Power! From engine to wheels ...
Intro ...
Originally with a 948cc 4-cylinder inline engine pushing out a massive 34 bhp connected to a 4-speed gearbox and a rear axle with a 4.55:1 diff. Max speed was shown as 72mph in 1958! Only difference on mine was I swapped out the worn Zenith down-draft with an SU 1/4" carburettor with pancake foam air-filter on a 2-part inlet/exhaust manifold from a Riley Elf. It felt a bit more responsive but probably didn't increase the power much although the engine had been over-bored and was +10 or +20 over-sized so a little larger than standard.
New set-up ... and this is almost complete ...
A 1275cc 1330cc MG Midget engine (over-bored +0.060"). The block is from an 80's rally-prepared Midget which occasionally found its way into an A35 as well. The engine was known as "No 1" for a simple reason! (See quote below).
Engine history: from the owner:
"No 1 race engine competed in the Coronation Rally over Eppynt in 1986. Finished 8th overall and 2nd in class (just beaten by Bob Fowden's son in a Cooper S). My Midget won best prepared car and its photo appeared in Practical Classics. Afterwards it went racing with MGCC with decent results. My old parts have history !"
MiniSpares Mega 6cc dished pistons and aiming for a CR of around 10:1. Using
ACL high-quality bearing shells and EN24 head studs. New nuts and bolts
throughout.
A 12G940 Mk 3 Mini Cooper head (1.4" inlet, 1.156" exhaust, part no 12G1805),
which should give an useful increase in bhp. Possibly modified for unleaded
fuel, otherwise I will run additives to prolong the exhaust valves/seats.
Kent Megadyne 266 cam with 1.5 ratio Roller Rockers. I know these rockers
are unlikely to produce much more power, but I felt the improved design would
help reduce maintenance, etc.
A 1098cc A40 MkII 1275cc Midget gearbox and a 3.9:1 diff ought to
give an increase in the top speed to allow it to cope better with motorways. HN17
hardened Midget half shafts to take additional power.
Electronic ignition with high spec HT leads and coil, although a PolevoltHS is under
consideration as is something like this 123 distributor system from SC Parts
Carburation will be kept simple with a single SU HIF44 1 3/4" as fitted to Metro in a
water heated intake. (Other future options are twin SUs or DCOE Weber side-draft, but
that's only if I tune the engine further ...) LCB exhaust manifold leading to large
bore exhaust and RC40 silencer box (Mini unit).
An MG Midget MkII was supposedly capable of mid-90's speeds and the A35 isn't that
much heavier. That was with a de-tuned Cooper engine producing 65bhp ... I'm hoping
to have bit more ...
It won't be quick by today's standards ... but it will be quicker than Austin intended
in the late 50s!
Engine build is progressing ...
- Cylinder head is complete. Head cleaned and painted including gentle grinding
of compression chambers, throats and ports to remove carbon and burrs.
Installed valves with new A+ seals, double springs (C-AEA525) and inner spring
spacers (C-AEA654), and refitted caps and collets today. (May 22nd 2015). New
stainless thermostat housing studs and nuts and new ARP heater outlet screws
(as in pic) ... btw the head is RED not pink ...
- crank, pistons and rods are in .. was held up when the new main shells I
bought turned out to be .020" over-sized not standard (June 13th 2015)
- new cam is in, as are new followers, and oil-pump (June 15th 2015)
- working on test fitting the timing gear, but the woodruff key on the crank
won't go in the keyway UPDATE! gentle rubbing on a diamond lap sorted that (at
the second attempt!)
- Timing gear is now fitted now I have managed to sort that errant woodruff
key (September 2015) but not the chain yet (IWIS) and then needs timing
