Luckily the day started clear and I went up to Peter Baldwin's for the previously booked rolling road test. The test started with checking the timing. I knew this was going to be out as I set it very inaccurately. We set it for maximum power and, curiously, ended up with it timed so as to indicate that the static timing was a couple of degrees after TDC. Perhaps the crank pully pointer is inaccurate? One problem with this is that the distributor in its new position just about fouls the top hose, and I'll have to move that around a bit somehow.
After that it was time for power runs looking at the fuelling. The car seemed
to be set up for decent maximum power, but it was rather rich when cruising on part-throttle. A while ago I bought
a set of Edelbrock jets and metering rods, reasoning that Peter probably would have any. (The Edelbrock/Weber carb
is a bit like a cross between the "normal" sidedraught Weber in the jets, and a bit like an SU carb in
the use of rods that stick into the jet and move up and down. Unlike an SU, the metering rods seem to just have
a step in them, rather than being tapered.)
So, I looked up the little graph and worked out what needed to be changed to go leaner in cruise without affecting full power and changed to the different metering rods that were indicated. The chart is shown here, with the factory setting for the carb in the middle (position 1) and the place we moved it to below (position 7). The black blobs are those that the standard jet kit supports, the white ones need different jets or metering rods.
On testing again, this seemed to achieve the desire effect. In fact, Peter commented that the engine was running "as sweet as a nut" which pleased me rather.
Hopefully, the effect of the rod change will be to make the engine use less fuel. Certainly, when blipping the throttle it spits out a bit less black smoke than it used to, which must be good.
As for power, and bearing in mind that Peter's road is well known to be optimistic, we started out at 220bhp and ended up at 275bhp. This is probably about 240 bhp in real money and I'm well chuffed. The car certainly goes like stink still....
(BTW, sorry for the absence of pictures, but our digital camera has been lost!)
in case you've got to this frame directly and can't get out, go here.