I'm getting some milled heads and a large cam for my 77. I need to cut the pistons, wondering if anybody had the Isky tool to rent?

Jack

 

Check with Ron or Mike from GMMG ... Vengeance Racing ...If I remember

correctly they have one...

 

How big a hurry ya in? I have one, but it'll be a couple weeks before I'm back in ATL...

 

iight let me start this slowly...

those tools do not do a great job

when u cut a piston u have to rebalance your rotating assembly.. so that means it has to come out anyway..

so then u can use a piston vice and flycut them CORRECTLY insted of the dinky niggerriged tool....

whats the bridge thickness in your particular piston? how much does the piston manufacturer of your brand of pistons recommed the max flycutting is?

why not opt for pistons you wont have to flycut.. custom pistons are cheap now days..

how are u gonna weight match the pistons after flycutting?


there are a TON more questions i have.. BUT thats a start..

 

^^^ very good point(s), all around especially about the engine balance.

Jack, you're going to have this engine screaming sometimes, 6,800 rpm is no joke when each piston weighs just 15-50 grams apart from each other.

I thought that was an extreme lift on the cam, you really should look into a set of custom balanced pistons, or at least weigh and drill the underside of your stock ones (to re-balance) after flycutting.


You can't get around the fact that ls-who has made very good points...

 

OK, i'll pull them out and get them cut by a machine shop.

 

Well i was thinking and i doubt the factory ones were balanced, and will it even matter if the pistons and rods are all the same weight when the crankshaft is not balanced?

 

Good point ive been thinking about doing what jack is doing as well need more info pleez

 

LS1's are internally balanced. "Within GM tolerances "

 

So what would you do firehawk???

 

I wouldn't flycut stock pistons. I'd buy a set of pistons that have the valve reliefs already made into them. Have the whole assembly balanced and build from there.

If I had to use the stock pistons I'd get a cam that didn't require flycutting (not worth it in my opinion), but if there was no way around the cam/stock piston thing, I'd have a machine shop do it right and then re-balance them. ~Joshua

 

if you removed the same amount of material from each piston... technically you should be removing the same weight.. correct? you are not just going to shoot in the dark when using a tool like that...you would use a press that is attached to a blank head and has a dial indicator to be precise...

 

In measurements of grams... jimmy-rigged flycutting leaves room on the table for improvement. For real.