I would like to report that the intake fits perfect, but cant.  It does fit OK.  No problem threading bolts.  It is a little low, with center of threaded head holes a little above center of the intake holes after compressing gasket.  It will make another cut on the heads easily done at some future time.  At least most all of the interference between the Blue thunder and the DS rear of the valve cover is gone.  The milling took all of the top intake flange of the heads off, even a very little from the skirt forming the base of the valve cover.  .045 may be getting close to max.

At maximum lobe lift the valve/piston clearance was way more than adequate. 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

What I do is to get the threaded holes in the head aligned just below center of the holes in the intake.  This way, as the intake is tightened and the gaskets compress the holes should center with each other.


Lawrenceville, GA

I'll let you all know how this comes out.  Heads are due tomorrow or the next.  Ended up having them take .045 off of intake side, nothing on deck side.  Are there any suggestions on how to determine port match?  I planned on just bolting up the intake with intake gasket and seeing if an imprint could be determined.

FYI, since questions regarding cost of machine work often arise.  The charge for intake mill, and chem dip is $70 here, with bare heads arriving at the shop.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Frank,

Not trying to be a smart a*@ or nothing but I think you meant the intake face is 75 degrees from from the head deck face, not 15 degrees.

With the block decks being 90 degrees from each other and the Head to intake face 90 degrees, this would be a perfect 1 to 1 ratio. If the intake was 45* to the head deck, this would be a 2 to 1 ratio (whatever you take off the head or deck you would need to double it at the intake.) If the intake surface was at 22.5* from a 90* which would actually be 67.5* to the deck of the head, this would be a 1.5 to 1 ratio. (whatever at the head or deck and 1.5 times that at the intake.) again divided in half to assume the intake is at 11.25* from 90* gives us 78.75*, this would be a 1.25 to 1 ratio.

So if the Y block intake is at 75* to the deck it would be around a 1.3 to 1 ratio assuming the block decks are a 90* V8, if the block decks are not 90* apart from each other then it changes the whole scenario.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Mike,

     All the theory in the world won't replace the fact that John's answer works. I based the first answer on the port faces being 90 degrees to the deck, They're not. They are at 15 degrees.

      When you mill a head with 90 degree ports, the distance between the heads or any point on the port face closes up at the rate of 1.42 x what is milled. Since there's two faces you'd take off half from each side. When you throw the extra 15 degrees in to the mix you have remove the height of that triangle into the numbers. Sit down with a piece of paper and trace how things move, and it'll start to make sense. I'm supposed to be an engineer and it took me about an hour to understand what happened. Your answer will work, John's answer will work a little better. Remember he's built about a 100 of these things, so he knows what works.

        For 90 degree faces, you have a right triangle, the distance between the heads being the Hypotenuse. C is the hypot, a and b are the other sides. When you mill the heads or the deck you reduce the adjacent sides. Formula is C= Square root of  A squared plus B squared.

   

Frank/Rebop

Bristol, In ( by Elkhart) 

As you can tell from all the foregoing posts, I am no expert here by a long shot.  This is how I figured the angle vs. the related calculation of head milling vs. intake milling.  I put a head on a horizontal, level surface, and placed and angle gauge up against the intake flange.  The anlge gauge said 75 degrees, so I took that to mean 15 degrees in relation to the heads as stated in the diagram, thus 1.4.  My trig. left a long time ago so cant go too much further on the angles and ratios.

Given all the experience presented in this thread, against the Hastings info., my current plan is to split the difference between the calculation and John and Frank's recommendation.  .033 vs. .046 comes out to .040.

Mike 

 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Mike,

I am a little confused as to how they came up with these figures, for one surface "B" is not at a 10* angle to surface "A". it may be at 80* which would be 10* from a right angle of 90*

I agree the angle has to be ratioed out. for example: a dial indicator at a 45* angle is reading twice the actual reading. so at a 45* angle the ratio would be 2 to 1 (head milling being the 1 and intake milling being the 2)

I am missing something here about how they are coming up with these formulas based on their angles?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

This is the Hastings reference that I made earlier:  http://hastingsmanufacturing.com/ServiceTips/how_to_grind_v8_ohv_heads.htm

Mike

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Frank,

I have been thinking more on this too.  All of the head milling has been done on my watch.  They had .025 taken off two years ago.  When I started the post my plan was to take .003 more, and then like I said, when I was at the shop decided to take .005 which would have equaled a total of .030.  Gary's warning on valve interference has sunk in, and I am going to call the shop Mon. can tell them not to take any further off the deck side of head, so it will stay at .025.

However, I am not sure the block deck hasnt been milled by a previous owner.

So, as I understand you and John's thinking, there is .053 milled (.025 head and .028 deck), .020 extra gasket thickness, net loss of .033, and .033 to be taken from intake side of head?

Mike

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Mike,

       John and I thrashed this out off line. Seems to me the right answer is whatever you take off the face of the head is what you take off the port face. Only make sure that the head gasket is the same thickness as what you started with. .030 = .030 per head

     He's closer to right than I am. Also, are you sure the heads haven't been milled before? 

    

Frank/Rebop

Bristol, In ( by Elkhart)