Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties Oil tank: to vent or not to vent?

Oil tank: to vent or not to vent?

Moderators: Curt!, Pa

Post Fri Oct 21, 2011 8:35 am

Posts: 41
Hello all, I have got to the stage of constructing an oil tank for my 45 engine. Need advice as wether a vent is needed or not. Looking forward to your views, thanks!

Post Fri Oct 21, 2011 10:09 am

Posts: 386
Yes, the vent is important. It allows pressure equalization between the engine and oil tank which in turn allows the gravity feed to work. If it isn't vented, tho oil won't flow!

Post Fri Oct 21, 2011 1:17 pm

Posts: 41
Thanks Robbie, should the oil tank be vented to the outside atmosphere or is there a specific part on the engine where it should connect to? Thanks, Joseph.

Post Fri Oct 21, 2011 2:17 pm

Posts: 386
To the engine directly. The fitting on the top rear of the right crank case is the vent line that connects to the oil tank. The system is sealed to the atmosphere.

Post Fri Oct 21, 2011 11:54 pm

Posts: 41
Thanks for your help Robbie and also to whom contacted me by pm :)

Post Thu Nov 24, 2011 3:25 pm

Posts: 41
I started my 45 engine for the first time today, and made sure that oil is returning back to the tank. Would extra venting to the outside atmosphere besides that already present with the crankcase be detrimental to oil circulation within the engine? Looking forward to your views.

Thanks and regards,


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