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Engine Drop - 1st time


Dusty

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I've been debating whether to start this thread as there's already an excellent one by Harvs not to mention the thousands of others across the interweb but as I'm a newbie 911 owner, I could use some wisdom and potentially help other locals by illustrating my failings. 

 

The reason for the drop is four broken exhaust head studs and to cosmetically refresh the engine/bay. The cars clutch/overall transmission is excellent (replaced/overhauled only a year ago by the PO) and a top end rebuild is evident although I cant tell where in the cars history this took place.   

 

Work began Sunday morning and I'd planned to drop both the engine & trans as per the Bentley manual although half way through, I was swayed by 101 projects so thought I'd keep the trans in place as I had no plans for it; big mistake... The disconnecting went very smoothly but during the drop, the engine couldn't back up far enough to release from the trans. The engine ultimately became wedged on the trans so I went back through the Bentley steps, released the transmission and after dealing with a stripped CV bolt, was then able to then drop the engine. 

 

Here's some shots from the beginning:

 

DSCF4020-Copy_zps794a535c.jpgPrep - whilst a mate uses the 911 bible

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Finally dropped the engine with the trans still attached at an angle (dont mind the wave in the floor);

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Trans finally removed as well as the CIS, tinware, shroud, fan etc.

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At this stage, there's no overwhelming issues I wasn't expecting but i'm yet to open the cam housings, heads, pistons/cylinders. There's a substantial amount of oil leakage from the oil breather to name just one that'll be rectified by the new gasket kit but the sheer tonnage of cleaning/re-painting will be a huge task in itself... 

 

I'll update as I can but most of my pics are taken of the detail - not the big picture.  Will try to take a few when I remember. 

 

Avert thy eyes!

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The tear down has gone about as far as I want it to go until an engine stand adapter arrives from the states. I'd seen examples of people using the universal mount but upon trying it for myself, I wasn't comfortable with the weight of the engine hanging off such a small section of the crankcase so bit the bullet on yet another specialised tool... If only I was planning on doing this more often.

No big problems so far except for one or two stripped bolts/screws etc. Unfortunately I have Alusil pistons/cylinders which is disappointing (if everything on the net is to be believed) but I won't be touching them except for temporary removal to install the new head studs. Apparently there's a world wide shortage of these fragile bolts so obviously there's a lot of muppets like me with their engines strewn across their garages...

It also makes me wonder, do I really need to order a full set of 24 or can I get away with the lower 12? The uppers look fine from my limited view with the cam housing still attached, I think I'd still replace the nuts/washers cause they're not so good but has anyone heard of a cracked upper head stud? It would basically give me more money for some extra treats like a renspeed trunk blower cover or some nice anodised engine tinsel! And Coaster, the heat tube is already ordered, that was considered a "necessary replacement item".

Other observations were that the cam removal wasn't that difficult, I actually had a harder time removing the woodruff keys holding them in and still can't remove one of the cam oil lines... The biggest surprise though is the amount of gunk that built up through various oil leaks. I pretty much had all 11 noted in Dempsey's 101 projects and it wasn't until pulling the shroud off that I could see the extent of the crud build up first hand. Trying to manoeuvre the engine for a quick pressure clean whilst in the garage has been the most challenging task to date, and one that I've unfortunately failed at.

Here's some shots of the progress, unfortunately I'm not as well ordered as many others who've done this but just think of the background as "ordered chaos".

 

Before - gunk in all its glory:

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After the first clean - there'll be others to come no doubt

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One heat exchanger removed but it's too tight to get the second one off without the engine stand

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It'd be nice if all valve adjusts had this much room

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This was an unexpected find - knew it had a stainless exhaust but not one of these. Bloody loud but I'm hoping that could be down to the massive canon tip that was previously installed?

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Dusty,

Can I ask two dumb questions and one sensible:

Why are you replacing the head studs if they aren't broken? (I'm assume they aren't pitted by corrosion.)

What's wrong with the Alusil P&C's on SC's?

Does your Mille Migila drone at highway speed?

Thanks!

Peter

BTW: Good work!

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LOL, thanks Tazzie, the number 24 and the reference to expense made me think the occasional troublesome cylinder head studs, rather than inlet and exhaust manifold studs which, I guess can be called cylinder head studs as well!

I'd just replace any corroded, broken, damaged or stretched thread ones but the fun bit will be getting them out!

