A429 Clipping Valves

I have a set of A429 cylinder heads that were used on a 502 cu. in. engine built 9 years ago. The A429 heads have serial numbers #74228 and #74216, valve sizes 2.25" and 1.77". Compression 12.5:1, solid roller - 276 / 286 deg.duration @ 0.050"
lift, .741" / .730" valve lift. Crower lifters and Crower rocker arms used.
The heads were taken off last fall - after a leakdown test - air could be heard rushing out a few exhaust valves.
Turns out that some of the valves were touching each other ( at overlap ). Initially there was no indication of valve contact when checking piston to valve clearance - no head gasket and zero lash.
I have heard of valve spacing issues with serial numbers 2000 - 5000.
Has anyone else had issues with valves touching on later A429 heads?

I have since replaced the 2.25" valved with 2.19"

I don't know of any later A429 heads after about #7500 which EVER came from FRPP with anything larger than a 2.200" intake valve but, mistakes have been known to be made...
IF there is at least .045" between the valves when they are on the seat there is usually no contact between them unless there is more than normal valve guide clearance.

Yup, whoever installed the valves violated the 4 inch rule. BT,DT. Problem has nothing to do with valve to piston clearance. The only way that I know of, to check for clipping, is to assemble the engine WITHOUT pistons, rods, oil pump and pan. look up the cylinder(s) while turning the crank and check for clearance between the valves at their closest point. I like to see a MINIMUM of .030-.040 clearance at the tightest point. OR, just abide by the 4 inch rule which states: "The combined diameters of the intake and exhaust valves must not exceed 4 inches".

What Randy and Chuck have told you is correct. The problem was that the fixturing for the valve guide centerlines moved, slipped or whatever. So those heads 2000 through 5000 or so, had a valve clipping issue with the 2.250" intake valves. When Ford realized this, their "fix" was to downsize to the 2.200" intake valve as Randy mentioned. In hindsite, it may have been a better solution to spread the valve centers back out to where they were originally. However, that wasn't the case. So whoever initially did your heads with the 2.250" intake valve, had the same problem again. You have done the right thing by downsizing the intake valve to the 2.190" that you have. Other things that can help, are to sink the valves some, radius the margin to face of the exhaust valve so they look like a lot of the Ferrea valves, and clip the margin to face of the intake valve with a little thin 45* clip. If the engine is assembled, and one still has the problem, they can loosen up the valve lash and that will help some also. It is the duration of the cam that's causing the problem, more than the lift of the cam.

Hope this helps,

Charlie

Many thanks guys - I learned the hard way. I am not sure there were any BBF forums around 10+ years ago.
The Galaxie should be back on the road very soon

I am also changing the pushrods from 3/8 X 0.080 wall to 3/8 X 0.120 wall.
The roller lifters have been changes to Crower Hippo roller lifters. These lifers have two oiling holes paralell to the
roller. My old Crower lifters had a single oiling hole perpendicular to the roller - opposite the oil feed in the lifter gallery.
I would like to know others experience with these new Hippo lifters - does the oil pressure drop? are oil restrictors required in the pushrods?

Thank you Charlie.

The valves I have installed are the Ferrea valves - great looking pieces. The valve face edges are radiused.
I was also hoping that the 92% valve throat diameter would be ok - it was about 89% with the 2.25" valves.
Maybe the low and mid lift flow will go up.

Cheers

Perry

Had the same problem about 11 yrs ago on a set of those heads. Downsized the intake valve and problem was gone. had me frustrated for awhile.