Now the Seven that I, or I should say,
my wife owns(!) is a Seven America, which means it has a 948cc
Austin Healey Sprite engine in it. It does have twin SU H1 carbs
(read: small ones) but even the published power output for the
engine in prime condition is a mere 43 horsepower. Granted, it's
pushing less than 1,000 pounds around, so the car is without
a doubt quick and fun, but plenty of Sevens have far more horsepower
on tap. So with just a bit of hesitation, I went ahead and volunteered
(I do that too much these days!) Apparently only one other Seven
owner was interested, but as I was the first to volunteer, I
was the 'lucky' one...
photo: 948cc BMC
'A' Series engine:
period published horsepower - 43
Thinking I'd have a bit of fun
while waiting for the day to arrive, I posted messages to a couple
of Lotus and Vintage Race email lists asking for subscribers
to have a guess at the output of the little engine in my Seven.
I had 19 repondents, several of whom own Sevens themselves, and
several who obviously don't! Some of the guess were humorous,
while others were actually pretty close. Here's what they were
in no particular order:
- 37 BHP at the wheels.
- I'll take a stab at 37 HP at
the rear wheels at around 5300 RPM in whatever gear you happen
to be in.
- My guess, 31bhp at the rear
- At the wheels? Probably about
- I'll put my money on 32bhp at
- My guess is that they will run
your 7 in third gear on the dyno and the figures will be around
the 39.6 BHP at around 5400 rpm. at the wheels Losses are usually
around the 25-30% mark on a chassis dyno vs. an engine dyno.
- at-the-wheels estimate - I'll
say BHP = 54
- My guess is 61 HP.
- The stock 43
- 12 ;o)
- 62 at the wheels!
- 56 hp
- 36 BHP at the wheels
- At the rear wheels I'm guessing
- I guess 52 bhp.
- Knowing that you are always
running at the highest state of tune, my guess is 49 BHP @3,500
- I would guess 40hp at the rear
So we obviously had a pretty
good range of guesses, some more optimistic than others. The
range was from 12 to 69 bhp, with most of the guesses in the
area of 30 to 40 bhp. Read on to see who was right!