Has anyone here notched a flat top Silvolite slug - and if so, how deep?

A retailer who sells them have told me that they don't "recommend" notching them - but the supplier (United" claim they are of a suitable thickness)

So I need some personal experiences....

how thick are the pistons?

They can be notched as long as you have at least .150" thickness left. I am going to put a sharpened 1/4" rod in a vise & the support rod for my dial indicator in the vise several inches away & set the dial indicator plunger down on the tip of the sharpened rod, zero it then raise up the plunger & set the piston on the sharpened rod & the plunger down on top of the piston & see how thick the deck is to start with & that's as far as I have gotten with this. I haven't yet found a co that sells a cutter that I can chuck in my drill press & someone welded? several small bars to the bottom face of an old valve & it worked to cut the soft aluminum piston but I dont remember how they did it.

Isky used to rent the tool,might give them a call.

Thanks Bro. I will check their site.

Isky sets a valve notching tool that is shaped like a valve, it has a pilot that passes through the valve guide thereby matching the angle of the cutter to the angle the valve would contact the piston...Basically you asemble the short block, bring the piston you'll be working on to TDC & put the head on with the cutter in place of the valve..Cut the relief then move to the next valve & then the next piston...
Go to the Isky site catalog, look for tools, then notching cutters...

they're for sale no rental...

I'm not as old as you imply,just started very young.Wouldn't suprize me if they stopped renting it,but I haven't considered using that tool in over 20 years.

They are still open at this hour? I thought they were closed for the weekend.

I checked their site & they have cutters for sale but no rentals & for their prices I'm gonna have to figure something out that's cheaper.

I never assume someones site has all the info. I'd call them to confirm before guessing. Thats just me. Hope you find what your looking for. You could modify a valve to do the same job. I would if I can't easily obtain what I need.

I think I am going to weld a small bar of tool steel to a valve do it that way I've been dragging my heels on this deal for too long.

Cool.

I had to notch a set of cast pistons ( sealed power I think) for my 318, enough to clear .526 intake and, .550 exhaust lift, the heads are angle milled so the notch isn't even starting out in the stock location. Been running them like that for a couple of years.

Just some thing to think about.

Thanks JBurch - Ive decided to buy one cast slug and get it checked and test cut...

Then I'll know which combo I will have to go with - a 318/349 with cast slugs or a 318/390 with forged an a new crank.