norm1
Part of things
Posts: 52
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Jul 29, 2012 20:26:22 GMT
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hi ,ive a 1700x/flow thats just started to blow a little oil out the dipstick .not loads just a bit ,been told i need to fit an oil catch tank  .do i just run a tube from the crank breather to a tank or do it have to have a return ,if it has to have a return where do that return to ?? allso from the crank breather theres a hose that runs up to the carb ,3ltr dgas carb do i just blank that off ,any help would be great ,thanks |
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Jul 29, 2012 21:33:07 GMT
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What I used to do with my crossflow was to pipe from th ecrank breather dorecty to a catch tank,I also drilled and welded a pipe stub to the rocker cover and also piped this to a catch tank..You do not have to have a return at all.With regards the carb take off form the Breather leave it as is so to speak.
One MAJOR question I will ask is are you perfectly sure the breather isnt blocked up at all as they are right so and so's for blocking
Dave
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mikeymk
Part of things
'85 Polo Coupe S 1.6 16v
Posts: 931
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Jul 30, 2012 11:14:31 GMT
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Your breather should already stop that from happening, you seem to have abnormally high crankcase pressure, so maybe your breather is blocked. If the breather pipe is blowing oil into the air filter, or breather filter if you've gone down that route, then that still suggests a problem (a canister on the vertical line can prevent oil getting spat out the top). But if you really need a catch tank, you can just make one from a screenwash bottle like i have. It never fills with any oil because it's not needed, but it's just a provision because my breather pipe goes to atmosphere instead of combustion. The catch tank was the earlier type screenwash tank, and the current one is now the big late type one (conversion was simply a case of painting it black, fitting inlet and outlet pipes, and a clear vertical tube as a sight glass).  |
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Jul 31, 2012 19:44:53 GMT
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It sounds like your crankcase pressure is too high as already said. And the guy with the screenwash catchtank shouldnt you have a filter on top to vent the pressure?
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mikeymk
Part of things
'85 Polo Coupe S 1.6 16v
Posts: 931
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Jul 31, 2012 22:56:20 GMT
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It sounds like your crankcase pressure is too high as already said. And the guy with the screenwash catchtank shouldnt you have a filter on top to vent the pressure?  ..conversion was simply a case of painting it black, fitting inlet and outlet pipes.. The outlet pipe isn't visible as it exits just under the expansion tank, the inlet is just visible in the side. The old top cap is blanked off with a more secure sealed one, as it's redundant. |
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Jul 31, 2012 22:59:14 GMT
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High crankcase pressure can be due to a worn engine rather than a blocked breather.
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High crankcase pressure can be due to a worn engine rather than a blocked breather. Fair Comment BUT the crossflow is notorious for clogging up the breather Dave |
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norm1
Part of things
Posts: 52
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hi thanks for the comments so far ,my engine is a 1700 x/flow built by dave longhurst many years ago ,big valve head ,race cam ect ,was built for short oval racing ,this problem ive got only started since i put on a facet fuel pump and regulator so may be over fueling ,ive a 38dgas carb gt manafold with a 4 into 2 into 1 exhaust ,,,,,been told by many that its a race engine so it should have a catch tank ? ,ive taken the breather chamber off theres a valve type thing in the top of it that i can blow down the valve it don't seem to shut off as i think it should .when i suck the valve it opens but very relucktent, the engine don't smoke sounds well no knocks or bangs and pulls like a train ,,, i rearly havnt a clue ,,, |
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.do i just run a tube from the crank breather to a tank or do it have to have a return ,if it has to have a return where do that return to ?? allso from the crank breather theres a hose that runs up to the carb ,3ltr dgas carb do i just blank that off ,any help would be great ,thanks 
