That's the point... exactly how you go about removing broken exhaust studs from aluminum cylinder heads for example. That area is far more delicate than this...

Well too late now...but I was going to suggest securing the engine, then attaching a strap around the transmission and pulling it with a come-along or ratcheting tie-down.

If extremely high tension on the transmission didn't result in separation, then alternating rounds of heat/mallet/penetrant could be applied (while transmission still under tension) until it broke free.

Next time.

Well done - You have jumped a hurdle that I hope to never encounter!!
Your 'shim' should work, however you could also insert a tube the exact width of the bell housing mount & let that take the bolt head pressure.

BTW which Dremel wheel did you use to cut the slot? I always thought they were too lightweight for a task like this ( I might buy one now).

I hope things will be straightforward for you from now on. Good luck
Peter in Australia

Removing exhust studs
 

If the stud is broken flush with the head, the only choice is to drill it out or have it removed using the EDM process. If there is any stud left to grasp, a little heat from a propane or Mapp gas torch will do the trick. Heat the head in the exhaust port until you see the thread locker on the stud start to bubble. Then, using a stud remover or a small pipe wrench, turn the old stud out. I just did a set of heads this way to allow for installing longer studs. Worked like a charm!

If it's broken flush to the head you can put a nut of appropriate size over it and fill with weld. Just another trick...

I have a small Dremel tool. There is now a larger one that looks like a small angle grinder. There is a cutting disc you can get for it which is approx. 3" in diameter. I used one of these on my smaller Dremel. I had to use some washers to make it fit as the hole in the cutting wheel is much bigger than the small screw on the tool itself.

The stud remaining in the engine casing is not protruding much and I will need to drill it out and use a stud extractor. Heat will be applied! The remaining stud in the bell housing will not budge. I have tried drifting it out but it is almost as if it has become part of the housing itself! I will need to drill this out but it's in an unthreaded hole so it should be relatively easy.

I should probably mention at this point that I am an trained aircraft repair stress engineer and so overcoming this type of problem with complex metallic structure is really my day job! And yes, aircraft do corrode!

At last after a delay of a month or so whilst I got the right tools, begged and borrowed engine crane etc, I now have my engine on a stand and ready to work on.

http://forums.pelicanparts.com/uploa...1373490211.jpg


http://forums.pelicanparts.com/uploa...1373490229.jpg


http://forums.pelicanparts.com/uploa...1373490248.jpg

Flywheel is looking a little rough though!

http://forums.pelicanparts.com/uploa...1373490266.jpg


http://forums.pelicanparts.com/uploa...1373490283.jpg

Oddly, the clutch action was perfect!

This is becoming more of a labour of love rather than a quick head stud fix, but I keep telling myself it will all be worthwhile in the end.

I know some don't like to see modifications like cutting into a trans. I think it's a great solution Keynsham1.

Thanks for your support! I never got any useful alternatives from this site to my problem, and it has worked well for me! I wonder how many people actually do this type of job. It is a massive task to remove an engine and gearbox and replace head studs!

Keep at it Keynsham - you had an unusual hurdle to clear, but you're back on track. Think if this as a series of small projects instead of one big one - that's what I did. Don't forget to have fun along the way. The satisfaction you'll feel at the end will make it all worth it.

Good Luck!
GK

Smoove1010 makes an excellent point... have fun along the way!

Recently had my 3.2 out to deal with a variety of things.

Will 2nd the motion on "series of small projects."

http://forums.pelicanparts.com/uploa...1373821965.jpg

Any progress reports - are you working in the shade?
 

Hi - Curious on how your project (or series of small projects!) is progressing.

I read that you are having wonderful summer weather, while we in Australia have miserable cold rainy days. Are you working outside under a 'shade tree'?:D

Peter in Melbourne

I'm glad I came across this thread. I too am in the middle of doing much of the
same aside from the stud. I had tons of little leaks and doing the ole "while I'm
at it routine."

While reading this a light when off. I found what I thought was a crack in my
bell housing. I know am convinced that at some point someone did the exact
same to remove my trans. Though going through my records I have been unable
to find where any clutch work had ever been done. This was odd to me because
I have what has looked like every single receipt for all the prior jobs on the engine.
So, your solution appears to be one that has been done before.

