View Full Version : TR6 Casting plugs aka freeze plug size TR6

07-18-2009, 06:43 PM
My eyes are not as good as the once were, so does anyone know the size of the casting plug size on the exhaust side of the engine? I measured 1.5 inches. Also the size of the plug for the rear cam journal, which I have at 2"?

Also, a list of plugs and sizes would also be helpful.


07-18-2009, 08:49 PM
Ray, I've got those numbers/sizes somewhere. Just let me find it.

07-18-2009, 08:58 PM
Here ya go. I knew that we discussed this here before.

Freeze Plugs for TR6 (https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/showflat/Number/554580/Searchpage/1/Main/55777/Words/freeze/Search/true/Re_freeze_Plugs#Post554580)

07-19-2009, 09:28 AM
Thanks Paul.

My original post referenced a TR6, when in actuality it is a TR250 engine, not that it matters. Anyway, I once again checked what I have, and the five plugs on the side and back, are actually 1.5", not the 1.375" as indicated in the reference. All the others are as specified.

07-19-2009, 05:54 PM
That's odd. I bought the 1.5" for mine, per the Dorman catalog and had to return them and get the 1.375" to fit. And I didn't fit them, the machine shop did. Maybe the earlier castings were bigger?

07-19-2009, 06:57 PM
Strange indeed, 1.5 is what they were.


07-19-2009, 09:36 PM
Very strange indeed, but after your piston story, maybe not so strange after all.

Dorman 565-025 Cup Type Expansion Plugs

Dorman 565-025 Cup Type Expansion Plugs Features:
Nominal Dia.: 1-3/8"
Metric Dia.: 35.24mm
Type: Brass
Height: 0.310"
Closed End Dia.: 1.382"
Open End Dia.: 1.392"
Brand: Dorman - AutoGrade - Boxed
Details and Features
* Oversize: No

Here's a picture of what I took to the shop after the exchange: