Wheels & Rims & The Plans of Mice & Men

Quick note on the rims we're running with. 

I removed the caked on grease & muck from the rims to take to shop to get new tires installed on them.

And while we were installing new tires, I dug out the two nicer rims that we scrounged from Crazy Ray's U-Pick-It, U-Pull-It that were on an old Datsun 260Z (it only had 3 attached); these rims have "cooling holes" in them, I figured I should put them on the front to help cool the brake calipers.

Vented rims on left, rims we were using on the right:

A collection of American Racing 4x4.5 rims

I decided I better measure the heck out of them to make sure they fit properly.

Long story short, both styles are exact matches, but both are +10mm offset instead of MGB spec’s +22mm wheel offset. Oops.

Both clear the calipers & suspension ok, so I think this just means the bearings et al get more leverage on them and will wear sooner.

The big difference between the rims is a show stopper: the lug nut holes on the “vented rims” are flat faced and deeper (20mm), causing the lug to use half the threads that it does on the non-vented rims (which have sunken and beveled holes, with steel inserts). The MGB lug studs are only 25mm long.

The MG lug nuts want beveled seats.

Non vented: blue is flat shoulder sunk 6mm in, white is additional 4mm beveled edge (these have steel inserts but you can't tell from the photo):

 

Vented rims: chalked area is flat face, about 0.5 mm sunk (the dirt makes it look deeper):

Sigh.Oh well. Not brave enough to alter the lug nut hole profile... yet.


Update 2013-05-22:
I was going to order a set of the steel inserts and drill out the Datsun 260Z American Racing 4x4.5 rims (on left of first photo above, with the vent holes)... until I stumbled upon the proper solution: Mag Lug Bolts.

The MGB takes 1/2-20 thread bolts; the trick is to get a set that has a shaft/collar that fits snugly into the wheel rims lug hole, is long enough to get plenty of threads but short enough so it does not 'bottom out' on the top of the lug. After extensive measurements with a caliper and taking one of the rims to the local Advanced Auto Parts store we found the perfect fit, right there on the shelf! Note hard steel washers included. Dorman - Autograde Wheel Nut Chrome Std. Mag 2-Pc 1/2 Inch-20, Hex 13/16 Inch Length 1.664 Inch part number 711-208

I mounted the wheel with only two opposite lugs to test how well the centering of the wheel on the hub worked - and it's quite fine thank you very much! Quite happy now.

DORMAN Chrome Wheel Nuts, 1/2-20 threads for MGB and American Racing mag wheels (flat lug seats)

Mag Lug Nuts on American Racing 4x4.5 mag wheels mounted perfectly on MGB

A few great links:

The MG Experience: MGB Tire Sizes

http://www.mgexperience.net/article/tire-sizes.html

The MG Experience: MGB Wheel Cross Reference
http://www.mgexperience.net/article/wheel-xref.html

MGB Stuff.org 
http://www.mgb-stuff.org.uk/offset.htm#2
http://www.mgb-stuff.org.uk/wheelstext.htm

Steel Inserts for Aluminum Rim Lug Nut Holes 
http://www.prestigewheel.com/RetaiWheelInserts.asp

Facebook page

Yes, we regrettably have a facebook page:  http://www.facebook.com/pages/Gormless-Racing-Mgb-Gt/119664898139570

Fuel Pump Protection Relocation Program - Complete!

Back in September 2011, we relocated the Holley Red Fuel Pump to be below the fuel cell, as called for in the "Previous owner didn't bother to read instruction manual for Holley Red Fuel Pumps" Manual. That's the actual title on the book, yes.

(view from top)

All that open space bothered me; images of detached LeMons Crap bouncing off the tarmac (Dave was hit in the windshield by the National Lampoon's Vacation Station Wagon dog at Summit!) and up into the fuel pump area causing damage seemed so unnecessary... and let's face it, if destruction is to be had it better be in a location that is film-able and far more spectacular than fuel starvation due to dead pump. Yawn!

So, here's the cage we've wrapped around the old 6V MGB Battery Compartment that now contains the fuel pump. It is specifically NOT solid metal/tin/wood/plastic/kerosene-soaked-rags, as the pump tends to get HOT and I wanted to extra soothing cooling of the wind through it's hair, so to speak.

Made out of "Hardware Cloth" which is galvanized steel with 1/4 inch spacing. See, the car's English, so I'm allowed too use inches as a unit of measurement, unlike those other Eurotrash weenies that have to use "metric", whatever the hell that is.

NASCAR called with job offer, I shrugged them off:

View from bottom, or "bum" as the English call it:

Views from the top:

Safety Wired all drain plugs, except the most important one, naturally.

