• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Vent tube

tinman58

Jedi Knight
Country flag
Offline
I am curious about the vent tube for the crankcase. I have the offenhauser valve cover with a breather vent added. I would like to plug the vent tube off. Is there any thing that would hurt the motor By doing so?
?
 
The TR3 ventilation is made so air from the radiator is forced into the valve cover vent under slight pressure. The air circulates through and around the internal engine, and then is pulled out the lower road vent tube by a slight vacuum.

The later Positive Crankcase Ventilation (PCV) system used by all modern cars pulls air from inside the intake filter, circulates through the engine, and is pulled into the intake manifold, so that all oil and contaminants from the engine are burned in cumbustion.

In answer to your question, you need a circulation of air in the engine, to remove blow-by. That requires a way for air to enter and a way for it to exit. One vent is probably not a good idea...but it will work. You will just force blowby containing oil all over the top of your engine.
 
Thank you . Makes sense. Appreciate the explanation.
 
You only think your engine leaks oil ,wait till you allow crankcase pressures to build up!!
Also make sure the bracket holding the vent is in good shape. It will fall off if it fails. This
leads to catastrophic engine failure in a short time as most of the oil heads south.
Have only seen it once, but it cost my customer a nice numbers matching motor on his 61 Tr4
Mad dog
 
Back
Top