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Re: Dimpled Thrust Cheeks And Coil Polarity!

To: british-cars@autox.team.net
Subject: Re: Dimpled Thrust Cheeks And Coil Polarity!
From: vernk@carver.DataFlux.BC.CA (Vern Klukas)
Date: Wed, 24 Aug 94 13:36:12 PDT
Ray James <rwj4123@sigma.tamu.edu> writes:

>The question: the crankshaft (reground) thrust is out of specs (now
>0.018, can't remember spec max, but it is 0.010 or so probably) with
>standard (new) thrust bearings.  I've ordered +0.005 thrust bearings,
>got them last night, but haven't installed them yet.  I decided not to
>get the 0.015 since they might have been too tight (spec also has a
>minimum, I think) Machinist (knowledgable) says I can dimple the back
>of the bearings with a center punch to raise deformations and
>effectively tighten the thrust clearance if needed.  I have about
>decided to do that, but thought I'd get opinions on the subject...Is
>there anything wrong with the suggestion to dimple (he called it
>knurl) the bearing back if needed?
>
Well, this is an available option in a pinch but it is not good practice. I
would go on (and on and on...) , but the rest of your post indicated you
don't need this.

>Also, I measured the clearance as per photo in Haynes MG manual, but
>the measurement pictured is *not* between bearing and bearing surface,
>but between the machined surfaces on aft fwd side of crank
>boss-to-which-clutch-attaches and aft side of rear main bearing cap.
>The bearings are in top half of bearing only, the bearing groove is
>terminated by the main bearing cap.  I expected to be required to
>measure clearance between bearing and surface.
>
>.. (light bulb goes on!) Thinking about it now I guess that I should
>measure max clearance (crankshaft pushed aft) and min clearance (crank
>pushed fwd) and subtract.  I didn't do it this way.  I only measured
>max clearance, as (I thought) was implied by Haynes.
>
>Help, what measurement is needed, please?

Whoa. You have measured wrong. As you have surmised in retrospect, the idea
is to measure the amount of freeplay in the crank by pushing full forward,
measure, pull full back, measure and subtract the two. Where you measure
from doesn't matter (as long as it's in the same axis). I would be very
surprised if your end float is .018. You should reorder standard thrusts
and then start over. A measurement made with old bearings is useless,
because you cannot know the wear on old bearing. The pros would measure
this by installing new bearings, measuring the clearance and, if required,
putting a different set of bearing in. The real pros would measure all the
various components and then calculate the clearance. BTY, you must have all
the mains installed and the caps torqued to spec for this measurement to be
accurate.

And don't feel bad, I could tell you about some of the lulus I've pulled.

And Then

Will Zehring writes:

>I am finishing up the wiring on the '63 B and have a question regarding the 
>coil.  In the Haynes manual it identifies the two plug connectors at the top 
>of the coil as "sw" and "cb."  When I look at the coil I see only a (+) and 
>a (-).  Keeping in mind that this is going to remain a (+) earth car, I 
>suppose that the lead that goes from the coil to the plug on the body of the 
>distributor is (-)?  Yes/No?

No. The - terminal should go to the ign switch. Coils are weird this way.
BTY, sw means switch and cb means contact breaker




Yers, Vern





_____________________________________________________________________
Vern Klukas                                       I'm a little teapot
vernk@carver.dataflux.bc.ca or                    Short and...
ug141@freenet.victoria.bc.ca or
inkspot@carver.dataflux.bc.ca




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