The Ford Barn

Cameron Koehn · 11-17-2021, 02:30 AM

So...I had someone shave my EAB heads just for a better sealing surface. They came back with that circle of dome progressively smaller towards the back of the head. I'll get a picture tomorrow. Is this something to be concerned about?

Mart · 11-17-2021, 05:31 AM

It sounds like they milled it at an angle.
Not good.
If the smallest still gives enough clearance, it could be re-milled to equal them up.
It might be a casting flaw, and the milling has made it more clear.
You need to take careful measurements to work out what happened.
The odd sized domes will lead to inconsistent compression ratio and the difference in squish may effect the smoothness of the engine.
Mart.

Bored&Stroked · 11-17-2021, 06:46 AM

Whomever did the work, didn't know how to setup these heads in their machine . . . or didn't know how to use the machine, or both. Post some pics so we can get the jest of how far off it is. Depending on the heads and application (piston height), you may not be able to mill them more. Hopefully the dome cut-outs are not already too small and the heads too thin.

I've seen a ton of older aluminum heads that have had the Hell milled out of them. The first issue is that the deck surfaces become too thin (making sealing an issue). The second issue is that the heads may need to be re-domed (not a cheap operation).

Pics will give us something to ponder . . .

tubman · 11-17-2021, 09:37 AM

And, as insurance, start looking for a replacement head. I had to have a head angle milled (front to back) to match a incorrectly decked block. I took .039" more off of one end, and the while the "circle of the dome" was progressively smaller, it was not that noticeable. It sounds like yours could be off even more than that.

JWL · 11-17-2021, 11:28 AM

It is likely the head was "warped" when the machinist tried to set it up. Most used iron heads are low in the center when fixtured under the mill cutter or grinding wheel. Some much worse than others. I straightened those with serious warpage before milling in order to retain reasonably equal chamber sizes. The end chambers can become considerably smaller, if not starting with a flat gasket face, by the time cleanup is achieved.

Cameron Koehn · 11-17-2021, 03:10 PM

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Desoto291Hemi · 11-17-2021, 03:23 PM

You might consider using a depth mic on the valve pockets and see if the settings are close .
There is a possibility that the original chambers were mis machined above the piston .
After all,,,,,even back then,,,,,all things were not perfect when new .
Machine settings could have been off,,,,or someone was having a bad day,,,,,or even training a new guy .
Check it and see for sure .

Tommy

Ronnieroadster · 11-17-2021, 03:56 PM

The machine shop completely ruined those heads.

Jack E/NJ · 11-17-2021, 04:05 PM

Parallel to spark plug holes.

Bored&Stroked · 11-17-2021, 04:45 PM

A complete mess . . . they're really not usable at this point. I'd be looking for another set of heads and a different machine shop. They've been way over-milled on one end - there is no way to "bring the material back".

cadillac512 · 11-17-2021, 06:55 PM

Ouch! Just asked for a cleaned up surface and that's what you got??? Wow...somebody needs a kick in the butt. Those heads are door stops now.
A little time spent setting up the cut would have prevented this...what a shame.

Jack E/NJ · 11-17-2021, 07:20 PM

CK>>>I had someone shave my EAB heads just for a better sealing surface>>>

Do you perhaps have a 'before' pix?

chain drive · 11-17-2021, 07:54 PM

that guy was a half of a bubble off and so is the machine

Jack E/NJ · 11-17-2021, 08:11 PM

If it were mine, I'd prolly tell the shop to tilt the machine the other way and shave the heads again FOR FREE so all the domes match like they're supposed. And smooth out the dome edges FOR FREE too while they're at it! Then figger out how to provide enough headroom to avoid piston & valve contact.Think of the compression this might make from this mistake! 8^)

Cameron Koehn · 11-17-2021, 09:09 PM

Well after some more extensive measuring, the head was warped and the machinist took all the warpage off one side. To make myself feel better, I'm telling myself that it was warped beyond repair to start with. Maybe that's not true. And, yes, I will be using someone else in the future. Vintage Hot Rods from Chico, CA, I will try them.

I almost cried when I tried to find the "before" pictures of the heads and realized that somehow I never took any. Took lots of pictures, but none of this.

Okay! I'm on the lookout for some good stock EAB heads. I do have a set of 8BA heads, but they are corroded pretty badly and i think they are slightly less compression, correct?

Jack E/NJ · 11-17-2021, 09:31 PM

CK>>>the machinist took all the warpage off one side. To make myself feel better, I'm telling myself>>>

You're obviosuly a nice guy CK. I'm prolly not as nice as you. But if it were mine, I'd still tell my machinist to try to make all the domes the same size and edges smooth FOR FREE to make myself feel better.

