1979 SC Chewed a Valve - Total Rebuild

[Flat6pac]

The oil pressure gets a flat aluminum, copper if you happen to have one.
Bruce

[OsoMoore]

Originally Posted by rwest

I haven’t read a lot of the middle portion of this thread, but did you have the heads rebuilt? I would think that old exhaust studs would have been in real bad shape and the rebuilder would replace them? If they did, they should come out easier than old heat cycled ones.

Heads were rebuilt, with a twist. One of my heads was destroyed when its valve went rogue. So I sent my heads along with a bonus used head to the shop.
My heads started with very long exhaust studs, as evidenced by the pile of washers that fell out when I took off the nuts.

When the refinished heads returned, 5 had long exhaust studs and 1 had a single short exhaust stud. I added a second matching short stud to the 6th head. But I had forgotten about the long studs, until I was looking at them sticking an extra half inch out of the exhaust headers.

So... the rebuilder returned 5 long studded heads, and a head with 1 short stud. I presume this means these are the original studs. Seems kind of odd of them.

[OsoMoore]

Originally Posted by Flat6pac

The oil pressure gets a flat aluminum, copper if you happen to have one.
Bruce

I probably have one somewhere in these baggies! Thanks for the info.

Also Wayne's book called for 25 ft/lbs on bigger camshaft oil line nuts. The crush washers were squishing more easily than that, so I stopped. Seemed too high of a torque target. They are all accessible, so if they leak I can redo easily.

[Henry Schmidt]

Originally Posted by OsoMoore

I probably have one somewhere in these baggies! Thanks for the info.

Also Wayne's book called for 25 ft/lbs on bigger camshaft oil line nuts. The crush washers were squishing more easily than that, so I stopped. Seemed too high of a torque target. They are all accessible, so if they leak I can redo easily.

What are "camshaft oil line nuts"?
If you mean, oil line fittings, hand tight with 574 on the threads. If you're using aluminum washers change them out for copper. The same for the banjo bolts.
574 on the threads and copper sealing rings.

Over the years we have seen some pretty low quality aluminum sealing washers (8mm case, valve cover, oil fittings). Too soft. That is one of the reasons why we source gaskets, seals and sealing washers from Wrigthwood Racing. Charlie is a perfectionist so you don't have to be.

[OsoMoore]

Originally Posted by Henry Schmidt

What are "camshaft oil line nuts"?
If you mean, oil line fittings, hand tight with 574 on the threads. If you're using aluminum washers change them out for copper. The same for the banjo bolts.
574 on the threads and copper sealing rings.

Over the years we have seen some pretty low quality aluminum sealing washers (8mm case, valve cover, oil fittings). Too soft. That is one of the reasons why we source gaskets, seals and sealing washers from Wrigthwood Racing. Charlie is a perfectionist so you don't have to be.

Yes, the oil line fittings. Thanks for the guidance, those are all very accessible so I can update.

[OsoMoore]

This morning I had a beautiful plan to do the fan, mount bar, drop on the still-fully-assembled CIS, and be ready for engine reinsertion tomorrow.

Well... that's not going to happen. When I looked into my #3 intake header, I saw some little bits of aluminum. So I pulled off a couple headers and peered into the airbox... large chunks of cylinder head. Yay!

So now I'm in for a CIS cleanup. Fortunately, I've done that before about 10 years ago. So the components are in pretty good shape, I have lots of pictures, and sort of know my way around.

I disassembled the lower stages and determined that, other than a little oil, nothing came past the throttle plate. So all the mess is in the bottom. Fuel distributor is safe, etc.

The challenges I've got:
1) I never really figured out how to take apart the bottom chamber of the airbox. It looks like it is glued or fused, in addition to the screws. That's where all the junk has landed, and it would be a lot easier to fix it if I could open it.
2) The stupid CA smog recirculator is still there mocking me. Can I just thread that hole and put a plug in it?

Some pictures of my discovery. I couldn't get a good photo of the view into the airbox, but there is at least one chunk an inch long. Also, there is the recirculator hole.

[PeteKz]

Fill it up with soapy water and shake/agitate the crap out of it.

[OsoMoore]

Originally Posted by PeteKz

Fill it up with soapy water and shake/agitate the crap out of it.

It was hard to make it watertight, but I did OK with some plastic wrap and shook it up with Simple Green. Got a couple more small bits out. Then looked in closely with a bright light, and worked a few hidden bits out with a brush.

I'm suspect I should replace the 10 year old intake sleeves, and the injector sleeves and orings. Mine still seem pliable... maybe that could wait?

[PeteKz]

My intake manifold sleeves are 45 years old and still not cracked. I'm still on the original injector sleeves and O-rings too, but I did replace the fat O-rings that hold the injectors into the sleeves. If it ain't broke, don't fix it.

[OsoMoore]

Hmm, I'll check them over carefully for pliability and cracks. Would be nice to save the time and cost. It snowed this morning, so I'm in danger if they salt, and I can't properly go warm it up on the road after the rebuild.

[Henry Schmidt]

Chasing air leaks in a CIS system can drive you absolutely crazy.
My $.02 worth.
Some times, peace of mind has genuine value.

[OsoMoore]

I spent a few hours carefully cleaning the airbox. Did multiple rounds soap and water, as well as brushing and scrubbing. I'm going to check again with the scope in the morning, but I'm sure there is nothing substantive left inside.

I also cleaned the header pipes carefully and they are shiny. I carefully scrubbed and checked the sleeves, I didn't want to use soap chemicals on them. They are still pliable an seem in good shape.

I also checked the injector sleeves and they seems fine. I'll replace the injector o-rings. I'll have to rebuild the CIS, but I've done that before and I'm not touching any adjustments like WUR or mixture. Even using the same exact spark plug type. So hopefully CIS won't be thrown out of whack.

The one big issue is actually not inside the garage:


We got hit with snow, and its going to keep freezing this week. Now I'm worried we'll get salt on the road, which will really hamper my ability to do a break-in run.

[OsoMoore]

Oh, question for you pros in here - what should I use as a seal between the airbox and the fuel distributor mechanism? It looks like there used to be some sort of felt seal? It was falling to bits.

Some Curil-T?

[Flat6pac]

911 110 394 02 Is the product for sealing the airflow sensor to the air box.
Bruce

[PeteKz]

It's not a critical seal. The air metering unit mounts on the low pressure side of the air box. Any automotive sealer will do.

[mikedsilva]

Originally Posted by PeteKz

It's not a critical seal. The air metering unit mounts on the low pressure side of the air box. Any automotive sealer will do.

um...

[PeteKz]

Don't want make it too hard to remove and clean off the sealer "next time."

[OsoMoore]

I've been pretty pleased with how well the CIS rebuild I did 10 years ago held up. I replaced all the tubes and cleaned everything out.

I peeked in with the scope it all looks clear. Hopefully tomorrow morning I can start to re-assemble the CIS.

[OsoMoore]

Arranging the hose clamps for the sleeves is a PITA. Finally got them all on and sitting properly on the engine itself. Waiting to bolt it down until I'm sure I don't need to adjust it some more.

Working with 30 degree headers is a good way to freeze your fingers.

[PeteKz]

Last time I had the CIS off my engine, I oriented the hose clamps on the manifold/airbox seals so that I could reach them with a long screwdriver with the CIS on the engine and the engine in the car to make it easier for my future me.