[Tigers] Backing up other cars

[Gary Winblad]

Interesting stuff!

What are those "anti rotate" pieces?
Gary

----- Original Message -----
From: Tom Witt via Tigers <tigers at autox.team.net>
To: tigers at autox.team.net
Sent: Thu, 21 May 2015 16:39:19 -0000 (UTC)
Subject: Re: [Tigers] Backing up other cars

I have the MGB arms on my Tiger.  They require about a 1/2” spacer on the front bolt to fill in a gap between the arm and the spindle. The two bolt holes do not align perfectly. You need to file or mill out one of the holes a small amount as I believe the spacing is too large on the MGB arm. If you are searching for every bit of help you can get, my recollection is that the front hole is filed towards the rear and that positions the arm about a 1/16”-1/8” more forward, rather than 1/16”-1/8” more rearward if you file the rear hole.  I did this over 10 years ago so check by observation for which hole to file, but the goal is to get the arm as far forward as possible. The backing plate/shield needs a notch about 1” high and about 1/2” deep as the arm positions in its path and you need the room for the tie rod end.  For the record I have 13” Cosmic wheels (like those on the Harrington Tiger) and they clear this modification though I believe I have about a 1/4” spacer under the wheel. Sorry for the vagueness but my car has been on jack stands for 15 years now and is currently buried in wood for my daughters Tiny House.

Regarding rack modification; my rack apparently had one of the ends damaged at some time in its life. Someone did a hack repair by simply welding on an Alpine section. A very dubious repair.  Some here were horrified when I shortened both rack ends and then cut threads with a die (left and right threads) as the original threads are rolled. The die was somewhat adjustable and I made light cuts after the initial cut. I constantly back cut after a few degrees of rotation of the die. I then lightly chased the threads with a fine file and did everything I could to remove burrs, tears, etc.. I did the threads likewise with a grade 8 bolt which attached to the tie rod end. To couple the two together I used the split tube and clamp that just about every American car had before struts became popular. They needed to be as short as possible and 70’s era AMC tubes (Hornet I recall) were used.  Both the adjustable die and the split tube/clamps were helpful because the diameter of the rack is not consistent. It allows for the incremental adjustment people desire and frankly I feel a whole lot more comfortable with this than a welded on Alpine piece.  That said, it would be something that one does at their own risk.  I don’t advise cutting up a stock rack, but in my case it seemed irrelevant.

Notes on the images:  I do not have the clamps on the split tube at this time, for the record I plan on having two clamps per side. Parts for the modification. Buried Tiger (will it EVER see the road in y lifetime???).




From: Gary via Tigers 
Sent: Wednesday, May 20, 2015 7:08 PM
To: Tom Parker 
Cc: Tiger's Den 
Subject: Re: [Tigers] Backing up other cars

Thanks Tom, but I knew all that..
What I was wondering was what tie rod ends
or machining on the steering arms did you
have to do?   The Alpine arms are slightly
longer than the MGB arms and should help
even more,  that was part of Doane's race
mods IIRC.  I haven' t heard of anyone else
using the stock rack like you.  Did you have
to "unbend" the rack arms and did you make
sure you didn't run out of rack ball joint
travel?  You should be able to do your own
precision alignment using the "strings"
method, I do.
Gary


Sent from my iPhone

On May 20, 2015, at 6:31 PM, Tom Parker <tkparker1941 at gmail.com> wrote:


  Hi Gary, and Buck, 

  First, Buck's right, and I think I implied that. The MGB arms DO NOT fix the Ackerman Angle issue in the Tiger. "The best we can hope for is a steering angle of  about zero degrees with the stock crossmember."  The issue is the MGA rack George fitted to the Alpine crossmember is way too far forward, and it isn't possible to get close to a proper Ackerman Angle. It isn't, imho, a problem with the rack, it's with the mounting position. For about $10,000 Dale can "fix" the problem by constructing a new crossmember with the rack in a straight line with the steering arms. Is it that simple? No, and I won't begin to try to understand the math involved. See DrMayf's article.

  What the arms do is what we both said earlier: the make the steering a bit easier, and they reduce the tire scrub a bit. That's all.  The MGB arms are about an inch longer than the stock Tiger arms. It's about as far as you can go, and it requires 15" or larger wheels.

  There are a few "solutions to the problem. I know the redesigned crossmember works, and I'be seen Alpine spindles reversed (swapped side to side) with Alpine steering arms to the front, but I don't know how close it comes to solving anything. And I don't know if that "fix" works with the Tiger rack.

  Now to the MGB steering arms: Randy Willett (willett581 at msn.com) did the modification. It involved elongating the center mounting hole a bit and adding a spacer to align the arm "parallel" (more or less) to the spindle. I torqued it down to Tiger specs, Randy argued for a bit more torque. He supplied grade 8 bolts. There's maybe an inch of thread left at the tie rod ends, and less than an inch clearance to the inside of the wheel. I'm not going to race the car, street or otherwise. The MGB "solution" helps, and that's all I was looking for. I knew up front it wasn't a "fix."

  So... a bit easier (lighter) steering, not as much scrub. With @ 0" toe the steering is quite sensitive. I used a Toe Alignment Bar; it's close to zero toe. How close? I dunno; that takes an alignment rack and the local guys aren't interested in aligning a car without alignment turnbuckles for less than @ $350.00. That'll keep 'till I get the Kitty back to Georgia.

  Tom
  '67 Mark 2


  On Wed, May 20, 2015 at 6:41 PM, Gary <garywinblad at comcast.net> wrote:

    Tom,
    Interesting... I bought some MGB arms a
    long time ago.  How did you connect them?
    Gary

    Sent from my iPhone

    On May 19, 2015, at 7:22 AM, Tom Parker via Tigers <tigers at autox.team.net> wrote:


      MGB steering arms with the stock Tiger rack (since Dale no longer makes the Midget rack kit...) solves a lot of the wheel scrub issues when backing up. The steering's lighter, too, by just a bit. DrMayf wrote (imho) the definitive analysis on Ackerman v Tigers issue. The best we can hope for is a steering angle of  about zero degrees with the stock crossmember. 

      Tom

      '67 Mark 2

      On Mon, May 18, 2015 at 10:21 PM, Jay Laifman via Tigers <tigers at autox.team.net> wrote:

        Every time I back up a non-Tiger, my predispostion to not going full lock on the Tiger seems to always come through and prevents me from doing it with the non-Tiger too.  I get a chuckle out of it each time - but I still can't bring myself to do it! 

        Just thought I'd share that thought.

        Jay