Removing studs

[BBH]

The rear manifold stud (nearest the exhaust outlet) broke off about 1/4 inch inside the block, and I will need a righthand extension for my power drill to remove it. (My engine is on my boat, and access space on the port side is about 7 inches.)

1. Where or from whom can I get the best righthand power drill extension that won't cost me an arm and a leg?
2. How can you maintain a straight-in position with the drill bit to avoid stripping the stud threads in the block?
3. For a 3/8 stud, what size drill bit is best, a 1/4 bit?
4. Can an Easy Out bit be used? (I have heard good things and bad things about Easy Out bits.)

After removing the nuts from the head studs, is it feasible to remove the head before removing the studs, to better apply penetrating oil to the stud threads before removing the studs? (Don Moyer's Overhaul manual removes the studs first.)

[Davis Modlin]

In the rebuild that I'm finishing right now, I removed the head and then the studs

Davis

[Don Moyer]

BBH,

It's extremely unlikely (practically impossible) for the last few threads of a hardened stud to hold so tightly as to cause the stud to fail that far below the surface of the block. Therefore, before doing anything else, please inspect the end of the stud that came out of the fourth hole. My guess (hope) is that you will not find a clear fracture zone across the end of the stud, but rather a round and corroded end to the stud.

If, on re-examination, you do find the above condition to exist with respect to the condition of the end of the stud, all you have to do to clean out the forth hole is take a small screwdriver and use it as you would a "star" drill, tapping and rotating it into the hole to clean out the calcified corrosion, which is all that's blocking the hole.

If, on the other hand, there is a small piece of the stud broken off inside the hole, it's best to drill out the remaining piece of stud using a factory fresh 1/8" drill bit, working up to 5/16", and then carefully dressing up the threads with a coarse-threaded 3/8" tap.

I strongly discourage the use of an "easy out". Contrary to what the name would have you believe, an easy out is anything but an easy way out of your dilemma. At least in this application, an easy out is clearly the work of the devil. They have a 100% failure rate in actually being able to turn a broken stud out, and (more importantly) in at least 50% of the cases reported back to us, the easy out broke, posing a far more difficult situation than before.

There's nothing really wrong with trying to remove a head without removing the studs, but we continue to recommend removing the studs before applying any great amount of force to remove a head. It's too easy to crack a head or to damage the block by going to a bigger and bigger hammer.

Best regards,

Don Moyer

[BBH]

It seems that I broke off a head stud -- there are six threads remaining on the stud, which has what I would call a clean fracture -- while removing the head nuts, in preparation to removing the head, which I haven't done yet.

How long is a head stud? (I have an early-model engine, and would like to have some idea on how far down I will have to drill to remove the remains of the broken stud.)

[Don Moyer]

BBH,

The overall length of a standard head stud is approximately 2 - 9/16". The threaded part of the stud is approximately 1/2", and will contain 7 to 8 threads. If I understand your situation correctly, the stud that you believe to be broken still has 6 threads showing, which means that only two threads (maximum) would be missing.

It's extremely unlikely (practically impossible) for the last few threads of a hardened stud to hold so tightly as to cause the stud to fail that far below the surface of the block. It's far more likely that the end of the stud corroded away, leaving behind a hardened calcified substance within the lower part of the hole.

If this is the case, all you have to do to clean out the hole is take a small screwdriver and use it as you would a "star" drill, tapping and rotating it into the hole to clean out the calcified corrosion, which is all that's blocking the hole, and then dress up the threads with a coarse 3/8" tap.

Best regards,

Don Moyer

[BBH]

I have been using a small screwdriver as a substitute star drill to clean out two of the manifold stud holes in the block, as recommended, but progress seems extremely slow. It feels that I am tapping against hardened metal rather than calcified material, but I'll keep at it. (What else can I do?)

I intend to buy new manifold studs once I get the holes in the block cleaned out and my manifold back from the machine shop, where they are drilling out a frozen stud and a broken-off 3/8 exhaust flange bolt at the exhaust end.

How far in the block do I have to clean out the two calcified holes to accept the new studs?

As stated in Moyer's Overhaul Manual, the manifold holes in the block extend into the cooling (water) jacket , but is it necessary to clean these holes all the way into the water jacket? (My center manifold stud hole in the block is open and I can insert a piece of wire into this hole, all the way across to the water jacket side plate.)

