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.