<VV> Engine building - bearing clearance

[corvair at mts.net]

On the other hand, I've gone through 4 crankcases here trying to find a good one. One was so badly warped the case halves wouldn't even meet at the flywheel end. So if line boring was a proven/popular/known working solution I would have gone for it a long time ago rather than digging up a new block every year or two for five years. It's TOUGH to find a good engine unless you're east coast/west coast where parts seem to be plentiful. And it's an awkward thing to get shipped in from somewhere.

Les
> 
> From: Tony Underwood <tony.underwood at cox.net>
> Date: 2010/01/22 Fri AM 09:34:15 CST
> To: <corvair at mts.net>
> CC: virtualvairs at corvair.org
> Subject: Re: <VV> Engine building - bearing clearance
> 
> At 09:18 AM 1/22/2010, corvair at mts.net wrote:
> >I've HEARD of line honing a block. I've never heard of anyone that's 
> >actually done it, how they did it, and what the results were like.
> >
> >Les
> >----
> 
> 
> Happens often with inline or V engine blocks all the time, not so 
> much with aluminum boxer crankcases like a 'Vair or other boxer 
> unless the engine is a bit of an exotic (Porsche Ferrari etc) that 
> commands some economic respect.
> 
> 
> I *have* heard of people who line honed a Corvair crankcase to fix 
> loose cam bores but it was a labor of love and they had easy access 
> to a machine shop...  otherwise it would be much simpler and cheaper 
> to pick up a good used crankcase for dirt cheap.   It's more a matter 
> of economics than anything else but yes you can line hone a crankcase...
> 
> 
> ...but not much.   A few thou is about all you can get away with 
> before you start having bolt hole issues with accessory components 
> like top covers and bellhousings and front housings etc.   However, 
> even so in these times 40+ years after the fact it's still pretty 
> easy to turn up an excellent used crankcase that needs 
> nothing...  which lends notion to the point that line boring or even 
> honing a Corvair crankcase is pretty much unnecessary and unwarranted 
> because replacements are available for less than the cost of the 
> machine work and you get to avoid the pitfalls of an abbreviated crankcase.
> 
> Let's not forget that you have to do it *twice*... once for the crank 
> and once for the cam.   And, if you had to take too big a cut from 
> the mating halves to clean up a discrepancy you could end up with 
> assembly issues with accessories' bolt holes not lining up quite 
> right.   Hone, maybe...  bore, avoid it.
> 
> 
> Or ask around this list for somebody with a crankcase they wanna sell 
> for a few bucks.   ;)
> 
> 
> 
> 
> tony..
> 
> 
> 
> 
>