dropping valves?

Moderators: Sluggo, Amskeptic

User avatar
hambone
Post-Industrial Non-Secular Mennonite
Location: Portland, Ore.
Status: Offline

Re: dropping valves?

Post by hambone » Tue Jun 16, 2015 8:50 pm

Try adjusting the valves again, mebbe yer nuts. COLD is cold you know.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Tue Jun 16, 2015 8:58 pm

Oh, they were cold. Took a few turns on the wrench to loosen them. Unprecedented.

After my 8.5 hour day, I tried to pull the heads this evening, just knocked off after taking the torque off of the head on cylinders one and two, had a couple nuts off when I remembered I still needed to take off the exhaust. Doh! Losing my light and steam, so tomorrow. I'll get some photos up.


neal
The slipper has no teeth.

User avatar
hambone
Post-Industrial Non-Secular Mennonite
Location: Portland, Ore.
Status: Offline

Re: dropping valves?

Post by hambone » Wed Jun 24, 2015 10:59 am

You get anywhere with this? Still trying to understand how both heads have stretched valves. Guess anything is possible.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

User avatar
tristessa
Trusted Air-Cooled Maniac
Location: Uwish Uknew, Oregon
Status: Offline

Re: dropping valves?

Post by tristessa » Wed Jun 24, 2015 11:42 am

hambone wrote:Still trying to understand how both heads have stretched valves.
One way it could happen is if they were cheap shitty valves that got installed...
Remember, only YOU can prevent narcissism!

User avatar
hambone
Post-Industrial Non-Secular Mennonite
Location: Portland, Ore.
Status: Offline

Re: dropping valves?

Post by hambone » Wed Jun 24, 2015 1:00 pm

Yep. So much junk out there...
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: dropping valves?

Post by Amskeptic » Sat Jun 27, 2015 10:38 am

hambone wrote:Only one he says.
What are the odds of both heads being bad? I guess it's possible, but not likely they'd fail in the same manner...
Chloe's heads were both bad. Wrong size exhaust valves in every cylinder. The erroneous assembly of one suggests that the other will have the same problem.

Sorry you are experiencing this, Neal, but if the engine is still fresh and breaking in, we expect valves to migrate a little down onto the seats, and the heads often migrate slightly closer to the centerline of the engine as they seat onto the barrels. This reduces valve clearances during initial thousand miles or so.

How many miles are on the engine?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Thu Jul 02, 2015 8:41 pm

Reference my spotty notations? What logic. So I did. Looks like Bertha's odometer reading at first fueling after firing up the new engine read 78838.whatever tenths on the last day of March, 2014.

10, 291 miles on this rebuild. Snugged up the heads three times, and all three times I was glad I did, they snugged further. After that, you know I tested every head bolt on this engine before starting to loosen them. All good but the bottom rear-most on #3. Not drastic loose, but not to spec torque.

The one valve I measured on the most obvious culprit, #2, measured fine. But it had been receding into the seat. There was a lip on the seat. That would suggest a wrong sized exhaust valve. What a concept. Too small!

Anyway. I'm still in limbo with very little progress. Although now that the engine is out, perfect time to swap bell housings of the transaxles. More new territory.


neal
The slipper has no teeth.

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Thu Jul 02, 2015 9:34 pm

I tried photoing, but, well. My initial concerns, plus the engine just didn't sound right. In terms of performance, the engine seemed spanking.

Image

Exhaust on the left.

Image

Oops, that was the tarmac of the Iquitos, Peru airport. Let me try that again.

Image

There's the lip.

Now I have only two sets of single port heads, the ones I had been running that were on Gretchen Ghia's original engine as purchased, and those that graced Ramona's engine that dealt with a piston failure, prompting this newly built engine.

Ever hopeful I trucked both sets down to Ashley at Always V-Dub and he immediately declared there were cracks about the spark plug of what I had been running. Tact isn't a concept he understands. Quit wasting his time with inanities. Boat anchor. And clean those things up for God's sake, bring 'em back, before I can render an opinion if the other pair are worthy.

Well it was Monday, so I went on down to the Lab and turned them over to a friend of mine who has access to the machine shop facilities of a small airport. After a week he cleaned up one of the four heads, tested springs, and inspected valves. He has a life apparently. Meanwhile my only runner isn't. Sigh.

