66 461 Press In Stud Question

[Clem Z.]

get a screw in stud without the hex

and just tap the head for 7/16"-14 and screw in the stud. most auto parts can get you a singles hexless screw in stud.

[Craig S.]

Re: 66 461 Press In Stud Question

Hi JR - good to talk again! I have been buried with work at IBM lateley and hardly had the time to even read any posts here or on Vetteheads. But I am on vacation for a few days

I agree on the screw in studs....I was just trying to be sensitive to Dave trying to minimize tear up. Personally, I really dislike press in studs. And I do have concern other studs may not be far away......maybe yanking the heads is the best approach for peace of mind. I never have confidence in others rebuilding work, so like you say, unless you did it yourself.........

I have a favorite machine shop here that I trust implicitly and maybe this would be a good time to freshen up the heads. From what I can see, the valve springs and retainers were redone, can't tell if the valves are new or just reground.

Sorry to say I won't be at NCRS in Old Town in a couple weeks Craig

[Craig S.]

Re: 66 461 Press In Stud Question

Joe - thx for your comments and I agree.....I personally like screw in studs. Maybe pinning is fine too, but my choice would be screw in I guess. I will talk to Dave, I am willing to help him pull the heads. I have a favorite machine shop here anyway I use for all my engine work. The peace of mind is important, and I worry about the other studs also if one came loose at just 4000 rpm. Take care!......Craig

[Craig S.]

Re: Duke and cam dynamics

Mike - thx for the input. This is exactly why I don't like second guessing someone elses rebuilds. We really don't know what cam or springs are in it, but I know the springs and reatainers aren't GM from the design and appearance. However, they may match the cam mfgr specs and grind, who knows. They do look new though.

My worry was if the rebuilder left the studs alone from the original past builds and there had been past abuse with valve float.....this may have exacerbaated the current problem. To me, 4000rpm is nothing at all, it should easily twist to 5500 on an L79. Makes me worry about the rest.....

Thx for the thoughts......Craig

[Craig S.]

Re: if a exhaust rocker fails

Clem - that makes sense! I appreciate the input. We probably should check for bent pushrods too....and check the lobe height on the cam with a dial guage. Maybe a lobe went away due to improper break in......Craig

[Craig S.]

Re: get a screw in stud without the hex

Thx again Clem and also Rob. I guess the real question is if we want to try and do an on car repair or just bite the bullet and take the heads off. I would guess what Rob mentions would not spot face the boss like a machine shop would do, rather, would be a hexless style like you mention...Craig

[Craig S.]

Re: 66 461 Press In Stud Question

Thx Rob - I may search for the restorer article....but if we do pull the heads, they will go to my favorite local machinist at get spot facing of the bosses and screw in studs across the board....thx!......Craig

This is all making me think I should pull the heads on my 67 L79 and do the same..... Craig

[Michael H.]

Re: Duke and cam dynamics

Craig,

I agree, it's beginning to sound like someone else (a previous owner) has had this problem on #5 cyl in the past and just pounded the original stud back in place. JR has the right idea. Screw in studs would be best.

If I remember correctly, several, or all, of the stud holes go directly through into water so it would be best to remove the heads for this operation to avoid getting metal chips into the cooling system.

[Clem Z.]

metal chips in the water jacket can be

prevented by just greasing the tap. make sure you drain the rad first to prevent a suprise.

[Craig S.]

Re: metal chips in the water jacket can be

Thx Mike and Clem - I didn't realize the studs were wet on the back (again, used to the boat anchor engine rebuilds). The grease method sounds like a plan, to avoid removing the heads. The heads are sealing well to the block now, no leaks etc. I think if we tap slowly, with grease in the chip clearance flutes in the tap, coulpled with removing and cleaning the tap multiple times in the process, it should be fine. Cast iron generates small fractured chips anyway, so this should work if we are careful. The hexless studs would work fine, but I was also wondering about using a boss fly cutter with a guide pin in the stud hole to spot face each boss to a smooth area to mount the hex style studs. I thought I saw one of these in the Goodson catalog somewhere, I will check. Thx again guys!.......Craig

[Craig S.]

Spot Facer that can be used with head on engine

This is the facer I remembered in Goodson....looks like it pilots off the hole and you can use it with the head on the engine. Then you could use the hex type studs to boot.....Craig




Stud Boss Facer from Goodson Machine Shop Supply

[Clem Z.]

chips in the water jacket

is not a big deal as they just fall to the bottom of the water jacket.

[Craig S.]

Re: chips in the water jacket

Thx again Clem for all your help!!!!!! Craig

[Clem Z.]

Re: Spot Facer that can be used with head on engin

i have one of those also but you will have a mess trying to clean up the chips because they fly everywhere and they work best in a drill press because you have to cut a lot of cast iron to get down to where you need to be.i do not think it would be a good idea to use it on the engine with a hand power drill. i have a set of 23 degree holders that bolt to the head to use it in a drill press

[Craig S.]

Re: Spot Facer that can be used with head on engin

Clem - thx for the input....it would be a snap on my Bridgeport knee mill I realize there would be a bunch of chips, but I was thinking of using a small cardboard tube around the cutter to contain the chips around the boss, and vacuuming frequently. Also plugging the drainback holes etc, and judicious clean up with brake clean. Since I am a shadetree machinist, I get all excited about cutting metal Craig