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Re: [Nobbc] Machine shop

To: North Bay British Car Club <nobbc@autox.team.net>
Subject: Re: [Nobbc] Machine shop
From: Greg Tatarian <gtwincams@gmail.com>
Date: Thu, 17 Feb 2011 19:12:17 -0800
On 2/17/2011 6:03 PM, craig murphy wrote:
>   Usually they would mill the flat surface of the caps, mount them up
> and bore into them with the cutting tool just touching the bottom of the block
> saddle, but not removing any material from the block side.
As you may know, that is often not possible, particularly if the block 
saddles are not true. In that case, or when repositioning the crank 
higher in the block will have a very detrimental effect, the block 
saddle and main cap are bored oversize, such as 0.015". This 
necessitates the use of bearings that are oversize on the OD, and if the 
crank is ground, undersize on the ID. The block in our Elan S4 was bored 
like this, because I swapped the round-shouldered caps with square caps 
from another block; honing would not have been sufficient to make them 
align properly. I made that swap to gain lower end strength and with the 
other mods to the engine, permit higher revs.
>   I bought a good used former Minimania-built 4 synchro remote change box
> and did some modifications to be able to make it the same ratios (using the
> same replacement gears) as the original S box.
Other than the change from originality, would you consider this a 
desirable upgrade? I like having synchros in first, but one does learn 
to get around that in a 3 synchro box...
>   I thought it would be risky to be this far into it and then
> put it back together without going the rest of the way.  This way I will have
> a base line where I know it was rebuilt by me fresh on x/xx/xx date.
Oh yes, that is always more comforting than guessing what may fail. And 
it can be really amazing what you find when you open up a motor or 'box 
that even a supposedly reputable rebuilder has worked on.
> The rest of my gearbox parts just landed in the US from England and the big
> brown truck should deliver those on Monday.
The gearbox parts for our Alfa (only about 2/3 of what it needed) cost 
over $800 - gearbox parts can get expensive very fast. But what a great 
feeling it is when you've replaced all the wear items in a 'box and it 
shifts like butter.

Good luck with the rebuild. Wanna hold a tech session on reassembling 
your motor?

Cheers,
Greg


> Cheers,
>
> Craig
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