evidence of the inability of the starter to mate with the flywheel can be observed in the two movies below. I used the disassembled starter unit (manually operated) and could not get the gear to "engage".

https://youtube.com/shorts/ZzElr95pwWM

https://youtu.be/HCpsppEebz0

So it looks like we are on the right track to move the pinion gear starter assembly away from the flywheel. I'll keep at it.

On the already modded/sacrificial starter, I would
1) narrow the outer edge lip 180 degrees (marked in orange on the pic I posted previously and a little off the bottom for a full 180deg),
2) test fit the plate and manual extend the gear to verify it will mesh. If it does not, completely remove the lip that was thinned and recheck. When it will mesh with the bolts installed,
3) Assemble the starter the last time,
4) lightly install the bolts, pull the starter away from the flywheel and snug the bolts (normal torque).
5) Operate the starter, and retorque. Lock washers or tab washers or safety wire will ensure the bolts do not loosen. It should be fine. The starter loading will help to keep it where it needs to be.

If you want to fit a standard, unmodded starter later, to keep from plugging the upper bolt hole and redrilling, the plate will need to be ground away an 1/8" down and out at a 45 deg angle instead of horizontal. This may require more material removal from the bellhousing where it hit before (due to the asymetrical shimming of just the lower bolt flange you tried before).

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Thanks again MiataV8! Love the 5 step program. The only problem I foresee encountering is the removal of the two bolts holding on the sacrificial starter's face. The screw heads are stripped out (from the original remanufacturer). I have a couple of techniques to try, and am confident I can get 'em. Will let you know how it goes.