[Don Moyer]

BBH,

Based on your earlier measurements (the stud hole being open to approximately 1/4" below the surface of the block), you must have started out with a section of stud/residue remaining in the hole of approximately 1/8" in length.

My best guess is that your biggest problem is the limited space you have to do this difficult work (7"). Here are a few things that come to mind:

1) Have your local machine shop make you a small tool consisting of a short length of hardened round stock (approximately 1 1/2" long, and between 3/16" and 1/4" in diameter), sharpened on one end and with a flat washer welded on the other end. A piece of the chuck end of a drill bit works well. Such a tool will enable you to use most of your 7" access to swing a medium sized hammer as you continue to work the hole. The purpose of the flat washer is to prevent the tool from slipping all the way into the hole when you finally break through - which is the optimistic point of view.

2) Seven inches of limited access must be a major problem for you in servicing other important items on this side of the engine, like the carburetor, fuel pump (and heaven forbid that you had to adjust your oil pressure or remove your valve cover). My second suggestion therefore is to cut a generous access panel to expose the area in which you are working. Many of our customers are providing attractive teak framed access panels for themselves around their engines, which ends up saving countless hours of time and makes essential service work much less frustrating.

3) Depending on what's outside of the engine compartment where you are working, a scaled back approach to (2) above would be to hole saw a couple of 2" holes directly opposite the defective holes. This would enable you to use a small drill in the hole, which should make quick work of creating a pathway through the blockage, after which the "star drill" approach should be much more effective.

With regard to how important it is to clean out the holes all the way to the water jacket, it's critically important. There simply isn't enough cross section of metal in the area of those holes to accommodate a tap (even a "bottoming" tap) to dress up the threads, and even if you could, there wouldn't be enough threads to support the stress of 25 foot-pounds of torque.

I strongly urge you to take a deep breath and continue your work with the most positive attitude that you can muster. My wife always pounds me into the ground when I dare to tread on this sacred ground, but I sincerely believe that work like you're involved in must resemble what women experience in the process of giving birth. Years from now, and long after you forget the pain, you'll benefit from seeing this job through.

Best regards,

Don Moyer

[BBH]

Don Moyer,

Thanks for the pep talk on sticking with removing calcified deposits. I am still at it.

The two manifold stud holes in questiion in the block are the front and rear holes. I can now run a 3/8 coarse tap 3/4 inches into both holes. but both holes are still blocked after that depth.

Using a mirror and flashlight, I can see into the front hole and see the end of the blockage, at what seems to be a shiny surface, which looks like clean metal. Can calcified deposits look like metal after their ends have been worked over with a flat-blade screwdriver (the star drill approach), or do the deposits always have a dull sheen, not bright?

Another problem has arisen. When I insert an ice pick in the front manifold stud hole, I can insert it 1-3/4 inches (from the side of the block) into a break at the bottom of the hole. I can also do the same, except for 1-1/4 inches, in the rear manifold stud hole. It seems that, in both cases, I have broken through the stud wall into another chamber. Is this the valve chamber possibly, or the water jacket, or nothing to worry about?

Thanks for the suggestion to cut out a panel for easier access to the manifold side of the engine, but the ice box is there, and I am leary of removing any of that. (When I replaced the starter recently, with a Delco, I had to cut out a portion of the side panel of the sink for access to the lower bolt on the starter. The starter side of the engine has even less access space than the manifold side.)

[Don Moyer]

BBH,

It sounds like you've clearly broken into the water jacket with the ice pick on both holes, and at 3/4", the tap itself must be past the depth of where the studs originally extended.

Please be careful not to use too much force when the tap bottoms out, because you could easily damage the outer threads. In fact, I would start running a new stud into the holes to check on depth and fit. If you're using a bottoming tap, you may indeed be deep enough (referring back to one of your earlier questions about having to get all the way through to the water jacket).

At this point, if you decide to go deeper, I would start using drill bits in the jaws of a small vise grip to work on the holes (starting with a 1/4" bit, and working up to a 5/16" drill bit). By the time you're able to get a 5/16" through the hole, you should be able to advance your tapered 3/8" tap,
but again, don't use too much force on the tap.

Don

[BBH]

Don Moyer,

So you are not under the wrong impression, I didn't break through the walls of the front and rear manifold holes in the block with an ice pick. While trying to work out the part of the stud still in each hole with a small flat-bladed screwdriver, I could feel that there was a small hole in the bottom of each stud hole wall. I then used an ice pick to try to measure the depth of the holes, hoping that I would not enlarge the hole unnecessarily, which I probably did to some extent. Perhaps I was the one that broke through the walls, but if I didn't, I have a theory.

