Removing Cams - Question

[cajun31]

If the compression is still good on that cylinder then I would also say that it is the valve stem seal.

[Radioguylogs]

Cams are out, and head is off.

Went smoothly, thanks to your collective advice.

Just like bikerphil said, the head was not a problem to break lose. A few light bops with a rubber mallet and it came free easily.

Surprised the studs have almost no rust. Nice.

Note: Head de-torqueing sequence is backward in the Clymer's manual. Clymer copied the diagram from the FSM. Clymer didn't notice the instruction in the FSM say to go backward from the tightening sequence, and then the FSM shows a diagram of the tightening sequence, which is a bit confusing. I had to look at the tightening instructions in the FSM to double-confirm what they meant.

More to follow.

[Radioguylogs]

BTW: Manual says to clean carbon off piston crowns but don't disturb the carbon ring at the top of the cylinders.

Do you guys think it's better to try and clean the pistons, or leave them? Seems like an unnecessary risk to get crud down into the rings.

[DiverRay]

If it's a LOT of carbon, you need to clean them. If it seems to be a thin coating, just leave it. I would work on what the exhaust ports now look like. An easy way to clean carbon is put some Berryman's B12 on the carbon and let it set for a bit. It will take the carbon off without scratching anything. Or you can wait until you have it back together, run until warm, and then spray some B12 into the carbs until it dies. Let it set for 20 minutes and then fire it up. DO NOT do this with the garage door closed!!

[bikerphil]

I think the same, leave alone unless excessive. Definitely clean the head though. If you need to scrape, use a rounded edge tool such as a thick feeler gauge, still have to be careful though.

[Radioguylogs]

Time for an update.

I did clean the head and the pistons.








I installed the new valve seals and got the head back on a few weeks ago.

At first I found three valves clearances had shifted to the low end of the spec due to light valve lapping. I re-shimmed those and measured the compression.

I got 155psi on all four jugs if I let the engine turn over about 20-25 times for each reading. I was pleased they all were the same and they were favorable.

After measuring the compression, another intake valve has clearance at the low end of the spec. Must have had some crud under the valve. I am still waiting for an ordered shim to adjust that one.

Mainly, I wanted to report the results, and thank everyone for their help on the sequence to remove and install the cams. It went easily and now it all makes sense.

[Radioguylogs]

As a side note, it's apparent that the Vesrah head gasket is made so you delete the seal around the chain tunnel (at least I hope so ).

Here is the old gasket laying top the new gasket:

[bikerphil]

Yes, that cam tunnel seal has been omitted from the aftermarket and OEM head gaskets for many years now.

[DEEBS11]

Mike, nice job on cleaning up that carbon. How did you end up doing it?