11 stud head

[wolseley 1000]

Hi all,

I need to drill two extra holes in my 9 stud block to get my 11 stud head fixed
and I can remember there is a description somewhere on my pc how to do it but its gone.
Can anyone help me with some information or experience?

[EAVB]

I'm sure there will be someone on here who knows better than me but the last one I did I put the head on, spot drilled through the extra holes with a tight fitting drill to get my reference points then, as the engine was in the car, I covered the the entire top of the block in masking tape then used a drill with a mag stand to make sure the stud holes were at 90 degrees to the mating surface. I also shortened the studs on the lathe by a couple of mm and had a quick measure up at the water pump end to make sure that I didn't break through into the water pump recess.

Although I'm not sure if that actually matters as I think the factory drilled blocks just went straight through anyway?

I had a hoover (or Dyson, can't remember) hose alongside the drill to catch as much swarf as possible.

After that I just tapped the holes out, removed the tape, put the studs in, refitted the head etc and drove off sedately down the road!

[251 ENG]

Perfect way to do it with engine in car

[Toby]

You can otherwise use a head gasket as a template.

[Vegard]

I've always used head gaskets as templates. I'd never do it with a hand held drill, this needs to be straight. I've got one 10studded engine due to a not vertical table on a drill

[66S]

For this type of operation, I make a tool consisting of a guide tube welded to a foot that is bolted to the block. This tool keeps the drill parallel while you're drilling.

Regards
Al

[mk1]

I use the first method, more or less identically. Although the crux of the matter is making the hole vertical. Its easy to wander when doing it by hand.

[medwaybeat]

A well greased drill and tap will help catch the swarf too.

[Vegard]

If the engine is in the car I would never attempt this. It'd be much better for you to run the 11 studded head with only 9 studs. You don't need 11.

[wolseley 1000]

OK,

my engine is still out so drilling itself is not the problem.
My main concern is that if I break through into the water pump recess the block is not useable any more. Is this so ?

[mk1]

It is not so, most of the stud drillings in an A series block go into the water jacket.

Just use some thread lock on the stud to seal it.

[guru_1071]

OK,

my engine is still out so drilling itself is not the problem.
My main concern is that if I break through into the water pump recess the block is not useable any more. Is this so ?

you just need to make sure that the stud doesnt go to far through and stop the water pump from turning - i made this mistake on a well skimmed 970 block, i doubt its a problem on a 1275

[wolseley 1000]

OK,

thanx all, my head feels better now and I think I know what to do next weekend.....

[Craig]

Make sure and use the correct size drill but .I had a customer years ago attempt this , he used a drill but that "FIT" the holes in the head , then proceeded to drill the block .Yeah the studs fit .............nice and loose !!!!!!

Craig

[wolseley 1000]

Hi Craig,

have just bought some drills of a friend of mine that works for a specialised company here in Salzburg. They produce these drills and I first couldn´t believe it that they are so expensive. The drills are of a special cobalt HSS material so they sell for EUR 10.- each in a regular shop. The one for the near side of the waterpump is 6.3 mm and the other one is 7.8 mm.
Will do a test drill and tap before .