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RE: Overdrives and rpm]

To: "'Thomas Wiencek'" <wiencek@anl.gov>,
Subject: RE: Overdrives and rpm]
From: "Bill Blue" <dablue@worldnet.att.net>
Date: Thu, 28 Jun 2001 16:50:52 -0500
I just rechecked the Coker Tire site.  They do not have 5.60 or 5.90's, but
they do have the 6.00-13.  They are B.F. Goodrich Silvertowns and the
diameter is given as 23.78".  It appears the aspect ratio for the 6.00 tire
was 90, not 82.  Looking at the designations, 5.90 vs 6.00, I wonder if they
are not two totally different designs. It seems strange that two tires
virtually the same size would be made. I was wrong on my earlier size for
the 165R-13, it is listed at 23.50".

Bill
-----Original Message-----
From: Thomas Wiencek [mailto:wiencek@anl.gov]
Sent: Thursday, June 28, 2001 9:10 AM
To: 'Jan Eyerman'; Jay_Laifman@countrywide.com; alpines@autox.team.net;
Bill Blue; owner-alpines@autox.team.net
Subject: Re: Overdrives and rpm]


I think somewhere in the archives there is more information about tire
sizes.  The stock Alpine tires were 5.50 x 13 or 5.90 x 13.  These were 82
series tires so the diameter is (0.82 x 2 plus 13 = 22.02 for 5.50's and
22.67 in. for 5.90's.  (and 22.84 for 6.00's) For modern tires,   22.76 for
155 80 x 13, 23.39 for 165 80 x 13, 22.65 for 175 70 x 13.  23.75 is a bit
high for a "stock" tire size.
I hope this helps.

On 6/27/01, Bill Blue <dablue@worldnet.att.net> wrote:
I got my numbers by going to the Coker tire site and looking up the
"original" tire size.  The 600R 13 (MIchelin) came up, along with the
factory spec outside diameter.  I then went to the Cooper Tire site (very
easy and informative place to get tire info)and found that the 195 70 13
otside dimeter is only 20 thou different from the original Michelin.  I used
23.75" in my calculations.

By the way, I noticed at the Invasion that most Alpines wear 185 70 13, with
175 70 13 a close second.  A few had 195's and most Tigers sported 205 60 13
in the rear, with a smaller size in front. Could someone clue me in as to
what is going on here?
Bill

-----Original Message-----
From: owner-alpines@autox.team.net
[mailto:owner-alpines@autox.team.net]On Behalf Of Jan Eyerman
Sent: Wednesday, June 27, 2001 7:48 PM
To: Jay_Laifman@countrywide.com; alpines@autox.team.net
Subject: Re: [Re: Overdrives and rpm]


I am not sure if those numbers are right, I have calculated 3500 RPM for a
'59
Minx with a 4.55:1 rear with 5.60x15 tires.  Even with smaller wheels, I
would
assume an Alpine with a 4.22:1 rear would have to do better, and a 3.89:1
rear
MUCH better.

Jan Eyerman
1959 Hillman Minx Series III DeLuxe
1973 Hillman Avenger DL




Jay_Laifman@countrywide.com wrote:
Tom writes:

>With all this talk of Overdrives, ...
>does anybody know how fast the Series
>V engine is approximately turning at
>65 mph?

My speedo is completely accurate, as it was just calibrated, but my tach is
probably off.  I do recall others reporting certain RPMS, etc.  I do
believe though that before I changed to the OD (and the speedo was not way
off), my tach would read about 4000-4100 at 65.  Now, with the OD and the
calibrated speedo, at 65 I'm reading about 3600.  I believe others have
reported 3300 rpm at 65.  For a long time, I've believed my tach to be
about 250-300 high.  So, this makes sense.

That all said, I think someone had and equation for all this, and thus had
the exact numbers, perhaps taking into account some tire size change too.

Jay

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