Quick question, does anyone know the size of the fittings on stock mercruiser oil coolers. Or know how to measure. Have an old hose that came off cooler. Want to order new coolers but not sure what size fittings need to be installed in cooler.
thanx

Unless you are ordering another merc cooler I doubt your factory lines will fit. I believe they are 1/2 hose with an inverted flare fitting. If you are upgrading your cooler to an aftermarket / high performance cooler then I believe the connections will most likely be 1/2 or 3/4 npt or atleast mine is. Good Luck!

I think TC is right. If you want aftermarket, you can convert to SS braided lines with NPT and/or AN fittings. Good luck.

Greg

Consider Aeroquip Socketless hose and fittings. Easy to work with.

I bought a new oil cooler with out knowing it had inverted flare fittings and I want to use an fittings is there an adapter that goes from inverted flare to 1/2 NPT.?
Thanks Todd

Looking at the old hose, one end has the inverted flare and the other end appears to be npt. Just don,t know how to measure to see what size npt. Hose is marked 5/8".

Go to the Aeroquip website listed below.
http://www.aeroquip.com/pages/lit.html
Download the Performance Products Master Catalog (A-SPPE-MC001-E).
Page 48 of 64 will show you all the actual fitting sizes (NPT and AN).
This should help.

Found it and thanks. I think I will be able to use this.

RLW,
Downloaded the PDF doc and it looks like the socketless hose is rated to 300. For and oil cooler application that seems it may be a bit low. The temp in the pan prior to cooler may be close to or exceed that;
http://www.hosexpress.com/hose/socketless/FC332.htm
Perhaps the hose is safe to 300 at 250 psi and when being used at say 80 psi the 300 or close to it would not be a problem. Do you know of anyone using this hose in oil applications?

There are many people running Aeroquip Performance AQP hose. Whether it be marine or other forms of motor-sports, Aeroquip AQP is the standard.
If you have 300 degree plus temperature oil running through your hoses and cooler, you have other issues to be addressed.
Most of the oil temp issues I see around here are people running too small of a cooler (hot) or not implementing an Oil T-Stat with an H2O T-Stat to get the temps up with their large cooler.