Thread: Bummed Out ! Valve to Piston to Close !

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I'm near the end of a 454 build and (project 454) and was really surprised and disappointed to discover that I only have .015 to .020 clearance between the piston top and intake valve at aprox. 10 degrees ATDC. I am going to put the degree wheel back on and double check my cam timing, but I installed it straght up and it checked out almost exactly to specs. Heres my combo if any one has any suggestions. Stock BLock -.025 on the decks, Stock Crank, Stock Rods, TRW 2465F Pistons I think they had a 25cc dome, .041 Gasket, 049 Heads -.015 with 2.19 Intakes. Pistons are .005 below the deck. Unless I've overlooked somthing, my theory is the combination of the larger valves sitting up higher in the chamber and the milling of the heads and the deck has created the problem. The cam is a Crane with 226/236 degrees duartion @.050, 112 degrees lobe seperation and .534/.553 lift. I never guessed I would have a problem and the worst part is Ive installed and tourqed the heads with new Felpro MLS gaskets ($85.00 each). I think I will have to pull the heads and sink the intake valves. Any other suggestions or help would be appreciated.

How did you determine the v/p clearance? I don't understand why you waited to bolt the heads on with the springs you're going to run to then compress the springs. What did you use to compress them to check the clearance?

if this pistons to valve is rigth. you need to cut the pistons this way to much to sink the valves . and i have had this happen alot on big blocks with stock type big block i mock them up before i balanced them and have i a set up rod stock type honed out just for this so if they are press on type i do not to get them press back off the rods if they need to by fly cut.or you can used the isky fly cuter that will do them on the engine but the head will have to come down the cutter work in the guild hole to hold it at the rigth angle or get one junk intake valve and ex valve and weld tool steel to them and used them to fly cut them .and drive it with a drill where the keeper groves are on them grined to a hex .the drill will hold them better and not screw up the guilds if the drill grabs and spins

Right, don't sink the valves, flycut the pistons.

If the heads are torqued on, how did you get the clearance? I would think you would have needed to get that BEFORE you assembled, to be able to read it. That is unless you have the heads torqued, and you pulled the piston from the bottom?