What I have been searching for is torque specs for the oil cooler bolts. Also, I
found that one of my lower bolts (closest to the rear of the engine) that hold on
the cooler was missing its washer. So, either Porsche only puts washers on
3 of the bolts or, again, the o rings had once been replaced and the washer
was not reinstalled. Did you have all 4 or did yours only have 3 as well? Would
you happen to know those torque numbers?

Thanks, keep pluggin along
Scott

I have ground to a halt at the moment. I am waiting for Pelican to deliver to me the two tools needed for removing the camshaft nuts. It seems impossible to get them in the UK. No second hand ones I could find. Porsche now claim they are NLS, and no dealer will lend them to me. I have an email from Pelican saying they are on order and should be sent out my the end of the month. I am sceptical. They also have to get to the UK and through customs so it could be a few weeks before I can continue. Very frustrating. I have had the flywheel skimmed in preparation for the new clutch, but little else.

I have ordered all the parts I think I need now so these should be arriving soon. I already have a pile of parts to fit and it is getting bigger.

Meanwhile the engine is sitting in my garage on a stand looking very sad for itself!

I am sorry to hear about the misfortune.

While you are waiting for the tools and the rest of the parts: I would take this time to clean clean clean as much as you can.... it's boring, but it will be rewarding when you're able to get back to work...

Plan B
 

You can use a 46mm socket and an air wrench to remove the two camshaft nuts. I used a lower setting on the air wrench and kept hitting the nut until it just started to turn. Once it was loosened about 1/4 turn it came off easily. Use the chain tensioner wheel to keep the chain tight while doing so. You can back completely off the rocker adjustments if you are worried about damaging a valve.

Posted from Pelicanparts.com App for Android

Thanks for the update. I am learning from your rebuild already! ;)

I havent started work on mine yet - but I have enquired around and managed to to get a local Pelican to agree to lend me these 'hard-to-get' tools when I commence my own project to fix the 3.0 head studs.
I hope its plain sailing with yours from now on.

Regards Peter in Melbourne
PS: Do you live in the village of Keynsham? I did some genealogical research for a very elderly lady in that town. She has since passed but it was fascinating detective work, as she thought she had an Australian connection.

46mm Crows foot tool
 

I have one of these that I won't likely need again. It was used one time to remove the cams from my SC engine. If you are interested, I will sell you this one at a reduced price. Don't know what the shipping would be from the States, probably somewhere between $35 - $50. If PP isn't able to ship the one you've ordered, at least now you have a backup plan!

I have just emailed Pelican to see if they will ever have these tools, otherwise I will be in touch! Thanks for the offer. You say 'one of these'. are you talking about both socket and crows foot or only one of the tools?

Cam Tool
 

What I have is the 46mm Crows Foot socket. It came with a bunch of tools that I bought from another PP member a couple of years ago. When I disassembled my engine, I used the Crows Foot socket with an air wrench to loosen the cam nuts. If you haven't removed the tensioners yet, the chains will keep the cams from slipping. The cams that I put back in the engine are a set of 964 cams that use the small center bolt and washer so I don't think I will need it again.

Good news! Pelican have confirmed that both camshaft tools are in the mail to me! I have been doing bits and bobs but I really need to get the heads off of my engine and get on with the stud replacement. I should have more to report in a couple of weeks. I have had time to assess my parts requirements though. This has led me to ordering all sorts of 'nice' parts such as turbo valve covers, stainless steel replacement fasteners for tin-work etc! The cost is rising by the minute, but it is going to be worth it at the end.

Better news!! I am now the proud owner of tools P202 and P203.

http://forums.pelicanparts.com/uploa...1378891822.jpg

This may not seem that exciting to some, but I have waited since July 15th for these to be delivered.

This weekend I will attempt the camshaft nut removal....watch this space!!

Did a bit of work refurbishing my compressor this evening so I can use air tools, soda blasting etc. Just before packing up I decided to try my new Pelican supplied sockets on one of the camshaft nuts....

http://forums.pelicanparts.com/uploa...1379195942.jpg

Easy! With two 18" breaker bars, it simply gave no resistance. My engine has never been apart before and so was last assembled at the factory. I suspect there is little or no threadlock making the task much simpler. I plan to see if I can get as far as one side head removal tomorrow morning.