My theory on the stud hole walls is that the walls were broken through some time in the past and let salt water corrode the middle of the front and rear manifold studs. Then when I tried to remove them, they broke off at their corroded points, and the part of the studs still in the block is hard metal, not calcified material.

As it is, the above is neither here nor there, but I am curious: Is it possible that the studs could have been corroded in their centers but not at their water jacket ends, or is this too far fetched?

I have ordered new manifold studs from Ken, which leads me to my main question: With the new studs, is it okay to use Permatex Aviation Form-A-Gasket on their block-end threads, or should I go with Locktite Stud-Locker? (I am leary of Locktite on the new threads because of the possible need for heat if I have to remove them in the future.)

[Don Moyer]

BBH,

There's no need to be leery of using Locktite. If you ever do have to remove them, it won't take very much heat. In fact, if the studs feel rather loose in the holes, I recommend going directly to JB Weld. In my opinion, it's more important to insure that you'll never have to remove these studs again than it is to worry about facilitating their removal.

Regarding your question about someone breaking through the end of the two stud holes in the past, I must not have been clear in our earlier discussion. All three of the manifold stud holes normally enter into the water jacket, so it's very common for the ends of the studs to be missing a few threads due to being corroded away. We sometimes find them with only 2 threads left.

Best regards,

Don Moyer

[keithems]

i have a late model a4, and i broke a thermostat housing stud about .25" down into the head. [don't ask....:o]

i assume i have to drill it out and replace it. :(

if so, which of the mmi repair stud kits should i get -- ktas 04 446 or oblk 06 446 -- and what is the difference?

is there any other way to fix this problem, at least for the summer? for example, could i fill the hole with jb weld and then drill and tap a shallow hole and insert a short stud to hold the thermostat housing only? or could i just widen the existing hole and jb weld a short stud in there to hold the thermostat housing? :confused:

i rarely need the engine for more than 1/2 hour to get in and out of the marina, though i was hoping to go on a longer trip this summer. :rolleyes:

thank you in advance for your help --

keithems

[keithems]

further clarification:

the stud is broken off about 1/4" below the top of the head, not the block.....it's the stud that holds down the thermostat housing, the one closest to the flywheel end of the head / block -- just above the port for the temp sensor...

how this happened....:o

girlfriend offered to loan me her deceased dad's beautiful snap-on torque wrench. my a4 runs well, but because i see a fair amount of white smoke / steam in the exhaust, i decided to re-torque the head bolts to 30-35 foot lbs.

but -- dummie me, i had never used a torque wrench before, so i expected it would skip -- not just click -- when i reached the torque i had set. :eek:

so -- dummie me -- i overdid the above nut and broke that stud. i then tried to remove it with a stud extractor, but that only cut it off about flush with the head. i then drilled a few holes in it and pounded in some e-z outs; a few of them fractured when i tried to turn them [i know, i know, but i hadn't gotten home yet to read where don says to avoid them -- dummie me] :rolleyes:

anyhoo - the result now is that the stud between block and head seems to be quite secure and unmoving; there's only a shallow hole in the top of the head, and no way at present to secure the thermostat housing. frankly, i think if i could do that, the block and head will stay together for the rest of the summer and in the fall i'll remove the head and hopefully enough of the thermostat stud remnant will be sticking out of the block to be stud extracted also; i just don't want to do it now, if you understand.

therefore, i'm more than willing to get one of the stud repair kits -- but which one? -- and should i get into the block at all if i don't really have a problem there with slipping studs, etc.?

-- if anything -- given the gallons of pb blaster i've already shot into the hole with no stud movement, i think that stud may have been jb welded in there previously by the p.o.

i also just read tonite on the mmi site about the perils of attempting to drill and tap a straight hole with the motor in the boat and the head still on it...

therefore, i await your response and advice.....


thank you, as always...

keithems :cool:

[ILikeRust]

I know you don't want to hear this, but I would remove the head.

You're going to have a hell of a time trying to get that stud out of there when it's down in a hole in the head - and you run the risk of inadvertently doing damage to the head while you're banging, drilling, etc., on that stud.

