heads on a 3.0 too do or not to do

C-Pierce · 01-02-2008, 04:15 AM

I am going to rip down my newest purchase '80 SC with 87K. It has been determined that there are 2 broken head studs so that is the reason for the teardown. I am wondering what the general consensus is on rebuilding the heads on a 3.0. My last car ('76 2.7) needed a few Ex valve guides.

thoughts?

thanks
Chris

Aurel · Aurel's Garage

My heads at 110k needed all new guides, new exhausts valves, two intake valves and two valve seats.

If you are going to redo your heads, it would be wise to replace the piston rings too...but then you are on the slippery slope...and some will tell you that you should also split the case to check everything.

You could also keep driving the car for a while if the broken headstuds are not on the same cylinder.

A leakdown test should tell you if you what shape your heads are in.
How much oil does the car use and does it smoke? That should also influence your choice.

Good luck

Aurel

cgarr · cgarr's Garage

87K is not a lot of miles but since your in there and if they are virgin heads the seats should take a 3 angle cut no problem, should have the sealing surface cleaned up or at lease checked since you broke some studs too. Then you can bump the compression, twin plug the heads, add some cams, ditch the injection for carbs,,,, GITTY-UP

North Coast Cab · North Coast Cab's Garage

How did it run before the studs broke?
If you are a major DIY guy and it ran well you could just do the studs and go.

Wise man would say you should do a lot more "while you're in there," but that could turn your $500 job into a $5000 job. If the "new"car is rather unknown then I would plan for more than less as it could have been driven for a while in this condition and there could be other damage.

C-Pierce · 01-02-2008, 08:37 AM

I know that there are certain years that ther were issues with valve guides but I thought that was for the early 3.2s I wasnt sure about the 3.0 SCs.

But I guess if I have them done it is worth it for peace of mind.

C

Looking for used SSIs or early heater boxes..

C-Pierce · 01-02-2008, 08:43 AM

Oh and I have a new set of reground 964 profile SC cams, I dont really want to spend the big dolar and ditch the CIS ( gets excellent gas mileage ) Car runs OK but it does make a Phat,phat, phat. sound not sure if that is a broken exh stud or head blow by. I thought about doing a leak-down test but maybe I should save the time and just go for the complete re-build.. so whats a grand? its a Porsche for gods sake!
I do know the PO had no idea that the studs were broken so she may have driven it for a while like that...

thanks
Chris

Looking for a set of used SSIs or early heater boxes.