• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!

    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Boo hoo hoo hoo! *sniff*

Thank you great masters. Your comfort is most dearly appreciated.

Would a burned valve cause extraordinary blow by? I could put a hose on my dip stick tube and use it to inflate my tires. Heck, what am I thinking! I should just buy an impact wrench and make the Midget my new air compressor!

The way my luck has been going, it is most likely a burned valve AND a cracked piston (and a worn crankshaft and a flat cam and worn tappets and...)

If I am lucky and my pistons are still in one piece, is it advisble to have them hot tanked and magnafluxed? Don't make fun of me if this is a stupid question.
 
Not the pistons, the rods.
 
I don't see how a burnt valve can cause very much blowby. I say this because the pressure in the cylinder that would leak by the valve seat would either go out the exhaust or into the intake. Sure some could possibly enter other cylinders that happened to have open valves but then it should be contained in that particular cylinder. For pressure to enter the crankcase, it would have to sneak past the valve guides and into the crankcase vice going out the exhaust or into a cylinder that was on the intake stroke. I guess it could happen but in my experience, excessive blowby has always lead me to find either a broke ring, burnt piston, or a slap wore out cylinder and ring combination. Just my $.02 and for what it is worth, I'm dealing with the same issue. I really don't want to tear the engine down right now but I know that it is inevitable. Still, a leakdown test would let you know exactly what is going on in the engine.
JC
 
Very correct, valve guides cause blow by also. But a leak down test is the way to go.
 
Back
Top