I would buy the Snap-On stud remover - available from Moyer - and remove all the head nuts, then carefully extract the studs using that Snap-On tool. It's expensive, but it is without a doubt the best way to get those studs out.

Also - forget the PB Blaster - use Kroil (http://www.kanolabs.com/). I'm not a paid spokesperson, although I should be, for all the cans of that stuff I've probably sold. I just know for a fact that it works better than PB Blaster or any other commercial penetrating lubricant I know of. In fact, a machinist magazine did a "scientific" (or at least a reasonable attempt at a standardized "scientific") test and found Kroil to outperform everything else. The only thing better was a mix of 50/50 acetone/ATF - which you of course could mix up yourself, but it doesn't keep unless you seal it tightly in a metal can, because the acetone will evaporate quickly.

Anyhow, I would get all the studs out, except that last broken one, and then carefully remove the head. You will then be left with about an inch of stud sticking above the block that you can work on. If you're careful, you can grab it with a big pair of vise-grips and apply some torque. Hit it with heat from a torch, squirt it with Kroil, wait, let it cool down, hit it with Kroil, apply some heat, apply some torque, wait. Be very patient. It might take you a couple days, working 20 minutes at a time, applying heat, applying Kroil, applying a little torque, until it finally breaks free.

It is possible for that you can snap that stud off, and then you'll really have a problem. So take your time and be patient.

How do I know this is the approach I would take?

Because I did the same thing you did - or at least a very similar thing.

See this thread beginning here (http://www.moyermarine.com/forums/showpost.php?p=32110&postcount=74). At that point, I already had removed all of the head studs, using the "expensive, but worth it" SnapOn tool.

I really can't think of a good way to get that broken head stud out without taking the head off, especially if it's down below the level of the head.

You don't have to take the engine out to take the head off.

[jpian0923]

Bills advice is the ideal way to handle it.

But, You could drill it. Start will the smallest bit possible. (buy the best bits you can find)

Try to get it centered. Graduate to larger bits taking care not to drill the coarse threads in the block.

Once you have hollowed out the stud you should be able to bend it in on itself and twist it out, or, twist it in.

That stud goes all the way into the water jacket. Leaving it in the water jacket for a season shouldn't be a problem.

You can retrieve it later by removing the water jacket side plate.

Clean up the block threads with the appropriate tap and put in a new standard size thermostat housing stud.

[jpian0923]

Dumb question:

Did the torquing solve the white smoke/steam problem?

If you are thinking head gasket leak I would check compression.

[keithems]

thank you both for your help, and to don as well....

however, before i begin, i need to ask one more time... [i know, i know....]

given that it's the peak of our short, precious season here...as a temp, less than ideal fix....why can't i drill and tap the hole down another .25" or so into the head and screw / jb weld a shorter stud into the head to hold the thermostat housing for the summer?

yes -- the thermo will probably leak some and the head will not be totally tight at that corner -- but i'd think i'll be able to do my usual 20 minute runs in and out of the harbor.

and if not, i can go on to pulling the head...which i did on the previous engine to get it out of this boat...and which i consider inevitable, seeing as the torquing did not seem to end the white smoke. [so -- yes -- head gasket -- but no immediate need since she ran well, never overheated or needed oil between changes]

only other question for now is if you think i need the snap on stud extractor instead of the craftsman one i just bought or the k-d one napa sells locally...

and thank you....

[ILikeRust]

however, before i begin, i need to ask one more time... [i know, i know....]

given that it's the peak of our short, precious season here...as a temp, less than ideal fix....why can't i drill and tap the hole down another .25" or so into the head and screw / jb weld a shorter stud into the head to hold the thermostat housing for the summer?

Because the stud is not threaded into the head - it's threaded into the block. That stud passes through a smooth hole in the head and threads into the block. You do not want to drill or tap into the head, because you run the risk of going through into the water jacket. The casting is thin enough as it is, without drill and tapping into it.

If you are very careful, you probably could drill out the stud all the way down into the head, pick out the remaining bits of it, and run a tap down the hole to clean it out. But I think that would be extremely difficult with the head on there, because you can't see the hole down in the block and can't really get down in there.

only other question for now is if you think i need the snap on stud extractor instead of the craftsman one i just bought or the k-d one napa sells locally...

