Group,
Three weeks ago I put out an APB for help on my "barking carburetor" problem.
Andrew Stark and Russ Moore focused more on ignition and fuel anomalies and
Kas more on valve or carburetion problems. Naturally I started with the
ignition system...it's easiest to get to. New points, condenser and coil did
nothing but make me feel better about giving some attention to these items for
the first time in several years.
There was little left to do but cave in to Kas' thoughts about valve problems.
As soon as I took the valve cover off, there it was. Three of the push rods
were displaced from their sockets in the rocker arms! All three were exhaust
valves and the valves were wedged in the closed position. How can a motor run
like this? Remember, I drove the car from the racetrack in Birmingham, AL, to
Atlanta, 150 miles at 2500 rpms and it did okay.
I put the pushrods back into place, adjusted the valves, checked the
compression and the motor runs like a ball-bearing sewing machine.
It's terrific to have everything working again but what's the deal? I've
never seen anything like this before; especially three offset push rods. How
sensitive are these things? I twirled them around and they looked fine to my
uninitiated eye. Do I need to replace them just for good measure or do I just
train myself to shift sooner. My normal shift point is 5500 rpms, but when
everything went wrong I was trying my damdest to keep up with Allan Pinel's
much faster TR-4 and I may have been enjoying just a little whiff of the
red-mist. It can happen.
The only time I may cheat on my 5500 limit is on downshifts, and this only on
a new track. Does the valvetrain know the difference between the load of
pulling for an up-shift and the blip for a downshift? The innards of my motor
are absolutely box-stock. The little bit of extra horsepower I have (125
[total] on a dyno) is derived from a mild cam and a little higher compression
ratio.
Obviously, my MO is dependability and lots of seat time - not blazing speed.
Birmingham was my first dnf in 18 races with this car. Maybe I lost a little
bit of my discipline and just wanted to be a race car driver for a few laps.
Andrew, Russ and Kas, thanks for your help
Richard
|