Piston ring worries

[MrStubb]

Wonderful!!! I really can't explain why this would help your issue yet. I know that the original intake system on mine (1980) looks to be kind of restrictive. I'm thinking pod filters when I can get to it. Speaking from experience with my 71 Chevy. Carbureted engines need to breathe really well both intake and exhaust to reach their potential. Any restriction on that engine either way would cause lost performance and poor fuel economy. After I rebuilt that engine it had a tendency to draw oil vapor from the crank case with the stock air filter. It had to do with the mid range cam we installed. We installed a small filter on the crank case vent. It all seems to come down to breathing. I have also seen where a small rodent (mouse) took up house keeping in in the air horn of one car's air cleaner. That little bugger made it seem the choke was closed causing a rich condition and really poor fuel mileage. I've got to get some sleep for my 3 am wakeup. But before I go Be proud I am. You're not some dumb college student. You've gotten further than I did (college? me? barely got thru high school). And thru the process of elimination and good advise from many others not so much mine. You have narrowed down the problem. Watch your oil. Never run with out some kind of filters on all 3 (2 carbs and crank case vent). And Drive Carefully.

 

[jcpwn3r]

Thanks!

I'm actually an electrical/computer engineering student so all this carb and vacuum stuff is fairly foreign to me (as you can tell by my obvious ignorance). Most I've dabbled with in terms of combustion is calibrating EFI signals for a CBR.

This is an educated (almost educated?) guess, but I think the reason that I was sucking oil into the cylinders was because the intake was super clogged. air couldn't get through to regulate pressure in the intake tubes, so that vacuum was sucked up the most available fluid, which was the oil in the block, to try and regulate pressure. At high RPMS it must have gotten worse because the choked intake couldn't keep up with the vacuum demands in the cylinder and more oil was sucked in. So much so that it filled the carbs with liquid oil and gas that can't atomize and basically bogged down the cylinder and burned slowly into that smokey cocktail. My plugs were black as night too.

once I freed up that sealed system, there was no pressure difference between the crank case and the atmosphere so it stayed in the block, and the carbs, now unrestricted, were able to breath easily and let the engine rev up to it's redline. I think that all I have to do is replace the air filter in the airbox and I'll be right as rain.

If anyone disputes this please correct me, maybe this can help someone else some day and I don't want to give them the wrong idea.

thanks again for enduring my stupid questions