Just wondering if anyone has a link that shows how to flycut stock pistons? If nothing like that exists, can someone explain the process for me? How involved is it?

TIA

 

I know for sure there is a thread here about that. I don't know of a current website with the info on it. If you search there's a good thread that had photos and all. It must be over a year old by now though. Good luck!

 

It's really not that difficult but I'm not sure what most folks here use to spin the cutter valve with the engine up under the cowl. I'm guessing a good 90 degree drill. Anyways, you basically replace the stock valve with a valve that has a cutter ground into the face of it. You usually run the piston to TDC, install the head with cutter, push down on cutter until it touches top of piston, set tool depth(I use a feeler gauge in between collar and valve guide boss to set my collar which is set screwed to the valve stem), drill until collar touches the top of the valve guide. I've always used a spare head to do this with so I wouldn't mess up the top of the guides or valve seats.

 

http://www.ffhp.net/tech_Isky.htm

 

Thank You!

Just what I needed!

 

welcome
Nino

 

Awesome. I needed that too......you gotta love the wealth of knowledge on here.

 

Any harm in flycutting if you dont need to? Like lets just say that youre cutting it close with P to V but still within spec, would flycutting just give you extra protection or would there be a downside? How far down can you safely notch the stock pistons?

 

You lose alittle compression depending on depth of cut. It also weakens the top of the piston some, also depending on depth of cut. Not a real issue unless you are spraying. Some people say max cut is .100" others say it is .080". I cut mine about .070". Just make sure if you cut the notches yourself to have a guide heads to use. You have to have half a head with a guide and even ground past that to fit the cutter. Another way to measure the cuts is to use a mic and just measure the width of the cut. Obviously the deeper you go the wider the cut gets.

Brandon

 

You cant fit the cutter under the stock heads when you pull them off? Who sells the cutter? (apparently isky)

 

No you cant fit the cutter in stock heads. Its like a 2.15" O.D. So you have to cut out the seat and still grind some more to get it to clear the combustion chamber.

Brandon

 

I think ill put my valve reliefes in the old fashioned way then. 7500 RPM on stock pushrods and valvesprings.

 

We offer a dummy head and flycutter for rent if anyone is interested