Source for rubber biscuit for stator wires

[SVSooke]

I appreciate all the responses, but I suspect I was not clear enough in my request/explanation.
First, I have rebuilt some stators.
Second, I despise the 18 gauge wire Suzuki chose in their ultimate cheapness.
Third, I want to use 16 gauge wire. Larger gauge, less loss, less heat, fewer failures (years of experience).
Fourth, I have tried reaming out the factory biscuits with disappointing results. They don't leak, but fitment is tricky, at best. If you ever looked at one, the path is not straight through from one side to the other. It angles, perhaps to minimize leaks?
Fifth, I would like to have some designed from the beginning to use 16 gauge wire.

It was in there,I missed it.Probably going to have to cast one as Dogma suggested .

 

[bwringer]

This company shows their silicone rubber products being used to make industrial gaskets and such. Kits start at $25-$30.
http://www.smooth-on.com/Industrial/c1275/index.html

This seems to be the most likely candidate -- they mention making gaskets from it. Shore 70 hardness is the same as most o-rings, which seems about right.
http://www.smooth-on.com/PMC=--870-Uretha/c1147/index.html

However, they don't list any specs on temperature or chemical resistance. Aaaaarggh.

Seems like it wouldn't be all that hard to make a mold from a sample "biscuit" then cast a bunch of blanks and drill holes for the wires. But would it be worth the trouble and expense? You'd also have to take into account that old biscuits are usually somewhat shrunken, so the mold might need to be modified a bit.

I don't think there's any particular reason the wires are at an angle. I've seen them at various angles and straight through. I think it's just happenstance during manufacturing.

 

[bwringer]

Hmmmm... what about this stuff?

http://sugru.com/about/

It's basically a putty that hardens. You could squish it into shape when installing the stator. Temp-resistant to 180C (356F) -- seems like that should do the job.

 

[koolaid_kid]

Thank you for the email. We call that piece a grommet and you can special order one if you need just that part. Part# is: RGR005 and they are $5/ea. Please call me at 1-800-521-0277 and ask for Amanda.

Thanks,

Amanda
Rick's Motorsport Electrics, Inc.
30 Owens Ct. #2
Hampstead, NH 03841

I ordered a pair. It will be interesting to see the fit and finish of a grommet that was not molded onto the wires.

 

[Steve]

Let me know what you think. I also contacted them and got the same response from Amanda.

I was getting ready to order a few of them, then saw your post.

.

 

[koolaid_kid]

Will do. I'll post some pics also. It's a shame their Search "feature" does not allow searching on part numbers.

 

[koolaid_kid]

Well, here are the grommet and wires pictures as promised.

The red wire is standard 18 gauge stranded copper wire.
The black wire is high temp 16 gauge stranded wire, which is what I am going to use.
If you compare the size of the holes in the grommet, the 18 gauge won't fit, much less the 16 gauge.
The holes measure approx. 1mm. (It is rubber, so it was difficult to measure w/o stretching the rubber.)
The 18 gauge wire measures 2.4mm, the 16 gauge wire measures 3.2mm.
One thing the high temp wire has going for it is the sheathing. It has some type of thin cloth outer sheathing, and then a thick inner sheath of some type of white plastic (at least it appears to be plastic).

Perhaps 18 gauge high temp wire could be forced through the holes (especially if lubricated first). For the 16 gauge, I will have to decide how to enlarge the holes. We'll see.

 

[bwringer]

Couple of possible approaches here.

Obviously, you could drill the holes a bit bigger until you can squeeze the wire through. You can probably get the "normal" wire through without drilling.

For the cloth-sheathed wire, you'd just need to drill a bit bigger, and likely squish in a dab of case sealer or RTV where the wires exit just to be safe.

You could also make a slit from the outside of the grommet to the hole. Pop the wires in, and re-seal with RTV or case sealer. Overall, I think it would be best to enlarge the holes as needed.

Fortunately, the grommet area isn't bathed in oil and it isn't under pressure.

 

[koolaid_kid]

Couple of possible approaches here.

Obviously, you could drill the holes a bit bigger until you can squeeze the wire through. You can probably get the "normal" wire through without drilling.
For the cloth-sheathed wire, you'd just need to drill a bit bigger, and likely squish in a dab of case sealer or RTV where the wires exit just to be safe.

This is what I tried with the first one. The drill bit just dug into the rubber and failed to enlarge it correctly. I think for the next one I will try the Dremel and see if my HF "special box" has some type of grinder bit or something other than a standard drill bit. I started looking when we were installing the lower control arm, but I was a bit preoccupied at the time.

You could also make a slit from the outside of the grommet to the hole. Pop the wires in, and re-seal with RTV or case sealer. Overall, I think it would be best to enlarge the holes as needed.

