Doug G

Mine needed .100 cut on both I/E and heads were shaved .050.

And I think 3Pedals was 6 or 8mm ?

3pedals

iTrader: (3)

I did not need any flycuts for the 227/235 114+4 cam, but when I put in the 650hp/7500rpm cam, I cut .070" flycuts for the intake, and my LY6 had exhaust reliefs on the pistons already.

Doug G

Maybe that was the arbor size or something ? Been a while now

3pedals

iTrader: (3)

Lol, yes I used an 8mm collet on the valve stem to set the depth of my cuts.
Anyway , how close are you to running Doug? Maybe pm me

89gmcs15

iTrader: (7)

I'm curious as to why nobody wants to flycut? If your runnin enough spray or boost to hurt a flycut piston you prolly have some money in your combo, why skimp an not get forged pistons with reliefs? Just seems like everyone wants to avoid flycutting even if that means giving up on power with a lesser cam?

3pedals

iTrader: (3)

I'm guessing guys are either afraid or don't know how to do it without spending money.
All you need is :
1 8mm/ 5/16" collet
Some feeler guages to set cut depth
Some adhesive backed 100 grit sandpaper
A drill
And a bunch of duct tape and time

Doug G

Due to the large valves and their placement, when you fly-cut, it places the cut over the ring land making it thin and prone to breakage when on the juice.
Most of us on a budget re-use the stock pistons.

89gmcs15

iTrader: (7)

I notice when I fly cut (.080) it did get close to the edge. And it wasn't too bad for me to do even bein my first time, I had the pistons out of the engine and off the rod. I made a wrist pin in the lathe that fit perfectly in the piston and allowed a couple thousandths movement of the piston while in the vice. I then set our facing tool to 2.2" and the agile on the vice to match the heads. Tested it on a old lq4 piston I had before I cut the ls2 slugs. It was a learning experience to say the least but only took about a hour once it was setup. I haven't hit the spray yet but I'm hopin they hold a 100/150 shot.

Sales@Tick

iTrader: (3)

Thanks! As others have said it has to do with the relief taking away from the top ring land thickness. Even my aftermarket wiseco's in my turbo engine have the exhaust relief taking away top ring land thickness. With nitrous you need all the ring land depth/thickness you can get.
Just because you did it, and are doing it doesn't mean he can or should.
Exactly it's really not that hard to do especially in a car that isn't a 4th gen F-body that has the engine crammed underneath the cowl.

anheuserbusch08

iTrader: (11)

it will have enough clearance on a dish piston with valve reliefs in them

jgillen91

iTrader: (1)

My cam on my rectangle port 370ci engine is 235/251 @.050 .623/.631 110+4.
Prc. 650. Springs, stock ls7 lifters, rockers. Heads milled. 040.
Runs 10.70's 126mph all motor. Th400 w/brake 4500 stall 4.11 gears. Shifting at 7400rpm

speedtigger

iTrader: (16)

Raceweight?

Sales@Tick

iTrader: (3)

I like those cam specs for that engine.

jgillen91

iTrader: (1)

3300-3400 lbs est. with driver