427 foam in valve covers

[Richard L.]

Re: 427 foam in valve covers

Joe, I wanted a thicker gasket to reduce the compression and the #1017-2 was thicker than the #1017-1. On the re-torque question, mine did not require re-torque as you stated, but I talked to a fleet mechanic the other day and he told me that when you re-torque the aluminum heads you must losen the bolts and then re-torque. I did not loosen the bolts, just tried to re-torqued them. Comments

[Joe L.]

Re: 427 foam in valve covers

Joe, I wanted a thicker gasket to reduce the compression and the #1017-2 was thicker than the #1017-1. On the re-torque question, mine did not require re-torque as you stated, but I talked to a fleet mechanic the other day and he told me that when you re-torque the aluminum heads you must losen the bolts and then re-torque. I did not loosen the bolts, just tried to re-torqued them. Comments

Richard------


I have never heard of loosening and re-tightening for head bolts with aluminum heads. Frankly, I would be very reluctant to do it that way.

[Richard L.]

Re: 427 foam in valve covers

Okay, here is an update. Pressurized the water system and the pressure did not move much. After 8 hours the pressure dropped almost 1psi, so there does not seemed to be a leak in the water system. Any ideas what to check next? Can it be humidity in the air that once the hot engine is turned off the water gets in through the valve cover breathers and condenses inside?

[Thomas H.]

Re: 427 foam in valve covers

Okay, here is an update. Pressurized the water system and the pressure did not move much. After 8 hours the pressure dropped almost 1psi, so there does not seemed to be a leak in the water system. Any ideas what to check next? Can it be humidity in the air that once the hot engine is turned off the water gets in through the valve cover breathers and condenses inside?

Did you pressurize it hot? Doing it with the engine cold may not show anything as the parts tend to expand when the engine is at temp.

Tom

[Tom L.]

Re: 427 foam in valve covers

Not tying to be a wise a$$ but think about it. A 1 psi drop in 8 hours... Would you want that kind of leakage in your home plumbing? There has to be a loss somewhere, even if it's your testing tool. Hope you find your issue. It's the kind of thing that would drive me nuts. Wish I had more experience with engines like yours but I don't. Good luck!!

[Richard L.]

Re: 427 foam in valve covers

Tom, my posting was looking for help, all opinions are appreciated. I did not take the reading hot as I have the oil drained from the engine with the valve covers off so I could monitor any leakage around the bolts and the intake with the system pressurized. The loss in 1 psi is probably do to the way I hooked up the pressure system, did it with a Mighty Vac.
I found no evidence of water leakage anywhere. Will eventually put oil in, seal things up and try again.

[Tom L.]

Re: 427 foam in valve covers

Sorry if I came across the wrong way. Being in the refrigeration business for so long I get sensitive to leaks. There are too many mechanics in my business that have customers convinced that a "small" leak is "normal" or "ok" and adding gas (refrigerant) is just a part of life. I'm sure you'll get to the bottom of your issue. Hopefully it will be a simple one.

[Richard L.]

Re: 427 foam in valve covers

Do the rocker studs on the aluminum heads go into the water jacket? I pulled the head bolts and they were all sealed okay. I left the pressure on the system for a week and there was water laying in the valve covers. The rocker studs are my next move if they go into the water jacket. Comments please.

[Domenic T.]

Re: 427 foam in valve covers

Richard,
I pulled studs on other engines and they did not go into the water jacket. I never did one on a BB or aluminum head. Richard, Some aluminum heads require washers under the bolts. I would see if yourr heads require them. Just a thought.
The worst case I ever ran into that put water in a engine was a crack in the lifter gallery. the water entered the lifter and was pumped thru the pushrod to the head. Rare Rare Rare. If that were the case you would find traces of oil in the coolant.
Is there much water in the pan? As I said in my other post, " the water and oil have to go thru the oil pump to make the foam:. The fact that you are finding unmixed water in the heads points to a leak under the valve cover or the Rare one where the water travels into the lifter thru the push rod. I will look at a set of BB heads (cast iron) and see if the studs enter the water jackets. If they do I will post in a few min.

DOM

[Domenic T.]

Re: 427 foam in valve covers

Richard,
Just looked at a set of BB square port heads ( cast iron ) and the screw in studs do not go into the water jacket. I remember washers used under the bolts on other aluminum heads that I worked on, but they were not Chevy BB.

DOM

[Richard L.]

Re: 427 foam in valve covers

Dom, Thanks for the input. I have the hardened washer under the head bolts. Hopefully someone with aluminum heads can chime in. I cannot see anywhere else the water is getting into the valve cover area except the rocker studs since the motor was not started, just left the pressure on the cooling system and the water was showing up. This is true of both right and left heads.

[Joe L.]

Re: 427 foam in valve covers

Dom, Thanks for the input. I have the hardened washer under the head bolts. Hopefully someone with aluminum heads can chime in. I cannot see anywhere else the water is getting into the valve cover area except the rocker studs since the motor was not started, just left the pressure on the cooling system and the water was showing up. This is true of both right and left heads.

Richard------



Some, but not all, of the big block aluminum head rocker stud tappings do go through to the water jacket.

I would recommend that you remove ALL of the studs, thoroughly clean the threads of both the studs and the tappings, apply sealer and torque to spec. You won't be doing any harm to the studs that don't go through but you'll ensure that all the ones that do will be sealed.

I'd use either Permatex #2 or Locktite Pipe Thread Sealer with Teflon.

[Domenic T.]

Re: 427 foam in valve covers

Richard,
From what Joe said, you will find that when removing the studs that coolant will start to seep out as you unscrew the stud. You will have to drain the coolant level and I hope that is the case. It would make sence to make the threaded part of the stud longer and enter the water jacket as aluminum strips easily, but they may be the same for Iron & aluminum. Good weekend job.

Dom

[Joe C.]

Re: 427 foam in valve covers

Don't forget to tighten the rocker arm nutz.

[Richard L.]

Re: 427 foam in valve covers

Dom / Joe, I have resealed the head bolts and the water system has been drained. I will refill the water and put the pressure back on the system this weekend. I don't like to keep pulling things apart with the aluminum heads. If this leaks again then it has to be the rocker studs and I will pull and seal them at that time.