Drilling a hole in the MGB Differential Drain Plug for the safety wire:

 

 Here is the differential drain and filler plug safety wired to the axle housing:

 

...and here is the transmission drain plug safety wired to... I have no idea what that piece is, but it moves with the transmission, so it's not just good, it's good enough. 

  

 Somehow when doing the oil change, I forgot to drill a hole to safety wire the oil drain plug. D'OH!

Here is a pic of the MGB differential plug removal tool Scot & I hacked up one late winter night in 2011.\; it's a 3/8th to 1/2 inch drive adapter which we attacked with a grinder to fit the square hole in the drain and filler plug.

DIY Air-Oil Separator - Crankcase Breather - Black Flag Avoider

So our die hard race fans may remember that one (of the many) Black Flags we received at Charlotte Motor Speedway in 2011was due to "Oil streaming down the side of your car like teary makeup down the face of a 13 year old Cure fan upon hearing Robert Smith combed his hair", as seen in this most-awesome photo:

Oops.

Anyway, that was due to having no oil collection bottle on the crankcase breather (among other things, but those were covered elsewhere... suspend your disbelief for a bit and follow me here).

So, this guy at work abandoned his nice aluminum water bottle in his old office, closed on the desk, for about 6 months. Then someone "helpful" put it in the kitchen for a few weeks, as a giveaway. It sat there for awhile, and so I finally opened it... and hooo boy that milk sure does curdle! It actually bent the bottom of the bottle out with it's botulistic-dreams of killing everyone in the office. So, I took it, washed it about 6 times, and decided to hack it to bits. I hate spoiled milk. And I hate to waste a cool spun aluminum-anything even more.

Here is how it unfolded on a quiet Sunday afternoon...

Step 1: buy a copper hose barb and matching cap (be sure to try the threads in the store, those plumbers are NUTSO with their wack-tastic thread pitches)

Step 2: Drill out the cap end to make it a nut:

Step 3: Lightly dent side of bottle to make an approximately-flat area so the hose barb seals ok, drill matching hole, duct-tape cap/nut to the end of your finger because that's the only damn way you could figure out how to thread the damn thing even after a damn pot of damn coffee, and thread it, tighten it to seal.

 Step 4: (not shown) Stuff some stainless steel pot scrubbers (make sure they don't have soap or any grunge on them, must be STAINLESS or the thicker plastic scrubbies) so the oil in the vapor has something to spray and condense onto, then fall gently undamaged-blowby-valve-seals-ly to the bottom of the bottle.

Step 5: Drill out the cap with a one-size -too-small drill and thread in another hose barb, then attach a crankcase breather filter to it. Ta da!

Step 6: Install newly-minted Air-Oil Separator/Crankcase Breather/Black Flag Avoider into rockum-sockum MGB-GT race car and Bobs Your Uncle you are ready for LeMons NJMP 2012! (pay no attention to those zip-ties pulling the bottle holder flanges together, those will be replaced with a metal spring once I make it to Pep Boys auto later this week... honest!)

New Throttle Cable, Finally

Our throttle cable has always been a mess; not sure how it lasted endurance 3 races.

I tried to Tap-and-Dye the end of the new throttle cable so i could positively hold it in the Weber DGV Carb attachment bracket, but I positively failed to thread it. I reek with a tap and dye set, leaving a swath of destruction in my wake whenever I attempt it. I decided to quit while I still had a functioning cable and purchase (with actual money!) a proper cable end/attach/adjuster bit.

Both bike shops in Mt. Airy were closed on Sunday, so I resorted to raiding my backyard stash of old Ten-Speed bikes I had been stockpiling to make my Baltimore Kinetic Sculpture Race vehicle. Below is the victim, and the two pieces it donated:

The Cable Adjuster needed to be drilled out a bit so the new throttle cable end would fit, here you can see the nice shiny newly drilled inside, and below that the end of the new throttle cable:

Here is the final setup, with much improved throttle feel, less cable wear, less cable-falling-out-of-bracket-and-getting-throttle-stuck-at-wide-open-SCOT!, less badness overall.

Yeah us. Maybe we'll finish a few damn laps this year.

Mirror Mirror On The Wall - YOU SUCK

One complaint from everyone that's ever sat in this beastie of an MGB is that the passenger mirror is too small, hard to position, it wiggles when driving, its face is flat and so doesn't see much, and the driver can't reach it him/herself to adjust it.

I believe we've put on, or tried to put on, a new mirror every single bloody race. I've had it with all the complaints (and to be fair, I was the one that complained the loudest about it).

One trip to Crazy Ray's U-Pick-It, U-Pull-It and ta-da! The biggest, ugliest, nastiest mirror I could find....

