A top the slipperly slope

[OldTee]

with out snow. Today, while pulling valve covers to do a valve adjust prior to finalizing the engine, Michelle said whats this. Well this..... is a factory head stud, barrel nut and washer. Everymans Porsche 911 engine nightmare.

So the engine will have to come down and the decisions and compromises begin, big time. I don't even want to think about all of what they are.

Damn....
ARF

[Rick V]

John, please don't hesitate to call me if you need a hand.

[OldTee]

How many hand$ do you have?

Got to thunk on it. Thanks.
:(
ARF

[Dr K]

John,
If you're going to do it yourself, please call me to help. Just remember that my inexperience hands to not rate even 1 "$" yet.

Peter

[cmartin]

Sorry for the bad news. It's a great time for a valve job though. How many miles?

[OldTee]

Sorry for the bad news. It's a great time for a valve job though. How many miles?


Timely question. I just posted the following over on Pelican to see what I get back.

Have at me boys and girls.

"Head stud broken, now what?
I am interested in the advisability of several "while you are in there" decsions I must make. I realize they are highly personal but there must be some common $ense logic about the way to go.

Background. The car is a 87 Targa with 97K miles of uncertian history. It was running fine except the clutch was shot. We are refurbising the whole car with new bushings shocks etc. and planned to refresh the engine with new hoses, some new sensors, gaskets, etc. When the valve cover came off to adjust the valves the head stud for #2 fell out. Leak down on all cyls was good as was the compression. (Ie) no symptoms. The engine is out of the car and on the engine stand. When finsihed the car will be a 'keeper' used for semi daily transportation and occasional DEs. I Don't plan to break the case.

Now the questions.

With this many miles is it advisable to just replace the stud?

Valve job now?

If I remove the heads to do a valve job must I also remove the barrels to replace the lower gaskets?

What is the going engineering cost to do the valves. Labor and parts?

Valve springs?

This is a lot to decide, but some of the experts here have faced this delimma. A road map would be appreciated."

ARF

[cmartin]

If it were me...

Send out the heads for a valve job. While the heads are off inspect the other head studs for any corrosion. The decision to make is if you want to replace all the studs, or just the bad one. Not a bad job, heck, I'm in the middle of it myself.

[hoophead]

Replace all the studs, or you'll be doing it all again same time next year...when I tore my SC motor apart due to 2 broken studs, I found that the PO had replaced only one of the lower studs :(

[Jase007]

John:

Sorry to hear of your troubles. If you are gonna pull the heads [gotta] then I'd send them out to. [as per C Martin]. ARP studs are nice but $$$. [same goes with race springs, titamium anything, etc...]:lol:

I'd start a spreadsheet for cost projection and if you don't have Wayne's engine rebuild book, pick up a copy. There are cost estimates in there as well though a little out of date.

3.2L weak points? Not much besides valve guides [not really a weak point] and rod bolts. Gonna have to decide how far you / Michelle want to get into it.

Good luck and let us know if you need a hand R&R'ing.

[markwemple]

Jase mentioned the "rod bolt" issue. That's where my focus would be. Any concensus on whether 1 broken stud, depending upon location, necesitates a tear down or a close eye. Just wondering if he can wait a while or if he's better off jumping in.

Sorry about the bad news. Now we know that Carreras are vulneable to this, the worst of 911 maladies ('cause they ruin an otherwise very healthy engine!).

[Dr K]

Question for all (suggested by Jase's comment):
If doing a valve job with new guides, etc., and you put in race springs, how much can you raise your red line (I suppose with a custom chip)? Are there other advantages to the more expensive springs?

[cmartin]

Are you changing rod bolts too? If not, I wouldnt raise the redline, at least past the standard chip ~200rpm increase.

[Dr K]

I'm not changing anything - already had my expen$ive (but successful) rebuild. I was just interested since I didn't spring for the race springs.

[cmartin]

I'm far from the expert on this, I've just been reading a lot as I'm in the middle of this myself. Valve springs help, especially if you change cam's, and are a nice to have in case you over rev. I'm sure you can raise the limit some, but I'm conservative.

[smdubovsky]

It was recommended to me to use the 993 head studs (if you dont go all the way to ARP). I have a pic of the part # if you need.

If you're going to pull the heads to replace all the studs, I don't think you have to replace the cyl base gaskets. I'd just lift the cyls on the pistons high enough to get the studs out (but not pull the cyls off the rings). Apply recommended green gooey CurilT and reinsert.

I wouldn't bother w/ rebuilding the heads if they're ok. Doesn't take long to check seat/guide wear and if they are ok, why remachine them? My 150k SC had near perfect seats (but one worn guide).

Though, if you get a motor down that far its awfull tempting to buy a full rebuild kit and put new bearings in...

