Author Topic: Moon disc questions  (Read 8172 times)

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Online Gary Perkinson

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Moon disc questions
« on: March 13, 2013, 03:05:19 PM »
Okay, so I just picked up a set of screw-on Moon discs for my HHR for Wilmington and Loring, and I have a couple of questions before I install them.

First, do the screw-on Moons have to come off when I'm running the car through tech (to allow access to the lugs)? I know I should ask this in the ECTA and LTA rules forums, but since I'm here, I figured I'd ask what they do at Bonneville...

Now, actual technical questions:

1. Which is easier--drilling the rim holes before the tires are mounted or after? I would prefer to drill them first, just because it seems like it would be easier than trying to drill them when they're on the car (especially since you're trying not to drill too far into the bead). My only concerns are a) would pre-drilled holes in the rim affect the ability of the bead to seat properly, and b) am I going to catch a lot of shit from the tire shop guys for having holes in my rims?

2. I plan on using a dab of clear silicone on each screw, along with some Loc-tite--is purple Loc-tite enough, or should I use blue?

3. Anyone here use small plastic washers between the disc and the rim?

4. What if I decide at some point to stop running the discs--will I have to deal with any leakage problems from the holes drilled into the rim?

Thanks!

Gary
LTA   G/BGALT Record (1 mile)     143.313
LTA   G/BGALT Record (1.5 mile)  148.321
LTA   F/PRO Record (1 mile)         114.668

Offline Seldom Seen Slim

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Re: Moon disc questions
« Reply #1 on: March 13, 2013, 03:17:37 PM »
I don't have all the answers for you, but did use the screw-on Moon discs for the first set of 'em I had.  I use them on our street vehicles - haven't tried racing with them so can't comment on stuff like whether you'll need to remove them for inspection, although I'm betting the answer will be that yes, they need to be off.

I found the screw-on type wasn't as good for street use as the Dzus type.  The screws loosened over time - measured in weeks or a month or two - and when they loosened the disc was allowed to move up and down, so to speak, as the tire rolled down the bumps and cracks of the highway of life.  That moving slowly enlarged the holes, making for looser still affixation.  Eventually I lost a disc - or two - as I was driving down the highway.  I've never had any issues with the Dzus button type.

I used sheet metal screws into holes drilled in the rim.  The screws went into the bead - but not through.  Perhaps I should have used longer screws so the rubber would have acted more like a lockwasher -- but I didn't.

I'd certainly consider plastic/nylon washers on the screws to help hold things tight -- and also to reduce the amount of corrosion that'll sooner or later show up on your discs.

I clear-coated the discs.  They still showed wear and crud after exposure to the highways and elements -- but lasted longer than if I had not coated them.

Of course -- how 'bout getting in touch directly with Moon and asking your questions of them?  Chances are that they'll have good information for you, especially since they're racers at Bville - as well as the mfr. of the discs.
Jon E. Wennerberg
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Offline ulrace

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Re: Moon disc questions
« Reply #2 on: March 13, 2013, 03:24:37 PM »
hey gary; Look forward to seeing you at wilmington. Most guys use dzus buttons to hold the disc on The tabs are welded to the wheels and you need three of them Speedway makes a couple mtools to help locate and punch the holes. if you drill and tap the wheels small (like 10-32) that will work fine and no it will not affect the tire sealing as you are i/4 "  or more above where the tire seals. I have lots of wheels that have been drilled for slicks where the screw goes into the tire and they do not leak. i would drill them before tires are mounted and then use a short screw. The only problem is they are a pain to take off (which you have to do) for the lug inspection, hence the dzus button method.
hope this helps. What have you done to the hhr? i've got a panel as a shop truck and they are likable.
bob
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pegasus racing

Offline jdincau

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Re: Moon disc questions
« Reply #3 on: March 13, 2013, 03:35:20 PM »
Yes you will have to remove them at inspection. Definately drill and tap them with tires off. Use machine screws with a safety wire hole thru them in pairs about an inch apart. A short piece of wire through through a pair bent over at the ends will safety them. Don't use sheet metal screws as they fall out and end up in someone elses tires. After the first year you will get extreemly tired of the remove replace drill and convert to Dzus buttons.
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Offline Stan Back

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Re: Moon disc questions
« Reply #4 on: March 13, 2013, 04:13:15 PM »
. . . or you won't check your tire pressure as often as you should and suffer problems because of that.
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Offline jdincau

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Re: Moon disc questions
« Reply #5 on: March 13, 2013, 04:45:13 PM »
Amen to that
Unless it's crazy, ambitious and delusional, it's not worth our time!

Offline fastman614

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Re: Moon disc questions
« Reply #6 on: March 13, 2013, 04:51:59 PM »
One other little trick to this - Identify which moon disc fits which wheel and orient a matchmak on the disc to another fixed point on the wheel (say, the valve stem).... It will aid greatly in the re-installation of the discs every time they are to be re-installed.... that is, unless you have plotted all of the hole co-ordinates into a CNC machine and have ALL of the holes drilled to within .001" of each other and within one minute of a degree of one another....
No s*** sticks to the man wearing a teflon suit.

