Hi List,
It seems to be the custom to give the list a bit of an update on their
Spridget from time to time and since I am doing a few things to my 69 Sprite I
thought I would say what I've been up to.
I have just fitted a set of the Nology plug leads that I have heard can be
worth 2bhp at the wheels on a 1275. The engine does appear to rev a bit
better but I haven't had chance to try a maximum speed run or get the car on
the rolling road (chassis dyno) to check them out. I had planned to do some
accleration tests but the cigarette lighter socket used to power the
performance meter didn't work so I didn't bother.
The mysterious misfire that comes in at about 6,000rpm disappeared a while
back and I have run over 6,500 rpm (3rd gear I think). BUT, it came back
again on Sunday (things that go away by themselves, come back by themselves).
However, I think I have found the problem now. When I went out for a run the
ign light came on as per usual and went out when the engine started. Later
that day (after the misfire had returned) I went to start the car and the
ignition light did not come on. I know from recent and previous experience
that the alternator wiring 'plug' can disconnect and sure enough it had. This
made me wonder whether the misfire is due to the alternator plug coming loose
and the battery not being able to provide sufficient power at high rpm to
charge the coil etc - In fact the more I think about it and recall alternator
failure on a previous car I am certain that this is the problem. I am going
to the scrapyard Saturday to get the clip that is missing from the alternator
and that will keep the plug in place.
In the search for more power I re-read DVs book and decided to replace the
4.5" aluminium manifold with a 6.75" steel maniflow. Having obtained a
manifold I also sent it off to be coated with an anti reflective coating (DV &
APT recommend this) - supposedly this combination could be worth 5bhp and
torque to go with it. Again, the proof will be in the dyno testing later in
the year. Getting the manifold to fit has been a bit tricky because with a 45
DCOE and an air filter the installation is very long. The inner wing already
has a recess to allow the exising (and very deep) K&N to fit ok. With the new
manifold I will be using a shallower K&N and K&N have been very helpful with
advice on minimum clearance for the ram pipes and bhp capacity of various
filters. It looks like I will have a solution by the weekend that will be on
the limit for ram to filter case clearance but ok for bhp rating. One job
that remains to be done is that the 'gutter' on the wing/fender will need some
relief to clear the outermost edge of the filter case by a small amount and
not enough to cause problems closing the bonnet/hood.
I'm looking forward to completing this job at the weekend and going for a test
drive.
Daniel1312
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