It didn't fall 'IN' the motor after all...

[bryant4]

but the motor wouldn't rotate by hand more than about 300 degrees...
Documented here:

I hope this isn't a 'Newbie Screwup'

so I decided to drop the motor and find the problem.

Now my motor looks like this:


and this is what I found that somehow was keeping the engine from rotating.


So, not inside the motor after all...

Now what to do...

A bit of background:
Bought the 1978sc with 193,000 miles in August '13 for $8k because it would not pass Calif smog test. The car had sat mostly undriven for the last 12 years snug in a garage .
I was sure I could solve the smog test problem with a freshening of the CIS system.


No history on the vehicle
Heads look clean inside, engine crusty outside

The PPI showed the following (pressure test, leak down):
Cyl 1: 150psi, 8% loss
#2: 155psi, 5% loss
#3: 155, 7%
#4: 130, 25% loss, blowby past ex valve seat
#5: 150, 25% loss, blowby past rings
#6: 145, 5% loss

NO broken headstuds, at least none discovered yet...

Clearly the engine needs lots of degreasing, but
Not much money available at this moment for a 'full rebuild'
I have replaced all the seals etc on the list of common leaks,
replacing clutch with new kit.

Want to get the car on the road and PASS SMOG ASAP.

so I am looking for advice on what to consider 'Essential' to do but also very "budget conscious'

[bryant4]

[smokintr6]

With those leak numbers I would do a valve job. Send the heads to Anchor Atlantic and be done with it. Have had excellent results with them. I would also be inclined to replace the head studs while youre that far into it. Also I can't tell how much stretch those chains have, but I would inspect closely the timing chains and tensioners.

[yelcab1]

I am not sure I would do a valve job yet on that engine. Clean it up, fix the leaks, tune it up, drive it hard for a month, and smog it.

[kodioneill]

Originally Posted by smokintr6

With those leak numbers I would do a valve job. Send the heads to Anchor Atlantic and be done with it. Have had excellent results with them. I would also be inclined to replace the head studs while youre that far into it. Also I can't tell how much stretch those chains have, but I would inspect closely the timing chains and tensioners.

Good advice very good.

[bryant4]

[bryant4]

I like your advice, yelcab1

It agrees with my wallet right now...

But I am gonna have a look at #4 and 5 since I am so close...
good chance it was just carbon, right? (ever hopeful...)



smokintr6, I agree with you but I'm trying to find a way around it...

[ClickClickBoom]

Hey,
Those leakdown numbers aren't that bad, get it running and drive it for 10 hours or so with an aggressive detergent oil(Brad Penn) would be a good choice. Then recheck the leakdown. Rings gum up and dont seal well and valves get crud stuck on the seating surface. If it runs well, get a pre-test done and drive it. Plan for the top refresh at your own pace.
Get a temp operating permit and get all the paperwork in order and drive it for a month or 2. CIS doesn't like to sit for extended periods, and that might be why it couldn't pass smog.

[RDM]

Beautiful color. But I'm biased!

I'd take the drive it for a while option. How far you've come (pulling the engine) is not nearly as far as where you'd have to go (pull heads). If money is tight and there's a chance it'll get better on its own, roll the dice.

[T77911S]

thats th abyss. i dropped a bolt in there last night. did not get it out yet. that place REALLY sucks

[bryant4]

[bryant4]

[bryant4]

the studs seem to have been replaced already.

All 24 are the same. ALL DILAVER?

they are powdercoated black.

they are NON-magnetic

[snbush67]

It's not too much of a job to pull the valves out and check the seats, lap them in by hand and put it back together. I would bet that the engine has had a recent top end and you just have some carbon in the seats.

It looks like it was probably tuned rich and someone didn't know how to properly flog the machine.

[bryant4]

just dug out my valve spring compressor for tomorrow morning...
I have a 3 day weekend so I plan a lot of 911 time...


Regarding lapping...
I have lapped motorcycle valves 'in the day'
but I didn't find much about lapping Porsche valves...?

[snbush67]

Same theory, use some grit, elbow grease and patience. Check often with blueing. If you have a way to apply vacuum you can check for a good seal when closed. I remember the shop where I built my motor had an attachment for an air compressor that was used specifically to check the valves to seat seal.

[snbush67]

Sioux Style Vacuum Tester

Cheap version:

Valve Seat Vacuum Tester

Cheaper version:

Vacuum Testers : Cyllinder Head Rebuilding : GOODSON

[NICE 69 S]

Put the plugs back in, fill the combustion chamber with water, blow compressed air into the ports. If air bubbles into the combustion chamber, more lapping required. This is the first thing I do after removing the heads to see what condition the valves job is in.
Bob B

[euro911sc]

Bob B: Nice! I'll have to remember that trick.

that mount where your bolt fell... it has a drain at the bottom that usually needs to be drilled out clean. Also, you might consider drilling an access hole through that mount so you can get a socket on the nut that is hidden. Makes it really easy to put it back on

[bryant4]

I cleaned up one head and lapped the valves and that worked great. I did it Makita style...

but one exhaust stud broke off below grade and there is quite a bit of guide wear... visible wear, pitting on one valve stem etc.
see pic...

So off they go to Ollie's in LHC
fancy valve lapping device

broken stud

note guide wear