REFLECTOR: vernatherm Brian Michalk

[Dane White]

(for those who may be wondering, this is a continuation of a discussion about how to regulate oil pressure on the Franklin 6A-350 engine)

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Actually, the set pressure on the oil system bypass is higher than the engine oil pressure set pressure. There's no need to mess with that as it's a manufacturer designed backup safety feature that should never be used in normal operations.

Increasing the stiffness of the oil filter/cooler bypass spring would only delay the oil bypass to the engine to an even higher pressure when the filter/cooler path is restricted or blocked. What advantage would that offer?

The oil system bypass spring opens only when there is a flow restriction or complete blockage of the normal oil path to the filter/cooler. Don't as me how I discovered that!

Installing a stiffer spring or adding washers at the end of the (other) oil pressure regulating spring are both effective in increasing the engine's oil pressure set point. I've done both and both work just fine. This is the forward (towards the firewall as mounted on our pusher configured engines) spring.

Don't mess with the aft (nearest the propeller) spring!

Yes, we are truly "experimenters!"

-Brammage

Dane White