an 10 adapter in water pump for heating?

[Camaro_Dan]

I bought a AN10 adapter to whatever NPT size are in the waterpump. The problem I have is that the adapter needs to go in longer into the waterpump. it sticks out too far! I bought a NPT Pipe tap and to try and tap it out a bit more in the water pump. but the WP is too shallow, the tap hits the bottom of the WP hole and can't go in any more.

I don't want it looking like this, how how you guys running AN lines to the heater core solved this problem?



here is how it looks now:


Thanks for any help
/Dan

[Matt@RFR]

First of all, if you have 3 or more full threads engaged, it's fine. If you want it deeper, and your tap is too long, then grind some length off the tap. It's done all the time and will work fine.

[Camaro_Dan]

yeah I want it down deeper. But I thing the adapter NPT side is too long. it will block off too much flow if I just engage it all the way down. could I cut off some of the adapter and thread that part down with the opposite of a tap (Don't know what it's called) I hade to order these NPT taps etc from the states because the whole of Europe doesn't use NPT. or are there other adapters that are "thinner" in diameter and also shorter?

[Matt@RFR]

No, that fitting is going to be a standard length, and there's no 'short' NPT fittings available.

Yeah, you can cut the fitting off, and then tap the hole deeper, but be very carefull..it won't take long before the tapped hole is too big and the waterpump is ruined.

The opposite of a tap is a die. You can buy them, but with the chamfer on the NPT die, you won't get any further than what's on the fitting now.

My suggestion is to tap it 1/2 turn, test the fitting, go another 1/2 turn, test the fitting, and so on, until you reach the desired depth. Then cut the fitting to the desired length.