warning to those flycutting with the isky tool
Thread Starter
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
warning to those flycutting with the isky tool Unless I'm overlooking something obvious...the tool isn't that great to use with unmodified heads:
If you remove your valve and try to cut reliefs using your stock (or ported) head as a guide the tool will NOT allow the piston to come to TDC for the cut. THis is due to the fact that the cutter head is .250 inches thick and will stick down below the head deck surface. This didn't dawn on me when I cut reliefs and just lowered the piston slightly in the bore to accomodate the cutter.
since the cutter (and valve)is on an angle with respect to the piston, lowering the piston will move the cut to a different place on the piston. the intake valve clearance issue is when the piston is near TDC after the exhaust stroke.
In order to do it right (from what I see) you either need to have a head with the seat cut out so you can recess the tool and allow for cuts at TDC or modify the tool (on a lathe) to allow for it to fit into the seat. I am doing the latter (just cutting some off the back of the cutter to allow it to recess into the valve seat)
When in doubt, reclay after cutting. I just measured that I needed ~.020 more room and cut .020 off the piston and didn't remeasure...the result was 5 bent intake valves. The valves all hit just above where my flycuts were <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />
<img border="0" alt="[angel]" title="" src="graemlins/gr_angel.gif" />
<small>[ April 07, 2003, 08:29 AM: Message edited by: Fireball ]</small>
If you remove your valve and try to cut reliefs using your stock (or ported) head as a guide the tool will NOT allow the piston to come to TDC for the cut. THis is due to the fact that the cutter head is .250 inches thick and will stick down below the head deck surface. This didn't dawn on me when I cut reliefs and just lowered the piston slightly in the bore to accomodate the cutter.
since the cutter (and valve)is on an angle with respect to the piston, lowering the piston will move the cut to a different place on the piston. the intake valve clearance issue is when the piston is near TDC after the exhaust stroke.
In order to do it right (from what I see) you either need to have a head with the seat cut out so you can recess the tool and allow for cuts at TDC or modify the tool (on a lathe) to allow for it to fit into the seat. I am doing the latter (just cutting some off the back of the cutter to allow it to recess into the valve seat)
When in doubt, reclay after cutting. I just measured that I needed ~.020 more room and cut .020 off the piston and didn't remeasure...the result was 5 bent intake valves. The valves all hit just above where my flycuts were <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />
<img border="0" alt="[angel]" title="" src="graemlins/gr_angel.gif" />
<small>[ April 07, 2003, 08:29 AM: Message edited by: Fireball ]</small>
On The Tree
Joined: Feb 2002
Posts: 148
Likes: 0
From: Round Rock, TX USA
Re: warning to those flycutting with the isky tool Damn! Sorry about that. I'm glad you posted on this though. I've been looking at getting the Isky tool and results from those who have used it.
Thanks for the heads up. Let us know how the modified tool comes out.
Thanks,
Kyle
Thanks for the heads up. Let us know how the modified tool comes out.
Thanks,
Kyle
TECH Fanatic
Joined: Dec 2002
Posts: 1,084
Likes: 0
From: Bring it........ b*tch
Re: warning to those flycutting with the isky tool Geez, what good is this flycutting tool if it sits below the deck surface?? Sounds like very poor design work to me. Thanks for giving everyone a heads up on the Isky tool.
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Re: warning to those flycutting with the isky tool Thats very good to know!
Would the same thing happen if you used a larger diameter cutter - like TWO sizes bigger than the valve you are trying to relieve?
...Is it possible to bend valves when you re-measure the cuts or only if you start the motor?
Did you flycut while the block was in the car?
Thanks..
Would the same thing happen if you used a larger diameter cutter - like TWO sizes bigger than the valve you are trying to relieve?
...Is it possible to bend valves when you re-measure the cuts or only if you start the motor?
Did you flycut while the block was in the car?
Thanks..
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Re: warning to those flycutting with the isky tool ...I don't suppose putting a few fat metal washers with a thickness of .250 in between the heads and the block would have helped????
....I assume the cutters did not come with directions...this STINKS!
Did the cutters score/scratch the old valve seats?
Sorry!
