Retorquing

[SC-Alfa]

I recently had an engine tear down with head stud replacement (racewear), reseal and top end rebuild done at local Porsche dealer.

It occurs to me that the head studs might need to be retorqued after a wear in period. The dealership didn't mention anything about this to me, but two questions.

1. Does it need to be done and if so after how many miles?

2. Is the price of a retorque traditionally included in the cost of the job?

[Peter Zimmermann]

When my shop did this repair (using factory o.e. studs) we would schedule the car for a 1K mile service. We adjusted the valves, checked head torque (always OK on aluminum cases), and changed the oil and filter. We charged for parts (VC gasket kit, oil filter, 2x seal washers and oil), the labor was N/C. This was costly for us, but I considered it an insurance policy to protect both the car owner, and my shop.

[SC-Alfa]

Thanks Peter. I used your 915 Trans DIY, couldn't have done it without you, many thanks.

[will hung]

If you DIY'd a 915 trans, you can adjust your own valves and tighten head studs. Get Wayne's book, "How to Rebuild and Modify your Porsche 911 Engine." He shows you the proper order to torque the head studs. From what I read, Racewear studs stretch with use. My engine has them and I needed to retorque them at the first 500 mile valve adjustment. At my second valve adjustment, 500 miles later, they were good.

[Bob Kontak]

Peter's comment is a plus one. The valve lash should be re-checked as well as head nut torque. Not sure if Porsche counts this into the original cost structure but I doubt it. An independent would cost a lot less for this procedure. Call the dealer and ask them, though.

Also, I experienced the same as Will Hung with my Raceware studs. First adjustment 15 years ago they needed tightening. After that, they have checked out ok.

[SC-Alfa]

I've done many valve adjustments on this car (had it 20 years). This is the first rebuild so I was a little foggy on the retorque. A little disappointed the dealership didn't mention it needed to be done.

[SC-Alfa]

Ok, not to belabor this, but I called the dealership and was told the head studs do not need to be retorqued. The mechanic who provided the advice is the dealerships old Porsche specialist.

[trak ratt]

Originally Posted by SC-Alfa

... A little disappointed the dealership didn't mention it needed to be done.

All the more reason to check everything.

[Bob Kontak]

I am as well.

To be fair, the deep retro-knowledge base of the dealership may be contained within one 52 year old wrench that does not schedule appointments.

Edit - Oops waited too long to post. Already mentioned.

[SC-Alfa]

I guess to be safe I'll crack it open and check everything out. Might wait till winter though

[Jeff Higgins]

It's just so darn easy to get to them when setting the valves, it really falls under the "why not"? catagory. Takes about ten minuts after you pop the valve covers.

I know everyone says aluminum cases should not require this, but mine did. There were a few loose ones after the initial 1,000 miles. I checked just for the hell of it, and was glad I did.

[tobluforu]

Two years ago I changed the cams and towers, should re-tourque everything as well on my 72, or leave well enough alone?

[cmcfaul]

My 73 E needed to have the head bolts tightened after a couple thousand miles. All the lower bolts were really lose. I am going to check them regularly until I am confident they are staying put.

A bit of a relief they just needed tightened. Thought at first the studs were pulling.

Mag case - motor rebuilt a year ago.

Chris

73 911 E

[j911brick]

I have rebuilt dozens of 911 motors and I see head nuts losing their torque all the time. Some more than others. Just depends on the case, studs, and how often its been apart. I usually torque the nuts threes times as I assemble the motor, then again after first run-in, then at first oil change (usually one hour), first service, ect. I basically keep checking them till they stop coming loose. Sometimes they are fine right off the bat; sometimes it has to be checked more than 5 times.

[Bob Kontak]

Originally Posted by tobluforu

Two years ago I changed the cams and towers, should re-tourque everything as well on my 72, or leave well enough alone?

The new cams and rocker arms mated up with each other. That probably caused a bit of expected wear/break-in. On the up side, the wear would cause the lash to get fatter which is way better than tighter. Picture the back of the rocker getting closer to the cam - the other end backs away from the valve stem. The downside is clatter and a wee bit of performance loss, if applicable. Not a crisis in the short term.

[Trackrash]

Are we talking about re-torquing or just putting a wrench on the nut and checking if they are tight?

I've been told to back off the nut a quarter of a turn then re-torque to the proper value.
What are everyone's thoughts on this?

I am assuming everyone uses anti-seize on the threads?

[gsmith660]

Did an upper end on my 77 and have checked at every valve adjustment with no loose nuts or lost torque this was 8 years ago but this will be the first valve adjustment since I turbo'd the motor so I will be very curious.

[will hung]

Originally Posted by Trackrash

Are we talking about re-torquing or just putting a wrench on the nut and checking if they are tight?

I've been told to back off the nut a quarter of a turn then re-torque to the proper value.
What are everyone's thoughts on this?

I am assuming everyone uses anti-seize on the threads?

Depends on the studs. Racewear recommends loosening and then torqueing in 3 progressive stages up to the final torque setting.