erikthegoalie

iTrader: (29)

OK here we go

1) Can you flycut pistons while they are in the block, and can you do it yourself with the tool from LG they rent out?

2) When do you HAVE to flycut....is there a tested combo out there where Flycutting is not neccesary, or should you do it on almost ANY h/c swap as a safey measure...

3) If you hav to flycut, how in the hell do you knwo how deep to go and so on....

THANKS
erik

Xtnct00WS6

iTrader: (8)

1. Yes you can flycut the piston while they are in the block and while the engine is in the car.
2. Having to flycut depends on many things like gasket thickness, base circle of the cam, milling of the heads, valve job, valve size (diameter), and valve margin (part that hangs down into the piston). You won't usually have to flycut unless you get aggressive with the cam duration or milling of the heads.
3. By measuring the Piston to Valve clearance. Suggested clearance is .080 on intake and .1 on exhaust. If your below those specs, you should flycut. I just wrote a how to on how to check ptv clearance here:
https://ls1tech.com/forums/showpost....64&postcount=6

erikthegoalie

iTrader: (29)

thanks a lot....ill read up

GuitsBoy

iTrader: (4)

The original guide at FFHP has been removed: http://www.ffhp.net/tech_Isky.htm

Im trying to get a cached copy from archive.org, but its not coming up for me either...

MrDude_1

iTrader: (4)

Xtnct00WS6

iTrader: (8)

Yeah, you're probably right. I don't think that has to do with ptv clearance does it? It was really late when I wrote that

GuitsBoy

iTrader: (4)

Pushrod, valvestem and lifter selection, but probably not P to V. To a very small extent though, lifter roller diameter plays a part since the bigger diameter roller increased duration just a touch.

MrDude_1

iTrader: (4)

nope. but it does change your pushrod length and/or lifter plunger travel

405HP_Z06

iTrader: (11)

I have it in .PDF format but can't post becuase it's too big. If anyone want's it, send me an email and I'll forward. aaronanderson@mac.com

GuitsBoy

iTrader: (4)

How big is it? Ill post it on my server is its not gonna kill my bandwidth... Shoot me an email to tony(a)ihearyou!com.

waterbug1999

iTrader: (3)

I did mine a week or two ago for my set up. I just made some phone calls and got some of the vendors advise. Double and triple checked. I used the LGM tool as well. Actually, it was ALOT easier then I though.

Xtnct00WS6

iTrader: (8)

Thanks for sending the PDF.

405HP_Z06

iTrader: (11)

200kb, really small when your talking file size. Let me know if you want it. It looks like the forum limit is 100kb for .PDF files.

GuitsBoy

iTrader: (4)

Okay, Flycutting guide rehosted:

http://www.ihearyou.com/~tony/pictur...nsIskyTool.pdf

Thanks, 405!

erikthegoalie

iTrader: (29)

Thank you!

erikthegoalie

iTrader: (29)

hey one question what is an ideal amount to flycut...for instance...can you go to much???? Is there a depth you can cut that will clear any set up and wont hurt performance?

THANKS

GuitsBoy

iTrader: (4)

I wouldnt go past .100 to .120 deep on stock pistons. I guess the ideal setup is to go as small as you can, while creating enough clearance for any cam youll be running in the forseeable future. Keep in mind, if you need .020 more p-v clearance, you can not simply cut .020, you have to cut deeper. Since the valve is on an angle, and p-v does not happen exactly at TDC, the valve will not fall directly into the releif, it may touch down on a shallower portion, or part that hasnt even been cut at all...

I started with a .075 deep cut when i notched mine.

erikthegoalie

iTrader: (29)

Did you do any measuring? or did youjust kinda think about it in your head and go with the .075 because it was a safe bet?
What set up are you running...I was thinking about the LG 205 cc AFR's milled to 59cc, and the G5X3, I was told by Bobby at LG that the pistons shoudl be flycut, but then i heard from others with this set up that you dont have to...car wont see track but maybe once and rpms stay lower than 6000 always...its like a weekend cruiser...

what do you think?

GuitsBoy

iTrader: (4)

I didnt measure before hand since i was still waiting on parts and decided to get the flycutting done ASAP. I did measure afterwards and I had better than .150 to .160 clearance. I have a torquer2 112 +2, GM MLS gasket, and stock valved heads milled .040.

Toxic_WS6

I got the isky intake and exhaust cutters off of ebay, and did both, then put head on other side of block. I only had to move cutters 3 times.