Triumph Repair: egr port, federal offence, thread gauge

Question
Hi Howard, I own a TR250 that I just had rebuilt. The original head was toast and I had to find a replacement. The replacement is from a later model and has an egr port built into the #5 exhaust port. What do I have to do to plug this port? It looks to be a fine thread and somewhere between 1/2" and 3/4" or possibly metric? Do you know if anyone makes a plug for this? I dread the thought of having to take the head back off as I just finished putting the engine and Trans back in the car. Hope you can help!
Thanks,
John

Answer
Hi John,
I doubt anyone makes a block off plug as it is a federal offence to disable any emission control component. I understood the federal law was that we were not allowed to modify any emission control component at the dealership but an owner could do it. That was what the dealership told us back when they first started putting EGR and the other components on engines. I would guess that if you were putting a head with EGR on an engine and in a car that never had EGR that you should be able to block off the port legally.

I don't have anything that tells me what thread size it is and I don't remember from back then. All you need to do is measure the hole and if you don't have a thread gauge just purchase a short bolt of that size in national fine (NF) and one in course. Or if the hole is not a standard thread just get a pipe die and cut it to take a pipe thread plug. I doubt it was metric as the only thing that went metric was brake lines late in BLM, but I don't think that even effected the TR-250.
Howard