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I'd just replace any corroded, broken, damaged or stretched thread ones but the fun bit will be getting them out!

If any are corroded , chances are the others are "compromised"!

Terrible Achilles heel of this engine

Getting broken studs out is always a learning experience , an opportunity to try new tools and a way of growing more hair on your chest  :)

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PeterM, there is a bit of droning from the exhaust but its fairly minor. It's more the outright noise of it which doesnt sound as refined as others I've heard.  I'll try replacing the tip cause I've got a feeling this may be partly responsible:

 

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As for the head studs, I think I'll wait until the engine is up on the stand and I can disassemble it further before making a call. It's too difficult to gauge the condition of the upper studs at the moment.

 

Definitely not looking forward to extracting the lowers at any rate, especially the four snapped ones. 2 of the broken studs won't have much (if anything) to grab hold of.

 

DSCF41711_zps8160baea.jpg

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Regarding the Alusil's, I'm quoting what I'd read mainly from Wayne Dempsey and other Pelicans but they say Alusils cannot be reliably re-ringed, something to do with the thin coating on the cylinder walls. I understand there's been success stories of people re-ringing them but more stories of the new rings never seating correctly and those owners then switching to Mahles.

 

As mine had good compression before the tear-down, I'm choosing not to poke the bear.  

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Have these lower head studs been broken for a long time?

Because you said earlier that there was evidence of Head work.

 

As the upper head studs are steel, you should find that they are OK.

Many recent Pelican threads say that heat is the key for removing the broken ones - good luck & continue with the excellent photos.

Peter 78 3.0 SC

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Peter, I'm unsure how long 2 of the 4 studs have been broken so wont know if there's head damage until I pull them when the engine is moved to a stand. I broke the remaining two while checking they were torque'd during a valve adjust around a month ago.

 

It wasn't popping under acceleration and none of the broken studs are at the extremities of the cylinder banks so hopefully the cam housings have been keeping everything together.  

 

The fact that the original broken studs were left in the engine is mystifying but gives me hope that its been a recent occurrence. My guess is that the PO performed a valve adjust, found the 2 original broken studs and took the car straight to the auction house knowing the repair bill he/she would've otherwise been in for. 

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I have a stud removal tool that you're welcome to use.  It clamps onto the threaded end of the stud without damage to the threads.  Only useful on the non-broken ones of course, but also have other implements that could help with the rest. 

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That'd be great John! I'll PM you.

 

I'm hoping to be at that point by next weekend. An engine stand adapter is holding up the process (as well as delivery of the replacement studs...) but at least its forcing me to spend the time on cleaning/painting etc. 

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Is it possible to weld on the dilaver Studs? I've heard it ends up as a bit of a breakfast. I'm presently channeling smooth, slippery thoughts in the hope that the studs just slide right out. If that works, I swear I'll give homeopathy a go.

 

Looks like my engine stand adapter is only a few days away and my cleaning/painting regime is nearing completion so will hopefully have some more interesting posts to follow. 

 

Thanks also firstone! 

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Is it possible to weld on the dilaver Studs? I've heard it ends up as a bit of a breakfast. I'm presently channeling smooth, slippery thoughts in the hope that the studs just slide right out. If that works, I swear I'll give homeopathy a go.

 

 

Good point and I don't really know to be honest, you could test welding one of loose broken studs first and see what happens.

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Update - the engine stand adapter arrived yesterday but it has not been pre-drilled for an engine stand... That'll teach me from buying one off flea-bay so after drilling for 30 minutes and making a 3mm hole, I'm now off to find someone with a drill press. 

 

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Is it possible to weld on the dilaver Studs? I've heard it ends up as a bit of a breakfast. I'm presently channeling smooth, slippery thoughts in the hope that the studs just slide right out. If that works, I swear I'll give homeopathy a go.

 

Looks like my engine stand adapter is only a few days away and my cleaning/painting regime is nearing completion so will hopefully have some more interesting posts to follow. 

 

Thanks also firstone! 

Well done on your efforts so far.   If I'm not too late, I strongly recommend cleaning as much as you can before taking too much of the engine apart.  Getting dirt etc. in the bores or crankcase is a serious no-no.

 

Good point and I don't really know to be honest, you could test welding one of loose broken studs first and see what happens.

My research suggested that welding a nut to Dilivar is nigh impossible.  Here's for getting the broken studs out.

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