New valve seat cutters how to use them ?

[WHEELSONLY]

My exhaust seats go from a 35 45 to a small 60 then to almost 90 would you consider this ruined ?

[skrews]

This is one of my go to exhaust cutters.
http://www.serdi-usa.com/cust/largepic. ... ng/607.jpg

[skrews]

Another.
http://www.serdi-usa.com/cust/largepic. ... ng/644.jpg

[ProPower engines]

My exhaust seats go from a 35 45 to a small 60 then to almost 90 would you consider this ruined ?

If you are referring to the pictured earlier they are not totally ruined but the engine will run with them.It will be a good time to practice seat replacement and do a radius job on the exhaust seats and blend in the undercut nicely to improve the flow a ton compared to the choked bowl you started with.

[WHEELSONLY]

Here is what I have it's pretty steep.. I can't afford to replace seats unfortunately these are not mine and hopefully I don't have to buy these lol..

[needforspeed66gt]

Hey nate where do you see the cracking at ? it would be nice to know where to look..

There was a run of 5.3L heads cast by "Castech" that commonly crack above the headbolt pad under the valve cover, there's an AERA TSB on it. The crack is generally easily visible with tracking from water coming through, these heads are just thrown away.

Here's a post about it... http://dannysengineportal.blogspot.com/ ... stech.html

The other one's are the heavy duty application 6.0L heads which are typically a 317 casting number, these motors are common in fleet applications and are run with crap fuel, I occasionally see them crack directly between the valve seats, never have seen one bad enough that it leaks on the pressure tester, but we either replace the head or pull the seats, do a quick weld repair and replace the seats.

[needforspeed66gt]

Here's what my typical LS valve job looks like on a set of LS3 heads.





On the intake it's a 37.5/45(.040" wide)/60/75 seat cut with a 89% plunge before hand blending.

The exhaust is a .475" radius coming out of a .060" seat, plunged again to 89% before porting.

I cut the factory heads in a similar manner, but don't change the venturi.

[WHEELSONLY]

Is the 89 plunge a 90 degree cut. ?

[needforspeed66gt]

Is the 89 plunge a 90 degree cut. ?

Yes, I use the sunnen adjustable counterbore cutter for installing seats to plunge at 89% - and hand blend or porting is done from that point.

[WHEELSONLY]

Copy that I did the same thing that's how I got the steep angle the is a tiny 75 and 60 below the 45 and I was going to hand blend also but wondering if there is enough room for a radius cut. Also looks like a tiny crack in between the seats in the photo above is that something to be real worried about. ?

[WHEELSONLY]

Here's a photo of the crack

[ProPower engines]

Seems like the next step before you go too much further is pressure test to see if it leaks. Alot of heads with two hard seats installed beside each other will show a surface crack between the seats which often does not amount to a problem but its still worth checking to be sure.

[needforspeed66gt]

Yeah, I generally attribute those cracks to detonation or hot spotting due to a lean condition as I almost always see them in LS heads that came off a heavy duty truck. I've yet to see one of those cracks actually leak, and likely it won't get worse if the running condition that caused it is fixed...but that said, I always either junk the head or pull the seats and weld it up so I've never tested that theory.