Depends on the style of stud puller. Is it one of the old-fashioned ones that simply grip the stud using a cam? Or is it the collet type, like the Snap-On, which threads onto the stud and then tightens down? If it is the typical cam-type, all that will do is ruin the studs. Feel free to ask me how I know this. I tried that before springing for the SnapOn. It's how I broke that stud. The SnapOn removes the studs without no damage at all, and grips them much more securely than the cam style.

Assuming that the other studs don't give you a terrible time and snap off, pulling the head and replacing the head gasket is about a half-day job. I don't see any reason why you couldn't spend a Saturday getting the job done - order the head gaskets and new studs ahead of time, pull the head, yank the old gaskets, scrape and clean the block and head, replace the bad studs, drop the new gaskets on, drop the head on, do the torque procedure, and on you go. Unless, of course, you encounter unforseen difficulties...

[ILikeRust]

To be clear:

If this is the style of stud puller you're trying to use:

http://s7.sears.com/is/image/Sears/00904458000-1

Don't.

Unless you want to destroy every stud.

This is the tool you want:

http://www.moyermarine.com/images/stud-remover.jpg

Available here. (http://www.moyermarine.com/cgi-bin/shopper.cgi?search=action&category=TOOL&keywords=all&template=Templates/B000_storebuilder.html)

[jpian0923]

I know this is counter to Bill again but try your temporary fix if you can deal with some water leakage. I doubt you will lose any compression from one nut not being torqued to specs. I would keep a close eye on the engine if it where me.

[hanleyclifford]

This is probably not what you want to hear but I have to go with Bill on this one. If it were any other stud you might get away with it but the stud in question is on the corner of the head and if you run without having torque there you risk a water leak, a compression leak, and most importantly a possible warpage of the head.:( This is painful especially this time of year, but you need to pull the head.

[ndutton]

I agree, pull the head.

Our sailing season in the West is year 'round so we don't feel the pressure of making do in favor of the season but how long would removing and replacing the head take, a couple of days tops? This assumes all the parts and tools are at hand. We've already talked about it as long as it takes to properly repair it.

I dunno, I hate the thought of a jury-rigged anything.

[ILikeRust]

how long would removing and replacing the head take, a couple of days tops?

The surveyor who did the survey for my boat when I bought it told me he had replaced the head gasket on his Atomic 4 while at anchor one day.

Assuming the other studs don't snap off and nothing else gives you a hard time, and that you've got all the new gaskets and studs you need, I don't see why it couldn't be done in an afternoon.

Once I bought the SnapOn tool, I had the head off in under an hour. A bit more time carefully fiddling with the broken stud to get it freed up. If I hadn't been proceeding with a complete tear-down of the engine, I could have cleaned everything up, slapped the gaskets in, and had it all back together in a couple hours total.

[ndutton]

I was factoring in dealing with the stud and less than ideal working quarters, but still, y'know??

[edwardc]

Bills advice is the ideal way to handle it.


I second that strongly!


But, You could drill it. Start will the smallest bit possible. (buy the best bits you can find)

Try to get it centered. Graduate to larger bits taking care not to drill the coarse threads in the block.


I don't think that's going to be possible, as he already stated that he broke off several easy-outs in the stud trying to get it out.

Easy-outs are hardened steel, and almost impossible to drill through. Inevitably, the bit drifts off of the easy-out stub, and drills an off-center hole, usually damaging the side of the hole and the threads. This could result in either damaging the head, or screwing up the threads in the block. This in turn, would require drilling out the block, tapping a larger size, and inserting a threaded repair collar (not a helicoil, they tend to leak).

All of this would take far longer than just pulling the head. I watched an experienced mechanic pull a head and replace the head gasket and the head in about 4 hours.

Just as a note, it is possible to remove the head without removing the studs. You just need to get enough PB Blaster or Kroil down around each stud (tap them gently sideways), and carefully pry the head up evenly. This would avoid causing any additionial problems, such as breaking off another stud!

[ILikeRust]

I have to admit, I missed the little tid-bit of information that you broke off a couple easy-outs in there.

I don't know how you propose to drill deeper in there, because - you ain't gonna do that, no how, no way. Not with a couple easy-outs jammed in there.

Easy outs are just as hard as, or perhaps even harder than, your drill bits. You won't be drilling those out.

[jpian0923]

Don't do this though! I had head removal problems and ended up doing this.