SMD
________
Lovely Wendie99 (http://www.lovelywendie99.com/)

[Rick V]

Ok John, here is my $.02
Pull the heads (both) replace all the head studs. disasemble the heads and inspect everything. Make all your re-build decisions at that point. It is very easy to get carried away with the WYIT stuff. Make a decision only after you have everything miked, and cleaned. You might find that a valve re-lap is the only thing required.
Personaly I would replace the rings as well. (I'm a file to fit type of guy)

[OldTee]

Ok John, here is my $.02
Pull the heads (both) replace all the head studs. disasemble the heads and inspect everything. Make all your re-build decisions at that point. It is very easy to get carried away with the WYIT stuff. Make a decision only after you have everything miked, and cleaned. You might find that a valve re-lap is the only thing required.
Personaly I would replace the rings as well. (I'm a file to fit type of guy)

This is in line with my thinking. My Loousiana Pappy told me to always sleep on a hard decision, de longer you sleep, de clearer is de decision.
ARF

[Trak Ratt]

Ok John, here is my $.02
Pull the heads (both) replace all the head studs. disasemble the heads and inspect everything. Make all your re-build decisions at that point. It is very easy to get carried away with the WYIT stuff. Make a decision only after you have everything miked, and cleaned. You might find that a valve re-lap is the only thing required.
Personaly I would replace the rings as well. (I'm a file to fit type of guy)

This is in line with my thinking. My Loousiana Pappy told me to always sleep on a hard decision, de longer you sleep, de clearer is de decision.
ARF
Totally agree, and very good advice. I agree on the rings too. Can’t imagine not replacing guides if over 25K on them though, especially if original.

[OldTee]

Response on Pelican sounds like a good approach to start with and the makings of a plan.

"boxermania
Member

Registered: Oct 2006
Location: Baton Rouge, LA
Posts: 61
OldTee

Since the engine is out and the car will be a keeper I would sugest the following:

1) Replace all of the lower studs with the steel version
2) Refurbish the heads (valve job) the whole job typically runs around $600 with out parts. There were some issues with the 3.2 valve guides early on but I would sumize that by '87 the issues where corrected
3)If the car had basic maintenance, you should still see the crosshatch (honing) on the cylinders with hardly any wear (ridge) on the cylinders. No need to go there, they are good for 200K+ miles.
4) replace the front and rear crank seals if there is evidence of leaks.

Of course reseal everything on the outside and you should have a sound engine for a long while.

Good luck"

Any comments.

ARF

[markwemple]

I've read too many articles about the Carrera rod bolts to not do those as well. Not sure if the '87 is late enough to not have this problem or if it ran the entire Carrera series.

[dyerkes]

I wouldn't worry about the rod bolts, they are plenty strong unless you've gone or are going with forced induction. I concur with the others, and would side on replacing all of the head studs so that you don't have a repeat performance down the road (after all you're talking about a 28 year young car!).

[Trak Ratt]

I've read too many articles about the Carrera rod bolts to not do those as well. Not sure if the '87 is late enough to not have this problem or if it ran the entire Carrera series.

I wouldn't worry about the rod bolts, they are plenty strong unless you've gone or are going with forced induction. I concur with the others, and would side on replacing all of the head studs so that you don't have a repeat performance down the road (after all you're talking about a 28 year young car!).

If you research the Carrera rod bolt issue I think you’ll find: because of longer stroke Porsche made rod bolt ends slightly smaller for clearance. As long as engine maintains ~stock specifications for size, compression ratio, RPM limit should be OK. Any combination of these that greatly exceeds stock specification means; replace rod bolts for insurance. So if you go to 3.4 but keep close to stock CR and RPM – OK. 3.2 + Higher CR, but same RPM – OK. 3.4 + 10.5CR (twin plug) + GT cams = :shock:

[William Miller]

I'd go all the way and refresh the bottom end too.
3-400 more at most for the parts and you'll probably do the seals anyway.
Hopefully you won't find anything when you open up the case, but if you do you will be glad you did. Then you will have a complete picture of engine and can document what you found if you ever sell in the long run.
The time involved is not much and you can get it done while the heads are out.
The only complicate part is cam timing and you'll be doing that anyway.
That's fairly easy after you look at it a while and the light bulb goes on!

Good luck whatever you decide!

[Trak Ratt]

I'd go all the way and refresh the bottom end too.
3-400 more at most for the parts and you'll probably do the seals anyway.
Good luck whatever you decide!
New bearings, micro crank, resize rods, oil pumps, rod bolts, gaskets, seals, clips, etc, etc, $400?????

[racer]

Do it right. Timmons 3.6 conversion ;) Sorry I couldn't ad anything constructive here :)

[Trak Ratt]

Do it right. Timmons 3.6 conversion ;) Sorry I couldn't ad anything constructive here :)996 engines fit right in chicksters :p

[mshell]

Thanks to all who are contributing to the collective knowledge. You all have given me many new vocabulary words to focus on.

All knowledge is worth having...
M

[Rick V]

Hey Michelle, Credit cards smoking yet? :)

[William Miller]

New bearings, micro crank, resize rods, oil pumps, rod bolts, gaskets, seals, clips, etc, etc, $400?????

Much of that is probably not needed. If it is you would probably want to spend the additional $$ now wouldn't you?

[Trak Ratt]

I'd go all the way and refresh the bottom end too. !

Much of that is probably not needed. If it is you would probably want to spend the additional $$ now wouldn't you?
Yeah, I know.