I ended up making the slit on the first one because I could not get the original wires out any other way. The exacerbated the drilling process.

Fortunately, the grommet area isn't bathed in oil and it isn't under pressure.

I wondered if it was under pressure, since it had a direct connection to the crankcase (you know, pistons pistoning, crankshaft cranking, etc.). I did use a bit of silicone (I forget which type, but it was probably Ultra Copper). I put around 500 miles or so on it so far and it does not leak a bit, but I was not pleased with the fit because I could not enlarge the holes enough.
I am considering making a grommet mold since I now have a perfect, unused grommet. Just tossing the idea around, but I was wondering what material to make the mold out of (one where the newly fashioned grommet won't stick when I go to remove it) and what materials to use if I took this route. I started looking at high-temp silicone as a material. However, the grommet is 0.500" thick, so it would take a while to cure.

 

[Dogma]

A machinist once told me that rubber machines OK while frozen. I don't know if that requires liquid nitrogen, or just ice. That may have been just urethanes too. Aren't I helpful?

 

[koolaid_kid]

A machinist once told me that rubber machines OK while frozen. I don't know if that requires liquid nitrogen, or just ice. That may have been just urethanes too. Aren't I helpful?

You are awesome, dude. The problem I am having is finding the rubber, urethane, etc. that is thick enough. The grommet is half an inch thick, and I have not seen anything even close to that.

 

[Dogma]

Thick enough to machine a grommet from stock? The machinist also told me that you only have a few minutes to work before the part warms up. I doubt you'd be able to cut one from solid sheet or block that someone like McMaster sells.

Hmmm. This machinist may also have been talking about grinding instead of cutting. Well, maybe it's an option to explore if nothing better turns up. Freeze it, chuck up on a rat tail file and growl it outta there.

 

[earlfor]

Solid heels from old shoes or boots or from a shoe repair shop should work just fine.
Also, before the days of fancy silicone, etc, gaskets and machinery oil seals and drive belts were often made from leather Stacking laminations horizontally would probably work well also.

Earl

 

[koolaid_kid]

IIRC, the bands on the transmission of the Model T were made of leather.
I can see myself going to a shoe repair shop and asking for their old shoe and boot heels. I may stop by one and see if they would sell me an entire sole made of flexible rubber-type material.
I appreciate the ideas, please continue to post if you think of something. At $5 a pop it would be nice to find a more cost-effective solution.

 

[emjay]

In some circles a rubber biscuit is slang for hockey puck.
Which got me to thinking. Maybe you could freeze one and then machine it.
Just freeze it again if it warms up.

 

[chuck hahn]

Heck..i would just squeeze a big thick pancake of silicone on a piece of waxed paper and let it harden real good..then just trim myself a new one out of that. Slit it to accept the wire pass thru and then silicone the slit shut arouind the wire. Its not a high pressure oil sealing area there anyways..Just needs to seal to keep oil from seeping and leaking out the stator cover there. Or maybe find a thick piece of neoprene and fashion one???

 

[koolaid_kid]

Heck..i would just squeeze a big thick pancake of silicone on a piece of waxed paper and let it harden real good..then just trim myself a new one out of that. Slit it to accept the wire pass thru and then silicone the slit shut arouind the wire. Its not a high pressure oil sealing area there anyways..Just needs to seal to keep oil from seeping and leaking out the stator cover there.

That is what I had suggested in post #29, just with a mold. Not sure which would be more work, a mold or all the carving. Seems to be the most cost-effective at this time.

Or maybe find a thick piece of neoprene and fashion one???

I haven't been able to find any that is 1/2" at a reasonable price (yet). Still looking.

 

[chuck hahn]

I would think just cutting one out would work..probably a dab of three bond around the edges to be sure it seals real clean too..probablu wont get a factory smoothe edge while trimming..but it seems doable!!!

 

[koolaid_kid]

O.K., let's say I did something like that. Perhaps use a piece of PVC pipe to make a circle (2 fer 1). How long does it take to cure silicone 1/2" thick? Understanding it is temperature dependent, let's say at 70 degrees F.
Hmmm, did some research and it seems it differs for each type and brand. Probably be best to do a batch of several at a time, perhaps let it cure for a week or two. Any thoughts?

 

[Dogma]

O.K., let's say I did something like that. Perhaps use a piece of PVC pipe to make a circle (2 fer 1). How long does it take to cure silicone 1/2" thick? Understanding it is temperature dependent, let's say at 70 degrees F.
Hmmm, did some research and it seems it differs for each type and brand. Probably be best to do a batch of several at a time, perhaps let it cure for a week or two. Any thoughts?

How many do you expect to need? I've been assuming you want just one or two, but sometimes I think you have more o a production run in mind. Knowing this would help steer ideas.