Cylinder head machining questions
#1
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Cylinder head machining questions
I'm going back to machining school soon and I'm looking for advice and guidance on valve jobs.
Where are you machinists placing pointers on the valve and on the cutter for best performance? I've been doing slighty above center of the valve and on the top of the 45 angle
What SEAT angles are you guys using for boosted motors, nitrous motors, NA etc
Tips and tricks you guys want to reveal for LS heads...
thanks
Where are you machinists placing pointers on the valve and on the cutter for best performance? I've been doing slighty above center of the valve and on the top of the 45 angle
What SEAT angles are you guys using for boosted motors, nitrous motors, NA etc
Tips and tricks you guys want to reveal for LS heads...
thanks
#2
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I put the seat cut all the way out to the edge of the valve. I like using a couple 45 degree cutter profiles that every SAM student gets that seem to work really well on the LS/SBF stuff. The top and bottom angles are not too far off the typical 30-45-60, but I have a 75 degree bowl cut under the bottom cut. The seat is only about .040 wide, so on power adder stuff, I might use a cutter with the same angles but a wider seat to help dissipate heat better.
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Okay, are you making a back cut on the intake valve? If so how wide do you leave the primary angle on the valve? I am an NTC student in MN. If you were to change the angles slightly is it a steeper 30 and 60? Also what do you mean by cutter profiles?
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When I make the bottom 30* cut on a traditional 3-angle performance valve job, I'll typically set the dial indicator .015 less than the diameter of the valve.
Once the seat angle is cut, the bottom cut sets the width of the seat and the top angle (60* for example) sets the width of the seat. Which I vary depending on the application.
Once the seat angle is cut, the bottom cut sets the width of the seat and the top angle (60* for example) sets the width of the seat. Which I vary depending on the application.
#6
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On both the intake and exhaust, the top cut should be steeper than 35 degrees. You can look at the spec sheets for a lot of the aftermarket castings online and most of them will be around 36-38 degrees on the top cut. On the intake side, I go steeper than 60 and more shallow on the exhaust. Both get a 75 bowl cut to narrow the bottom cut to about .100" wide.
I don't manually cut each angle. You can purchase cutters with the profile you want built in. Newen, for example, has dozens of cutter profiles available with the top, seat, and bottom angles built in. You can even design your own. Some even have multiple radii for exhaust valvejobs.
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Bringing back this thread with more questions.. What size intake valve can you fit in a 5.3 862 head in regards to no shrouding? 2" possibly? It will be on a 3.898 bore iron block. Also, I'm really interested in these conical valve springs that comp cams offers. Any thoughts/reviews on those?
#11
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Bringing back this thread with more questions.. What size intake valve can you fit in a 5.3 862 head in regards to no shrouding? 2" possibly? It will be on a 3.898 bore iron block. Also, I'm really interested in these conical valve springs that comp cams offers. Any thoughts/reviews on those?
I had the Comp conical springs in my Trans Am. One broke, valve dropped, now I'm replacing engine. Not sure why it broke but I probably wouldn't risk it in this time around with the new engine.
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Thanks. I started in 2005 when I went to SAM but I was lured into the Oil & Gas industry a few years ago. I still help out at a local shop on weekends when I have time.
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Quick question. Looking at pistons and rods for my build.. Im looking at pistons that utilize a 1.313 or 1.314 piston ch but the specify using a 6.125 rod on there specs. Can i use a 6.098 or 6.100 rod with these pistons? If theyre the same pin diameter i dont see an issue. If i use the 6.100 rod with 1.314 it would put me at zero deck
#18
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Quick question. Looking at pistons and rods for my build.. Im looking at pistons that utilize a 1.313 or 1.314 piston ch but the specify using a 6.125 rod on there specs. Can i use a 6.098 or 6.100 rod with these pistons? If theyre the same pin diameter i dont see an issue. If i use the 6.100 rod with 1.314 it would put me at zero deck
On the stock 9.240 deck and a 6.125 rod/stock stroke and 1.314 ch, the piston would be 0.010" out of the hole before squaring the decks.
Obviously the pistons are designed for a stock stroke and will not work with a 4" crank and typical rod lengths.