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December 27, 2003
Thanks to all the "start-up" advice, the initial run-in went without
a hitch. But a strange problem cropped up. Engine is a fresh high
compression 1275 with PCV only. It would run very well for the first
few minutes, and then start to belch smoke the likes of which few
could imagine. It would do this for a couple minutes, then run
normal again. Also, I could not get it to idle below 1200 rpm
despite the fact that the carbs were fresh and were properly set up.
With throttles CLOSED it still idled at about 1200.
After doing WAY too much wrenching and very little thinking, I
decided to have a beer and evaluate the problem. (Also, the plugs
were clearly oil-fouled). I took a pair of vice grips and pinched
off the hose to the PCV valve, and the engine now runs PERFECT. Was
able to immediately dial in the mixture and can set the idle where
ever I want it. It's really a thing a beauty.
Obviously, I'm sucking oil from the crankcase via the front cover.
The front cover is new and I verified it has an oil separator in it.
The oil cap is a vented one, again new. I installed the PCV system
(yes, it is a nos valve functioning properly) so as to limit oil
leaks. What should I do? Should I just vent the front cover thru a
filter to atmosphere? Should I try and "re-index" the oil cap (drill
out the air opening) to lower the "draw" at the PCV valve?
I am beginning to appreciate the importance of all air that enters
the engine being "metered". I am running port vacuum to my
distributor and have no other "air source" entering the engine except
thru the carbs. When I pinched off the PCV (which dumps into the
manifold, so it is not metered), I was able to quickly dial the thing
in to the point that it ran like a well oiled sewing machine.
Amazing.
Other than drink more beer, what should I do?
As always, thanks much.
Paul
"dfwip" < dfwip@... > 27883
Posted on December 27, 2003 04:02 PM
Posted to category(s) Braking System | Carburetor | Cooling System | Cylinder Head | Electrical System | Engine (external) | Engine (internal) | Exhaust System | Gauges | Ignition System | Intake System | Interior | Lubrication System | Tuning
