explanation of blow-by....

[SOUTHERN SMOKE]

here recently i have seen quiet a few thread on blow-by, and alot of questions to be asked, so i thought i would throw this up to help with people who would like to ask about blow-by...

The term BLOW-BY denotes the escape of compression and combustion gases past the pistons and piston rings into the crankcase. All engines have some blow-by. Excessive blow-by is usually found by higher oil consumption. If you are using a quart of oil in 1000 miles than you have a problem. Blow by is a time factor problem. Cranking speeds leave more 'time' for compression to pass the pistons and rings, resulting in harder starts on a cold engine. Once piston speeds pick up there is 'less' time for the compression to pass the pistons and rings and engine runs. This is why we get " it's hard to start but then it runs good"

you will also hear some say that it may be from valve guides or seals, well not saying there hasnt been a case but it will be highly unlikey because, most diesels are not equipped with a intake manifold vacuum, thus makes it unlikely for oil to pass the valve guides without vacuum. oil will however pass through if the valves and guides are worn enough to be off-set, but most will notice this as well as having a bad idling, rough running engine.

hope this helps those with the question of blow-by.

__________________
CLICK---> GEORGIA CUMMINS CREW

"There are no stupid questions, just stupid people."

Originally Posted by milldog

Unless she makes the move first then show her the sambo stick!!!