Removing head studs from the block???

I've got to remove the head studs from a 400 block and they are of course seriously stuck. I'm guessing the procedure would be about the same with any of the ferrari engines so I was wondering if anyone has had success with any particular technique?

My thought is to knock out the cylinder liners and then heat the block with a torch until the studs turn but I thought it best to ask if there is a proven method before I start experimenting.

 

It's probably better if you could preheat the entire block in an oven.

That aluminum is gonna suck up the heat like mad. Spot heating will likely introduce a bunch of unpredictable stress.

I don't know of a better way though if they won't come out cold (that's pretty unlikely without a fight).

You MIGHT try double or triple nutting them and hitting them with an impact gun. You might get lucky.

 

A method I use almost daily on manifold studs that are threaded into aluminum heads is to shock them with an air hammer rather than heat anything. Using a dowl type bit in my air hammer I apply light steady vibration to them and you can see the corrosion break up. I then do the double nut thing and out they come. Ive never used this method on a head stud but Im sure it would be effective without damaging anything since the power application to the stud is low but direct I would also add wd-40 prior to this as an extra measure. This method has always worked and always amazes me because it gets the worst studs out without heat or damage.

 

First use a proper stud removal tool never 2x 3x nut a really stuck stud. Second apply any liquid wrench or wd-40 and gently heat the block just to draw the wd-40 into the threads. This is a different method than heating the crap out of something like a stuck rotor on a hub. Then use an airgun in reverse on your stud puller and it will back right out. An airgun not only shocks the corrosion like newman said but it also insures that you are putting pure twisting out force on the stud with no side loads which can cause other damage on the way out. The proper stud tool is one that is a thread grabber which is matched to the size and pitch of the threads.

 

A good example of the thread matching stud remover is the Snap-On collet type stud remover.

The Snap-On collet type (see picture) are 2 pieces, a collet (inner piece) thats threaded with the exact thread for the stud you're removing.

You screw the collet onto the stud. The collet is split so the threads can compress inwards, grabbing the entire surface of the stud threads. The outside of the collet has a conical taper.

The 2nd piece, an outer 'socket' is tapered on the inside, & has a bolt on the end that pulls the collet up into it, thus compressing the threads onto the stud's threads with a lot of force. If you can get a nut & washer on the stud, there's an excellent chance that one of these will pull the stud (or else break it off if you twist hard enough).

Down side is that these removers are about 30% larger than a large spark plug socket, so don't work well in tight places.

A full metric set is very expensive, see:

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=10349&group_ID=1247&store=snapon-store&dir=catalog

About a year ago I just happened to stumble across a set on eBAY, said what the heck & threw in a laughably low bid. Turned out to be the only bidder! I don't need it often, but when I need it, I need it very badly.

mk e,
you've helped me enough times, would be glad to loan you the holder & collet you need for those studs. Just send me eMAIL with the thread size (M12x1.25?) & I'll get them out priority mail.
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Verell,
Thanks! The size is M11x1.0.....which I don't see on the snap-on list so I'm guessing that is a size you don't have

I suppose I could make one if they are not available.

I tried double nutting (no room for 3), but of course the impact wrench just undoes them. Tack welding a nut on after hammering the snot out of the stud (thanks Paul) took out the 2 I tried it on. If the tool is unavailable, I can carry on welding.

 

Excellent, might take a while but it sounds like you'll get them out, just cross your fingers the threads stay where they were intended, in the block, lol.

 

I did this and also used an NC tool holder with the right size collet to grip the stud all the way at the bottom so you don't bend it . .. this was after I snapped one off . . . that was fun Using the wrench that tightens the collet in the tool holder with a cheater bar pulled them right out with heat . . . unscrewing the stud is the direction you're tightening the collet . . . doesn't have to be a tool holder . . . regular 5c holder would work with the right collet most likely.

I too thought I'd have to heat soak the block to get them out but the torch did it with lots of penetrating oil/WD40 . . . when I'd see the penetrating oil boiling out of the area around the stud it seemed like the perfect temp.

Good luck,

Sean

 

Yep . .. one of the funnest things I've ever helicoiled

 

BUMMER, thats a size the set doesn't have, also looks like Snap-ON doesn't have it loose piece either.

I'd say keep tacking & welding since it seems to be working.

BTW, how are you tacking the nuts on?

Last time I tried that with a MIG, the M8x1.25 stud kept snapping off just below the nut.

