billthe3

If more people want pictures of the steam vent kit hole, I have my head off in the garage with the hole drilled out (fresh from lindsey) and I can take pictures of the hole and pipes it comes with.

dlr944

What convinced you the steam vent kit will work?
Thanks

RKD in OKC

Seeing air bubbles going from the head thru the clear vent tube on a fully bled system convinced me.

billthe3

Nothing inparticular - I sent my head to lindsey for some work and they drill and tap all the heads they work on for the steam kit, so I figured since the hole was there I might as well do it.


Oh yeah! The one thing everyone agreed was good about the steam vent kit was that it automatically bleeds any air out of your cooling system. If you have one you don't have to bleed air out manually. The general consensus in another thread was that the $40 kit was worth it for the self-bleeding capability alone, much less any coolant benefits. Of course it makes it a lot easier to drill the hole with the head off.

billthe3

As per requested, here are some pics of my head with my sophisticated measurement system.

In the one that has the hole traingulated with the square (pic #3), I was trying to hold the bottom edge of the square as parallel to the intake-mounting edge as possible.

Pic 4 has the bottom of the square sitting on the edge of that blocked passage, or whatever that is, so the measurement to note is from the lip of the blocked passage to the center of the hole.

Pic 5 is showing the hole through the water passage next to cylinder head. Everyone can feel free to oogle the o-ring in the pic.

KuHL 951

Thanks for the great pics Bill. That's exactly what I was looking for. Now to pick which head to do mine on.

aribop

Did anyone ever mention what size hole to drill and what size tap is needed?
Thanks.

Bri Bro

Drill (21/64") and tap (1/8" National Pipe Thread)

aribop

Awesome. Thanks, Brian.

nize

the steam bubbles re-appear every time the piston walls get hot enough to boil the coolant at the back surface of the walls. eventually, an 'air cave' will form at the back of the motor, regardless of how well you've vented the coolant.

read this;
http://www.turbo944.com/bbs/config.cgi?read=1068

and this;
https://rennlist.com/forums/showthre...54#post3756254

Laust Pedersen

Oh, so we are talking steam (not air) bubbles/pockets in a slow flowing area of a very hot engine. That makes some sense then.

As I learned and Pauerman pointed out, some (probably the early) Cometic MLS gaskets have almost no transfer holes to the cylinder head in that area, which would make things worse.

Laust