mdrew

I've broken four T40 bits trying to get the retention plate off for a cam swap in an LS7. The moron who did the last cam swap must have been a gorilla, in addition to using non-serviceable loctite. I'm hesitant to use too much heat, but it looks like I may have to. The bits are top quality, USA bits too. I spent an hour digging the broken end of one of them out already, don't want to do that again. I've tried using both propane and map gas. I've also tried using an impact tool (the kind you smack with a hammer). The block pulls the heat away pretty quick, but I'm not quite ready to get the rose bud out, as I don't want to get into cam bearing problems. Figured it was worth asking before I get too carried away. Anyone run into this before??

DietCoke

iTrader: (18)

Dremel the heads off. The plate is so thick there will be plenty of material to grab onto with vicegrips once you get the cam plate off. Those bolts are super soft and shitty.

JS01

iTrader: (10)

As a next to last ditch deal I have hammered in the next size up torx bit into the retainer plate bolts and freed the bolts up. I've had a decent success rate removing over-torqued cam retainer bolts from backyard cam swaps this way. Using an impact with this method increases the success also.

mdrew

They are countersunk, so I can't really cut the heads off. These things are in harder than hell.

DietCoke

iTrader: (18)

Yes you can. Just dremel the centers of the heads, and the outside will fall off when you get in deep enough (countersunk). The screws are WAY softer then the plate. I've probably extracted 10-15 screws this way. A medium burr or 5/16 drill bit makes short work of them

mdrew

I was able to use a chisel on one bolt, smacking it loose. The other I ended up drilling out. I used a 1/2" bit to hack the majority of the head off, then I ran a 5/16" in a half inch. I then pried the plate over the remnants of the bolt head. Destroyed the plate, unfortunately. Some people, and this D.B. is a professional tuner who "specializes" in vette engine mods. The pinhead didn't even install the valve springs correctly and I had a whopping 85 pounds of seat.

veee8

iTrader: (40)

They are a special bit called Torx Plus. Notice they are slightly rounded on the corners. GM and ATI use these special little guys.
I have been there several times with previous "tuners" At this point you will likely have to be creative to get them out. Go ahead and pick up new screws and a new plate. Heat from a propane torch or a high powered heat gun will help. A chisel, and or a punch and hammer will get them out if the Torx Plus heads are stripped. The new screws will have the loctite already applied.
Without proper shimming and checking, a lot of LS7's get setup with the wrong spring pressure.