Found that if I gas welded the nut on, the stud wouldn't snap. Someone said it was because the MIG could dump in energy quick enough so that there was a narrow stress plane formed, while the gas created a more gradual temperature profile w/o a sharp delineated stress plane. Sounded reasonable at the time.

 

I was afraid or that.....stupid ferrari sizes.

I'm tig it them.

I've got a 5c collet block that's a hex and a socket to fit it I think. I'll give that a try and see what happend. If not, back to welding.

 

Thinking about it, the tool holder works better 'cause your tightening it as you're trying to unscrew it . .. don't think you can rig up the 5c holder like that to get it tight enough. I'll send you it if you want. You might even be able to re-use some of the studs.

Sean

edit: realized you don't care about re-using the studs where you're going

 

Mark,

I have had limited luck with WD-40 and Liquid Wrench when trying to remove engine studs. Then I found AERO KROIL and have had much better success (www.kanolabs.com). 2 years ago, I had to pull the head off my sailboat's 1960 Atomic4 engine. I tried several stud pullers including the Snap-on tool, none of them worked. After soaking the studs with KROIL over night, the studs came out without any fanfare. I also used KROIL when disassembling the 308 engine 2 winters ago. (I know, this sounds like a commercial, but sometimes you find something that really works). Good luck.

 

Haven't tried Kroil, but have had very good luck with PB Blaster penetrant.

Just pulled some badly corroded studs out of Chris's tranny, they came right out. Chris had been pre-soaking them with PB for a week.

I usually don't remember to start applying it ahead of time(DUH), but even so, it makes a big difference. MUCH better than the current Liquid Wrench formula which is better than WD-40(which isn't even intended to be a penetrant).

 

Would NEVER use anything but Aero Kroil.....have used it for years and there is nothing better. IMO liquid wrench(old formula was just OK) is nothing compared to it....and as for WD-40 you have got to be kidding, as already mentioned it is not and was never formulated as a penetrant.

 

I'm buying some of this stuff.

 

order placed

I think I tried the only 2 easy ones....the next 2 show no sign of coming out. I pulled the water separator, regulator and quick connects off the air line to get the gun pressure up, no luck. I put a breaker bar on them but it looks like the stud wants to twist.

I’m out of oxygen for the touch, so that will be tomorrow’s stop I guess.

Anybody know how the cylinder liners come out so I can get the torch in were it can do some good?

 

I knew they were 11mm x 1.0mm (Lamborghini used that same oddball size ) so the "right tool" was problematic. If you're not reusing the studs it doesn't matter much how you get them out. Tig welding the nuts and rattling them out with the gun looks like a winner.

 

you're right, the 5c hold was useless and I tightened it with a 2 foot wrench.

 

Nope not kidding. Sean is on target get the WD to bubble and it soaks into the fastner and it comes right out. I have kroil on a back shelf. Used it maybe once. WD always does the job . Sean you can have my kroil never found a use for it. See you at WSIR 1/13/08 with Alfa?

 

Oh is you are welding and snapping off the stud at the weld here is what the hillbilly does and it works everytime. You wrap the stud base at the head with a big soaking wet towel. Weld the nut and hit it with a propane torch using mappgas or an oxy torch until red and liberally sprinkle kasdenit on the stud then spray cold with wd-40! Knock it our with the airgun. Go ahead and laugh.... then thank me after it works.

 

Assuming they are same as a 308, then a tight slip fit. They may just wiggle out, or you may have to use some kind of puller. The later nikasil ones are shrunk fit, and would need a much heavier puller.

Just curious why you have to pull the studs? Are you thinking of relocating them in the block to accept the TR heads?

 

The QV nikasil liners are a slip fit, they push out by hand often, at least mine did.

I whacked on 1 of these, but just destroyed the block of wood...stupid pine.

No.....that would be crazy

 

I ended up making a puller . .. . you might get away just making a "puck" that fits in the bottom of the sleeve . .. I think it was hard to get a square hit though.

When I reassembled the motor I made sure the sleeves slid back in by hand . . . it was amazing how much they distorted with just the slightest inteference from the block.

On the 308, the puck needed one side machining away to clear the main cap. I'm gonna be tearing down my other motor here this week . ... because it wasn't sitting in a bone yard for 10 years like the other motor I did I'm hopeful the sleeves won't need as much HP to get them out .

Sean

 

The 400 needs the cut for the caps as well. It looks like I'm making a pull then, that sounds like the best way to go.

Good luck with the new one!