Turbo threads

[MazakMan]

Hi, wondering if someone out there can help me?

I was removing a water cooling pipe from a garret t3 when the banjo bolt sheared (b*g**r!!) leaving me a jagged rusty stump left in the turbo and a pointless bolt head....

I daren't try and take the other one out in case that shears too, all i want to know is what the thread size is (diamter, pitch and thread form) so i can drill and tap a new one.
Thanks

MazakMan

[stevieturbo]

Usually M16 x 1.5 I think.....

But not always Im afraid.

[MazakMan]

Would it really matter that much if i tapped out a different thread?

The bolt that was left in the hole looked fairly well fused into the turbo body so i think i should be able to get a half decent thread into it even if it's not the "correct" one...
If i use M16 x 1.5 it'll be easier to get a new bolt presumably?

Also is there anything in there i should be careful of when drilling it out or is it just a water jacket?

MazakMan

[stevieturbo]

I guess as long as you dont break through, you could tap it whatever you wanted.

It is just a water jacket, surrounding the centreal bearing/oil core.


You could also just forget about the water completely though.

[Boosted LS1]

stevieturbo said:

You could also just forget about the water completely though.

I've read that the water cooling only extends the life of the turbo but doesn't increase it's performance. I've certainly used turbo's without the water connected.

Boosted.

[MazakMan]

I'm not sure about not using the water cooling, I'm not going for outright performance - I want it to be a fairly longlived turbo cos i can't really afford to get it rebuilt regularly

MazakMan

[stevieturbo]

The water only came about, so as to reduce the need for a cool down period after some spirited driving.

Just dont thrash the life out of the car and switch it off...drive for a mile or 2 easy before switching off, and use good oil..

A few very simple measures, will mean the turbo can last a very very long time, water or no water..

[MazakMan]

To be honest i don't want to give up on using the water cooling because i turned down plenty of chances to buy non cooled turbos in favour of a cooled one and I'd feel like a plank if i didn't use it now!

Incidentally the banjo bolt thread turned out to be M18 x 1.5, so stevieturbo was right; there is (annoyingly after having tapped two different threads in the same hole now - lucky i went from small to big not the other way!!) variation in the bolt sizes.

MazakMan