Milwaukee Midget

[Milwaukee Midget]

Bob, as usual, you're right.
I just shipped them out to California but I'll update the instructions.
Nate Jones also straightens rims, so the assemblies will come back trued and balanced.

[Seldom Seen Slim]

I betcha you didn't know that Nate Jones has the keys to a battleship.  A real one.  Really.  Ask him for the story.

He mentioned his mom was from Green Bay.

I suppose you dated her at one time?

Nope, not if memory serves correctly.  I stick to girls in the 25 to 45-year old range (and Nancy, of course).

[fordboy628]

WARNING! ! !

NO WHINGEING ZONE . . . . .

midget,

I have made arrangements for you to have available for the September race, both a 4.55 diff, and a 4.88 diff, at no cost.   Of course you are responsible for their return in good condition.
Both are complete std BMC "pumpkin assemblies, to fit the std axles and std prop shaft.    I am waiting to hear for certain, but I suspect both are welded diffs.   Not sure if I can get access to std open differentials.

I called in some favors to make this happen, so . . . . . . 

Hey, if you don't like the rpm the prop shaft is going to turn, replace it with a chain and sprockets . . . . . .

[fordboy628]

Didn't the Spridget community panic when H Todd Wheeler showed up at the Runoffs in the 70s with Lola gearsets adapted to his stock gearbox? I know you and Mark have relationships with Spridget folks in the SCCA and MWCSCC communities?Any possibilities with some CenDiv racers? My relationships dissolved after Istopped racing Spridgets in '80. PS: Hi Mark, it's Vic, former Apex customer.

Hi Vic,

See above reply.

Glad to hear you're still kickin', as many of our friends from the "Apex Days" are now gone.

Apex is still ongoing though.  Hasn't changed much.   Still Bill and Raghead #2, but now includes Will, the next generation.  And Bill T now owns and occupies the whole building.

If you are going to be in Chicago, you should stop by there.   It's a "Time Warp" trip.  Or perhaps an episode of the Twilight Zone now.

 

[Interested Observer]

Wow!  4.88 + 21" + a few more revs   could be formidable!

Whats the length between U-joints, OD, and if possible, wall thickness?

[4-barrel Mike]

Hey, if you don't like the rpm the prop shaft is going to turn, replace it with a chain and sprockets . . . . . .

Soicihiro's wacky S600 IRS?  Owned one briefly in early 70's.  It would be a tough fit in the Midget.   

Mike

[Milwaukee Midget]

23.5 long, 1.75 diameter - unknown thickness. Nicely welded, balanced, not a lot of mass.

I installed a second drive shaft loop.

Four day event - Rookie O and rookie pass for Nick on Friday with a shakedown pass by me before I let him behind the wheel. Maybe a shot toward the end of the day?

Monday is backups, so Saturday and Sunday are haymakers. Really don't want to spend 2 hours changing out diffs in the desert if I can help it.

Does a diff or tire change require a reinspection?

[jacksoni]

The online calculators I find say critical speed for that shaft (wall thickness likely .093" per one of them) is >20k rpm with therefore the "safe" half speed >10k rpm. A chart for more usual shafts doesn't even start until > 40" length.

The initial inspection is for safety. As long as you don't remove the cage or fire bottles or something, you do not need reinspection for tires or gears. I've done tire changes in line many times.  Can change engine if you want (as long as class stays the same). After qualifying and are in impound I don't think you can change the engine but still anything else goes. A class change requires reinspection. These would have to qualify as JMHO of course but I think you are safe to change those without issue.

[Stainless1]

Safety first... are your driveshaft hoops 360... not required but... it's your butt
Just a thought... figured the Midget floors are thin...
Have your spare tires and wheels inspected at initial inspection... since they are not the same... you don't need any hassles... tires are a safety inspection item
Take the driveshaft to a shop that makes them and have them check it. 
I would take other diffs for emergency use only... or to try to go faster after you set the record.
A lot will be known about the engine's untested territory by the end of the first day... with any luck
 

[Stan Back]

Speaking of changing rear gears . . . years ago we thought the answer was PosiTraction!  Turns out it was only good for sight-seeing.  Put the ol' 3.00 one-legger back in and recorded the next day.

[Milwaukee Midget]

Speaking of changing rear gears . . . years ago we thought the answer was PosiTraction!  Turns out it was only good for sight-seeing. 

Switching from a front-facing hood scoop to cowl induction at the two . . . That's creative. 

Stan, what do you think is happening with a posi rear end that caused you to spin? You're not the only one who has warned against it, but a proper gear set on our end may require a welded diff.

[Stan Back]

I don't have anywhere near an idea on that.  I made one run with it, didn't opt for a second one.  Spinning at Bonneville (especially when it's hard and not gouged up) was not a scary deal.  You can see (unlike at El Mirage).  With a car that's got a whole lot of weight down low (the huge frame is all boxed 1/4-inch steel with judicious (we thought) pounds of lead shot in it.  I was amazed at how little it upset me.  I don't recommend that for cars with other configurations.  We set every record with 1-legged differentials.  That, too, may not be for everyone -- to each his own. 

[jacksoni]

I thought the mantra was " if you spin with  a posi, put an open in it; if you spin with an open rear, put a posi in it."  With spin sensitive cars- like high power, short wheel base- with a posi you light up both rears thus losing mechanical grip and are more likely to go around while an open rear which is putting power to both while having traction, only one spins when you exceed that so may still have some directional stability. At least that's how I interpret it. Have had posi in all my cars without issue ( except once when I had a set up where the center of gravity was moved way up and the car was squirrely from the start and on one run I got distracted and lost it, spinning. Fixed the CG issue and now goes straight again. Course I don't have the power to spin the tires at any speed like some so maybe my experience here isn't worth much. I don't think you have any issue with a welded rear, MM. Causes more trouble pushing it around in the pits or on pavement though....

[Milwaukee Midget]

Well, it's certainly not a high power vehicle. But it's our hope thst it's a "just enough power" vehicle.

[Milwaukee Midget]

Okay - just dropped off the driveshaft at the shop. They're going to try and seek out a set of Spicer solid, permanently lubricated U-Joints for it. The ones in there now are drilled for grease zerks, and they survived 8,500 in 2014, but I have no idea what brand they are.

I'm making the assumption that they are inherently weaker because they've been drilled.

The guy didn't blink when I told him I needed it balanced to turn at 10,000 rpm - I expected some push-back, or at least some questions. But I did arrive while it was all-hands-on-deck trying to get the day's UPS shipments out.

And I was wearing a Bonneville T-Shirt . . .