As for corroded or pitted heads, I've used JBWeld to fill the pits if heads aren't warped. Smooth the cured epoxy with ScotchBrite pads. Seals fine with well-greased head gaskets. The other option is to give your machinist another chance on a light shave job to make the pits small and shallow enough to be inconsequential---FOR FREE again.

Bored&Stroked · 11-17-2021, 09:59 PM

When you go to Vintage Hotrod in Chico . . . make sure you say "Hi!" to my good friend John Beck (he's the one who will probably do the work on your heads).

He has helped us dyno tune the FlatCAD Bonneville engine (at his facilities) - really knows his stuff and is a heck of a solid dude.

rotorwrench · 11-18-2021, 09:45 AM

They may have been milled before too. I always look at the bottom of the thermostat housing area when judging used 8BA family heads. If there is a good step between the bottom surface of the stat housing area and the head deck parting surface then the heads may still be a standard dimension. When you see one that is flush or even milled like those then you know it went too far. The dome areas and valve recess areas can be opened a little bit with machine work but that just makes the casting thinner there and can lead to heat cracking.

deuce_roadster · 11-18-2021, 10:56 AM

Good for you noticing that they ruined your heads before you installed them and created even more problems. Never go back to that machine shop unless you think they will buy you another pair of heads.

11-17-2021, 02:30 AM	#1
Cameron Koehn Member Join Date: Oct 2021 Location: Willows, CA (rural) Posts: 58	Uneven Head Dome Sizes So...I had someone shave my EAB heads just for a better sealing surface. They came back with that circle of dome progressively smaller towards the back of the head. I'll get a picture tomorrow. Is this something to be concerned about? __________________ Flathead Flatfender Last edited by Cameron Koehn; 11-17-2021 at 03:01 AM.

11-17-2021, 05:31 AM	#2
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,754	Re: Uneven Head Dome Sizes It sounds like they milled it at an angle. Not good. If the smallest still gives enough clearance, it could be re-milled to equal them up. It might be a casting flaw, and the milling has made it more clear. You need to take careful measurements to work out what happened. The odd sized domes will lead to inconsistent compression ratio and the difference in squish may effect the smoothness of the engine. Mart.

11-17-2021, 06:46 AM	#3
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,067	Re: Uneven Head Dome Sizes Whomever did the work, didn't know how to setup these heads in their machine . . . or didn't know how to use the machine, or both. Post some pics so we can get the jest of how far off it is. Depending on the heads and application (piston height), you may not be able to mill them more. Hopefully the dome cut-outs are not already too small and the heads too thin. I've seen a ton of older aluminum heads that have had the Hell milled out of them. The first issue is that the deck surfaces become too thin (making sealing an issue). The second issue is that the heads may need to be re-domed (not a cheap operation). Pics will give us something to ponder . . .

11-17-2021, 09:37 AM	#4
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: Uneven Head Dome Sizes And, as insurance, start looking for a replacement head. I had to have a head angle milled (front to back) to match a incorrectly decked block. I took .039" more off of one end, and the while the "circle of the dome" was progressively smaller, it was not that noticeable. It sounds like yours could be off even more than that.

11-17-2021, 11:28 AM	#5
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Uneven Head Dome Sizes It is likely the head was "warped" when the machinist tried to set it up. Most used iron heads are low in the center when fixtured under the mill cutter or grinding wheel. Some much worse than others. I straightened those with serious warpage before milling in order to retain reasonably equal chamber sizes. The end chambers can become considerably smaller, if not starting with a flat gasket face, by the time cleanup is achieved.

11-17-2021, 03:10 PM	#6
Cameron Koehn Member Join Date: Oct 2021 Location: Willows, CA (rural) Posts: 58	Re: Uneven Head Dome Sizes Sponsored Links (Register now to hide all advertisements) IMG_20211117_102424177.jpg IMG_20211117_102428552.jpg IMG_20211117_102433794.jpg IMG_20211117_102439985.jpg IMG_20211117_102757008.jpg IMG_20211117_102808905.jpg __________________ Flathead Flatfender

11-17-2021, 03:23 PM	#7
Desoto291Hemi Senior Member Join Date: Oct 2019 Location: Carthage , Tennessee Posts: 199	Re: Uneven Head Dome Sizes You might consider using a depth mic on the valve pockets and see if the settings are close . There is a possibility that the original chambers were mis machined above the piston . After all,,,,,even back then,,,,,all things were not perfect when new . Machine settings could have been off,,,,or someone was having a bad day,,,,,or even training a new guy . Check it and see for sure . Tommy

