Plugging the two extra cooling holes in an XJ6 head.

[3edc4rfv]

The XJ6 head I've been rebuilding for my E is almost done. Can I tap the two extra holes in the rear (they're pretty close to a 1/4 pipe thread) and use brass setscrews as plugs (with some red Locktite)? While I can machine aluminium plugs, it doesn't seem necessary, unless folks are going to tell me that they've had problems with brass or copper ones (different expansion maybe)?
Thanks.

[PeterCrespin]

That would be fine. Alloy is advocated if the head is to be skimmed when all head work is finished.

[Tom W]

You might get problems with galvanic corrosion using brass plugs.

[Series1 Stu]

No. There's a very low risk of galvanic corrosion between bread and aluminium.

Regards

[Tom W]

There’s some risk of corrosion as brass an aluminium are separate on the galvanic scale.

https://www.fastenal.com/content/feds/p ... rosion.pdf

Brass and aluminium together is not ideal, even though they do already exist in together in the cooling circuit. I always find it nerve wracking removing a temperature sender from an aluminium casting if it’s not been removed for a very long time.