There is one significant difference between aircraft engines and Spitfire
engines. Most aircraft engines are aluminum while our beauties are iron, each of
which have their own set of characteristics. Fortunately, ours are not as prone
to fatigue as an aircraft engine but that doesn't mean that we can get away
without properly torquing our heads. If we ignore proper head torquing,
sometimes we get lucky and just blow a head gasket. Or the head warps a bit and
needs to be re-surfaced. It is rare that it gets to the condition where the head
cracks, at least for us street drivers.
If it sounds like I know what I'm talking about, I actually don't have a
clue...well maybe just an inkling.
Vic Whitmore
76 Spitfire
Thornhill, Ontario
Dean.Dashwood@enron.com wrote:
>
> Yesterday, by pure coincidence, I happened to read an article relating to
> this. Actually, the article was about metal fatigue in light airoplanes,
> but a significant part of it dealt with metal fatigue in cylinder heads
> caused by incorrectly torqued studs, and I figure that most of the stuff
> that applies to piston engines in aircraft also applies to our cars, so
> here's the URL:
>
> http://www.avweb.com/articles/metfatig/
>
> I'd be interested to hear from someone who knows more than me, how relevant
> they think this article is. (Ok, so I guess the bit about leaking oil from
> the propeller hub doesn't apply to LBCs.....)
>
> Dean
> ----------------
>
> Date: Tue, 19 Sep 2000 22:12:47 -0700
> From: "John Weber" <weberjm@teleport.com>
> Subject: cylinder head
>
> Joe, et al:
>
> Yesterday, when I dropped my head off for rebuild, the mechanic reminded me
> to torque the head immediately after the engine warms up...and to do it
> again at about 500 miles. This agrees with this list, plus agreeing with
> the Haynes book in the engine rebuild section.
>
> They also said to torque it to 50 vice 46. Any thoughts on this? I was
> under the impression that too much torque was not good.
>
> And on another note, I remember a thread where the little pieces of wood
> for
> the front? plate were needed. BPNW includes them in their engine gasket
> kit. NFI on my end. Just noted that they were in the kit when I unboxed
> it
> the other day.
>
> John
> '75 Spit
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