Ok so one of the heater take off studs is cactus leading to a little leak there.

Are these easy to remove and replace? Any tricks?

They are 1/4 UNF.

Can I replace them with bolts?

Thanks guys.

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Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

You sure can replace them with bolts, 1/4" UNC.
You may have a bit of trouble removing the stud remnants however depending on the rust. You might be able to catch the top of the old stud with a pair of pliers or vice-grips, otherwise you will need a fine easy out.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

These 2 studs into the head are 1/4" UNF, not UNC.
Sure, bolts are less hassle.

If you need to drill it out and retap, do it properly; use a bench drill or milling machine.... I have a 1275 head here where somebody didn't- the drill wandered and finished up into the water jacket and out the side of the head!
I fixed it by boring the head for an insert, but it wasn't easy.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

As it happens I bought a small easy out the other weekend. ...

Thanks guys

_________________
Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

If the stud is broken off be careful with that Ezy-out. They are hardened and brittle. If it breaks in there it will not be `Ezy' to get `out'.

I am a fitter/machinist by trade, and have removed many busted and corroded studs from car engines and outboard motors. No way will I use an ezy-out on small studs, they break too easy.
The correct engineering method is drill a concentric hole in the stud to the tapping size of the thread (in your case, 5.5mm) then screw a 1/4 UNF tap in. It will pick up the thread remains and they will come out with the tap. The thread should be undamaged.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

The stud is there still and I should be able to get it out.

I would have left the ezy out till last but as you say the tap is the go.

Thanks for the heads up in any case.

_________________
Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

I would sooner weld a nut onto the stub of a stud than I would try using an easy out.

Weld on a nut, and you've got a bolt.
And the heat from welding likely loosened it up.

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You're so square
Baby I don't care

It's only a 1/4" stud, can't be that tight. Yep welding a nut on is fine.

A pair of vice grips will get it if there's enough sticking out to grab onto.
Warming the head up a bit helps too.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.