Thanks for the info. Ardun's have always been a
mystique to me, but I'm afraid my budget will
force be to be happy with my finned aluminum
Evans heads. But that's OK, think of all the guys
who just read the magazines and wish they could
have any kind of toy!
Dick J
--- ardunbill@webtv.net wrote:
> Hi Dick, good question about the block deck
> when you put Arduns on a
> flathead. The short answer is you don't have
> any problems about it and
> no welding is necessary.
>
> A factory-relieved (Ford made some, and by the
> way my dad's '51 Hudson
> Hornet also was factory-relieved, as I observed
> when it got a new gasket
> at high mileage) or other relieved block cannot
> be used with Ardun
> heads.
>
> In the early days people sometimes welded in
> the valve relief area on
> the left bank of the flathead block as the flat
> surface near the bores
> in sometimes a little less than 1/8" wide. It
> is really not necessary
> to do that however and the practice today is to
> skim the deck down on
> that side (for some reason it usually seems to
> be 'higher' on the left
> side anyway, which if you don't skim it gives
> you lower compression on
> that side) until you get 1/8" of sealing
> surface from all the valve
> reliefs to whatever bore size you are using.
>
> The original intake ports are ignored. The
> original exhaust ports on
> the block have to be sealed with plates and
> gaskets, they fill up with
> oil from what flies around in the engine, which
> is of no consequence if
> it doesn't leak, but makes a mess when you
> eventually open it up. I
> find that NAPA 1/16" rubberized cork gasket
> material seals the exhaust
> port plates indefinitely.
>
> There are three schools of thought for Ardun
> head gaskets. 1. one
> piece dead soft copper about .040" thick, with
> or without o-rings around
> the bores to 'key' it. 2. copper o-rings
> around the bores with
> separate paper gaskets maybe .005" thicker to
> seal the water holes. 3.
> traditional composite gaskets with metal around
> the bores and maybe the
> water holes. Each system has its advocates.
>
> I will say getting a permanent 100% seal at the
> cylinder head joint is a
> basic issue with the Ardun, but it is done all
> the time, and all engines
> have the same basic issue, which still today
> occasionally causes
> trouble.
>
> As with any other cylinder head joint, the
> mating surfaces of the block
> and head have to be reasonably flat and free
> from deep scratches.
>
> Various operators torque their Ardun head studs
> 35 to 60 ft. lbs, but I
> like the low end for mine because the thick
> aluminum casting must expand
> a lot when it heats, increasing the torque, and
> I have this theory,
> learned working on aluminum motorcycle engines
> all my life, that with
> aluminum structures you want the minimum torque
> that will seal reliably
> under all working conditions, any more just
> distorts the parts. Cheers,
> ArdunBill
>
>
|