Re: Converting early 105 to 2-liter

[Scott Fisher <sefisher@domain.elided>]

Les Singh wrote:

First off, thanks for the tales from one who's been there -- I've heard
from several folks in the past few days, and I'm getting a clearer sense
of what's actually involved.  Thanks to all of you!

One comment:

> There is another samll hassle if you need to use an older
> bellhousing on the 2 litre gearbox - you can't. The designs are different
> and you'll find oil pouring out of the 2 litre gbox into the 1750
> bellhousing which has an opening for the selector rods.

Actually, when I replaced the gearbox in my 1300 with a 2-liter unit
some three years ago, Jon Norman sold me a part to keep this from
happening.  In fact, I erroneously described it as a pilot bushing to
someone else in other email; that wasn't it at all (that's what you need
to do this job on an MGB, which is a whole different kettle of eels).

It's in fact an oil seal, which allows you to mate a later gearbox with
an earlier bellhousing.  Cost about $5 US, Jon had 'em on the shelf. 
Tap the old one out with a big hammer and a piece of wood, press-fit the
new one in carefully by hand, and all is good.

To keep all thanks and attributions straight, Larry Dickman at APE told
me I had to get the oil seal, and Jon Norman knew exactly which part it
was.  Nice to be a short drive from such incredibly knowledgeable
suppliers.  Nicer still that Jon will UPS me stuff. :-)

I thought I'd pass this useful tip on to the rest of the list, as it's a
tiny but significant step in using the updated transmission.

The other step: slip a piece of 5/8" heater hose over the transmission
bolt before slipping it into the new soft mount inside the circular hole
that holds the gearbox to the chassis.  Otherwise you'll get the same
problems I'm having with reverse -- basically, the car judders and
shakes whenever I back up.

Took me a while to figure out why, but it's because the geometry is
different on the transmission mountings from the Sixties to the
Eighties.  In the Sixties, the bolt passed through the center of the
rubber mount; later gearboxes have the mounting bolt offset far from the
center.  In a car with a hydraulic clutch, this is no problem -- but in
a car with a mechanical clutch, backing up reverses the torque on the
gearbox and actually causes the clutch cable to tighten, which releases
the clutch, which unloads the torque, which causes the clutch to
connect, which torques the gearbox, which tightens the cable, which
releases the clutch, which unloads the torque, which causes the clutch
to connect, which (see "feedback loop").  Makes you look like a complete
idiot trying to back out of a parking spot.

> These considerations aside, the 2 litre will fit straight into your GT.
> Your 1300 transmission complete with bellhousing may bolt on to the 2
> litre, of that I'm not sure, 

There's some difference of opinion about whether the 1300 bellhousing
will fit over a 2-liter flywheel/ring gear, but there's also an opinion
that this may not be necessary -- I'll post more (or write it up for the
Cams, or both) when I learn more.

> some interesting ratios for the racetrack, maybe not so good for the street!

Since I've got the 2L box already, that should be no problem.

> If you have the Dunlop brakes you may want to get a whole rear axle setup
> with the lsd as well as the 2 litre front hubs and brakes ( whole
> suspension units is the way to go)

Yes indeed -- another great tip for uprating older cars: A couple years
ago, I rebuilt the front calipers on my '67 because the ATE calipers on
my car were no longer available.  It was $11 for the rebuild kit (and I
trust my own work when rebuilding brake cylinders, I used to rebuild
them regularly on the race car so I know the drill on cleanliness and
anal-retentiveness), and I was broke at the time, but I was sorely
tempted to spend, what was it, $160 for the kit to convert BOTH sides to
larger, vented Spider brakes, hubs, and uprights.  The works, ball joint
to ball joint -- just bolt 'em in, bleed the brakes, mount the wheels
and go.  If I don't do that this summer, I suspect I may over the
winter.

> Hope this helps.

A great deal, as I may be starting my "shopping trip" as early as Sunday
at the APE swap meet.

> Les - in the brakeless Green GTV in Wellington, New Zealand
> a million curses on the heads of the designers of the rhd Ate system with
> underfloor tandem mc, two boosters and built-in gremlins!!!

(Two boosters?  What did they do, look at a Rover 2000TC and think it
was a good idea? :-)

Thanks, Les --

- --Scott

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