-8 or -10AN external oil cooler line ?

[williamsGN]

I see the recommendation from TBs.com write up to use -8. My builder is suggesting -10. But since flow is only is good as the smallest point in the system, I don't see how using -10 is any improvement since you have to step down from 7/8" for the fitting to 3/4" to get into the oil cooler adapter.

Only fitting I could find in -10

Aeroquip 4740-10B Male Inverted Flare SAE 45 Degree Fitting Socketless

 

[TurboTR]

Well there is loss within the lines too. It takes power to pump the fluid through the lines. The loss increases with decreasing line size, and with increasing line length.

The radiator I bought from CAS years ago had -10AN fittings installed for the custom submerged oil cooler.

TurboTR

 

[TR Custom Parts]

Ran -8 lines for years on my GN. Only screw in adapters I could ever find that work with our radiators goes to -8. Worked fine and that is the size I use in the kits I sell.