john.r.davies Posted August 10, 2008 Report Share Posted August 10, 2008 Stan, That MGB just connects the crancase breather and the rocker cover to the inlet manifold, via what looks like a one way valve from a brake servo system. Lots of people do this, though the rather large gaps in the block and head casting between the cam follower casings mean that there can be very little pressure difference between the two chambers. I don't think that it would allow any significant oil to drain back into the crankcase. If what collects in my catch tank is anything to go by, I would not want any of that in my sump! It's a thick, gooey mess, that looks like snot. Sure, there isn't much, and as a race engine, it's built with loose rings so there will be more than in a road enegine, but even so, what blows by the piston rings has a lot of water in it. so best removed, to catch tank or burbnt in engine. John Quote Link to post Share on other sites
Guest ntc Posted August 10, 2008 Report Share Posted August 10, 2008 (edited) Stan,That MGB just connects the crancase breather and the rocker cover to the inlet manifold, via what looks like a one way valve from a brake servo system. Lots of people do this, though the rather large gaps in the block and head casting between the cam follower casings mean that there can be very little pressure difference between the two chambers. I don't think that it would allow any significant oil to drain back into the crankcase. If what collects in my catch tank is anything to go by, I would not want any of that in my sump! It's a thick, gooey mess, that looks like snot. Sure, there isn't much, and as a race engine, it's built with loose rings so there will be more than in a road enegine, but even so, what blows by the piston rings has a lot of water in it. so best removed, to catch tank or burbnt in engine. John Totally agree John but i would not put any back into the engine burnt or not, all i do when changing oil is mix it with old engine oil and send it for recycle Neil Edited August 10, 2008 by ntc Quote Link to post Share on other sites
foster461 Posted August 10, 2008 Report Share Posted August 10, 2008 Stan,That MGB just connects the crancase breather and the rocker cover to the inlet manifold, via what looks like a one way valve from a brake servo system. Lots of people do this, though the rather large gaps in the block and head casting between the cam follower casings mean that there can be very little pressure difference between the two chambers. I don't think that it would allow any significant oil to drain back into the crankcase. If what collects in my catch tank is anything to go by, I would not want any of that in my sump! It's a thick, gooey mess, that looks like snot. Sure, there isn't much, and as a race engine, it's built with loose rings so there will be more than in a road enegine, but even so, what blows by the piston rings has a lot of water in it. so best removed, to catch tank or burbnt in engine. John John, I thinik that is the same FRAM PCV valve that I have and I may be wrong about the drain back to the engine. Another explanation is that he has two points of crankcase vapor extraction, one on the valve cover and the other on the block and these are both under partial vacuum via the PCV valve and the flow is back into the inlet manifold. Totally agree about the snot thing. Stan Quote Link to post Share on other sites
RobinTR6 Posted August 11, 2008 Author Report Share Posted August 11, 2008 John, I thinik that is the same FRAM PCV valve that I have and I may be wrong about the drain back to the engine. Another explanation is that he has two points of crankcase vapor extraction, one on the valve cover and the other on the block and these are both under partial vacuum via the PCV valve and the flow is back into the inlet manifold. Totally agree about the snot thing. Stan OK, rehijacking this thread, I have fitted the 'ratsport' oil catch tank and all appears well and shes running sweetly. I remember someone showing me that the had fitted a catch ttank and fed one of the hoses back to the block on a PI car thru the blanking panel where the mechanical fuuel pump would go. Is this andf output from the tank, ie oil back to the engine or another breather outlet ??? Quote Link to post Share on other sites
john.r.davies Posted August 11, 2008 Report Share Posted August 11, 2008 Think it through, Robin. Crankcase pressure due to blow-by from piston rings. The crankcase connected to the - rocker cover (oh hear the word of the lord!) So a pipe into either will sense - raised pressure! And see above - you wouldn't want what collects in the catch tank back in your sump. Think of it as the rectum of the engine! John Quote Link to post Share on other sites
RobinTR6 Posted August 13, 2008 Author Report Share Posted August 13, 2008 Think it through, Robin. Crankcase pressure due to blow-by from piston rings. The crankcase connected to the - rocker cover (oh hear the word of the lord!) So a pipe into either will sense - raised pressure! And see above - you wouldn't want what collects in the catch tank back in your sump. Think of it as the rectum of the engine! John JOhn OK, all that makes sense but the ONLY reason I asked is someone showed me their rebuilt (BY Revingtons) engine on triple webers which had a pipe from the rocker cover and one from the fuel pump blanking plate connected to the 'oil catch tank' does that mean that both of those were for OUTPUT from the engine ? Quote Link to post Share on other sites
Guest ntc Posted August 13, 2008 Report Share Posted August 13, 2008 (edited) John, I thinik that is the same FRAM PCV valve that I have and I may be wrong about the drain back to the engine. Another explanation is that he has two points of crankcase vapor extraction, one on the valve cover and the other on the block and these are both under partial vacuum via the PCV valve and the flow is back into the inlet manifold. Totally agree about the snot thing. Stan Hi Stan you might find this useful http://www.burtonpower.com/technical_1/eng...her_system.aspx .What I was trying to point out as in this article connecting the PCV to the inlet manifold is not a good idea Neil Edited August 13, 2008 by ntc Quote Link to post Share on other sites
foster461 Posted August 13, 2008 Report Share Posted August 13, 2008 JOhn OK, all that makes sense but the ONLY reason I asked is someone showed me their rebuilt (BY Revingtons) engine on triple webers which had a pipe from the rocker cover and one from the fuel pump blanking plate connected to the 'oil catch tank' does that mean that both of those were for OUTPUT from the engine ? The systems that I have seen that hook into the blanking plate use an oil separator, not simple catch tank and they use that connection to put oil back into the engine. The crankcase ventilation and how the output of that is handled is really a system and you need to know how it all works together to make sense of the individual parts and connections. Stan Quote Link to post Share on other sites
smizgals Posted August 14, 2008 Report Share Posted August 14, 2008 OK, rehijacking this thread, I have fitted the 'ratsport' oil catch tank and all appears well and shes running sweetly. I remember someone showing me that the had fitted a catch ttank and fed one of the hoses back to the block on a PI car thru the blanking panel where the mechanical fuuel pump would go. Is this andf output from the tank, ie oil back to the engine or another breather outlet ??? Robin, Can we see a picture of your installation? Stan Quote Link to post Share on other sites
RobinTR6 Posted August 14, 2008 Author Report Share Posted August 14, 2008 Robin, Can we see a picture of your installation? Stan Stan will try this weekend. Its the 'Ratsport one' here http://shop1.actinicexpress.co.uk/shops/Ra...Oil_Catch_Tanks One of the inlet pipes is connected to the existing outlet from the rocker cover and the other blanked off. Havent settled on position yet as that partly depends on the answer to the question. At present I have put it where the coil would reside on a seperate bracket. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.