Blowby and Carbon Monoxide?

[Kurt]

I thought I knew the answer to this question, but am now unsure. My engine has some blowby and I notice that after motoring under load for an hour or so I will get smoke in the cabin - worst when I don't run the blower, not very bad at all when I do. I have noticed that my blowby is worse now than it was a year ago. At the same time that my blowby has become worse, I get elevated carbon monoxide readings on my detectors - they used to always read zero. However, I have also done a recent exhaust system overhaul (I kept the original manifold, but everything else is new). At first I assumed the problem was with the installation of the exhaust flange. I took it off and saw that only one gasket was used, so I put two on. That seemed to help the problem a little. QUESTION: does crankcase blowby contain carbon monoxide to the extent that it would cause elevated readings on detectors? Does blowby contain as much carbon monoxide as exhaust?

Before I screw around with my exhaust installation more, I was thinking about getting PCV kit to see if stopping the blowby would cure my problem.

[Marian Claire]

Not sure about this. But I would think that blow-by is exhaust / combustion gasses that escaped around the rings instead of out the exhaust valve. Dan S/V Marian Claire

[Dave Neptune]

Cabin fumes

Kurt, yeh what you are describing is "blow-by" and it can be eliminated!!!

Get the PCV kit available for the A-4. It is better for the engine as it reburns the "blow-by" and sends it out the exhaust. It will also keep the inside of the crankcase much cleaner as well as the air we aLL BREATH. I put one on mine and was absolutely amazed at how well it cleaned up everything including the cabin!

Dave Neptune
1970 E-35 Mk-II original A-4 still ticking!!!

[keelcooler]

Kurt,
Elevated readings from blow by, yes. Go with the PVC kit. I used to see blow by at the fly wheel and the carb breather pipe couldn't handle all the smoke. With the kit installed I've got a clean cabin,it works.

[Kurt]

Thanks, guys - I'll give the kit a try!

[pearson coyote]

blow by and cabin fumes

Had the same issue on our trip from Portland Or to our home port in Cathlamet, about 2 hours into the run the O2 sensor went off, cabin was full of "blowby", so I turned on the engine room exhaust fan, opened up a couple of windows and the hatch. The following week I purchased an installed the Indigo PCV kit, adjusted the carb and all is good. The Indigo product was the exact fix and was a very straight forward install.

Good Luck

now if I could just find "neutral" when docking I would be a happy sailor...