Itinerant Air-Cooled

Isn't there anybody left that actually double-checks their work??? So sad!!!

Very interesting...nice to dissect and get to the bottom of it....

Well, I think you knew from the closing gaps on successive valve adjustments that it was either stretching valve stems or sinking valve seats. I'm glad you found the answer in time to avoid a catastrophe.

Tim

I'd like to say "FFFUUUUUUUUUUUU-"

Damn man, that is a real pity! At first I thought that it was incorrectly machined from your pictures, as I kept reading I saw that there have been very heinous things working in there. =\

Seriously, +1 to vwlower, how can you miss that? I can say this even more so that I've been in the machine shop these days doing some good work, and I don't even remember how many times I checked dimensions on stuff that was "Mmm, that's close enough."

And to think I'm going to be engineering something that will be built in China... =/

Just think if someone else less inclined to check the temperatures of the running TBRRD would have eventually encountered? That apparently would not have lasted much longer. 38 hours? What a marathon!

total cost for this repair seems to have been relatively low, which is so impressive considering how bad it could have been in the hands of someone that needed to rely on a shop to do it, let alone what *could* have happened had it dropped a valve seat and all the parts that would then be needed to repair.

I look forward to the rest of the story - even after hearing the punchline.

satchmo wrote:Well, I think you knew from the closing gaps on successive valve adjustments that it was either stretching valve stems or sinking valve seats. I'm glad you found the answer in time to avoid a catastrophe.

Tim

This was a remarkable testament to the incredible toughness of these single port heads. Original valve seat inserts did not move in the cylinder head aluminum, but they apparently were heated to such an extent that the valves were making an impression in the seat contact area. That squiggly little profile line I drew in TX ER 05f was a "mold" of the valve itself! What temperature could possibly ruin the hardening treatment of steel inserts? The little F.I. TRW valves were a strange rust red color without a speck of carbon or anything on them, they were blast-furnace clean, yet they maintained all dimensions.

This particular failure-in-the-making was not the catastrophe I was nervous about. It was a fresh new vista of extreme localized heat.

This one was similar to what happened in the Squareback, where the closing #3 exhaust valve clearance made me think that the valve was stretching or the seat was moving in the aluminum (which destroys the interference fit in short order boof! hula-hoop! destruction!), but in fact, it was a relatively benign soft seat where the healthy valve could have safely migrated until there was just no adjustment available any more.

If I were to get new seats for those heads, I don't know that I could trust them to stay in place like these troupers did. Makes me soooo annoyed to see these poor seats ruined in original heads with such nice valve guide clearances.
ColinInLouisianaDodgingHailForecast

airkooledchris wrote:total cost for this repair seems to have been relatively low, which is so impressive considering how bad it could have been in the hands of someone that needed to rely on a shop to do it, let alone what *could* have happened had it dropped a valve seat and all the parts that would then be needed to repair.

I look forward to the rest of the story - even after hearing the punchline.

Two Used Heads ............................ $ 80.00
Overhaul Gasket Kit (with front seal) .. $ 19.99
Valve Lapping Compound .................. $ 4.99
Paper Towels and Carb Spray ............ $ 5.69
bonding with poor struggling engine ... priceless
........................................... Total $110.67

Xelmon wrote:
how can you miss that?
I've been in the machine shop these days doing some good work, and I don't even remember how many times I checked dimensions on stuff that was "Mmm, that's close enough."

The new sooper-dooper 3-in-1 valve grinding stones that bzoot! knock out the whole 3-angle grind in 7 seconds, may make some hurried harried burned-out machinists ASSUME that all is perfect and they just slap that puppy together.

I do not assume, because me and my razor blade are too panic stricken at the horror just unleashed by my shaky hands.
I use Sharpie Marker black (headliner-dot Sharpie black, in fact) instead of the classic Prussian Blue, but it works just as well to show me how parts are interacting with each other. Throw in a little prayer action for good measure "please work! please work! please?" and, well, I am in Louisiana and it is running very nicely ... except for a developing cam rattle.
Colin

Colin you are still one of the people out there I would most like to have a "breakdown with", and still right behind Joni Mitchel (because I have always found her very interenting, probably not much help in fixing a bus).

Any change in the CHTs?

PART TWO (24-38 hours)

Woke up for day two of Fixing That Which Should Not Have Needed Fixing. James Dwan is telling me that I have a "lake of oil under the engine which fell off the jack".
"Ha ha, you're funny, James, cut it out. Where is the coffee?"
TX ER 24


After a delightful hour of mucking about in the slippery slime with my raging lungs add a clogged dose baking id ibpossible do do a dab digh widdout sdeezidh, I am ready to reassemble with nothing but questions about slapping used razored drilled and filed used heads onto this once tidy little engine unit painstakingly put together by a man who cared. "Who cares? I got to get to Atlanta."
TX ER 25


Five hours later as I hit 30 hours in this garage, the long block is together (had to recharge the camera battery AND re-disassemble/reassemble the stupid right side to re-reinstall the under cylinder deflector plate).
TX ER 30


And one hour after that, the cylinder covers and manifolds are on. IS THIS ENGINE STILL GOING TO OVERHEAT????
TX ER 31


At 32 hours, the engine is mostly together, but I am getting deeply stupid and slow, dis coad is addoyig be haf to deadh.
TX ER 32


My back is killing me, my neck is a knot, my lungs are searing, but that's OK, the jack hangs up on the garage stepdown and stops me dead in my tracks. The engine has skidded on the jack and is no longer gorgeously balanced. Under the engine, I am prying up on the jack to unhang it and shove it another inch or so, cursing "I cadt take this crab, you have to get id the car!"
TX ER 33


James & Fam come home to see this hopeless yanking and sneezing.
"Need a hand? I just need to go in the house a minute."
"DOE. I have to pretedt I'b odd a desert isdad add will die if I dodt figure it out!"
"I like your perseverence," and James disappears into the house while I disappear into grump. Got the engine in though.
TX ER 34


Notice that it has taken FOUR!! hours to hook up some wires and fuel hose. You know why? I'll tell you why! I have gone completely utterly stupid tired sick and tired.
TX ER 38


Here, it is running. It is running! I am am walking dead. This is a deeply unflattering portrait of fatigue that beats that all-nighter with Mitch and Melissa in Montana on July 4th-5th.
TX ER 38b


Drove it down the street. Not bad, different though. No longer has that spiffy together feeling. These used heads are trying to make sense of what has happened to them.
"Weren't we sitting in a trailer full of junk just last week?"
"Yeah, what was with that finger lapping?"
"Finger lapping? I was going crazy with that razor blade scraping my spigots."

Engine has three hundred miles on it now. Runs cool. Cruising at 60-65, it sits at 320-340* with a little run-up to 360* on the hills. Max so far has been 372* It runs cool! These mud-caked greasy heads are nice and cool. Car has lost some power, but I can drive flat-out with abandon now. As it should be. No worries. No babying it. Just hit the road. Like these old air-cooled VWs were famous for. Now the car and I are bonding on a whole new level. It is mine now.
Colin

So it was running hot because the smaller valve wasn't able to dissipate heat as well as the larger, thus the heat built up?

neal

Glad you were able to get to the bottom of it. I assume you'll keep the valve as a souvenir?

Amskeptic wrote:

It is mine now.
Colin

=D>

That's all any bus could hope for, or bus owner for that matter. #busbonding is as important as anything else you do with it, so everyone knows where each other stands.

That picture with the engine tilted off the jack and sitting in a puddle of oil makes me feel...satisfied. It is good to know this kind of thing happens even to the most experienced among us.

Tim