I spent the day futzing with the car. I may have been overly
conservative when timing it. It checks out to 3 deg BTDC by my (cheap)
timing light.
Before retarding it the last time, pulling up a long hill, in third or
fourth, at about 3400 rpm, I'd hear one little "tick" that sounded
like a the rattle of pinging, only much quieter. I wasn't always sure
whether I had heard it, that it wasn't just something rattling in the
engine compartment, or what. However, after pretty much losing one
motor to pretetonation, I'm just a touch paranoid.
I've ended up richening the carb 1 1/2 turns over what it was on the
dyno. When I went two turns richer, I think that the idle speed may
have fallen off about 100 rpm. Other (apparantly random) factors also
seem to affect idle speed by 1-200 rpm, so I backed it off half a
turn.
I was trying hard acceleration runs up Alba Road (it averages 10% over
4 miles). I never heard any pinging. After running hard uphill, I
pulled off in a pullout, turned the motor off and it did not runon.
Later, after a more leisurely drive down hill on Felton Empire, when I
turned the car off it ranon. Likewise, when I parked it after driving
home I'd have a bit of runon.
The plugs look just about exactly perfect. They are a light brown,
darker then the light straw I saw earlier today. There was just a
trace of soot away from the insulator after a couple short moments of
idle or near idle as I parked it in the carport.
If it runs on when cooler, but not when run harder, could it be too
rich? To cold of a plug?
I'm tempted to put in a couple gallons of racegas after driving to
work tomorrow (and making room for the race gas) to see if that makes
any difference. I'll definitely run race gas at the track this
weekend, and may even bump the timing up a bit to take advantage of
it.
Before my last test run, I did a baseline compression test. It was
interesting in that I did two sets of measurements. One with the
throttle closed, one with Wide Open Throttle. I did this to get a
baseline from which to guage future compression tests.
1 2 3 4
closed 160 157 155 160
WOT 167 165 160 167
I'm running the 190 deg F thermostat. Under normal conditions, I can
actually see when it opens and closes as the temperature will rise to
about 200, then suddenly (in about 5 seconds) fall to about 180.
I am puzzled as to why I have worse runon after driving the car
"easily" than after driving it hard. If my plug was too cold, or
mixture too rich, I'd expect to see a lot more soot.
On a non-technical note, just as I was pulling out for my last test
drive, a white '67(?) spitfire Mk II drove past. I honked, he
waved. He ended up pulling off just before where I was going to pull
off, so I stopped to chat with him. Of course we know several people
in common, and more cars in common. When I told him I had an engine
hoist, I made a best friend for life. :) He said that he had seen me
out in my driveway, and even knew that my car used to be yellow. He
had thought about stopping by, but never had as he didn't know what
sort of a reception he'd get.
While we were chatting, we also saw a really pretty black MGA and a
red Alpine. Both in very nice condition, as was his car. It almost
bothers me that our toys have gotten to the point that there are fewer
and fewer cheap beaters that a younger enthusiast could afford to buy.
First Generation Rx7s, seem to be at the tail end of that stage, 240Zs
just graduated from that stage a few years ago, and Miatas seem to be
the current "sports car that almost any enthusiast can afford to pick
up used", though there don't seem to be too many below the magic $1000
point. At least not too many that run.
--
I've found something worse than oldies station that play the music I used to
listen to. Oldies stations that play the "new" music I used to complain about.
lrc@red4est.com http://www.red4est.com/lrc
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