Source for 3.5" or 4" Duct Flange?

[tx_jayhawk]

All,

My oil temps are a little higher than desired on my O-360 RV-7A with firewall mounted SW oil cooler. I'm currently running 3" scat from the #4 cylinder to the firewall mount. I'd like to increase to 3.5" or 4" scat, but I am having trouble finding a duct flange that size (Spruce has only up to 3").

Any good leads? Would also be interested in feedback if others have done similar.

Thanks,
Scott
7A

[Mike S]

IIRC, the one on my 10 is 4".

Check with Vans.

[scsmith]

I made my own 3.5" flange and had it tig-welded onto a short section of 3.5" tubing. I think Van's sells 4".

Nonstopaviation.com sells a 4" butterfly valve that you can control in the cockpit to adjust oil temps in winter. They describe a 4" flange, but don't seem to have one on their site. So they must assume you get it from Vans.

Try part VA-187 $15.50

[mburch]

Van's P/N VA-187.

mcb

[jetrench]

Try Spectre Performance, part number 91489 is a 4" aluminum intake duct mounting plate $14.99
http://www.spectreperformance.com/#CATALOG.91489