Inliners International Forums General Discussion Engines Chevy 250 "water" questions

For anyone who has this data handy, or has something torn down enough to measure, I'd greatly appreciate any info you can provide...

I'm looking for the fitting size and thread type (ie NPT, etc.) for the _2_ threaded fittings on the passenger side of the water neck housing. The top one is for one of the heater hoses and the bottom one is for a sending unit.

Also, has anyone here ever knocked out what looks like a freeze plug on the driver's side of the water neck housing? Is that side threaded? As in, could I, thread the heater hose fitting into that side and cap off the passenger side opening?

And last, but not least...

For the Clifford Chevy 250 water heated intake (42-4501 6=8 Chevy 194-230-250-292 Cast Alum, Street Flow Intake Manifold. Water Heated (Code: 42-4501)

What is the thread size and type (NPT, etc.) for the 2 water ports on the side of the manifold?

Thanks in advance for any assistance you can offer.

Aren't those 3/8 N.P.T.????.....If memory serves me correctly they are the same as the cyl. head temp sender...(just checked an early 292 with threaded heater connection and it is 3/8 N.P.T.)....don't have a clifford here but I believe them to be 1/4 N.P.T.....fats

Thanks,

Larry at Clifford emailed me today and said the manifold fittings are 3/8" standard ... whatever 'standard' is. I'm going to guess NPT.

I'm still looking for the heater hose fitting thread size... and the sending unit fitting just below it.

To clarify... the fitting I'm trying to size the threads on is the LARGE one just to the passenger side of the water neck on the water housing. Since that heater hose is either 5/8" or 3/4", the threads are going to be much larger than 3/8"

XXL, The fitting you have circled I believe is 1/2 NPT.....there are many variations of that water neck depending upon year,emissions etc.....some years had thermal vacuum switches installed in the water neck for E.G.R. and cannister control. ...there still would only be two options on thread size; 3/8 NPT and 1/2 NPT.....3/8 NPT taps require a .579 drill so are larger than standard 3/8-16 bolt thread.....hope this helps......fats

Pipe thread is much bigger then standard straight thread.

http://www.mcmaster.com/#2526a33/=4yh92b

http://www.mcmaster.com/#2525a175/=4yh9r4



Joe

NPT is measure as the inside diameter of the fitting being put in the threaded hole. Joe is right, much bigger than national standard thread, whichis measured by the outside diameter of fitting or bolt being put into hole. Hope this helps. 1 OL REDNECK

It is 1/2" NPT. Todd