Definitely no threadlocker on cam hardware.

Engine teardown
 

Be certain to bag parts according to their location or use. Makes reassembly much easier! Also, if you line up the parts bags (I use zip loc bags) in order of disassembly it will help you to reassemble in the correct order. Good luck!

So today I have had some fun! I have managed to remove the dreaded 46mm nut, the timing chain box, Cam box and heads, and barrels on one side only of my engine.

The camchain box came away with little trouble. The biggest problem was getting the woodruff key out of the camshaft itself. Why is it books always just say 'remove the woodruff key and...' not 'attempt to remove the woodruff key, hit it a bit harder, have a coffee, swear a little, try again etc.etc'.

http://forums.pelicanparts.com/uploa...1379272309.jpg

Anyway it all came apart eventually. I rotated the engine to get at the side for dismantling and then spent ten minutes clearing residual oil spills from the garage floor.

http://forums.pelicanparts.com/uploa...1379272347.jpg

Heads and cam box came off easily enough. It was apparent that there was a lot of oil around the heads at either end. This is where two of my studs have snapped so I can only assume that the lack of clamping leads to a path for oil escaping up the stud holes.
The head sealing ring (head gasket?) on No.3 had a crack in it and might have been leaking although there are no obvious signs.
http://forums.pelicanparts.com/uploa...1379272423.jpg

Pistons and barrels are generally in excellent condition, but a little grubby.

http://forums.pelicanparts.com/uploa...1379272472.jpg

All the valves look to be good prior to head disassembly. The motor has only done 74K miles so it should all be in good nick really. Note the oily corners where the studs had failed.

http://forums.pelicanparts.com/uploa...1379272501.jpg


http://forums.pelicanparts.com/uploa...1379272521.jpg

Tinware all OK except for the piece at the rear (clutch end) of the engine, which has rusted and virtually disintegrated. That part will need replacing, but the rest will look good after a clean and repaint.

http://forums.pelicanparts.com/uploa...1379272541.jpg

Last picture shows where I am now. I have three lower studs snapped off on this side of the engine. the two end ones are only a few millimetres from the case so are going to be nasty. The third from the left has snapped level with the top of the barrel. All lower studs show signs of corrosion and pitting damage.

http://forums.pelicanparts.com/uploa...1379272581.jpg

Having read Waynes book on engine rebuilds I had assumed that I would have Alusil bores and not Nikasil, as the Alusil are much more common. I had planned to remove barrels and pistons without removing one from the other so I could simply refit later.

I did not succeed here however and managed to pull No.3 off its piston. There is not much room for error if you want to get the piston pins out without the rings coming out of the barrel. Anyway, after a quick check, I have Mahle barrels with magnetic bores, and therefore Nikasil barrels. This is good but leaves me now to decide whether to hone the bores and fit new rings or just reassemble as before. The engine ran perfectly, burnt no oil and all rings are intact with no signs of wear or any other marks to the bores or pistons. Maybe I need to dismantle the other side before I make a decision!

So does anyone know a good way to remove a very short Dilivar stud from an aluminium crank case without using a professional?

Last night I took out four of the six lower studs on one side of the engine. Three were intact and on was broken about a third of the way down. I was able to unscrew them using a stud extractor. I didn't use any heat. Once the initial crack of the Loctite was over, they unscrewed quite easily. I now have two left on this side which protrude about 3mm from the case. I cannot get hold of them with any tools and even after filing flats on the sides of one, vice grips still wouldn't budge it. I am going to have to file them flat and drill them out. I am not looking forwards to this as it is not something I have had great success with in the past.

You're making good progress. Those short studs look like they will be difficult. I would rather get a pro with experience to remove them rather than make a mess of the block if it doesn't go right.

EDM might be the best option here. Do a search of your local area for a portable service which can be done in your garage.

I'm watching with interest. Good luck.

a currently very active thread in this same forum has to do with removing a broken stud. You might want to read that first before drilling. TIG welding has something to do with it.