....I assume the cutters did not come with directions...this STINKS!
Did the cutters score/scratch the old valve seats?
Sorry!
Thread Starter
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: warning to those flycutting with the isky tool putting washers between the head/block will be the same as lowering the piston in geometry...will result in same problem
The cutter is nowhere near the valve seat and will remain that way once cut to my specs
The cutter is nowhere near the valve seat and will remain that way once cut to my specs
Trending Topics
Thread Starter
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: warning to those flycutting with the isky tool </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by robertbartsch:
<strong> Thats very good to know!
Would the same thing happen if you used a larger diameter cutter - like TWO sizes bigger than the valve you are trying to relieve?
...Is it possible to bend valves when you re-measure the cuts or only if you start the motor?
Did you flycut while the block was in the car?
Thanks.. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">flycut on an engine stand
starting the motor didn't cause it.. revving to ~5K plus caused it. I do use an oversize cutter (1 size bigger than valve size). 2sizes bigger would have resulted in the cutter sticking out yet further necessitating the piston to be lowered further...no help
<strong> Thats very good to know!
Would the same thing happen if you used a larger diameter cutter - like TWO sizes bigger than the valve you are trying to relieve?
...Is it possible to bend valves when you re-measure the cuts or only if you start the motor?
Did you flycut while the block was in the car?
Thanks.. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">flycut on an engine stand
starting the motor didn't cause it.. revving to ~5K plus caused it. I do use an oversize cutter (1 size bigger than valve size). 2sizes bigger would have resulted in the cutter sticking out yet further necessitating the piston to be lowered further...no help
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Re: warning to those flycutting with the isky tool How far does the cutter protrude from the bottom of the head? The reason I ask, is that when discussing this very tool with LG, he told me to bring the piston to TDC, set the head on the block, run the bolts in until snug, and rotate the cutter. He said to keep doing this until the head sat flush with the gasket/ block surface, and then check V/P clearance to see if any more needs to be removed. That technique seems like it would bypass the issue you had. What do you think?
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: warning to those flycutting with the isky tool Judson from SAM used this cutter for his project car and he had 2.055" valves, i thiunk he even went to 2.08" eventually and said cutter worked fine. What size valves did you run Fireball? Was your cutter a 2.06"? We did Slowhawks pistons with 2.06" Tool and 2.02" valves and he has no problems. I know he missed a gear racing me too!
Result: no damage.
Result: no damage.
Re: warning to those flycutting with the isky tool One of the sponsers rents a head (with valve seats removed) and cutting tool for I think $90,when you return the head and tool you get some of your money back.I think it's TEA but not positive.
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: warning to those flycutting with the isky tool </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by felton316:
<strong> If you don't mind me asking, where can this tool be bought at? Right now I have the heads off, and I might try this.... </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Isky cams rents or sells the tools.Phone # is 323-770-0930
<strong> If you don't mind me asking, where can this tool be bought at? Right now I have the heads off, and I might try this.... </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Isky cams rents or sells the tools.Phone # is 323-770-0930
Re: warning to those flycutting with the isky tool </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> Judson from SAM used this cutter for his project car and he had 2.055" valves, i thiunk he even went to 2.08" eventually and said cutter worked fine. What size valves did you run Fireball? Was your cutter a 2.06"? We did Slowhawks pistons with 2.06" Tool and 2.02" valves and he has no problems. I know he missed a gear racing me too!
Result: no damage. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's me <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> My intake valves would of hit by now if they were cut in the wrong position. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
<strong> Judson from SAM used this cutter for his project car and he had 2.055" valves, i thiunk he even went to 2.08" eventually and said cutter worked fine. What size valves did you run Fireball? Was your cutter a 2.06"? We did Slowhawks pistons with 2.06" Tool and 2.02" valves and he has no problems. I know he missed a gear racing me too!
Result: no damage. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's me <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> My intake valves would of hit by now if they were cut in the wrong position. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
TECH Addict
Joined: Nov 2001
Posts: 2,593
Likes: 0
From: TEXAS
Re: warning to those flycutting with the isky tool </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Isky cams rents or sells the tools.Phone # is 323-770-0930
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks, I shall give them a call tomorrow. I'm just a little worried, since I'm about to install larger valves and running the 227/224 cam. Better safe than sorry....
