674 replies to this topic

[S pack]

Tapping a thread into the cast iron will be easy. You will need to ream the existing 3/8" stud hole out to tap a 7/16" thread for the 7/16" screw in stud as well as you may need to remove the head and have the stud boss machined down to suit.

 

I understand that with the non adjustable rocker heads the bosses have to be machined down to remove the thickness of the hex nut that is built into the screw in studs or the studs will sit too high. Don't know if it's the same deal when fitting screw in studs to an adjustable rocker head.

 

You may also need to change the rocker arm to suit with a 7/16" stud. Hopefully someone else will know more about this.

[madtoranajzedded]

you will need some kind of sealant bud as they go into the water jackets,thats what drag lc has mentioned in an old thread as he changed a stud,id be getting 3/8 screw  in studs put in,take it to a machinists shop and they can do it for you.i got mine done a little while ago at jan n albies,john brookfield put em in for me for i think it was 220 bucks,probably double that now but worth the peace of mind..i put s/t rollers on with pr 726s chromemoly pushys undercut,.i dont think your std tappets will go on 7/16 studs so you will be upgrading .but not sure bud .

 

 

Maz

Edited by madtoranajzedded, 24 February 2014 - 01:26 PM.

[S pack]

LC Workshop manual says to coat interference fit surfaces of new stud with SL90 gear oil.

There is/was a special tool for installing new studs but I would reckon a piece of 5/8" diameter brass rod (drift) about 6" long and a hammer would probably suffice.

 

Learn something new every day. Always believed the studs didn't go into the water jackets, boy was I wrong.

 

Cheers

Dave.

 

edit: Be careful not to drive it too far into the head.

Edited by S pack, 24 February 2014 - 01:39 PM.

[Bullet]

You could use a smear of permatex or loctite 515 is good stuff also.

Cheers bullet

[S pack]

Oh ok will do, will this shrink it?

Make it sit level with the others?

Yes (a poofteenth) & yes.

[Bullet]

With a tolerance fit, if both the stud and bore we're perfect then sealer wouldn't be needed thus why the LC manual says to use oil.
Because you said the old stud was scored, the bore will most likely be the same so a light smear of sealant is good insurance in my book.
Stick a screw driver down the hole to see if it has a bottom, but a steel ruler across the other studs to get the hight would be the go.

Cheers Bullet

[Rockoz]

If you got a CO2 fire extinguisher you dont need you can use that to cool the stud down before fitting.

Works for putting track pins in dozers so should go well for a little stud like that

[hanra]

On occasions when Ive been gettin down to the last stubby and had to fish around the bottom of an esky thats had 2 bags of ice in it, I reckon the iced water feels colder then sticking your hand in a freezer. Ive go no scientific proof behind that though.

[kiwi-lilj]

I had a similar problem years ago with rocker studs snapping. After the 5th one I pulled the head off and had it modified for screw in studs. I ended having to take it off again as some coolant was leaking out of the old roll pin holes.

If you are going to give your engine a bit of a flogging you may as well fix it properly the first time.

[hanra]

Iced water will transfer heat/cold much quicker (obviously) but the -30c of the freezer will beat the iced water hands down for temp every single time. Case in point....how many times have you frozen a Great Northern solid in your esky?

Good point!!!!!

[Rockoz]

I can just see the look on the oh&s wankers face now.

Mate of mine always takes 3 or 4 with him to do track pins.

Cost of recharging extinguisher more than made up by time saved.

Has a dry powder mounted to the vehicle for the OHS tools

[S pack]

Awesome input thanks guys. I'll freeze it, why not. Just so glad I didn't have to spend 80 dollars on a tin I won't use again. Why doesn't everyone use permatex if it does the job?

Mark, so if the bore is perfect, why the oil? Being an interference fit you wouldn't want any lube, would you?

There is coolant in the boss, can I still coat the stud and fit it or do I need to drain it first?

Never had to replace a rocker stud but my guess is the stud should be such a tight fit in the hole that without lube it may bind before it is driven in to the correct depth.

 

Was thinking about whether or not the stud holes in the bosses should or shouldn't penetrate into the water jackets.

If the holes were blanked off from the jackets then driving the stud in would compress the air trapped below it and may prevent the stud seating down to the correct depth. So if this theory is correct then it makes sense that the stud holes open into the water jackets.

Edited by S pack, 24 February 2014 - 05:20 PM.

[Bullet]

Agree with Spac, oil is to stop it binding up, good point too with the air lock!

[madtoranajzedded]

dave is a thinker  .the top of the boss must be burred too for the scratches or just the way it came out,would taking the lip off with a file help when seating or ?

[S pack]

would taking the lip off with a file help when seating or ?

lip on what exactly???