11-17-2021, 03:56 PM	#8
Ronnieroadster Senior Member Join Date: Dec 2010 Location: East Coast in CT Posts: 1,529	Re: Uneven Head Dome Sizes The machine shop completely ruined those heads. __________________ I use the F word a lot no not that word these words Flathead , Focus and Finish. "Life Member of the Bonneville 200 MPH Club using a Ford Flathead block" Owner , Builder, Driver of the First Ford Flathead bodied roadster to run 200 MPH Record July 13, 2018 LTA timing association 200.921 in one and a half miles burning gasoline. First ever gas burning Ford flathead powered roadster to run 200 MPH at Bonneville Salt Flats setting the record August 7th 2021 at 205.744 MPH

11-17-2021, 04:45 PM	#10
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,067	Re: Uneven Head Dome Sizes A complete mess . . . they're really not usable at this point. I'd be looking for another set of heads and a different machine shop. They've been way over-milled on one end - there is no way to "bring the material back".

11-17-2021, 06:55 PM	#11
cadillac512 Senior Member Join Date: Apr 2019 Location: Kansas Posts: 921	Re: Uneven Head Dome Sizes Ouch! Just asked for a cleaned up surface and that's what you got??? Wow...somebody needs a kick in the butt. Those heads are door stops now. A little time spent setting up the cut would have prevented this...what a shame. __________________ "It don't take but country smarts to solve the problem" (Smokey Yunick) '41 Merc Town Sedan / 260" 8CM engine '66 Fairlane four door / "warmed up" 302

11-17-2021, 07:20 PM	#12
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Uneven Head Dome Sizes CK>>>I had someone shave my EAB heads just for a better sealing surface>>> Do you perhaps have a 'before' pix?

11-17-2021, 07:54 PM	#13
chain drive Member Join Date: Oct 2020 Posts: 73	Re: Uneven Head Dome Sizes that guy was a half of a bubble off and so is the machine

11-17-2021, 08:11 PM	#14
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Uneven Head Dome Sizes If it were mine, I'd prolly tell the shop to tilt the machine the other way and shave the heads again FOR FREE so all the domes match like they're supposed. And smooth out the dome edges FOR FREE too while they're at it! Then figger out how to provide enough headroom to avoid piston & valve contact.Think of the compression this might make from this mistake! 8^)

11-17-2021, 09:09 PM	#15
Cameron Koehn Member Join Date: Oct 2021 Location: Willows, CA (rural) Posts: 58	Re: Uneven Head Dome Sizes Well after some more extensive measuring, the head was warped and the machinist took all the warpage off one side. To make myself feel better, I'm telling myself that it was warped beyond repair to start with. Maybe that's not true. And, yes, I will be using someone else in the future. Vintage Hot Rods from Chico, CA, I will try them. I almost cried when I tried to find the "before" pictures of the heads and realized that somehow I never took any. Took lots of pictures, but none of this. Okay! I'm on the lookout for some good stock EAB heads. I do have a set of 8BA heads, but they are corroded pretty badly and i think they are slightly less compression, correct? __________________ Flathead Flatfender

11-17-2021, 09:31 PM	#16
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Uneven Head Dome Sizes CK>>>the machinist took all the warpage off one side. To make myself feel better, I'm telling myself>>> You're obviosuly a nice guy CK. I'm prolly not as nice as you. But if it were mine, I'd still tell my machinist to try to make all the domes the same size and edges smooth FOR FREE to make myself feel better. As for corroded or pitted heads, I've used JBWeld to fill the pits if heads aren't warped. Smooth the cured epoxy with ScotchBrite pads. Seals fine with well-greased head gaskets. The other option is to give your machinist another chance on a light shave job to make the pits small and shallow enough to be inconsequential---FOR FREE again.

11-17-2021, 09:59 PM	#17
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,067	Re: Uneven Head Dome Sizes When you go to Vintage Hotrod in Chico . . . make sure you say "Hi!" to my good friend John Beck (he's the one who will probably do the work on your heads). He has helped us dyno tune the FlatCAD Bonneville engine (at his facilities) - really knows his stuff and is a heck of a solid dude.

11-18-2021, 09:45 AM	#18
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: Uneven Head Dome Sizes They may have been milled before too. I always look at the bottom of the thermostat housing area when judging used 8BA family heads. If there is a good step between the bottom surface of the stat housing area and the head deck parting surface then the heads may still be a standard dimension. When you see one that is flush or even milled like those then you know it went too far. The dome areas and valve recess areas can be opened a little bit with machine work but that just makes the casting thinner there and can lead to heat cracking.

11-18-2021, 10:56 AM	#19
deuce_roadster Senior Member Join Date: Oct 2011 Location: Shelton, WA Posts: 3,800	Re: Uneven Head Dome Sizes Good for you noticing that they ruined your heads before you installed them and created even more problems. Never go back to that machine shop unless you think they will buy you another pair of heads.