Exhaust port holes

[Lindsay S]

My Golden Flash iron head has small holes in the top of each exhaust port where the pipes go; that could possibly be threaded. Has anybody come across this before, is it ‘factory’ or is it somebody’s modification to stop the headers from vibrating out? See attached picture.

[limeyrob]

Looks like a mod to me.  Probably to retain the pipes, wonder if it worked?

[berger]

i have seen them with springs attached to the exhausts

[Rex]

Looks like a mod to me.  Probably to retain the pipes, wonder if it worked?

Obviously not as the pipes aren't there, are they?..

[berger]

Rex 

[Triton Thrasher]

Maybe had pins or screws through into the pipes, to hold them in.

[muskrat]

G'day Lindsay.
I did that to my A7SS head to use a spring onto the pipes.
Cheers

[Lindsay S]

That certainly seems a possibility, either that or a grub screw. I have read that Siamese pipes can be a problem with regard to falling out, so maybe the previous owner of this head had those fitted to their bike.
I bought this head off eBay to replace the head on my engine which has a rather unfortunate crack from a valve seat to the spark plug hole!

[berger]

i put a tie bar and allen grub screw on mine

[raindodger]

I have the same holes in my A10 head, I always thought they were oil drain holes.
The head gasket and the block have holes in a similar position.

[berger]

raindodger you are looking at the wrong holes mate.

[Joolstacho]

Is raindodger a father?

[raindodger]

Yes, he is!  But the eyesight is not what it was

[Joolstacho]

Lucky wifey then... "missed by that much!"

[raindodger]

Keep it clean, Lads.