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks, I shall give them a call tomorrow. I'm just a little worried, since I'm about to install larger valves and running the 227/224 cam. Better safe than sorry....
TECH Addict
iTrader: (9)
Joined: Apr 2002
Posts: 2,085
Likes: 0
From: Texas, it's like your state, but better.
Re: warning to those flycutting with the isky tool FB,
why wouldnt isky have notified you of this problem in advance and if not, shouldnt you be entitled for a re-embursment at least if not payment for you're damaged parts? do you think that the lifters pumped up that much at 5k as to bend valves? thats insane! almost like variable valve timing. crazyness...
<small>[ April 07, 2003, 11:39 PM: Message edited by: VentsWoker ]</small>
why wouldnt isky have notified you of this problem in advance and if not, shouldnt you be entitled for a re-embursment at least if not payment for you're damaged parts? do you think that the lifters pumped up that much at 5k as to bend valves? thats insane! almost like variable valve timing. crazyness...
<small>[ April 07, 2003, 11:39 PM: Message edited by: VentsWoker ]</small>
On The Tree
Joined: Jan 2003
Posts: 148
Likes: 0
From: in the air of course!
Re: warning to those flycutting with the isky tool Its not their fault in any way. They supply a tool. nothing more. Its not up to them to make it work on an LS1. Brian simply messed up, besides, how can you cut them, and then not put the head BACK on, and measure PTV <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Thread Starter
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: warning to those flycutting with the isky tool I'm runing 2.02 valves
since the valves are on an angle with respect to the heads...I'm not so sure that keeping the head loose then cutting then tightening down the heads then cutting, etc is great since it won't be cutting where you want to cut. as you tighten down the head, the cutter will cut untouched piston so eventually you will have the same problem as I encountered. besides there are no cutting tines on the side of the tool so it couldn't really account for the lateral motion across the piston as the head is lowered. Just playing around I tried the same thing by tightening down the head and raising the piston into the cutter...it just reaches a point that it binds (because it isn't designed to cut that way)
I'm not blaming anyone but myself...but the tool is definately not intended for use as a cutter on a stock head...need to have the seat cut out to provide room for the cutter. This is what TEA provides if you rent from them from what I read <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
since the valves are on an angle with respect to the heads...I'm not so sure that keeping the head loose then cutting then tightening down the heads then cutting, etc is great since it won't be cutting where you want to cut. as you tighten down the head, the cutter will cut untouched piston so eventually you will have the same problem as I encountered. besides there are no cutting tines on the side of the tool so it couldn't really account for the lateral motion across the piston as the head is lowered. Just playing around I tried the same thing by tightening down the head and raising the piston into the cutter...it just reaches a point that it binds (because it isn't designed to cut that way)
I'm not blaming anyone but myself...but the tool is definately not intended for use as a cutter on a stock head...need to have the seat cut out to provide room for the cutter. This is what TEA provides if you rent from them from what I read <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
TECH Apprentice
Joined: Jan 2002
Posts: 302
Likes: 0
From: olathe, ks
Re: warning to those flycutting with the isky tool </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by felton316:
<strong> If you don't mind me asking, where can this tool be bought at? Right now I have the heads off, and I might try this.... </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have a new and unused one. Intake only, one size over stock sized valves.
<strong> If you don't mind me asking, where can this tool be bought at? Right now I have the heads off, and I might try this.... </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have a new and unused one. Intake only, one size over stock sized valves.
Thread Starter
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: warning to those flycutting with the isky tool Sweet...my tool has been successfully cut down to allow clearance for the piston to come up to TDC.
Shop said it was a PITA to do since its a very hard tool steel <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
Oh well...I double check to see how it works now then I'll replace the pistons with ones I bought from valvegod <img border="0" alt="[worship]" title="" src="graemlins/gr_hail.gif" />
Shop said it was a PITA to do since its a very hard tool steel <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
Oh well...I double check to see how it works now then I'll replace the pistons with ones I bought from valvegod <img border="0" alt="[worship]" title="" src="graemlins/gr_hail.gif" />