"Old" lame-ass mirror on the left, "New" Jurassic Park mirror on the right... OH HELL YES:

 

If I remember correctly, it's off a mid-ninties Astro Van... go ahead, you can say it: "That's Classy!"

As far as wiring it goes, well, there are many many wires and supposedly you tell them apart by something called "color", though I've never believed in such a crass concept.

I tracked down the connectors on the web and ohm'ed it out; wired it up; fabricated a sturdy mount for the control switch:

 

 Spot the new Joystick! The driver can easily reach it...

 Mirror mount, outside view; this actually took the most time I believe:

 Mirror mounted, inside view:

Here are the wiring diagrams for 1997 Chevy Power Mirrors. The passenger side mirror that I grabbed must have been a replacement because the colors match a drivers side mirror, at least that's what the people I live with tell me...

More Fuel Pump Coddling - Vibration Dampeners

Installed a set of "Vibration Dampener Mounts" (Lord Mounts) that I bought from Pegasus for $4.99 each; part 3048-02 10-32 Male-Male Shock Mount, .75 dia x.62 high. Probably could have gone one size larger, but it seems pretty stable. Next step for the fuel pump area is fabricate metal mesh to go under the pump to keep road debris from molesting it...

Bogging Down Exiting Corners - Weber DGV Accel Pump?

During our last few races (ok, all of our races), I've noticed the ol' chap tends to hesitate when exiting corners. Up till now I've assumed that's just the carb being slightly dirty or temporarily starved when stomping on the gas (right after holding your breath through the tight corners).

It's been nagging me for a year now; something's wrong, but not sure how to troubleshoot it without having someone hang on the hood while we drive around the track?

Then I stumble across this little gem of a description from the Pegasus Auto Racing Supplies catalog:

Accelerator Pump Diaphragm Assembly, Weber 32/36 DGV

 
If your car bogs down exiting corners, your accelerator pump may not be pumping! When the throttle is opened all the way from idle, the accelerator pump should deliver a shot of fuel directly into the carburetor throat. If this shot is not visible (with the engine off), the diaphragm may be ruptured.






You know what today is? DAY I GOT COOKIE!!!

Problem may still be elsewhere, but boy does that description fit! With all the crap and junk and dirt and bits and crud and grime and filth and rubbish and mud and garbage we pulled out of the tank and carb and filters at 24 Hours of LeMons Summit Point Capitol Offense 2010, it is very possible this contraption is hobbled.

Thanks Pegasus for the schoolin'. Order placed.

[UPDATE 2012-04-08] Either we don't have a Weber DGV, or Pegasus sent us the wrong part... either way, it don't fit no way no how. We need the part shown in photo above; the part we received was not 'square' and the brass pin in the middle was mush skinnier and was not spring loaded.

Bob found and took out the old part, and it looks like there could be a little leakage around the circular shape of the rubber is.

We put the original piece back in until we get our hands on the unobtanium accel pump...

Brighter Brake Lights, for those about to pass us (eg, everyone)

Last year we added some old-time beehive-style brake lights (re: cheap). Watching the car on the track I noticed the brake lights were a little lame in the daylight, and I've finally got 'round to fixing that.

 Here is the difference in brightness between the standard bulb and the SuperBrightLeds.com part 1156-R19-WV:

 

The "bulb" itself (actually 19 LEDs and a circuit board) is a tiny bit taller/wider than the red lens... 

... so to make the retaining snap ring hold the lens properly, I de-nubbed the lens to allow more 'grab' area between the ring and the black base (as seen in photo 2). [ note: if you are extremely bored or have a snap ring fetish, you can see the retaining snap ring in photo 1 if you zoom in on one of the lights; it's the silver that goes around 7/8th of the circumference.]

De-nubbing:

The punchline? Naturally after doing all this hacking resulting in just-ok results, the exact same beehive brake lights are pre-made with LEDs by SuperBrightLeds for the same price as the LED bulb alone! Although, to be fair, their assembly is sold as a marker light and only has 6 LEDs, whereas my hack has 19...

Light, seeking light, doth light of light beguile

In preparation for the ChumpCar's 14 Hour race at VIR- the beautifully named "St. Guinness - Patron Saint of Perpetual Indulgence Challenge Pint Race", we've added some (non-Lucas) headlights to the MGB-GT.

While they may be cheap, at least they're weak so we won't notice nor care when they finally get smashed up. You may call that "Planning Ahead"; we like to call that "Not Really Giving A Flying Fark."

Lights are Pilot NV802CP Off Road Lights, 100 Watts (I'm guessing total; they don't actually say).