[Healeys] Alloy Head

Larry Varley varley at cosmos.net.au
Sat Nov 1 15:02:38 MDT 2014

Hi Guys, all interesting stuff, I absolutely agree if the head is 
cracked, it's a boat anchor even though the six cylinder heads out 
perform the 100 heads in that regard. I would not throw money at 
attempting to repair a Healey iron head. In regards to fitting I prefer 
the modern composite head gaskets with steel rings around the combustion 
chambers. You can also use a very light smear of gasket sealant along 
the spark plug side edge water galleries to prevent weeping from the 
galleries close to the edge.

On 2/11/2014 7:51 AM, Curtis Arndt wrote:
> Larry,
> 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 "Bernoulli 101".
> 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 in Concours.
> 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 interested.
> Cheers,
> Curt Arndt
> AH Concours Registry Chairman
> On Sat, Nov 1, 2014 at 12:44 PM, Larry Varley <varley at cosmos.net.au 
> <mailto: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.
>     Regards
>     Larry Varley
>     BN1
>     BT7
>     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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