Oil Blowing Out Of Filler Cap?

[Mark Cosh]

took the car for a longer run 60 miles or so today, after pushing the engine a couple of times 5.5k revs the was a couple of little misfires but at the next lights i could see burning oil off the exhausts. temp seemed ok and fans not on. the on another hard blast all ok until back to gentle drive when i started misfiring amd the engine cutting out. temp shot up so slowed down and car returned to normal. back in garage it appears oil is blowing out of the filler cap. it doesnt look like gasket gone and now the car is behaving again other than a weep from the filler. this is beyound me....where do i start chaps?

[zerorace]

i take it it is a pinto

start with the crank case breather

 

what is the water level like?

[Mark Cosh]

water down a little yes its a pinto with twin webbers. i know this may seem dafy but where is the breather?

[Dave R]

under the webbers, and another on the filler possibly... should go to a catch tank if you are running 40's/45's, to the manifold if its a downdraft

 

if sidedraughts, or going to a catch tank, it should have the valve disabled in the bottom where it plugs into the block

[Mark Cosh]

ok checked for blockages and all seemed ok. car restarted are cleaning off oil and evenutually ran sweet. toook he out again today all going well the cylinders started to shut down. ended up needing a tow home. horribe feeling i need to do another compression test. so my question now is......... anyone any idea of rebuild costs?

[Dave R]

has the valve been removed from the bottom breather ???? it will be a disk in the end of the bit that plugs into the block

[chris brown]

Sounds like the negative pressure valve is still in do as Dave says remove it and stick a screwdriver or similar through it then replace it and run a pipe from it to a catch tank. In the original system this valve was connected to the inlet manifold and relied on vacuum to open and alow the crankcase to breathe.