The dreaded dilivar head studs?

[ducatist]

My 83 SC snapped a few head studs last month and I was quoted $4,500 to make things right again. I thought I'd give it a shot myself even though I'd never removed an engine before - that's the kind of optimist I am. Working alone, the engine came out in 6 hours using Wayne's nice step by step guide...a helper would have been nice on the lowering part, but sometimes a man has to work alone I stripped the engine down in about 4 more hours until the 19mm bolt on the cam shaft stopped me cold. Ronnie's.930, who lives just on the other side of the lake from me, was kind enough to loan me his P237 tool and I was able to remove the cams, rockers and cylinders in 2 hours. I decided to save the dreaded head studs for a fresh new day...today. I went to Lowes to arm myself for the battle - oxy/mapp torch, 2' leverage pipe, 10" pipe wrench. It turns out I was over prepared since all 12 dilivar studs came out without heat or leverage. I just used the little 10" pipe wrench and spun them out almost effortlessly. I guess, when it comes to head studs, it really is a lottery, but by the time I extracted the last six studs, I had it down to one per minute. I did use my grinder to flatten a half inch section of the threads so my pipe wrench could get a sure bite, but even with the grinding, the whole process took about 15 minutes.

I'm not trying to gloat over my luck or brag about my mechanical prowess (since I'm an average shade-tree mech at best)...I just wanted to share one non-nightmarish head stud experience to help balance out all the doom and gloom posts that almost scared me away from the job.

The moral of this story is that one guy with no experience and limited tools, but with Wayne's guide can remove and disassemble an SC's engine and remove the head studs...by himself. Now, if that guy can reassemble and reinstall said engine remains to be seen. I'm planning to get on that by the weekend if Pelican ships my new studs, rings, gaskets etc. by then. Wish me luck.

[porterdog]

Originally Posted by ducatist

Wish me luck.

Luck!

Keep us posted.

[markivtruck]

I have some new studs if you need them at a good price

[JJ 911SC]

Great.

Hopefully you have a pics time line and posting some pics would be good.

[Flat6pac]

Now is the time to get the valve job done.
Bruce

[Brown747]

You were lucky to have enough remaining broken stud existing to remove with the pipe wrench. Good luck with your re assemble.

Thor

[ducatist]

Agreed...I was fortunate. All three were broken at about the same place (about two inches down from the barrel nut). Two on cylinder 4 and one on cylinder 3.

Originally Posted by Brown747

You were lucky to have enough remaining broken stud existing to remove with the pipe wrench. Good luck with your re assemble.

Thor

[ducatist]

Originally Posted by Flat6pac

Now is the time to get the valve job done.
Bruce

This whole thing started out as a valve job It'll be much easier with the engine out in the open. I'll be doing the cam timing before that...this is quite the education.

[ducatist]

Originally Posted by JJ 911SC

Great.

Hopefully you have a pics time line and posting some pics would be good.

I had my GoPro HD cam taking pics every 60 seconds, but I've had difficulties uploading to this forum - it's obviously more complicated than headstud removal

[ducatist]

Originally Posted by markivtruck

I have some new studs if you need them at a good price

PM sent

[ducatist]

Originally Posted by porterdog

Luck!

Keep us posted.

Thanks...will do.

[ducatist]

For those who are interested in photos of this project, the following link will take you to more than you want.


Free Cloud Storage - MediaFire

[ducatist]

Links to many more pics:
Free Cloud Storage - MediaFire


Free Cloud Storage - MediaFire

[Brown747]

Great looking car!

PM sent.

Thor

[SuperOldSchool]

Do you have Alusils? If yes did you rering them?

[brads911sc]

Use Supertec Studs.

[ducatist]

Originally Posted by brads911sc

Use Supertec Studs.

I went with the OEM stainless from our host...the car has 85K on it so, when it's time for the topend rebuild in a few years, I may revisit the studs along with some performance upgrades, but right now, I'm more interested in getting the car back on the road.

[ducatist]

Originally Posted by SuperOldSchool

Do you have Alusils? If yes did you rering them?

and no, I'm going to follow Wayne's advice and stay with my original rings (with the exception of the oil ring on cylinder 1 which was found to be broken). I would have liked to have left the pistons in the cylinders, but just couldn't manage to make it work out that way.

[KTL]

Plain steel OEM studs are plenty good for a std street engine build. They never seem to break.

For future reference, you shouldn't have to grind flats on the studs to get them off with the pipe wrench. A pipe wrench is specifically designed to bite into round surfaces. I know the stud is small in diameter. But if you get the pipe wrench closed down as tightly as possible on the stud, it'll bite. The harder you pull on a pipe wrench, the harder it grips.

Looking at the pictures, make sure to take a look at the input shaft seal on the transmission (behind the shaft tube). That trans housing is very wet looking.

Engine looks like it was really dirty as evidenced by all the dirt on the cam towers behind the valve covers. In hindsight it would have been good to wash the engine before you disassembled too much of it. As it sits now, you have to be very careful about avoiding dirt & crud from getting into places you don't want it.

There's a ton of dirt on top of the case and the heads and towers really need a good cleaning. Doing so will help the engine run cooler. The 911 needs every bit of air cooling you can give it and dirt does a great job of insulating the engine instead of allowing the alloy surface area to do it's job- release heat to the atmosphere.

Nice BMW 540? I had a E39 M5 for a while. Fun car. Way more horsepower than anybody really needs........

[ducatist]

Originally Posted by KTL

Plain steel OEM studs are plenty good for a std street engine build. They never seem to break.

For future reference, you shouldn't have to grind flats on the studs to get them off with the pipe wrench. A pipe wrench is specifically designed to bite into round surfaces. I know the stud is small in diameter. But if you get the pipe wrench closed down as tightly as possible on the stud, it'll bite. The harder you pull on a pipe wrench, the harder it grips.

Looking at the pictures, make sure to take a look at the input shaft seal on the transmission (behind the shaft tube). That trans housing is very wet looking.

Engine looks like it was really dirty as evidenced by all the dirt on the cam towers behind the valve covers. In hindsight it would have been good to wash the engine before you disassembled too much of it. As it sits now, you have to be very careful about avoiding dirt & crud from getting into places you don't want it.

There's a ton of dirt on top of the case and the heads and towers really need a good cleaning. Doing so will help the engine run cooler. The 911 needs every bit of air cooling you can give it and dirt does a great job of insulating the engine instead of allowing the alloy surface area to do it's job- release heat to the atmosphere.

Nice BMW 540? I had a E39 M5 for a while. Fun car. Way more horsepower than anybody really needs........

All good tips...thank you.

When I tried to remove the studs with the pipe wrench, it was very slow going since it would only bite once out of every 20 or so attempts...so, I bought a smaller pipe wrench thinking smaller jaws would provide better bite, but same result. 10 seconds with a cutting wheel and the stud had a nice flat spot to bite and the job was done in minutes. I was going to toss the 29 year old corroded dilivar studs anyway, so I didn't care about rendering them useless.

The original plan had been to remove the engine and take it to a mech to have the studs removed, but once I got it out, I just kept working on it. I should have taken a break to clean it, but it was apart before I knew it.