What is flycutting?
Thread Starter
11 Second Club
iTrader: (14)
Joined: Nov 2004
Posts: 1,653
Likes: 1
From: Michigan (Macomb or Lansing)
What is flycutting? What is flycutting?
what is involved?
How much does it usually cost? (searched and found this part 400-600$*edit*)
what is involved?
How much does it usually cost? (searched and found this part 400-600$*edit*)
Last edited by pHEnomIC; Sep 16, 2006 at 11:42 PM.
flycutting is notching the pistons so the valves do not collide with them. usually done when an aggressive lift on a cam is involved. i don't see it being 4-600. considering i can have an engine thrown together for 300. what is involved is a shop machining the valve reliefs in the pistons to a larger size to accomodate for larger valves and/or that uber lift i spoke of.
Well the heads have to come off and that is usually a pretty expensive process according to most shops. You have all your gaskets that need to be replaced and shop fee's including anti-freeze and other odds and ends.
What insane cam do you plan on putting in anyway? most of these off the shelf grinds like the G5X1, 2, 3, MS3, MS4, CheaTR, T-Rex....ect do not require flycutting unless you have modified cylinder heads. You have a long way to go if you are worried about getting a cam that is going to be tagging the valves to the pisons. Starting with gears in place of those 3.42's most likely.
What insane cam do you plan on putting in anyway? most of these off the shelf grinds like the G5X1, 2, 3, MS3, MS4, CheaTR, T-Rex....ect do not require flycutting unless you have modified cylinder heads. You have a long way to go if you are worried about getting a cam that is going to be tagging the valves to the pisons. Starting with gears in place of those 3.42's most likely.
I did my own with guidance from Guitsboy while the engine was still in the car. Here's some pics Guitsboy posted of his setup. He made his own cutters and stems out of old valves and an old head with the pockets removed and used sanding disc to do the cutting. You can buy cutters and you can also rent the cutters and an old head from http://www.lgmotorsports.com . You need a good electric drill and a high quality 90* angle drill adapter. It's a real pain in the **** to cut the 2 back passenger cylinders.
http://www.ihearyou.com/~tony/pictures/flycut/
http://www.ihearyou.com/~tony/pictures/flycut/
How deep can you flycut the stock pistons? I mean, how much clearance can I gain? I'd like to flycut mine, then mill the heads to make up for the loss of compression, although it's just slight.
Real deep according to TSP and the following thread. 
.080 to .100 seems to be enough for most applications.
https://ls1tech.com/forums/generation-iii-internal-engine/336108-max-flycut-depth-factory-ls1-piston.html
.080 to .100 seems to be enough for most applications. https://ls1tech.com/forums/generation-iii-internal-engine/336108-max-flycut-depth-factory-ls1-piston.html