Online Gary Perkinson

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Re: Moon disc questions
« Reply #7 on: March 13, 2013, 06:08:44 PM »
hey gary; Look forward to seeing you at wilmington. Most guys use dzus buttons to hold the disc on The tabs are welded to the wheels and you need three of them Speedway makes a couple mtools to help locate and punch the holes. if you drill and tap the wheels small (like 10-32) that will work fine and no it will not affect the tire sealing as you are i/4 "  or more above where the tire seals. I have lots of wheels that have been drilled for slicks where the screw goes into the tire and they do not leak. i would drill them before tires are mounted and then use a short screw. The only problem is they are a pain to take off (which you have to do) for the lug inspection, hence the dzus button method.
hope this helps. What have you done to the hhr? i've got a panel as a shop truck and they are likable.
bob
B/GC firebird
pegasus racing

Hey, thanks, Bob. Yeah, my original plan was to get the jig from Mooneyes and have the tabs welded on and then use the Dzuses...I'm sure it's a thousand times easier. Then I decided to go with smoothies and baby moons, but THEN I decided I didn't really like the baby moons, so I ordered the discs, but since I had already painted the smoothies and don't have welding capability, I said SCREW IT and got the screw-ons...  :x  As someone else posted, I'm sure I'll be ready for the Dzuses after about a week...  :-D

The only thing I'm really doing to the HHR at this point is getting an HP Tuners street tune from Jannetty Racing in Connecticut. That'll turn the car's top-end limiter and torque-management system off and smooth out the RPM curve. Oh, and I have new W-rated tires on there. Other than that, it'll be entirely up to the stock Ecotec four-banger to perform...looking forward to it!

Gary
LTA   G/BGALT Record (1 mile)     143.313
LTA   G/BGALT Record (1.5 mile)  148.321
LTA   F/PRO Record (1 mile)         114.668

Online Gary Perkinson

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Re: Moon disc questions
« Reply #8 on: March 13, 2013, 06:12:13 PM »
Thanks for the info everyone...I'm looking forward to screwing and unscrewing 24 screws many, many times this summer...  :-o
LTA   G/BGALT Record (1 mile)     143.313
LTA   G/BGALT Record (1.5 mile)  148.321
LTA   F/PRO Record (1 mile)         114.668

Offline bearingburner

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Re: Moon disc questions
« Reply #9 on: March 13, 2013, 07:37:24 PM »
I would highly recommend of renting or making a jig and welding on tabs for Dzus fittings. We made our own jig and can put ant Moon cover on ant wheel in no special orientation.

Offline Rex Schimmer

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Re: Moon disc questions
« Reply #10 on: March 13, 2013, 07:38:28 PM »
Gary,
I put some Moon disks on a road race car back in the 80s, we thought it would make us faster at Daytona, don't know if it helped but it sure looked neat. Anyway to get around the removing disc to check air pressure I cut some small windows in the disk that lined up with the air valve and it eliminated the need to remove to check air pressure. If you do this be sure to clock all of the tapped holes in the wheels to that the disks are interchangeable from wheel to wheel. Just a thought.

Rex
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Offline Peter Jack

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Re: Moon disc questions
« Reply #11 on: March 13, 2013, 08:05:01 PM »
Gary, DON"T use sheet metal screws. Drill and tap for machine screws if you want to go that route. Sheet metal screws will loosen off and end up in either your tire or someone else's. If it's your tire you won't be happy, if it's someone else's you'll be more than a little unpopular.  :roll: :roll: :evil:

Pete

Online Gary Perkinson

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Re: Moon disc questions
« Reply #12 on: March 13, 2013, 10:27:17 PM »
Gary, DON"T use sheet metal screws. Drill and tap for machine screws if you want to go that route. Sheet metal screws will loosen off and end up in either your tire or someone else's. If it's your tire you won't be happy, if it's someone else's you'll be more than a little unpopular.  :roll: :roll: :evil:

Pete: I'm getting screws from Mooneyes, but a lot of people also seem to like the 10-32 buttonhead allen screws for the discs. If nothing else, they look better....

Gary

LTA   G/BGALT Record (1 mile)     143.313
LTA   G/BGALT Record (1.5 mile)  148.321
LTA   F/PRO Record (1 mile)         114.668

Offline Dr Goggles

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Re: Moon disc questions
« Reply #13 on: March 14, 2013, 01:01:33 AM »
We drilled right through the wheel and welded stainless nuts on the back, stainless M6 Allen heads through the disc....our wheels have that ring about a third of the way from the centre and the Moons we have are the ones with the crown in the middle, I popped them and they sit on that ring.....worked well.
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Offline Seldom Seen Slim

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Re: Moon disc questions
« Reply #14 on: March 14, 2013, 09:23:56 AM »
The jig for welding the tabs onto the wheels - is free from Moon.  I think I remember that they send it along and either bill you for it/refund the $$ when you return it, or don't bill you at all - as long as you do return it.  Whichever -- it's way the easiest way to do it.

I do like the idea of tacking nuts to the inside of the wheel - for using machine screws.  That'd work.  Yes, I have lost sheet metal screws to the highway.  I remember driving along a busy freeway in some city and hearing a clank - then seeing a Moon disc roll past me, heading the same direction as we - as I hit the brakes because of traffic. :lol:
Jon E. Wennerberg
 a/k/a Seldom Seen Slim
 Skandia, Michigan
 (that's way up north)
2 Club member x2
Owner of landracing.com