Hi Chris,
I see the "thicker" cylinder head wall around the spark plugs as an
improvement to the 100 and 100/6 cylinder head castings. The earlier heads are
prone to have hairline cracks from valves to the spark plug hole. This might
be cured with the thicker wall. Often factory modifications had good reasons.
Josef Eckert
Konigswinter/Germany
Hi Josef.
I'm sorry. I pretty much just use my phone on this email account. I couldn't
remember who guided me to the original casting numbers, a few years back, and
corrected me on the 960 being just for BJ8's. I'm pretty sure it was was you.
Thanks for that.
As you said. If all is fine, don't change it. But if you want your car to
perform as it was originally "designed", then this is a serious issue. Harry
Westlake designed BMC A, B and C series heads. And 100/4
heads. His name "Westlake patents" is cast into many BMC products.
Harry NEVER wrote in his patents "it's ok if the end of the spark plug is give
or take a couple of hundred thou up the spark plug hole".
Well. Not in the paper ones I read.
If your car is ok, that's fine.
I'm just trying to help other owners (with info Peter Molloy identified in my
engine rebuild 12 years ago - and Peter is the only race engineer in the
Australian Motorsports hall of fame).
And I got around to taking pics a year ago. And I've spent 5 years in a very
nasty divorce, so maybe I'm just lazy.
But generally, I've shared most "secret squirrel" Healey performance stuff
that I found in my Healey, that many Healey guys never share publically. I
ALWAYS have shared.
Personally, my philosphy is I'm happy to help a Healey beat a Jag, an MG, a
Triumph etc. I really don't care if I help another Healey beat me. Never
cared. I want Healeys to win. Who cares who's Healey it is.
It's about Healeys being up there. I'm not alone. Why does e.g Rich or Roger
or David or whoever tell everyone what is concours correct?
Because they want to see a higher standard. Me? I'm the same, but from a
performance perspective.
If you are happy with your head - you shouldn't do it.
Yeah. A 960 head "works". So do stub axles on non BJ8 3000's. Should you crack
test your non BJ8 stub axles?
It's your call. You dont need to crack test them because they work?
Geoff Healey was compelled enough to write a tech Bulletin to explain that non
BJ8 stub axles will fail in competition. Back in about 1990.
About 25 years after the cars were out of production, Geoff wrote an article
warning about failure rates of pre BJ8 stub axles. Over 50% failure rates.
If you've got pre BJ8 stub axles, and never had yours crack tested, and they
are "fine", and you know the intimate history of your car, then all is good in
your garage. Or not?
You asked "Why should you do that?"
You don't have to do anything. It's your car. I'm just sharing my information.
Take it all with a grain of salt.
Everyone has an opinion. Even Geoff Healey.
This list is for sharing information.
Asking "why should I do that???" is not conducive to people presenting
opinions, and evidence to prove their opinions. Look at the pics on my
website. You tell me how you have a correctly machined 960 head.
Sincerely.
Chris
PS the aluminium head you but WON'T be based on the 960 design, if it's FIA
approved as a homologated replacement.
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