[keithems]

thanks for all your input....

believe it or not, actually had to go to work last 2 days, but now that i may have some time.....fyi....

ordered the kroil [silikroil, actually] and yesterday spoke with ken at length [very helpful!] and ordered the stud remover, head gasket, a few new studs, thermo gasket, etc., etc., so, as you can see -- i'm hoping for the best, preparing for the worst....

while i'm awaiting their arrival, i may try to drill out that stud hole in the head a bit and install a helicoil or repair bushing or something....i consider that to be low risk; plus i have another head from my previous a-4...

then again, i may not....maybe just see if i can get the &*&%^ head off, pull & replace the bad stud, and install the parts when they arrive....

meanwhile, i'll be mixing up that weird brew of acetone and atf.... :cool: [is mopar atf3 ok?]

i'll update as things progress...

k

[edwardc]

while i'm awaiting their arrival, i may try to drill out that stud hole in the head a bit and install a helicoil or repair bushing or something....i consider that to be low risk; plus i have another head from my previous a-4...


But it's not "low risk" because the stud is threaded into the block, not the head. You risk damaging your block. The head just has a smooth unthreaded hole through which the stud passes freely. Well, relatively freely. The combined drag of 14 studs does add up when trying to remove the head with the studs in place.

[keithems]

no -- the problem rt now is in the head -- the head is attached to the block just fine, so i may try to see if i can insert a short stud in the head to hold the therm housing in place and not mess with the block at all -- just a jury rig for this summer till i do it rt in the fall --

however, haven't got to it today at all, and tomorrow the mmi parts should arrive -- so most likely i'm gonna do what everyone has advised and do it right the first time -- remove the head to get at the bad stud...

[ILikeRust]

no -- the problem rt now is in the head -- the head is attached to the block just fine, so i may try to see if i can insert a short stud in the head to hold the therm housing in place and not mess with the block at all -- just a jury rig for this summer till i do it rt in the fall --

however, haven't got to it today at all, and tomorrow the mmi parts should arrive -- so most likely i'm gonna do what everyone has advised and do it right the first time -- remove the head to get at the bad stud...


I would really urge you not to try to tap threads into the head to hold a stud in there. I think you run the risk of ruining the head completely by creating a leak through into the water jacket. Besides, you would have to use a fatter stud, because the standard studs will just pass right through the smooth (non-threaded) hole in the head. So you would have to cut threads in the head (where there are no threads currently) and then use a fatter stud to screw into those threads - and a fatter stud won't go through the hole in the thermostat housing, unless you enlarge the hole. So you basically would have to ruin the thermostat housing for it to work. Either that, or you would have to cut threads in the head and insert a Helicoil or something. I suppose you could JB Weld a stud into the head, and then melt the JB Weld out later, once you actually take the head off.

I don't like jury-rigged, half-arsed fixes, myself, which is why I've been such a PIA and keep insisting you should take the head off... :D

In any event, let us know what you do and how it works out - you've obviously piqued our interest!

[Al Schober]

Recommend you stay away from acetone and ATF - acetone is very high volatility. I used to use kerosene and ATF until someone turned me on to PB Blaster - vastly superior.

Al

[ILikeRust]

The main hazard from acetone is its low flash point. Acetone has a flash point of about 0 degrees F. Other than that, it is not toxic and won't kill you, unless maybe you drink it or huff the concentrated fumes.

Gasoline is much more dangerous than acetone, and most people don't give it a second thought to keep gallons of it in their garages and sheds.

I've wanted to give the 50/50 acetone/ATF mix a try after reading the comparison results in "Machinist's Workshop" magazine, but I find Kroil works better than anything else (the magazine article also confirmed this) and I've got a bunch of it, so I just stick with that.

[edwardc]

... acetone ... is not toxic and won't kill you...

!!!??? Acetone is a known carcinogen!! I avoid all skin contact and fume inhalation. Makes it a real pain to work with! Pity, because its such a useful solvent. Sometimes nothing else will do.

[ILikeRust]

!!!??? Acetone is a known carcinogen!!

Sorry, but that simply is not correct.

I have been in the environmental safety and health field for over 20 years. I spent 11 of those years traveling extensively all over the continental U.S. delivering training courses to teach people how to comply with EPA, DOT and OSHA regulations regarding management, transportation and disposal of hazardous wastes and hazardous materials. I currently am a practicing environmental attorney.

Many years ago, EPA regulated acetone as a "toxic chemical" under a law requiring companies to report their use of "toxic chemicals." After rafts of data were submitted to EPA by industry, EPA concluded and ruled that acetone was not "toxic" under that law. Chemicals are regulated as "toxic" if data shows they have certain toxicological effects, such data indicating the chemical is carcinogenic, teratogenic, mutagenic, or causes target organ effects or nervous system disorders.

