----- Original Message -----
From: Jim Davis
To: amphicar-lovers@yahoogroups.com
Sent: Friday, June 11, 2004 7:01 PM
Subject: [amphicar-lovers] wheel bolt pattern
I'm thinking of putting a new set of wheels on amphi and was
wondering if anyone knew what other cars used the same bolt pattern?
Any direction here would help.
jim davis
64 soon to be
I'm still thinking about the wheel bolt pattern. I had previously posted a
site that listed a number of standard patterns:
http://www.tirerack.com/wheels/tech/boltpatt.htm
They listed three sizes of 5-bolt patterns that I thought were close:
4.25" 107.95mm
4.50" 114.30mm
4.53" 115.00mm
But close doesn't count, so I got out my digital calipers and got some data
off of my hubs. Now, 5-bolt patterns are not directly measured, since there
are no bolts directly opposite each other. You need to measure bolt spacing
from two adjacent bolts, and then use some geometry & trigonometry.
Remember, 5 bolts means that the bolts are spaced radially every 72 degrees.
Measuring the distance between the centers of two adjacent bolts (and let's
say these are the bolts at the 7=oclock & 5-oclock positions) gives you a
chord. Split this chord in half, and erect a line normal to the chord,
toward the bolt hole center. Continue this line, and you will intercept the
bolt center on the far side (the bolt at the 12-oclock position).
You can now solve the right-triangle formed by the 1/2 - chord at the bottom
and the known angle of 36 degrees.
SIN 36 degrees = (1/2-chord) / radius,
or, radius = (1/2 chord) / (SIN 36 degrees).
Now, just double the radius, and you have the bolt-hole diameter.
As usual, life is never exact (maybe my studs are crooked or bent, maybe my
hubs were made on Monday). I measured my pattern two different ways, and got
111.43 mm and 112.28 mm. Maybe I could call that 111.86 mm +/- 0.43 mm.
Either way, that doesn't look close enough to any of the above standard
patterns.
Some searching at:
http://realbig.com/detomaso/1997-12/143.html
shows a metric pattern of 5-bolts on a 112mm (4.409"), and it says it was
used on:
Audi - 5000 Turbo, Quattro '86-'87
Mazda - RX7 GSL '86-'87
Mercedes - all '77-'89
VW - Transporter, Vanagon '71-'89
Hmmm, there's those old Transporters again <g>. (I went to a couple of tire
& wheel sales sites, and the 112 mm diameter checks out for the Audi, Mazda
& Mercedes! OTOH, the sites don't let you search by bolt-circle diameter, so
you would never know this size was available!
Meanwhile, this same site talks about compatibility of cars that use a
5-bolt by 4.50" (114.3 mm) pattern, which is the same as the "Mid-60's Ford
Fairlane" wheel. (The Ford Fairlane is listed in the old parts
cross-reference as a match for Amphis, but..........)
AMC Gremlin, Hornet, Pacer, Javelin, Matator, AMX
AMC - most models (exc. Jeep) '40-'89
Chrysler/DeSoto - all full size RWD cars (exc. Imperial) '37-'89
Datsun/Nissan - 1600-2000 '65-'73- 300ZX, 200SX V6 (some) to '89
Dodge van
Dodge 1/2 ton PU
Dodge - all full size cars & P.U.'s '37-'89
Dodge - Dart, Demon, Swinger '73-'80
Ford 1/2 ton van
Ford Granada, Monarch
Ford - All full size cars '49-'72; '79-'85
Ford - Fairlane '62-'79
Ford - T-Bird '55-'71; '77-'79
Ford - Mustang (5-bolt) '65-'73
Ford - Maverick 5-bolt all
Ford - Mustang SVO '85-'86
Ford - Ranchero '68-'84
Ford - Aerostar, Probe, Bronco II/Ranger to '89
Hudson - all '48-'56
Lincoln - all '70-'72; '80-'89
Mazda - RX7 Turbo, 626, 929, MX6 '86-'89
Mercury - all full size cars '52-'54; '61-'72; '79-'85
Mercury - Cougar '67-'79
Mopar '73-up "A" body
Plymouth - all full size cars '37-'89
Plymouth - Barracuda '70-'74
Plymouth - Duster, Valiant, Volare '73-'80
Pontiac - Tempest, LeMans '61-'63
Studebaker - all '51-'66
Toyota Crown, Hilux PU
Toyota - 2WD P.U. '69-'89
Toyota - Supra Turbo '86-'89
Volvo 122, 1800
Now remember, this second list is only a cross to the bolt-hole pattern!!
This says NOTHING about RIM WIDTH, OFFSET, BORE DIAMETER or WHEEL DIAMETER.
A Gremlin wheel / tire sure won't fit a 55 Studebaker or a Datsun 300ZX. The
purpose of this post was just to get some research about bolt patterns on
the record. OTOH, my measurements seem to show that the "mid-60's Ford
Fairlane" wheel IS NOT an exact match for the bolt-circle pattern. Maybe you
can MAKE it work, by drilling out the wheel lug-bolt holes a little bit.
And the first list above indicates that there is / was a European metric
standard of 5-bolt by 112 mm bolt-circle. This is satisfying, not only
because it agrees with my data, but it's also a whole metric dimension.
(When you are working in the English system, you choose nice round numbers,
like 4", or 4.5". You don't use something like 4.409", especially not in
1960. And the Germans wouldn't have used something like 114.3 mm either.)
When I get around to it, I'll measure the wheels and post some info about
them. If anyone else would like to give it a try, you could measure and post
the offset, bore diameter (which ought to be about 65.25 mm) and rim width.
There just might be some hope of a readily available match if we think about
plus-sizing (uhhh, pardon, the ricer look, where you go to larger wheel
diameters while going to a smaller profile tire, thus giving you the look of
more wheel and less tire). In plus-sizing, you maintain the same OD of the
tire, so your clearances are similar and your speedo has little error. Also,
you gain some more diamater of the wheel ID, so clearance of brake drums is
better. (The big down-side is that the thinner tires are less tolerant of
pot-holes.)
Ed
El Cajon
67 Rust Guppy
