Azar

iTrader: (13)

Is there a guide or anything on how to take the measurements and how to figure out how deep you need to cut??

I'm really looking at flycutting as my setup may very well need it. My heads were milled .05 and then I will be running a 228/232 cam. I read the Isky how to guide, but I want to know how you figure how big your cuts need to be and what not, can anyone help me?

orangeapeel

iTrader: (18)

I have seen a document showing this around here.

Tri5Nerd

iTrader: (3)

Here you go. I've been thinking about doing this but you'll have to ruin a set of heads to do it right.

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

Xtnct00WS6

iTrader: (8)

You don't really need a spare head with the valve seat taken out do you? Couldn't you just not put the piston exactly at TDC?

Tri5Nerd

iTrader: (3)

Don't know, maybe someone with more experience with doing this can provide some insight.

Azar

iTrader: (13)

Already saw the isky thing...

God, if you can hear me.......HELPPP!

GuitsBoy

iTrader: (4)

Thats a negative, ghostrider. Reason being is that the valve is at a 15 degree angle. With the piston 1/4" down, the cutter will have moved over considerably. when the engine is running and the piston comes up to tdc, the valve will be directly over the uncut portion. Look around for a head that somebody tried porting themselves, but went through a waterjacket. You can probably get one preyyt cheap. If you have access to a lathe, I can write up instructions on how to make your own cutter from a 5/16 bolt, scrap steel and adhesive sandpaper, so that you dont have to buy the isky one for a few hundred bucks.

http://www.ihearyou.com/~tony/pictures/flycut/

-Tony

198c5

i think lg rents the tool to fly cut check with them or other fourm venders sure someone could help u locate a tool.

Xtnct00WS6

iTrader: (8)

Ohhhhh...Had to think about that one for a sec. Damn.

What do you think about getting a piece of metal and make it to the right diameter. Then attach it to the bottom of a spare valve?

Tri5Nerd

iTrader: (3)

That's an idea, how about using the heads you're going to install with a spare valve of the size you want cut, i.e..2.04" then attach adhesive sandpaper, maybe 60 grit and the loose collar? the only problem I see here is that the valve stem might not be long enough to put the loose collar on and you might damage the head where the valve sit.

You would have to be very precise with cutting the sandpaper to match the size of the valve.

GuitsBoy

iTrader: (4)

Well, you usually want to go a bit bigger than the valve. Usually 2.125 / 1.675 cuts. And I would certainly not use a good head to do the cutting if you plan on using the head again.

JRracing

iTrader: (35)

Here is what I did. I called TEA and they loaned me a blank head with no valve seats in it. For tooling purpose. But the cut the valve stem holes to 11/32". I bought a 11/32" pilot tool from Isky cams along with the right size cutters needed for the int/ext.

I used clay on top of the pistons, bolted the head on with the gasket, then rotated the motor a few times. Pulled the head back off. I cut a pie piece out of the clay and measured how thick it was at the shallowest point.
Trust me, a home made tool will not get it done. You WILL end up buying the right tools. The cutter starts cutting on the edge of the tool first. It would wear out the sand paper very quick. The tool is made of a very hard steel.

I was not sure how much to cut at first and ended up cutting deeper than I needed to.
I learned a lot doing this.
I will put up some pics in a sec!

JRracing

iTrader: (35)

I'm selling these tools now that I'm done with them. PM me for a price if you are interested.

GuitsBoy

iTrader: (4)

I take it you didnt bother looking at my pictures then did you? Ill make it easier for you:









This home made cutter has sucessfully cut pistons in 4 engines.

GuitsBoy

iTrader: (4)

By the way, JRacing, It looks like you went way past the recommended .080 max .100 depth for stock pistons. I really hope you didnt compromise the pistons's structural integrity.

JRracing

iTrader: (35)

I did go way to deep on the ext. The int side has .100" clearance. I talked to someone at TSP and they have went as far as I did and it held up for two years before bending a rod. They measured a stock piston for me and it came out to be .320". So I know I'm a little over half way through it. I pray it holds together. I will know in about a month when I start racing.

Sorry guits, I did'nt see your pics of the tool. It looks pretty good. How many grinding disc's do you go through to get an engine done. It seems like it would use them up quickly. What did it cost to make it?

GuitsBoy

iTrader: (4)

No prob, im just the guy who likes to do things at home when people say you cant do it I use one disk for each valve relief. Its a little time consuming having to trim 16 sandpaper disks and pull and restick them on, but atleast theyre cheap.

The 5/16 x 6" bolt was about $1.00, the three nuts were about $.10 each, the collar was just under $2.00 from mcmaster-carr. The steel, i had laying around, but would be pretty cheap anyway. You do however need access to a lathe, and you need a 5/16 tap. Just drill the center hole, tap, thread onto the bolt with the head cut off, stick it in the lathe, and turn it down to the desired diameter. You then need to chamfer the edge even with the valve seats removed. I just ground the edges down with a dremel. The adhesive sandpaper comes in packs of 5 6" sheets for about $3.00.

Altogather it probably cost about 10 bucks and an hour of my time to make. Although you do need a head without valve seats. With a helper peeling and applying the disks, I can flycut a motor in well under an hour.

JRracing

iTrader: (35)

Thats dam smart of you to make that tool. They are very exspensive from Isky to order.
What size cam are you running on that motor and what cc size in the heads?

Galen

iTrader: (3)

Guits Boy, why couldn't you just use a couple of junk valves to do the same thing? I plan on doing this within the week and was planning on just using the valves. If I can't, I would like to know before I have the top end torn off my dd.

Thanks!

Galen

GuitsBoy

iTrader: (4)

Thanks man, im running a comp XE-R 232/234 .595/.598 112 +2. My heads are home ported 241's milled .040. With a GM MLS Gasket, and 1cc reliefs, Im at 10.85:1 compression. The cuts are about .075 deep. I used a nickel to set the depth.