You likely would be surprised at how few chemicals are classified as "known" carcinogens. Acetone definitely is not among them. Further complicating this question is whose definition of "carcinogenic" are you using. Most U.S. regulatory agencies (including EPA and OSHA) tend to refer to the International Agency on Cancer Research's (IARC) data and classification system, but that's not the only one.

When you're dealing with health and safety effects of a chemical, very generally speaking, you're concerned with short-term exposure effects and long-term exposure effects. Most of us would be dealing with short-term exposure - a few minutes here and there, on the occasions we would use it.

The most immediate short-term hazard of acetone is its flammability. That's easy enough to deal with - just use it in a well-ventilated area (outdoors, if possible), and make sure there are no sparks, flames or other sources of ignition nearby. Also don't store it in plastic containers, because acetone will soften, degrade and weaken most plastics. That's why it comes in a steel can when you buy it at the hardware store (as well as because of U.S. DOT regulations).

The health hazard of acetone exposure is respiratory tract irritation and irritation of the mucous membranes (eyes, nose, etc.). If you breath the concentrated vapors for a while, you'll get dizzy and feel weak, you might feel nauseous and sleepy - but if you get out of that atmosphere and breath fresh air, it will go away.

As I said before, gasoline is far more hazardous to safety and health than acetone. Acetone has a flash point of 0 degrees F; gasoline has a flash point of -55 degrees - so it is far more flammable. Gasoline also is flammable over a much broader range of mixtures with air - which is why it's such a good fuel, and why it's so easy to make an explosive atmosphere with a gasoline spill inside a boat. Not so with acetone. Its flammable range is narrower than gasoline. Gasoline also contains some chemicals that actually are, in fact, known carcinogens - most notably benzene.

And yet I've known lots of people that like to use gasoline as their general-purpose solvent. Not to downplay the hazards of acetone, but as between the two, acetone is much safer and less hazardous to your health than gasoline, and several other solvents.

Methanol is much worse for you than acetone, as is methylene chloride.

[edwardc]

Bill,

Wow! I certainly bow to your superior knowledge and currency in this area. I admit my information is based on old sources, it just never occured to me that a "toxic chemical" would get downgraded.

And all these years I've been taking pains to avoid exposure. :o

After your post, I did some digging to try and get a little more current. And it supported every thing you said. I do appologize for passing bad info.

I found numerous documents, as recently as 2005, where the EPA classified acetone as a "Group D carcinogen" (inadequate evidence to classify). This is certainly a confusing designation, as anyone hearing "Group D carcinogen" without the parenthetical explaination is likely to assume it means "carcinogenic"! Its easy to see how the mis-information persists.

Sorry for the hijack. Lets return to the stud removal problem. :D

[keithems]

still awaiting the arrival from mmi [due today], and i see the kroil shipped today -- meanwhile, just finished replacing redvan's serpentine belt and tensioner -- it broke 2 days ago 50 mi from home in the middle of nowhere -- p.t.l. for aaa! -- all online sites say it's easy to change, but -- trust me -- not on a caravan -- plus most of my tools are -- guess where? -- da boat!

anyhoo -- the message i've taken away from this detour is do it right the first time if you don't want to be stranded in the middle of nowhere [or da lake -- towboat u.s. notwithstanding] -- so u can guess that i'll be lifting da head if at all possible....:)

meanwhile -- isn't acetone = nail polish remover? not that i use it for that, but about half the world does...

plus, although i love my a4, it's only part of da boat -- which -- being fiberglass -- requires its own special kind of care, cleaning, and upkeep -- and for us fiberglass jocks -- acetone is the primary solvent for those tasks....

off to jim the head guy to check my spare head; meanwhile -- will update later.....

[ILikeRust]

meanwhile -- isn't acetone = nail polish remover?

Yes. Although these days, they now have "acetone free" nail polish remover, which is the citrus-based stuff.

I know this because in addition to my wife, I have two teenage girls in my home.

[keithems]

as i mentioned, had to detour for a bit to replace my serpentine belt and tensioner....went to the web for help, of course --

here's what i found ..... just in case any of you want a laugh or need another reason to be grateful for all the help don and ken provide, as well as all the afourians.....:D

http://www.youtube.com/watch?v=4W9rg-2cEHQ&NR=1

[ILikeRust]

And some people think they've got poor access to their Atomic 4s!

