nitrous Pistons

anyone see a problem with a Pistons top ring land being down .400 on a nitrous engine ?
will it cause any issues

How deep is the valve pocket?
How much nitrous?

that's about the range I shoot for on a nitrous motor depending on "valve pocket depth" that is what will determine the weak spot of the piston.

.320  valve pocket , old Pistons ring land was .350  down and had 1 1/6 top ring on a 4.560 bore .
pistons cracked in the valve pocket at the ring land , Ross says there .117 thick at valve pocket

going 4.600 bore this time , changing ring package to a 1 1/6 top .173 radial back cut AP steel, second ring .043 Napier , with a 3 1/6 standard tension oil ring , or a 3mm 22 pound oil ring from total seal , , and moving the top ring land down to .400

400 shot

This is a loaded answer I know but I would run them..... this is just me I'm sure others will chime in on what they feel is comfortable for them

this engine has 14.1 compression with 190 pounds of cranking compression , Im thinking about lowering the compression to 13.5 and putting more exhaust lobe on the camshaft , this is the 2nd time I've had this piston problem ,, I know it could be the tune , but I don't think so

I had the same problem with the standard diamond piston about .060 thick in the valve pocket and that didn work.diamond said they could make me a heavy nos piston and that fixed the problem.the ring package looks correct,M2 tool steel rings are what most are using these days but buy what you can afford.

Larry T wrote:I had the same problem with the standard diamond piston about .060 thick in the valve pocket and that didn work.diamond said they could make me a heavy nos piston and that fixed the problem.the ring package looks correct,M2 tool steel rings are what most are using these days but buy what you can afford.

how far down did they place the top ring land ?

I am not sure I don't have the piston in my hand how ever I do have the piston part number 94844