Measuring Valve Cover Rail

[1 Wild R/T]

So I'm slowly building an engine for my Coronet... As most of us have fought valve cover leaks this time I'm hoping to reduce the chances of a leak... Lotta guys have talked about the rails not being flat.... I currently have a head in my mill, leveled ( almost, might shim it slightly still) & squared... Tomorrow I might mill the rail but today I measured it.... Thought some of y'all might like to see the results...

First reading. -.012
Second reading .004
Third reading .025
Forth reading .026
Fifth reading -.005

So on the exhaust side of the head which is where they always leak about .040 variation... To be honest I expected more variation.... But I have the technology to make it better so I will...

[IRON MAN]

Very interesting. Evidently the rails are a wee bit low at the center.

[73_Cuda_4_Me]

Hmmmm... I wonder if it were bolted down to the table similar to how it would be on the block how much it would flatten out, if any...???

[1 Wild R/T]

Hmmmm... I wonder if it were bolted down to the table similar to how it would be on the block how much it would flatten out, if any...???

Last time I checked cast iron has little in common with rubber....

Well I milled the first head (cut like butter) & set up the second head... Second head had over .125 variation... Started milling & discovered a couple really hard spots in the casting... Burned up a USA made Do-All HSS end mill.... tried a second USA made Viking carbide end mill & even going slow, using air to cool & taking little bites burned that end mill too.... Decided if I'm just gonna burn up tools I have a Chinese end mill a buddy gave me, he was saying how good they work... Figured I'll burn that up.... Nope... It cut right through the hard stuff.... WTH... A China tool that actually works??? I've heard it happens, never seen it happen before but I have now.... We're screwed...

[73_Cuda_4_Me]

 

Heads never warp?

Honing plates serve no useful purpose?

Blocks never have to be decked?

As a former machinist for a railway maintenance equipment manufacturer, I've seen and dealt with heat shrinkage and distortion in castings.

I wasn't being critical, merely asking a question. Heat shrinkage would affect the head casting lengthwise, which is why I asked.

[1 Wild R/T]

Heads never warp?  Sure they do....  But generally not .040 or in the case of head #2 .125

Honing plates serve no useful purpose?

Blocks never have to be decked?

As a former machinist for a railway maintenance equipment manufacturer, I've seen and dealt with heat shrinkage and distortion in castings.

I wasn't being critical, merely asking a question. Heat shrinkage would affect the head casting lengthwise, which is why I asked.

You have legitimate points but I'm confident that it's a heck of a lot better now as a machined surface than it was before "as cast"  even if when bolted to the block it should pull .005 warpage into the rail it would be far better than before plus it would be spread over the length of the head, head number two had .070 variation over less than 2"....

[73_Cuda_4_Me]

@1 Wild R/T - I am sure you are 1000% correct!

I really appreciate your sharing your skills, efforts, and photos, as I am sure everyone else does as well. That is what makes this site so amazing.

   

[1 Wild R/T]

Since the rail is angled in relation to the head gasket surface I needed a way to tilt the head, If I had enough screw jacks maybe I could done something with them, but I do have a tilting rotary table so I mounted & squared the rotary table to the mill table, bolted the head to the rotary table & squared the valve cover rail to the mill table... I made sure to lock the rotation & angle adjustments down... All in all I think it worked pretty well.... I've been at my buddies automotive machine shop when he was cutting intake surface which requires angling the head surface, he used an adjustable angle plate that's 12" long so honestly not allot more support than my 10" rotary table...

[73_Cuda_4_Me]

 

Would love to see pix of how they turned out!

[1 Wild R/T]

Would love to see pix of how they turned out!

[RUNCHARGER]

Looks great. I know you're aware but anyone else double check your vc bolt lengths if doing this.