I'm having the bore alignment checked because of my swap from stock studs and
bolts to higher torque ARP hardware. Jack said it is rare for the mains to
need line honing unless something catastrophic happened previously. He said
rod bores almost always needed touching up after switching to ARP.
I had no problems driving with my 3 synchro box over the last 8 years and was
completely used to it. I think having 4 synchro will be nice, especially
being able to use first gear when slowing down without rev-matching, or
hearing my wife grind into first the few times she drives the car and forgets
about using second gear to slow down first gear. I've kept the 3 synchro box,
so if I come across a first and reverse gear (and some of the other worn
parts), I'll collect them over time and perhaps rebuild the box to have as a
spare. -this is what everyone says I'm sure, but it probably rarely happens
in real life.
The 4 synch box was $600 and I've spent another $500 on gears and rebuild
parts. It was another case of probably didn't need a full rebuild, but I
didn't know the history so I did it. A lot of the parts I'm replacing look
like they are in very good shape (bearings, baulk rings, forks, etc) but I'd
hate to have to tear it down again in a year because something decided to go
out.
Re: tech session; I'm no expert rebuilder. In fact Haynes and an Australian
service manual get about equal face time to the gearbox and motor. I guess
I'm saying that I wouldn't want to teach anyone else how to do what I'm doing
for the first time on this motor, but if others want to contribute their
knowledge and experience, it could make for an interesting and fun session.
Cheers,
Craig
> Date: Thu, 17 Feb 2011 19:12:17 -0800
> From: gtwincams@gmail.com
> To: nobbc@autox.team.net
> Subject: Re: [Nobbc] Machine shop
>
> 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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