Excellent progress - well done! :)

How do the head-to-cylinder sealing surfaces look? Any damage from exhaust leak and/or head slap? If so, fly-cutting may be required.

Great progress! The cylinder bores look good (still see crosshatch). Of course, the best is to check everything.

If you cannot find EDM service in Bristol find a really good machinist, they can handle it on a good vertical mill with careful setup - be sure they know that it is loctited so they can heat it while machining. If mag case and case savers not in it then of course they can just set up for drilling the case savers.

Cleaning is the monster job but you already mentioned soda blasting so you oughta get it looking great. I found that after blasting and rinsing a part a spritz of vinegar from a spray bottle would tell me if I missed any and I could rinse again. There are some rather difficult nooks and crannies that it can hold on to rather tenaciously.

Slowly but surely, the work progresses. I have had no luck so far trying to remove the two broken cylinder head studs I have which are only protruding from the casing by a few millimetres. I have ordered the small Dremmel cutting tool that has been used with success in another thread and will be trying that soon.

Meantime I have begun working on the heads and cambox already removed.
It all looks good but is very oily.


http://forums.pelicanparts.com/uploa...1380140356.jpg

Below you can see where oil has leaked from the end of the rocker shaft over time. I have the rocker shaft seals to fit when I reassemble them. £3 each for a flat round rubber seal! A real con I think. They should be pennies! Still, we are all stupid enough to pay for them (me included), so we will continue to be ripped off.

http://forums.pelicanparts.com/uploa...1380140377.jpg

The heads came off the cambox with no trouble.

http://forums.pelicanparts.com/uploa...1380140398.jpg

On first inspection all looks good. None of the valves show any obvious signs of wear. The white deposit on the exhaust valve apparently comes from unleaded fuel and these buildups can be huge.

http://forums.pelicanparts.com/uploa...1380140300.jpg

Below is a picture of the exhaust valve port from a a 1970 Rover 3500S P6 I restored. This build up blocked a large section of the port.

http://forums.pelicanparts.com/uploa...1380141111.jpg

I have removed the two valves from Cylinder head number 1 and was surprised to find excessive wear in the exhaust valve guide. The top edge of the guide is a knife edge and the valve moves around 0.060" sideways just before it seats. The engine has only done 74K miles so I find this very surprising. The inlet shows little wear. Needless to say I am not going to bother taking the other two apart. All three will be on their way to my local repair shop for new guides to be fitted. The valves look fine so I will be reusing them unless advised otherwise.

Wow, a lot of leaking oil and wear on the guide. Think they may be connected? :)

Is your indicated mileage correct?
 

With that unusual wear on your exhaust valve guides & rocker shafts, I would be suspicious that the indicated mileage is not correct.

Last picture he posted was of a different engine guys. Looks like his valves are still installed in the heads...

Good progress on your tear down. I don't envy you on the head studs. I had just enough left on 2 of them to get an extractor on them.

Soon you will be here, bagged tagged cleaned and lined up for assembly. :)

http://forums.pelicanparts.com/uploa...1380152823.jpg

The last picture is indeed of a different engine. I have removed only the two valves from cylinder number 1 and found valve guide wear. I haven't posted a picture but might do later today. The mileage is correct as I know all the previous owners from new and the complete history of the car. I don't believe the engine has ever been out before as there are no signs to show it.

Below are a few pictures that show my rather strange exhaust valve guide wear.

http://forums.pelicanparts.com/uploa...1380221130.jpg

It is very apparent that the inlet guide has a good wall thickness but the exhaust valve guide is almost knife edged!

http://forums.pelicanparts.com/uploa...1380221145.jpg

You can see when the valve is in place, the huge gap. Surprisingly, the valve seats are in good condition and perfectly round. Heads 1, 2, and 3 are going in tomorrow for new guides!

The inlet and exhaust guides are the same part according to my parts catalogue. I did wonder if this was actually a design feature!

did you try vibrating the stud ?

or tighten it up before trying to take it apart

I tried pretty much everything. It is still in the gearbox, which is sat on a shelf as a 'to do later' job! I thought I would be able to remove the remaining part with a drift, but it just feels like it has become part of the casing. I will drill it out eventually I expect.