Theese heads are pretty good, and the ports are more than big enough for
the given spec. There are 3 areass that can be developed: the valve seats,
a nice 3 angle valve seat cut is definiatly a good thing, matching the
manifold and head ports can also be a good idea and maybe finishing the
rough casting marks (this one is more for the spirit then for
performance...). Thats all.
Much-much more could be done with balancing the moving parts, and making a
perfect tune-up preferably on a rolling road.
gergo
2013/8/25 Patrick & Caroline Quinn <p_cquinn@tpg.com.au>
> G'day Elton
>
> I have just had the engine of the BN3 rebuilt. It is an early smooth
> crankcase six-cylinder and was fitted with a 12 port head by Geoff Price of
> the Donald Healey Motor Company in 1962.
>
> As part of the engine rebuild the cylinder head was also done. After a
> complete clean in a caustic solution the combustion chambers were ported
> but
> not polished. The sharp point at the top of the heart shape were rounded to
> avoid hot spots and each chamber was cc'd so they are all the same. Then
> the
> inlets/outlets were machined to match the manifold gasket. New valves,
> springs, guides and inserts were fitted. The rocker gear was also rebuilt
> with a new shaft and bushes.
>
> I will be using a standard exhaust manifold and twin H6 carburettors. It is
> fitted with standard 2,912cc pistons and a slightly warmer than BJ8
> camshaft.
>
> Can send photos if you wish.
>
> Hoo Roo
>
> Patrick Quinn
> Blue Mountains, Australia
>
>
>
> -----Original Message-----
> From: healeys-bounces@autox.team.net [mailto:
> healeys-bounces@autox.team.net]
> On Behalf Of Elton Schulz
> Sent: Sunday, 25 August 2013 1:52 PM
> To: Healey List
> Subject: [Healeys] Porting a BJ7 head
>
> Fellow Listers,
> Any benefit of porting a BJ7 head? I'm using standard pistons, standard
> compression and a BJ8 cam grind. Also two standard HS6 carbs.
> Thanks in advance,
> Elton
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