As per the title, the little vent tube that comes out the top of the head fell out when I was connecting the hose to it. What's the best way to retain it?

Thanks in advance!

JB Weld epoxy

Thanks! I was thinking that, but wasn't sure if it would hold up.

JB weld will hold the tubes in place. But then block them off with a very short bit of hose and a bolt.

There was testing done about 10 years ago that showed considerable oil getting sucked from the engine, through the heads, into the collector before going back into the case. blocking the head vents did not create abnormal running conditions, and kept engine oil where it needed to be - in the engine. Jake did the testing, and I don't recall if the results were posted here, on Shop Talk or on his old forums.

There is a reason the later heads did not have the vents.

Zach

Thanks Zach!

I have read the arguments about not venting the heads. My other engine doesn't have those vents, however, I'm constantly having problems with my valve cover gaskets getting sucked out of place at high rpms. So I'm tempted to leave them vented on this engine just to see what happens. This is probably called learning the hard way, haha.

You can argue with these two guys if you want. But I hear they dabble a tad in Type 4s.

https://newsite.hamheads.com/2016/12/10/typ...tests-analysis/

I've lost that tube, twice, in my race engine, reslting in an oil-down track (and a lot of unhappy competitors). Mine in both cars, street and race, are drilled and tapped for 1/2" NPT plugs. Can be done with it in the car, but much easier on a bench.

I'm certainly not going to argue with them, based on my 4 hours of T4 engine experience

Regardless, it seems you are indicating that JB weld is not a solid long term fix, and I should really put an NPT plug in there.

No, that wasn't a commentary on the efficacy of JBW, as I never did that.

Both times on mine - one on each side - I "field-fixed" it at the track by slightly swaging the inserted end with an appropriate-sized socket, slagged it with silicon, and tapped it in with a small hammer. It seemed to "permanently" fix it for the time being.

There was actually a third time I had a similar problem, with Chris Foley's Fprod engine, where the hose - tightly worm-clamped - slid off the tube (this one was on the aluminum valve cover.) That was "field-fixed" by drilling a hole across the worm clamp, hose, and tube and inserting a cotter pin, along with a lot of silicon. It still exists on Chris' engine to this day...

All three times, the side that popped off was on the outside of the corner. Not only did that make a friiiiggin mess on the track, it also implied to me that that side of the valve cover was likely getting filled with oil and the increased fluid pressure led to the failures. Just a WAG, but it seems to follow.

After all this, and after reading Hoffman's opinions, when I rebuilt the engines (street and track) I removed the vent tubes and and drilled-tapped for NPT plugs.

Greg

Edit,..I still chuckle at this...

I have used HAM heads for years and have known Len for about 20 years . When he ships his heads , whether new or rebuilt , they come with the heads taped and a set of vents and a set of plugs . Your choice. Thanks Greg for posting Len's report

Hey Al, hey Greg. Hope you guys are all doing well.

The easy button for getting a thread in the vent hole after the al tube falls out is to run a 1/4" npt tap in. No drilling necessary. The hole is on the large side already, but you don't need a deep thread to keep the fitting in place since it doesn't have much pressure. Just be sure not to run the tap in so far that a nipple bottoms out against the outside of the head before it can tighten into the taper.

If installing a plug this isn't much of an issue. Use a socket plug and coat it with the sealant of your choice.

Venting will not stop valve cover gaskets from sucking in. You need containment rails inside the covers. 3M yellow gorilla snot really pins the gasket to the cover well and may be sufficient, but at elevated revs the crankcase pressure pulse frequency gets intense. The negative pulses come fast and hard and can suck an unsecured gasket in, even if vents are employed. Seen it first hand. Led to a fire in one case.

Wow, thank you for all the great responses!

I have the containment rails on my to do list. I'll have to look up gorilla snot.