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I've joined the broken head studs club ...


Harvs11

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Amanda, it's been about 12 months. Initially it was only the stud on no. 2 head which went. This isn't such a problem because the head is supported by those on either side. The stud from the outside of no. 3 was a more serious problem. The corner of the head deflects under load at higher revs and lets the combustion gasses past the head gasket. This is the noise I heard.

I've been worried every time I drive it and I'd had enough. The decision to fix it was to prevent further damage and also give back some enjoyment when I drive it. A bit like your IMS. It was running OK but the worry was there that it gives out.

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Amanda, it's been about 12 months. Initially it was only the stud on no. 2 head which went. This isn't such a problem because the head is supported by those on either side. The stud from the outside of no. 3 was a more serious problem. The corner of the head deflects under load at higher revs and lets the combustion gasses past the head gasket. This is the noise I heard.

I've been worried every time I drive it and I'd had enough. The decision to fix it was to prevent further damage and also give back some enjoyment when I drive it. A bit like your IMS. It was running OK but the worry was there that it gives out.

 

Ok gotcha. How long do you expect the build to take?

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I should get my self an aircooled 911. looks like 6 bolts and the engine comes out. 

 

Good luck sorting the gaskets.. when i sorted mine out, i pretty much gave up and just put what i think goes where it fits. 

 

Are you getting the head resurfaced? I would look into it as you could have warped it a little from the broken stud. Even if it's 0.05mm out, putting stress on the head to make it flat could cause damage in the long term as it will be going to heat cycles. 

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Got busy tonight. New socket from PP made light work of the cam nuts. Once they were off it was smooth sailing getting the cam boxes off. Had dinner and got the heads off. I was surprised how easily the head nuts cracked and undone. A couple were almost loose.

Heads and cylinder tops look OK. I'll get them checked and decide if a top-end rebuild or machining is required. I'll post some pics later.

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here's a couple of pics from the garage last night. pls.  excuse the grainy images

 

headless motor with home-made cylinder savers.(stops the cylinder falling off when you turn the motor)

296A8AC6-7B18-4C80-8E68-9C20DC48B1D4.jpg

 

Heads-  you can see the oil seepage past the broken studs on cyl. 2 and 3

15A905AC-FAEB-4B44-932A-E55D4B5A774B.jpg

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It's been quite a few hours just cleaning up this week. Mostly getting gasket faces all pristine again.

Interesting find on the head gaskets. It looks like they were sealed in with Loctite or similar. I hadn't intended pulling the pistons from the cylinders but it was necessary to get the seal grooves cleaned out ready for the new gaskets

On the positive side, the blow-by on cyl. 2 & 3 hasn't damaged either the cylinder or heads.

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were the rings worn to cause the blow-by? 

 

Have you worked out what needs to be sorted with the build? 

 

No,

Harvey is talking about any possible blowby damage caused by the broken studs allowing the gas to get by the head & cylinder creating deteriorating of the mating surfaces.

The blowby you are thinking of is totally different .

 

Dave

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Blow by was past the head gasket due to the stud allowing the head to lift off slightly under load. The resulting noise is what started this. Rings were not the problem here.

So far it is a clean up and re-assemble with new exhaust side head studs and all new gaskets and seals.  I'll also put in new fasteners/nylock nuts where I can.  While I'd like to have a factory fresh finish on the engine, that would require a far more extensive tear down than I am prepared to do.   It will just have to be a "clean"  engine, not concours standard.

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I had a case of fumble fingers the other night.  Snagged an oil ring while removing the pistons/cylinders.  They break REAL easily. Resulted in a visit to a local P car engine builder today to have the cylinder honed ready for a new set of rings. It could have been worse. I found all the pieces of broken ring, so none went in the case. Phew!

Otherwise P's & C's are in good nick so no other machining is needed.

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I've reached something of a milestone tonight.  The dismantling has ended, now it's time to put it all back together.  The job I was dreading most, removing the old head studs, turned out to be quite an easy job.  60 seconds of heat around each stud before winding it out using a ring spanner on double nuts.  Some even came out without heat but I had to lean on a couple. The broken studs actually came out very easily. I ground flats on the shaft and held it with vice-grips.  

 

one of the broken studs (centre of image) 

11187318864_ea3b948f65.jpg
 

11305531133_d1d69d0c84.jpg
 
btw thanks again to JustJames for excellent service getting parts delivered overnight from Autohaus Hamilton in Sydney to me in Melbourne.

 

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  • 4 weeks later...

I managed to get a few good days between Xmas and now putting my engine back together.

It's all gone pretty smoothly so far. Setting up the chain sprockets and dialing in the cams was a bit tedious but worked out ok. Today I got the block all sealed up with the chain box and valve covers fitted.

I'll be sitting on a beach for the next week. When I get back it will be time to get the intakes fitted, take the engine off the stand and the gearbox back on.

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Hi harvs

my first post on this thread (and for a while in general), loving following your progress. I feel like I am learning a bit about these engines through your efforts to continue posting. Thanks again and looking forward to seeing the end result.

Andy S

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Harvs I take my hat off to you.

Mate can you do me a huge favour and SMS me your number as I think I've list it between phones or pm me yours so I can call you tomorrow.

Need to ask you a quick question.

Look forward to buying you a beer for the posts in Canberra soon.

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Missed you on the SMT last weekend mate.

Hurry up and get that baby back on the road!

SMT would have been a nice way to top off the year.  I can't wait to get the old girl back on the road.

 

Here's a couple of photos to update the progress

 

New exhaust side studs fitted

FD1730F1-D2CF-464F-AB25-3E638DF2CADF.jpg

 

Looking like an engine again  :) with all new gaskets and lots of bling from all the new Nylock nuts 

7D00CB50-5A0E-4F30-9B7A-64900DE9AE49.jpg

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