Springs tested consistent. Odd spotting on the underside of the exhaust valve in question, cleaned up, the lip was even more apparent, and glaringly ovaled worn out valve guides. No cracks around the spark plug.

A few valve guides, not all. Assurances new seats could be installed and peened in. Valve guides are cheap, got the oven to bake the heads and install new.

Then he asks do I want a 30k mile head or a 100k mile head. A opined for the 100k head. He told me to buy a new one then.

Tomorrow I'm running into town pick up new german heads and exhaust valves.

The saga continues.


neal
The slipper has no teeth.

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: dropping valves?

Post by Amskeptic » Thu Jul 02, 2015 11:23 pm

ruckman101 wrote: Image

There's the lip.

The saga continues.
neal
You know what I see? I see an incredibly massive contact area. Were these seats 3-angle ground in the beginning? Normally, the 75* and the 15* angles skinny the contact area to between 2.5 and 3 mm. Your photograph reminds me of my Squareback, where **the seat was incorrectly hardened** during manufacture. Who did your head work for the March 2014 build?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Fri Jul 03, 2015 7:05 am

The same fellow who "rebuilt" my transmission.

neal
The slipper has no teeth.

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: dropping valves?

Post by Amskeptic » Fri Jul 03, 2015 9:18 am

ruckman101 wrote:The same fellow who "rebuilt" my transmission.

neal
It's on him. That is not normal.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Sat Jul 11, 2015 12:22 am

He machined with no regard to the condition of the heads.

Got back my two sets of single port heads from my bud Cliff. Dipped, cleaned, cracks outlined. Conclusion. Of the four, one pair could be viable with some additional work. Good golly one from Gretchen, one from Ramona. The heads working cylinders one/two.

Cliff rated them, with additional work, 30k heads. You want 100k? Buy new heads.

I have an investment in the bottom end. So I made a similar investment in the top end and bought new heads. Brazilian. Bare. With a new set of exhaust valves. I gotta give Bertha Chloe cred.

Tomorrow I begin building up my new heads. I'll save the two "potential for a few more miles" heads, and strip the boat anchors of valves, springs, retainers and keepers.

And rather than just "slapping a new pair of heads" on this bottom end, recalculate my compression ratio and rocker arm geometry. Currently I have shims everywhere.


neal
The slipper has no teeth.

User avatar
asiab3
IAC Addict!
Location: San Diego, CA
Contact:
Status: Offline

Re: dropping valves?

Post by asiab3 » Sat Jul 11, 2015 1:51 am

Good on 'ya for remeasuring the important stuff.

Are the new heads the AutoLinea variety? Word on the street is that some need significant "help" in the cooling fin casting department to make them proper air-cooled equipment.

Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: dropping valves?

Post by Amskeptic » Sat Jul 11, 2015 10:20 am

asiab3 wrote:Good on 'ya for remeasuring the important stuff.

Are the new heads the AutoLinea variety? Word on the street is that some need significant "help" in the cooling fin casting department to make them proper air-cooled equipment.

Robbie
Oh yes, get some strong light shining through.

Here's a flashing blocked AutoLinea head:

Image


......... after some drilling:

Image
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Re: dropping valves?

Post by ruckman101 » Sun Jul 12, 2015 6:42 pm

I always file away casting obstructions on heads and cylinders.

Not AutoLinea, Brazilian VW. Bare. New exhaust valves. The yellow/amber waxy protective coating proved to resist everything I brought to it. Tried soap and water, Goof Off, Carb cleaner, nothing. Had no brake cleaner.

So today I loaded them up along with my collection of used dual port heads and trotted off to my friend Cliff's shop, my first visit. He is set. It seems to be a pretty full on machine shop. Dipping the new heads cleaned them right up. A few big globs here and there, but I can deal with those while filing out the flashing. After I get Bertha back on the road, I'm going to revisit, and get some valve grinding, fly-cutting, valve guide replacement practice on the dead heads, and then the only two viable single ports.

Every single dual port head had cracks in the combustion areas, readily apparent by media blasting clean the area. (One of those boxes with the reach in gloves. Man it worked great. Had one potential head I went to town on and it looks like it had been dipped, but then the crack between valve seats jumped right out.)


neal
The slipper has no teeth.

Post Reply