Drain Tap Hole Blocked

[Macker2]

Evening all,
The drain tap hole on the back of the block is solid with rock hard crud, so I was thinking of drilling it out, but I am a bit worried about going in to deep.
Does anyone know how far to go before you break through into the water jacket.

Thanks. Macker

[Spider]

I have done that a number of times to get some flow through them to get some chemicals in there to finish the job. They do go in a long way (about 3") before you hit any cast iron, but you will know that for sure and even if you do nick it, it isn't going to matter as long as you don't keep trying to drill! You will definitely feel the difference!

Last few times to clean the cooling jacket up I've used CLR, works way better than any so called radiator flush I've used before.

[Macker2]

Cheers Spider,
Managed to clear hole,it was solid for 3" as you said it would.
Macker

[Spider]

Yeah, it's kinda un-nerving that first time, just how far it goes in!

Glad you've sorted it.

[Vegard]

Yeah, it's kinda un-nerving that first time, just how far it goes in!

Is this even legal?

[rich@minispares.com]

Yeah, it's kinda un-nerving that first time, just how far it goes in!

Is this even legal?

it depends if your dressed as jimmy saville at the time.............

[Spider]

Yeah, it's kinda un-nerving that first time, just how far it goes in!

Is this even legal?

I've Greek origions, of course it's legal

[Macker2]

[Chalkie]

Last few times to clean the cooling jacket up I've used CLR, works way better than any so called radiator flush I've used before.

What's Clr?

[Spider]

Last few times to clean the cooling jacket up I've used CLR, works way better than any so called radiator flush I've used before.

What's Clr?

http://www.clrbrands.com.au/

They are available in most parts of the world.