New head gasket leaks water

[38plymouth]

I swapped out my stock head for a Fenton aluminum head that I've had for years. I've had the head on and off this engine at least five times since I owned it and never had an issue. This time however water was seeping out on the passenger side rear right above the rear intake and exhaust manifold. I ran it through a heat cycle and it leaked even worse when it cooled. I checked the torque and everything was good. The book says to torque the nuts to 55 to 60 foot pounds for an aluminum head. I pulled all the nuts back off cleaned the studs really good lubricated and reinstalled the nuts and that seemed to help. I ran it through a heat cycle and saw no leaks. This morning the leak is smaller but it's still there. I checked the torque on the cool engine and nothing changed. I did bump up the torque to 65 foot pounds on six nuts near the leak. I ran it to another heat cycle and so far so good but I believe once it cools again it might come back.

Not sure what to do now. What is the highest safe foot pounds I can try? Maybe try bars leak? I really don't want to tear this thing back down.

I don't believe the head is warped, it was fresh from the machine shop 4 years ago but just putting it back on now. I checked it with a straight edge before install. I used a new fel pro gasket and cleaned everything really well and used the proper sequence when tightening everything down.

[38plymouth]

The leak is smaller and slower now and is only below the nipple for the the heater hose. I tempted to lighten the nut closest to the leak a little more but I'm afraid of stripping the stud of snapping it off.

[Sniper]

IIRC, it's a 7/16-20 thread.  Depending on the grade, max recommended torque value is 73 ft/lbs, for the nut.  Assuming it is FNL grade 9.  I don't know what you are using though.  I don;t think your issue is a loose nut though.

[kencombs]

What kind of gasket (composite, copper etc) and brand did you use? Was any sealer used?

 

There have been several reports of new aluminum head having some porosity.  Is yours for sure leaking at the gasket and not a pinhole?

[38plymouth]

16 minutes ago, kencombs said:

What kind of gasket (composite, copper etc) and brand did you use? Was any sealer used?

 

There have been several reports of new aluminum head having some porosity.  Is yours for sure leaking at the gasket and not a pinhole?

Fel pro gasket and no sealer. I have never used sealer on the fel pro style gasket, I think it says you arent supposed too. It's definitely seeping past the gasket. 

[kencombs]

1 hour ago, 38plymouth said:

Fel pro gasket and no sealer. I have never used sealer on the fel pro style gasket, I think it says you arent supposed too. It's definitely seeping past the gasket. 

You're correct on the sealer, at least on the MLS designs.  I seem to recall that sealer can be applied to one side of the steel on one side only gaskets.   I'm not sure if the older gasket designs ever got the latest tech factory sealers applied.  I've seen several NOS gaskets for sale and they almost never are of new design.  Hard to match the process to gaskets when using unknowns like that. 

Edited October 18, 2021 by kencombs

[Sniper]

The only authoritative source I can find for the Fel Pro HG on our engines is from The Montana MoPar boys.

 

http://www.moparmontana.com/tech-faq.html

 

HEAD TORQUE
Your block should ideally be decked to give a smooth flat surface for optimum sealing. Head bolt holes should be chamfered and thread chased with a tap after decking. A modern composition head gasket will give the best results  and these are available off-the-shelf from Fel-Pro for 23" and 25" Mopar flathead 6's. Fel-Pro recommends using a sealant on the copper (block) side of the gasket. Vintage double sided copper gaskets require sealant on both sides. A copper spray such as Copper Coat works well. EDGY heads have a very smooth, flat surface for use with modern gaskets.  Due to this, no sealant is required on the head side of the Fel-Pro gasket.

Any head fasteners that go into the coolant jacket (ALL of them do on Mopar flathead 6's!) should have a non-hardening PTFE sealant such as ARP or Permatex applied to the threads. Hardened and ground flat washers should be used, and need an ID chamfer if using bolts (chamfer goes up). ARP makes the best ones and are available directly from us. Ensure that the fasteners you are using fully engage the threads in the block. If using ARP studs, the upper threads, and nut/washer faces must be coated with ARP assembly lube.

Torquing should be done in three stages following the order on the attached picture. Use of a high quality torque wrench is highly recommended. Torque values for 23" and 25" Mopar flathead 6's are as follows:

First stage: 25 ft-lbs
Second stage: 45 ft-lbs

Third stage torque is fastener dependent:
Stock head bolts: 65-70 ft-lbs (with sealant on the threads, oil underhead and on washer faces)
Stock studs and nuts: 52-57 ft-lbs (sealant on block threads, oil on top threads and nut/washer faces)
ARP studs and nuts: 63 ft-lbs (sealant on block threads, ARP lube on top threads and nut/washer faces)
 
Run the engine to normal operating temperature and allow it to fully cool over-night before retorquing.
Repeat this procedure at least three times, or until there is no more appreciable take-up on the fasteners.

