I looked at the Hastings website a while back. They have a kind of calculator for figuring the amount to mill intake manifolds. Following the basic instructions, checked the head's intake flange angles, and came up with a 1.4 ratio of intake milling to head milling. In other words, say a net loss of .030 come from head and deck milling, after taking into account extra comp. gasket thickness. Multiply that by 1.4, and intake needs .042 taken off. Can someone verify this as correct or not. The intake goes into the shop next week.

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,

        If the manifold faces were 90 degrees to the heads tha would be 100% correct. On a Y block they're not. You're dealing with a compound angle because the port face is angled. I'm not sure what that angle is. Ted or John can give you the actual number, but I'd start with .030" on the manifold also.    

Frank/Rebop

Bristol, In ( by Elkhart) 

Mike:

Way back in the '50s Hot Rod Magazine had a chart for manifold milling.  1.4 was the number for the Y Block.  I personally mill the manifold side of the head instead of the manifold, that way I can switch manifolds and not have to mill each one.  The heads can be swapped from engine to engine without manifold milling also.

John in Selma, IN

John - "The Hoosier Hurricane"

Hmm. Milling the heads would be better. Now to take them back apart again.

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.

I took the heads off and dissassembled them per Hoosier's suggestion of taking meat of their intake flanges.  There were several things of interest.  The heads and a Felpro comp gasket were torqued to 73 ft. lbs about 1 month ago.  No motor startup.  The torque required on removal was only 55 lbs on some, 60 lbs. on others, and only one held at 70+.   So on the next assembly I will retorque after a week or so. 

The compressed gasket thickness was .044 with a mic.

Quite a few of the intake valves were a mess.  They looked worse than the exhausts on their flutes, like combustion gases were leaking back into the head intake ports.  Heads only had 2000 miles since rebuild.  Maybe the unknown NOS 270 cam required different than stock valve clearances.   Even if so it has been replaced.  

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 meant to add, if you take off .030 from the heads take 020 off the intake faces or half of the .042" you calculated. I'm sure you knew that but reminders dont hurt.

Frank/Rebop

Bristol, In ( by Elkhart) 

46y: Re torque loss, are those old head bolts? Maybe they are heat effected & stretching?

Paul

The original Grade Five head bolts are notorious for stretching.  Switching them out to a Grade Eight bolt should alleviate most if not all of this problem.  Just be sure to use hardened washers under the bolt heads and then insure that the bolts are not bottoming out in the bottom of the head bolt holes.  Making sure that the bolts hand screw into their respective holes to a distance less than the thickness of the head bolt washer is the easiest way to determine that the head bolts are not too long.

Lorena, Texas (South of Waco)

Frank, I was going to have the .042 taken from each head's intake surface.  Yes No?

.028 have been taken off the deck and also .028 milled from the head's deck surface.  How would you make sure the bolts arent bottoming out?

The bolts are from one of the later model truck engines and have markings that look as if they are grade 8.

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:

.042 off each head is correct.  Also, the original Y head bolts have 4 marks, which makes them grade 6.  Why bolt manufacturers didn't make the number of marks match the grade is beyond me.  Anyway, the originals do stretch, no matter the grade they are.

John in Selma, IN

John - "The Hoosier Hurricane"