Re: [AMC-list] Nash 234.8 OHV six

[tom jennings <tomj@xxxxxxx>]

On Wed, Mar 17, 2010 at 08:27, Frank Swygert <farna@xxxxxxx> wrote:

> Other than being OHV the 232/258 has very little in common with the older
> engine. The 232 was a clean slate design by the same engineer hired to make
> the first AMC V-8, David Potter. Some of the engineers who worked on it
> *might* have been junior engineers at Nash in the 40s and 50s, but that's
> doubtful. Oh, and the insert bearings -- but they are different sizes. There
> are no parts interchanges.
>
>
Frank's right here; I've recently had both apart, so ignoring written
history and looking at iron I can tell you only what I can see.

The blocks are utterly and completely different. The 195.6 block is ANCIENT
technology, mold-wise. I'm sure AMC kept up with casting tech as well as
anyone, but the molds are very simple stacked rectangles, very little
complexity overall. The 232 is far more complex, I assume to be thinner and
lighter with better strength (Barney Navarro said he chose the AMC six for
the Indianapolis car because 'it had the strongest bottom end of any
American production engine').

There are some small assemblies that are the same, or very close, eg. 'take
this part make it fit the new motor', mostly no-brainer stuff. Timing
chain/cam setup is the same in design (but so is nearly every other inline
6). The timing chain housing is more complex on the 195.6.232 is much
simpler; just a cover on the block casting. Funny, the damper oil seal is
the same part number, probably before 1950 through the end of the 258 at
least, maybe the same as the 4.0, dunno.

The aluminum 195.6 lifters are the same as 232 I am told. Haven't checked
part numbers or anythng else. Maybe AMC took new-engine (232) design (hyd
cam and lifters) and stuck 'em into the alum 195.6 or vice-versa.
Engineering costs, that'd be a savings. How's it compare to the V8 system?

Crank butt, block rear the same, but that's not a coincidence.

Nothing in the head is the same -- and cyl heads are 95% of the combustion
system anyways, who'd want to copy that crappy old wedge?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.amc-list.com/pipermail/amc-list-amc-list.com/attachments/20100317/79a602f0/attachment.htm>
_______________________________________________
AMC-list mailing list
AMC-list@xxxxxxxxxxxx
http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com