Fly cutting pistons

well it seems i need to fly cut my pistons for the ex. valve and may need to enlarge the one for the in. anybody got a example of where the one for the ex. should go? or know where i can buy the tool for doing them in the block , 1 shop said $300-500 to do it if i bring the pistons in another said bring in short block n round 1000$ , i told him for that i`d buy new pistons , really need flycut lay out for d0ve-c heads , hope someone can please help flat top zero deck

I took my valves out of my head & took an old valve I had & epoxyed some 80 grit to it using the head bolted to the block for a guide & it worked great. I masking taped the whole cylinder up with the piston all the way up so no metal could get in the cylinders.

mustangjeff wrote:I took my valves out of my head & took an old valve I had & epoxyed some 80 grit to it using the head bolted to the block for a guide & it worked great. I masking taped the whole cylinder up with the piston all the way up so no metal could get in the cylinders.

Did the same with mine, except I had an old head to work with.
I used an over sized valve, and made a stop for the valve stem so each cut would be the same depth.
Make sure each piston is top dead center.
Also, stick the hose from a shop vac into the exhaust port when doing the intake and visa-versa, it really helps with the dust.
This works GREAT and saves $$$.
Good Luck!

very good idea ill give it a try i have a old d0ve-A head i can use, now if i can find a junk 1.8in ex and a 2.3 in. intake ill be set , thanks for the input ,greatly appreciated

Isky makes a tool for doing it with the heads on the block. I believe they will rent it to you if you don't want to buy it. Worked well for my buddies Cleveland. Check out valve notching tool on page 17 of this catalog.
http://www.iskycams.com/onlinecatalog.html

512Fairlane wrote:Isky makes a tool for doing it with the heads on the block. I believe they will rent it to you if you don't want to buy it. Worked well for my buddies Cleveland. Check out valve notching tool on page 17 of this catalog.
http://www.iskycams.com/onlinecatalog.html

cant get the page to load , thanks for the info though , ill check again in morn

The sand paper glued to the valve is a lot more forgiving than that tool (cheaper also). I used self stick 80 grit and a 2.40 valve (my intakes are 2.25), and cut the sandpaper with about 1/8" overlap all around the valve. I used a drill to turn the valve.
It took two pieces per cylinder to cut .064 more on the valve relief.
MAKE SURE you tape around the pistons tightly if you are going to leave them in the block, no matter which method you use. I used 2 plys of masking tape.
Make sure you use a stop on the valve stem to make sure they are all the same depth.
It took more time to install and remove the heads than cut the reliefs.

You need to fly cut for exhaust valve clearance on a Big Ford?

DaveMcLain wrote:You need to fly cut for exhaust valve clearance on a Big Ford?

I question that too..... are you sure the cam is installed or ground properly?

the guy that did the valve job on my heads ( own local speed shop) told me with piston at zero deck and 10thous. he took off heads, 600 lift cam i would probably need a relief for ex. and may need to enlarge intake, im not sure? , should i put heads on with out gskt. install solid lifter cam t-chain rockers, put bore scope in plug hole and slooowly rotate and watch??????, just dont want to F anything up , cant afford any mistakes , have built a bunch o chity`s and bop`s but this is my first BBF n im still a greenhorn

I think you should put some clay or silly putty on the piston bolt the head and one set of lifter, pushrods, rockers on without the gasket and rotate it over slowly with a wrench or ratchet. If the valve hit you will feel it if it is bad and if you feel nothing pull the head and check they clay to see how much it is compressed

OR put some clay on the piston, put the head on with the gasket (don't need to torque it all down) and push the valve to the appropriate amout of lift. Pull the head and check the piston the valve clearance.

That's a way to check it, but someone on here might have a better idea.

EDIT-You tree'd me never mind.

You have to do it with the cam while rotating the motor over because at tdc depending on cam timing the valve may not be there yet.

i was going to clay them and talked my self out of it because its not a exact reading, thought about trying to use my dial indicator , i know all bout them bent vlvs i been workin on them darn imports over half my life , maybe i should just clay em and quit worrying so much like i said i just dont want to F nothin up, thanks Erv.

the modeling clay method is the simplest and easiest way to do it. i usually check clearance with an indicator while the degree wheel is attached then just to doulble check myself i put a little clay in and verify

i'd clay it and check but i'll bet you have plenty of v/c.it should'nt even need one on the ex. with that cam.

Unless you have a "domed" piston, the exhaust valve to piston clearance will be plenty with the camshaft you describe.

With the check springs installed, put a cheese-it cracker between the roller rocker and the valve stem. Have valves set at zero lash.
Turn the engine over by hand.
If you have a clearance problem the cheese-it will explode.

A piece of solder placed in the spark plug hole will give a a good indication if properly placed.

Curt wrote:A piece of solder placed in the spark plug hole will give a a good indication if properly placed.

done this many times when pullen the head wouldnt an option.

ribald1 wrote:With the check springs installed, put a cheese-it cracker between the roller rocker and the valve stem. Have valves set at zero lash.
Turn the engine over by hand.
If you have a clearance problem the cheese-it will explode.

That made me laugh! I can see it now with cheese-it crumbs all over the place

ribald1 wrote:With the check springs installed, put a cheese-it cracker between the roller rocker and the valve stem. Have valves set at zero lash.
Turn the engine over by hand.
If you have a clearance problem the cheese-it will explode.

where could i get some of these cheese-it crackers you speak of? should they be fresh?

ribald1 wrote:With the check springs installed, put a cheese-it cracker between the roller rocker and the valve stem. Have valves set at zero lash.
Turn the engine over by hand.
If you have a clearance problem the cheese-it will explode.

Can you please make a video of this method and post it? What Flavor of Cheese-it's is appropriate to use?

dfree383 wrote:

ribald1 wrote:With the check springs installed, put a cheese-it cracker between the roller rocker and the valve stem. Have valves set at zero lash.
Turn the engine over by hand.
If you have a clearance problem the cheese-it will explode.

Can you please make a video of this method and post it? What Flavor of Cheese-it's is appropriate to use?

I'm partial to the white chedder myself, hope it's not the originals. They turn your fingers an ugly chevy orange