 

[38plymouth]

This is what I  dealing with, it's much smaller than it was yesterday so pulling the nuts and oiling the threads helped. Or increasing the torque in that area helped. I'm going to keep warming it up and letting it cool and recheck the nuts for several days. I don't want to have to start over.

[38plymouth]

This is what I  dealing with, it's much smaller than it was yesterday so pulling the nuts and oiling the threads helped. Or increasing the torque in that area helped. I'm going to keep warming it up and letting it cool and recheck the nuts for several days. I don't want to have to start over.

[Sniper]

Out of curiosity, did you run a draw file across the top of the head to check flatness?

 

https://www.wonkeedonkeetools.co.uk/files/what-is-draw-filing

[38plymouth]

Just now, Sniper said:

Out of curiosity, did you run a draw file across the top of the head to check flatness?

 

https://www.wonkeedonkeetools.co.uk/files/what-is-draw-filing

No, it was checked at the machine shop 4-5 years ago when the spark plug threads were repaired. I checked it with a straight edge before the install and it looked perfect.

[Sniper]

I actually meant to say the block, not the head

 

[38plymouth]

Anyone want to venture a guess on how much my compression increases from the aluminum head? I was at 98,98,96,98,100,104 with the stock head. I did gain 2 pounds of vacuum at idle. It's now hovering around 19-20.

[38plymouth]

[38plymouth]

2 minutes ago, Sniper said:

I actually meant to say the block, not the head

 

No...

[DJK]

I would be a little hesitant to increase the torque on only a few bolts, just saying.

[38plymouth]

I put them all at 65 this morning. I also found 2 that needed a quarter turn this afternoon after a cool down. One was in the center one row away from the leak. 

[kencombs]

4 hours ago, Sniper said:

The only authoritative source I can find for the Fel Pro HG on our engines is from The Montana MoPar boys.

 

http://www.moparmontana.com/tech-faq.html

 

HEAD TORQUE
Your block should ideally be decked to give a smooth flat surface for optimum sealing. Head bolt holes should be chamfered and thread chased with a tap after decking. A modern composition head gasket will give the best results  and these are available off-the-shelf from Fel-Pro for 23" and 25" Mopar flathead 6's. Fel-Pro recommends using a sealant on the copper (block) side of the gasket. Vintage double sided copper gaskets require sealant on both sides. A copper spray such as Copper Coat works well. EDGY heads have a very smooth, flat surface for use with modern gaskets.  Due to this, no sealant is required on the head side of the Fel-Pro gasket.

 

 

Thanks for finding that for me Sniper.  I looked and looked before my earlier response.  That is exactly, even the Copper Coat, what I did on my 230 that hasn't been started yet.  I knew I read that somewhere!

[Bryan]

5 hours ago, 38plymouth said:

Anyone want to venture a guess on how much my compression increases from the aluminum head? I was at 98,98,96,98,100,104 with the stock head. I did gain 2 pounds of vacuum at idle. It's now hovering around 19-20.

Okay..see how it works.

Edited October 19, 2021 by Bryan

[Dodgeb4ya]

Some of the stud and water jacket holes are really too close to the crush ring of the head gasket IMO.

[38plymouth]

1 hour ago, Dodgeb4ya said:

Some of the stud and water jacket holes are really too close to the crush ring of the head gasket IMO.

Not really sure what you are seeing, but, good news it looks like, the leak topped. 

[Dodgeb4ya]

Oh..

it just looks like the gasket barely seals these stud and water holes..

Looks like from the picture maybe the water port holes are cast slightly off compared to the factory head...maybe just the picture.

[capt den]

2 questions. why would you swap this head out 4 or 5 times since you owned the car? what is the advantage of the aluminum head over the stock cast iron head?

[TodFitch]

6 minutes ago, capt den said:

. . . what is the advantage of the aluminum head over the stock cast iron head?

Aluminum is a better conductor of heat than cast iron so it is less likely to have hot spots that can result in pre-ignition. So you can usually run a higher compression ratio with an aluminum head than you can with a cast iron head (all other things being equal). On an Otto cycle engine the higher the compression ratio the higher the efficiency (amount of potential power in the fuel converted into usable mechanical power) but the compression ratio is limited by the onset of pre-ignition. End result is an aluminum head generally gets you more power out of the engine.

 

It also looks cool.  

[38plymouth]

1 hour ago, capt den said:

2 questions. why would you swap this head out 4 or 5 times since you owned the car? what is the advantage of the aluminum head over the stock cast iron head?

Stripped spark plug threads and just doing various work to the car over the years. I finally had all the plug threads redone at a machine shop. The Fenton head raises the compression and it's MUCH lighter than the stock head. The aluminum head also looks really cool especially with the fins on it. I also made a promise to an old guy years ago when he gave me the head. He used it on a race car in the 40s and he saw me at a car show one day and insisted on giving it to me. I promised him that I would put it on the car just for him. He's probably gone now but it makes me happy knowing I kept my promise to him.