[keithems]

hi again all!

ok -- took everyone's advice and pulled the head -- it came off surprisingly easy in a few hours.....studs i took out [only about half] are clean and threads intact -- i also removed the bad stud :D....also removed the manifold [pretty clear] and the water jacket cover [omg! -- so many flakes, etc., inside!]

[this motor came from boston [salt water], but i had figured whatever problems it had would be cured by our deliciously pure great lakes fresh water [kind of like putting an old race horse out of stud - don'tcha think?] :rolleyes:

so -- 1st question -- what's the best way to clean out the water jacket? how do i inject muriatic acid in there safely? - and more importantly, get it out? [engine is still installed in boat.] is there any other solvent that's preferable? what about clr, lime away, vinegar, or automotive radiator flush?

i also noticed a gouge in the surface of the block under the thermostat housing area. it's possible i did that with a screwdriver -- but i think it was more likely there previously [of course! :cool: ] since when i first got this engine home, one of the first things i noticed was a lot of rust and scale on the head and block at that corner. so -- 2nd question -- what do i do about this gouge? jb weld or sealer when i install the head and new gaskets? file / sand as smooth as possible? anything else?

meanwhile, while i was removing this head, i took the head from a prior engine to jim the head guy. jim claimed lots of experience with "these older engines" -- and he cleaned, magnafluxed, and checked it for flatness, and said he found it necessary to machine it because of one "weak spot" along the side. i gave him this head yesterday, and again he said he'll likely have to machine it, at least a little....

thus, 3rd question: ken [at mmi] told me that these heads should never be machined. what do the rest of you think? should i grab the head back from jim before he ruins it? :( -- or just let him go ahead as he sees fit?

and last but not least -- the 4th question: the valves seem to operate fine but show some signs of carbon and dirt, etc. what is the best solvent to clean them...and what do i use to get under them?

pls. let me know what all of you think..........

and as always, thank you for your help and care...

k

[hanleyclifford]

I do not advise machining a head unless a compression or leakage problem existed and the head was found to be warped or distorted. This can be tested with a steel straight edge and a feeler gauge set. Machining a head should not be thought of as a routine or precautionary procedure.

[ILikeRust]

I had the head and block on mine surface ground, not milled. I made it very clear to the shop that I wanted them to take off as little as possible - just enough to remove the pitting (there was some, due to the leaking head gasket, which apparently had been leaking some time) and get a clean, flat surface for the new gaskets.

[ILikeRust]

By the way, once the block was surface ground, I had to have them re-cut the valve seats, as part of them disappeared as the block got every so slightly shorter. The I lapped the valves into the newly-cut seats.

[jpian0923]

Q1: Page 2-5 in Moyer manual has Acid flush instructions.
Q2: JB Weld will work. (I learned the hard way)
Q3: Follow what the above guys said. You have two head gaskets to make up for any imperfections.
Q4: I "love" carb cleaner and elbow grease for cleaning engine parts.

Just my opinion though...

[keithems]

Q1: Page 2-5 in Moyer manual has Acid flush instructions.
yes--i know, but am hoping to avoid the muriatic acid--

also, i don't think all those flakes will flush out or they would have already--so i'm gonna try to vacuum them out while everything is off and open

Q2: JB Weld will work. (I learned the hard way)
do share -- or tell me where you've already written about it --

Q3: Follow what the above guys said. You have two head gaskets to make up for any imperfections.

trouble is i'm in between the above guys and jim the head guy who's actually doing the work -- i guess i'll tell him to measure and clean, etc., but not do any surfacing, etc. till he tells me how much out of flat it is, if any

also -- only the head can be worked on, since the block remains installed in the boat


Q4: I "love" carb cleaner and elbow grease for cleaning engine parts.
i have both --

actually, not seeing much i can clean, besides the rust flakes in the water jacket --

based on the mmi manual -- i'm not taking the valves out with the engine in the boat -- so -- the only things i see to clean on the top of the block are the tops [bottoms?] of the pistons [makes things pretty, but does it matter?]

and the valves and seats...

so -- should i mess with the valves and seats? if so, what do you recommend to get under them and clean the seats without removing or damaging them?

or do you recommend i "dfwi"? :rolleyes:

thanks once more

k