Itinerant Air-Cooled

Can you crank the engine over for a dry and then wet compression test? You don't need much- just shove it's current long-ish block-ish state in a White Westy of some number. Crank it over six heavy pulses per cylinder and that will tell you if you're good to go. (Keep the distributor in, though.)

If you don't have/can't get a compression gauge, install all four spark plugs and crank. Listen intently for even pulses. Gung-ung-ung-ung-ung-ung is good. Gung-ung-UNG-ung-ung-ung-UNG-ung is bad.

I honestly don't know if the back of the valve or valve seat itself would be the first to succumb to repeated bashing with a screw… Could you get a nice macro photo of the valve tip of both intakes and exhaust valves on the offending cylinder head? I would be curious to see any exaggerated wear on the valve tips. Have you done a valve adjustment since the noise appeared? (Your gas test should be performed at the exact point of rotation as a valve adjustment- TDC on the compression stroke on each cylinder ensure that the valves are as closed as they get. Try the test on the other side of the engine for comparison. If all four are close, I'd consider rocking it!)

Robbie

Although my gut feeling says it fine, my gut feeling has been wrong several times with these Vw's. I have this one all torn down other than the fuel pump, oil cooler, distributor, heat exchangers and generator stand. I might as well take the head off and take a better look.
I think I will build up the new long block since it has a year warranty and put some miles on it. I am now looking for extra parts to build it up with so I can leave this one somewhat together.
I knew I should have picked up extra tin at the swap meets. Practically giving it away at the swaps but you pay through the nose if you have to order it from the Samba classifieds.

71whitewesty wrote: ↑

Mon Aug 28, 2017 9:33 am

Although my gut feeling says it fine, my gut feeling has been wrong several times with these Vw's. I have this one all torn down other than the fuel pump, oil cooler, distributor, heat exchangers and generator stand. I might as well take the head off and take a better look.
I think I will build up the new long block since it has a year warranty and put some miles on it. I am now looking for extra parts to build it up with so I can leave this one somewhat together.
I knew I should have picked up extra tin at the swap meets. Practically giving it away at the swaps but you pay through the nose if you have to order it from the Samba classifieds.

Sean, Sean, Sean. Do the gas in the intake port test and make sure the intake valve is closed. It's easy. TDC distributor rotor at your offending cylinder's spark plug wire. An inspection CANNOT discern a leak. No time for sloppy, vague suppositionishness.

So, if the head is off already, just fill the combustion chamber with gas. Both ports should remain dry for several minutes.

Too many buses, too many engines, makes Sean a distracted Forensics Scientist . . .
Colin

Too many busses? Nah...

drober23 wrote: ↑

Tue Aug 29, 2017 4:50 pm

Too many busses? Nah...

Ha!
It was your Conscience that led you here, and it is your Conscience that will steal your sleep until you can verify that each of your sixty three gorgeous-but-troubled VWs is running well or has found a good home.
Colin

Ok, ok, I'll do a better investigation before I pull the head off. Thanks for the kick in the pants. I'll re test today.

Alrighty folks, the leak down test passed with flying colors. I guess my guessing that the valve was closed on my first test was wrong, holds gas all day long.
Now I'm quite sure I have a perfectly good back up motor and that screw was just screwing with me. I'm glad I caught it in time and not on a long trip or it would have caused major problems as soon as the screw wore down enough to slip into the cylinder.
So I usually learn things the hard way and obviously still learning that way.
The HFM longblock is enroute and will be here any minute now. I'll still go with that one since I better break it in and get a few miles on it to make sure it's good to go.
Thanks for all the suggestions.

71whitewesty wrote: ↑

Thu Aug 31, 2017 2:29 pm

Alrighty folks, the leak down test passed with flying colors. I guess my guessing that the valve was closed on my first test was wrong, holds gas all day long.
Now I'm quite sure I have a perfectly good back up motor and that screw was just screwing with me. I'm glad I caught it in time and not on a long trip or it would have caused major problems as soon as the screw wore down enough to slip into the cylinder.
So I usually learn things the hard way and obviously still learning that way.
The HFM longblock is enroute and will be here any minute now. I'll still go with that one since I better break it in and get a few miles on it to make sure it's good to go.
Thanks for all the suggestions.

Nice! You dodged a bullet for sure and, AND you got a new engine past the wife as well. "But honey, just listen to that noise! The motor is going bad".

Well played.

71whitewesty wrote: ↑

Thu Aug 31, 2017 2:29 pm

Alrighty folks, the leak down test passed with flying colors. I guess my guessing that the valve was closed on my first test was wrong, holds gas all day long.
Now I'm quite sure I have a perfectly good back up motor and that screw was just screwing with me. I'm glad I caught it in time and not on a long trip or it would have caused major problems as soon as the screw wore down enough to slip into the cylinder.
So I usually learn things the hard way and obviously still learning that way.
The HFM longblock is enroute and will be here any minute now. I'll still go with that one since I better break it in and get a few miles on it to make sure it's good to go.
Thanks for all the suggestions.

So I can call you if Chloe grenades . . . .
"hey Sean, can I have your spare engine for just ten or twenty thousand miles, I'll return it at the end of the month."
Colin

Woohoo! Now as you tidy up the shop space, can I pretty please have a picture of the valve tips, if you still have the rockers off that side of the engine?

I hope your HFM engine is trouble-free. And I hope the almost-grenaded engine sees the road again one day in bus 3.

Robbie

Amskeptic wrote: ↑

Thu Aug 31, 2017 4:51 pm

So I can call you if Chloe grenades . . . .
"hey Sean, can I have your spare engine for just ten or twenty thousand miles, I'll return it at the end of the month."
Colin

Colin's Obsessively Thorough and Exacting Engine Break-In Service.
Rings Guaranteed To Be Sealed.
Valves Adjusted To The Finest Degree.