I’ve been busy working on engine solutions. I managed to get
hold of an EA 81 out of a Brumby which was getting an EJ transplant. Thanks
So after I pulled all the unnecessary equipment off the
engine, I decided to install it to the car before I rebuild it, so that I could
sort out any issues prior to rebuilding it. I’m glad I did as there were some
issues to deal with. The engine bolted to the FWD single range 5spd with no
problems. That was the only thing which was a bolt on. The 81 has a smaller
spigot on the crank for the flywheel but a larger bolt PCD than the 71 flywheel
which is a bit of a bummer as the flywheel I have for the 71 has been
drastically lightened. This just means that I will have to lighten the 81
flywheel and keep the flywheel/clutch assemblies with the relevant motor, not
such a bad thing as they’ll be balanced as an assembly anyway.
The next thing I realized was that the tapped bolt holes
which my engine mounts bolt to are 5mm wider per side as well as 5mm lower.
This may not be a problem in a production car as the rubber mounts would
probably accommodate this comfortably, but in my car the mounts are rigid and
any offset needs to be dealt with. The way I dealt with this was to make new
engine mounts. That was all fine and dandy until I realized that the new engine
mounts would foul on the gearshift linkage. Luckily I was able to slightly
modify one of the mount to clear the linkage. There is some very slight
differences in the top bellhousing mount holes which just required that I
machine new spacers which now need to be engine specific.
The major difference is that the 81 deck height is roughly
1” wider than the 71 which means that my twin Hitachi carb manifold will not
fit, and I’m not about to cut this up to suit.
So I could run a single Hitachi on the standard manifold,
after lots of excess manifold protrusions are cut off and the thermostat
I could make a manifold from scratch to suit the twin
Hitachi’s, but I figure if I’m going to make one I should make it suit a better
carb. I think an IDF Weber would be a good thing so I’m in the process of
buying one of those and I’ve modelled the manifold in CAD, to be fabricated
from aluminium. I will not have the coolant passage running under the inlet
tract, this will be plumbed directly to the thermostat housing which will also
have to be fabricated as a remote unit.
I considered fuel injection as an option, which would make
for a really easy and desirable inlet configuration, but the system would bring
with it, unwanted baggage. The car does not use an alternator as there is not
enough room for one, so running an injection system that is reliant on battery
power would be a bit of a drain on the system.
Apart from the above, injection would also add unwanted complication in
terms of wiring, tuning. At this stage I just need something simple and
reliable. I may consider injection down the track, but for now a carb will have
So I’ve made all these changes to suit the new engine, apart
from the inlet manifold, so these will be squirrelled away for use when I want,
or need to use the 81. I figure it makes sense to make the car suit the 81 as
they are a lot more available than the 71’s. First up I’ll be rebuilding the
old 71 and I’ve sleeved the cylinder head and inlet manifold where they were
excessively ported. I will be using the 81’s rocker assembly on the 71 until I
can source a replacement set.
So I haven’t been idle, I’m doing something every day, but
life and work get in the way of building racecars.