Paul F

iTrader: (2)

You always use an oversized cutter when doing the reliefs so I don't see a problem unless the pockets aren't deep enough. We've only used the Isky cutter here in the shop with NO problems with the radius around the valve.

Fireball

iTrader: (21)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Paul @ Thunder:
<strong> You always use an oversized cutter when doing the reliefs so I don't see a problem unless the pockets aren't deep enough. We've only used the Isky cutter here in the shop with NO problems with the radius around the valve. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You all must use some magic. I did exactly the same (oversize cutter) and it don't work. (I followed the advice Geoff gave me when HE sold me the tool for my 2.02 valves). I even tried again (with the damaged pistons) and it barely even makes it to the point where the valve hit. There's nothing difficult here..its basic geometry...if the piston can't come to TDC with the head bolted down like it should be..then the cutter is NOT on the right location on the piston

I hope some of you are SURE you aren't having problems. Don't THINK you are not having problems just becuase the motor is running ok <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

Funny thing was I never knew I had a problem...car ran good (440 RWHP + 124 mph traps) despite having 5 bent intake valves.

Paul F

iTrader: (2)

Like I said we've used that same tool many times with no problems. The pistons were cut with that tool in my old solid roller motor. That motor had ~.100 clearance and was reclayed after cutting and had plenty of radius clearance with 2.02 valves. The pistons and valves were in perfect condition when we tore the motor down after several missed shifts and lots of times off the rev limiter.

Granted having a head with no seat would be the best way to do it for sure.


Paul

Fireball

iTrader: (21)

what size cutter did you use? I measured mine at 2.060

Beeler422

iTrader: (3)

I have LS6 heads. If I was to use a bare head to do this, (not my current heads) could I use an LS1 head or would it have to be an LS6 head?

Beeler422

iTrader: (3)

ttt

Fireball

iTrader: (21)

My modified too works well...the cutter is pretty much flush with the head deck and allows the piston to be at TDC. Cool part is that it actually cut the piston where the valve hit <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

so I went ahead and pulled all the pistons and will reassemble with fresh slugs from valvegod (when they arrive) remeasure clearance and recut.

Beeler, IMO unless you use a way oversize cutter I would want to do them with the heads I was running...if your ported heads are milled and you use stock heads to cut its like having the piston lowered slightly in the bore so the valve-to-piston contact area will be in a different location (see my reasoning in my first post). Using a way oversize cutter (at least 2 sizes bigger) will cut a larger area that probably will compensate. but the cuts will result in larger reliefs and an increased loss in compression ratio. Besides your pistons probably already have sizable reliefs since they are forged aftermarket units...

LS1derfull

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Fireball:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Paul @ Thunder:
<strong> You always use an oversized cutter when doing the reliefs so I don't see a problem unless the pockets aren't deep enough. We've only used the Isky cutter here in the shop with NO problems with the radius around the valve. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You all must use some magic. I did exactly the same (oversize cutter) and it don't work. (I followed the advice Geoff gave me when HE sold me the tool for my 2.02 valves). I even tried again (with the damaged pistons) and it barely even makes it to the point where the valve hit. There's nothing difficult here..its basic geometry...if the piston can't come to TDC with the head bolted down like it should be..then the cutter is NOT on the right location on the piston

I hope some of you are SURE you aren't having problems. Don't THINK you are not having problems just becuase the motor is running ok <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

Funny thing was I never knew I had a problem...car ran good (440 RWHP + 124 mph traps) despite having 5 bent intake valves. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">440 rwhp and 124mph with 5 bent valves!!?? Maybe 5 bent valves is a speed secret?? !! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Beeler422

iTrader: (3)

Thanks Brian, I'll take the heads off to see if they already have reliefs or not.

Fireball

iTrader: (21)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong> 440 rwhp and 124mph with 5 bent valves!!?? Maybe 5 bent valves is a speed secret?? !! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm just reporting what I found...since it was a clearance issue...it had a high probability of doing it first time I went over 6K rpm...

They weren't majorly bent...the car ran fine, started fine...but there was exhaust contamination in the intake ports...so they weren't really sealing great <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />