911 sc headstuds

[Neggy]

Ok, I’ve recently bought a 911 sc 1981. I still haven’t fetched the car yet but I’ve fetched the engine which is in bits. I’ve started cleaning the case half’s and checking condition. All the headstuds are tight and look to be in good condition. I’ve read lots about head studs and apparently the exhaust studs are the ones that are non magnetic and so are made of dilavar. When I’ve checked my headstuds they are all non magnetic which contradicts what I’ve read. Could they be aftermarket or should I replace them all anyway? I pulled one out to see how hard they are to get out and it came it out relatively easy. If replace which is best for a budget conscious road car and from where? I’m going to be doing all the bearings and all other parts needed to refurb the motor so I will order everything at the same time. 
Thanks for any help

[Zelrik911]

Hi Neggy

Those coated studs look like replacements from a rebuild at some time fairly recently.

You could replace all them with non-dilavar (which are inexpensive), but if these studs seem to have been installed properly - I would not replace them.

Spend your money on buying the good aftermarket head nuts be extra careful  when tensioning them. 

Why was the motor in bits, was it a poor rebuild?

Good luck with your rebuild.

[Mike D'Silva]

bugger... how did I miss out on a deal like this? Did you post about this motor on Pelican Parts? I'm feeling a bit of deja vu...

As for headstuds, if you don't know how old, I would toss them. If it's a big HP build, you should get some ARP. If it's a stock build, just get some steel ones from James at Autohouse. 

Replace all of them. Chase out the threads with a thread chaser NOT a tap. Henry from supertec uses blue loctite for his studs. If you are worried, use red and hope you never have to remove them again. (Next persons problem in 30 years hopefully).

What else are you going to upgrade?

If you need some cams, I have a set of 964 available (shameless plug!)

Mike

 

[Neggy]

Thanks for the reply zelrik911, I didn’t realize I had recieved any responses. I don’t know why the engine was taken apart because everything seems to be in good nick. I haven’t got any paperwork with the car so no service history what so ever. 

On 08/05/2023 at 13:37, Mike D'Silva said:

bugger... how did I miss out on a deal like this? Did you post about this motor on Pelican Parts? I'm feeling a bit of deja vu...

As for headstuds, if you don't know how old, I would toss them. If it's a big HP build, you should get some ARP. If it's a stock build, just get some steel ones from James at Autohouse. 

Replace all of them. Chase out the threads with a thread chaser NOT a tap. Henry from supertec uses blue loctite for his studs. If you are worried, use red and hope you never have to remove them again. (Next persons problem in 30 years hopefully).

What else are you going to upgrade?

If you need some cams, I have a set of 964 available (shameless plug!)

Mike

 

Thanks mike, no I’ve not posted anything any where else. I don’t know about upgrades, at this stage I’m just cleaning everything up and seeing what I need, I’m pretty certain the barrels and pistons will need a refurb or replacement as there are scratches in the bores from poor storage other than that I’ve not seen many problems yet, I’m still learning as this is my first Porsche engine build, where is best place for barrels and pistons? 

[Peter M]

1 hour ago, Neggy said:

where is best place for barrels and pistons? 

Once you price a new set you may need a strong drink and a sitdown!  Except for the cost of plain steel head studs, the price of parts for these engines is just astonishing.

Suggest you carefully inspect and measure up your current P&C's first to make absolutely sure you can't reuse what you have.

If the pistons are still in spec, including the ring grooves but the cylinders are badly scored you can have the cylinders repaired by Nikasil plating and just treat the pistons with a new set of rings.