[Healeys] Alloy Head
cnaarndt at gmail.com
Sat Nov 1 14:51:34 MDT 2014
With all due respect, I'm going to totally differ with your statement.
Some years ago Mark Lambert, Healey restorer in Nashville, TN and technical
adviser/expert for the club did an extensive evaluation on the original
Aluminum head developed and sold by SC in England. The original cast iron
Westlake head is constrained by porting that is too small (intake and
exhaust ports on the same side) . SC redesigned the porting on the head and
substantially increased the airflow, almost doubling it in the process.
This is the standard head SC originally developed, and not the upgraded
ones that Denis Welch did a few years later, using the same basic casting
from the same foundry.
Lambert's testing is essence said that where the old stock engine had a
power band of 2500 to 3500 RPM, an otherwise stock engine with the aluminum
head now had an effective power band of 2200 to 4200 RPM, effectively
double. He also went on to say that a stock 100 with an aluminum head
would easily out perform a stock modified 100M. And you don't need the 1
3/4" H6 carburetors of the 100M/Le Mans. The H4s work great since now that
you have sufficient airflow, it's the higher velocity provided by the
smaller diameter 1 1/2" H4s that make it perform even better... Basically
Plus no cracking issues. I have four 100 engines and 7 heads, and 6 of
those heads are "boat anchors"... Too cracked to repair.
The another benefit is that since the heads are identical in all respects
down to the original "Westlake" casting numbers, you won't loose any points
So why put good money after bad with a cast iron head that will eventually
crack, or crack again if repaired (ask me how I know this) when you can
have superior performance, reliability, and originality, all in one package.
I will try and find what issue this was written up in for anyone that's
AH Concours Registry Chairman
On Sat, Nov 1, 2014 at 12:44 PM, Larry Varley <varley at cosmos.net.au> wrote:
> Hi Ray, my personal opinion is that unless there is a problem with your
> iron head don't bother. You probably won't see any noticeable performance
> increase and any small weight saving or improvement in heat dissipation
> really would not be worth the money. The original Weslake design works very
> well, and modifications to the original ports and combustion chamber design
> can easily lead to no improvement or worse performance at lower speeds.
> Stay away from Webcon in the UK at this stage as they were making an
> Austin A70 commercial head thinking it was Healey. I don't know if they
> have changed it yet. The A70 commercial head had smaller and deeper
> combustion chambers and with the Healey sized valves they were fitting had
> shocking valve masking. I would not be paying extra for a Denis Welch head
> for a road car, so any supplier that can supply a faithful reproduction of
> the original should be ok.
> As a matter of interest "Head Stud Developments" here in Australia are
> also in the process of making a 4 cylinder alloy head, but I think they are
> not quite ready for sale yet.
> Larry Varley
> Nash Healey Lemans Coupe x 2 :)
> I am thinking about an alloy head for my 100. This is a request for list
> wisdom on several issues. I'm thinking "fast road" as I have a 3/4 cam.
> What make / supplier, about what price, what has been your experience with
> one, what else should I be aware of? Are there any pros or cons involved
> here. Thanks Ray Juncal _______________________________________________
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