aluminum BE radiators on ebay, drain plug thread?

[TulsaFred]

I installed one of these units and it works well. The one I bought has a plastic drain plug with an O-ring. Unlikely to hold up and looks wrong. I've been unable to find out what the thread is. It doesn't seem to be an NPT, or a metric thread, at least not one available at the hardware stores. I took the plug to Lowes and tried it in their thread examples mounted in the hardware section - both SAE and metric - and it didn't fit any. Also tried NPT fittings over in plumbing, also without luck. I asked the seller what the thread was and he replied "don't worry about it". It doesn't look to be tapered and it is between 1/4 and 3/8 diameter. I'd like to fit an adapter and/or brass petcock. Any ideas?



https://www.ebay.com/itm/3Row-Radia....TRC0.A0.H0.Xbugeye+sprite+radiator.TRS1.TSS0

 

[Trevor Jessie]

I do not know what size it is. However, it looks like there would be significant material to cut some new threads in there.
Do you have a hydraulic store near you?

 

[TulsaFred]

Hi Trevor,
What type of hydraulic store do you mean?
Fred

 

[SD Bugeye]

I wouldn’t worry about it
it is fine
plastic plug in radiator would be fine by me
a brass Petcock in an aluminum radiator would worry me more .
Run with it all good.
we use plastic plugs all the time at work
most likely it’s straight cut pipe thread with an oring seal

 

[Trevor Jessie]

We have Parker Hydraulic stores here.

 

[TulsaFred]

I'd prefer not to have a plastic plug for the aesthetic on a car of this era, but its no big deal. I would still like to know what the thread is in case the flimsy plastic plug gets stripped or I lose it. Maybe I'll take the plug to a plumbing supply company when I get some free time.

 

[SD Bugeye]

If it is straight cut pipe thread
https://www.mcmaster.com/#brass-straight-thread-pipe-fittings/=1dvfw3i

 

[nomad]

Sure its not the same thread as the stock radiator pet ****? British Standard non tapered. Just fitting a stock Sprite Brit temp bulb to a Datsun head and the threads are the same.

Kurt

 

[TulsaFred]

Sure its not the same thread as the stock radiator pet ****? British Standard non tapered. Just fitting a stock Sprite Brit temp bulb to a Datsun head and the threads are the same.

Kurt

Not sure, good thought. I did buy a petcock from bugeyeguy.com. It is 1/4 NPT and doesn't fit (too small). I'll look around for a temp bulb to test it. Unfortunately I have to drain the radiator each time I check it...

 

[nomad]

Don't know why I put a space in petcock!

 

[dklawson]

I'd prefer not to have a plastic plug for the aesthetic on a car of this era...

Please don't take this negatively but you have installed an aluminum radiator in the car. The original appearance is already gone.

You said the thread was between 1/4" and 3/8" That's awful small for a normal pipe plug... metric or SAE. Borrow some calipers and measure the thread OD in a few spots and average it. Then take the plug back to the hardware store and compare its thread pitch with every fastener that looks close in pitch (ignore the diameter... just see if you can identify the pitch). Once you have the diameter and an educated guess on the pitch post that information here and I'm sure we can help you come up with something.

 

[BlueMax]

A Vernier Caliper, SAE, Metric, & Pipe thread gages should eliminate all questions to what your replacing.

 

[Jim_Gruber]

Make it easier just go by a radiator repair shop and you are fixed in just a few minutes.guy charged me $5.00 and done. Same thing for a drain plug on a new gas tank. That cost $25 and about 15 minutes to get soldered it.