Subject: Re: A Healey by Anyother Name...
You will probably get a couple of answers to this question, but I will throw
my $.02 in. It is from memory so where I'm not sure I've put "~" or "?".
This gives just some of the highlights that I can remember right now.
There were lots of interior and exterior detail changes not mentioned
BN1 - Original 100/4 4-speed tran w/low blocked off. ~90hp. 2 H4 carbs.
BN2 - Improved 100/4 Stronger rear-end, different gear ratios to make low
gear useful. Engine tuned for more power (~98hp?)
There was also a 100/4M (for Le Mans). This was a further tuning of the
100/4. It included engine and suspension parts and a cold air box. If I
remember correctly, it could be ordered as a performance option from the
factory, installed by the factory, when you ordered your car. You could also
order the kit and install it yourself. This leads to some confusion as to
which cars are "true" 100/4Ms.
The 100/S (Sebring) used a different numbering system. I think it began with
"AHS" but I'm not sure. This is probably the most desirable Healey ever made.
It used a cross-flow head on a mostly standard 100/4 block to generate ~130hp.
It also had a heavy-duty suspension and other racing mods.
BN3 - Experimental car new 6-cylinder 2.6L engine in BN2 frame. Not produced.
BN4 - Original 100/6 new 6-cylinder engine in "stretched frame". 2+2 seating.
4-Port head. I think that later models recieved the 6-Port head.
BN5 - Experimental car. Low-cost entry model with reduced performance based
on 100/6. Not produced.
BN6 - 2 Seat version of BN4 with 6-Port head. 2 HD6 carbs.
100/6s with 4-Port heads developed ~102hp. Those with 6-Port heads, ~111hp.
Product standardization also forced a new tranny and rear-end.
BT7 - Original 3000. 6-cylinder bored out to 2.9L. 2+2 seating.
BN7 - 2 Seat version of BN7
MkI. 3000s had 124 hp. 2 HD6s.
In '61 or '62 the MkI. became the MkII. Hp went from 124 to 132. Carbs went
from 2 HD6s to 3 HS4s. Tranny went from side-shift to center-shift.
Available in both 2 and 2+2 seating.
BJ7 - New version of the 3000 MkII. New center console, roll-up windows,
new convertible hood. 2+2 Seating. Change to 2 HS6 carbs. 130hp.
Simulated wood dash.
BJ8 - 3000 MkIII. More horses, 148hp. 2 HD8 carbs. Late in production, the
frame was modified to give more ground clearance.
_____________ _____________ Robb Pryor, Pyramid Technology,
\____________\_____________/____________/ 1295 Charleston Rd.,
\__________ __________/ Mountain View, CA 94039
\________ AUSTIN-HEALEY ________/ VOICE:(415) 965-7200