K100 head venting
Turbo Mini Forums

Hi!

This is my first post here, even though I've been reading TurboMinis for some years now. Pretty interesting stuff going on here!

So - seems like a lot of people here runing BMW bike heads. So I thought this was a good place to ask, even if my engine will stay n/a (hope that's ok ).

My question is, how do you guys prevent air locks in the head? I'm asking because the water oulet in the bike head is, if you put it on an A-series, not on the highest spot anymore.

I was thinking about a smal spout somewhere higher on the head with a venting hose that goes to an expansion tank (which I'm going to fit anyway).

And one little question:
What are these holes for?



Kind regards,
Jan

[X] nail here for new monitor

I think those small holes are to allow any air escape, not sure there will be any use for them on the A series block as i think its solid where they end up.

I like your thinking with the vent to an expansion tank from the highest point. fdo you know where the highest point is on the K head when its on a mini block? can you just drill into that point and tap in a brass fitting or somthing?

Ok, so I'll blank them.

The highest point must be either one of the centre core plugs (between the spark plugs) or somewhere above the std. water outlet from the looks of it.

If it is a core plug - would be rather easy to "abuse" on of them as a vent/outlet. Or maybe there's enough meat to put a Mini heater valve to where the ignition leads leave the head (that "tunel" area).

But if I'm reading right bewteen your lines noone's bothered before and it's actually not a real problem.

Kind regards,
Jan

Edited by Asphalt on 10th Oct, 2009.

[X] nail here for new monitor

if its just a vent you want to do, it only needs to be 3-4mm.

but as far as i know no ones bothered.

I have a sort of vent in one of the core plugs in the spark plug gallery and Jimster has a blead off from the top of the coolant gallery at the front of the head and runs it back to the expansion tank/ swirl pot.

Air locks/ trapped air is only ever a problem on filling. Its easy to move it by leaving the rad cap off and running the engine up to temp untill the stat opens, then top up, go for a blast and then re check the level. Its never usualy a problem after that.

Just build the engine and dont worry too much about it :)

Oh, and those three little holes are to prevent steam pockets between the bores. I dont have ANY holes between the block and the head for coolant, and it doesnt appear to be an issue

Edited by Sprocket on 10th Oct, 2009.

On 10th Oct, 2009 Sprocket said:
Just build the engine and dont worry too much about it :)

[X] nail here for new monitor