I'm confused on the Isky Tools website. My intake valves are 2.08/1.60. I need a cutter for the intake and one for the exhausts. What are the PNT cutters compared to cuttters only? PNT pilots? All the pics look the same. Valves stems are 8mm. I need to cut 2/200ths int. and 1/750 ex. Can someone direct me to the right tool??????? Thanks David

 

If you're using 2.02 valves you need to cut the reliefs bigger than that. I have the tool and it measures 2.12 on the intake and 1.63 on the exhaust. Remember that the interference point is not at TDC. The intake usually hits nearly 20 degrees ATDC as the valve accellerates to the open position faster than the piston can move away from it. The valve is also moving at an angle , meaning the further down the piston is in the bore, the closer to the cylinder wall the valve moves. So you must notch the piston with the piston down the bore a little and make the notch bigger than the valve to give you adequate room. On the exhaust, the valve is closing as the piston nears TDC. It's probably going to interfere a few degrees BTDC. Again the notch has to be a little larger and pushed to the outboard side by notching the piston a few degrees BTDC. I have a dummy head that I use to make it easier. The tool has an adjustable stop on it. I set the piston at its interference point and set the head on with the tool in place. I let the tool touch the pison and set the stop at .080 above the guide just using a feeler guage( or whatever depth I'm going to cut) I just use my cordless drill and run it down until it hits the stop. Then repeat this for each cylinder.
Unfortunately , I don't have the part # for the tool but that's the size I would use. Hope this helps a little. ANDY

 

Andy, that was the idea, I am going to use the stock LS1 heads (99) for a guide but was told to do it at TDC or I'll hit the wall. My valves are large, 2.08 intake/ 1.60 exhausts. Do you have the tool for that?

The Isky site shows a 1 3/4 cutter(1/750) , which should be exactly what I need for clearance on 1.60 ex. valves. But the intake shows 2 1/8" (2/125), and 2 1/4" (2/250). I need 2/200 clearance on the 2.08 intake valves, and don't want to give up any compression. And I guess the pilot is extra, 5/16" should be my 8mm, right? That totals $257.00 for tools I'll only use once, I sure need a good friend....

David

 

Actually I have the tool in my hand. It is 2.125 on the intake but it's only 1.63 on the exhaust. 1.75 seems too big for the exhaust. If it were mine , I'd send it to you in a minute. I borrowed it from Derek at MMS just today. I wish I could. I don't think you'll be able to do it at TDC anyway. The tool is pretty thick. It sticks down below the deck of the head by about .250 . That's about where I think you should do it anyway. Wish I could help you more. ANDY

 

Boo-Hoo... :sad: When you say you have "The Tool", you mean you have a pilot and 2 cutters, right? I just want to make sure I'm not missing something.

Do you know of anywhere else I can get what I need? I've checked all my buddies at the local shops (Comp Cams, Lunati, etc...)

 

Don't mean to hijack the thread, but is that with the stock bore? I thought no one was using bigger than 2.055 with the stock bore, and some sticking with 2.02", because of valve shrouding unless bore was increased.

Thanks.

 

Yes I have both cutters and the pilot. Sorry.
Miles: The 2.08 valves are not as efficient as they would be on a larger bore , but they do work. Actually , if I were doing a large bore motor I'd jump up to 2.10. I did a cam on a car a couple of weeks ago that had 2.08 valves on a stock bore and it made 430 RWHP so something must be working!

 

Andy, well I did it. Ordered 1 3/4" cutter for 1.60 valves and 2 1/8" for the 2.08 valves, and 5/16" pilot. Now I just hope Isky has them in stock, I'm having them next-day aired. I bet they don't have them. :( Any other sites and can try if they don't?????????? Thanks

David

 

They mak a 1 5/8 " one. I think that would be better for your exhaust valves.

 

Uhhh...like that car would be mine dude, and it works so well I am just looking at the ATI and I have been wondering...do I really need to put that thing on...the evil demon says...what the hell are you thinking of course you need to put that thing on.
Andy clearanced my pistons..took some time though...I think he finished it in a day. I have the 2.08's