A Bad Day

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bus71
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A Bad Day

Post by bus71 » Fri Apr 20, 2018 5:50 pm

It was a beautiful day here in the valley so I decided to take the 71 bus into town. Have been spending time over the last couple years restoring rodent chewed wiring, rebuilt the trans nosecone, resealed this and that and cleaned the engine and transmission, greased shift rod bushings, etc. Engine is a rather tired 1776 but deemed serviceable. Good oil pressure.
I was cruising at a steady 60. Gauges looked good. A sudden loss of power. Pulled off thinking points? , Fuel issue? All looked good. Started it up to a horrible clatter. Immediately killed it. No oil loss. Rattle directly under the engine. Rod city. Called a buddy for a tow.
This has never happened in 30 years of hard road trips and desert temps. I can't complain. This bus has never let me down. It died in good weather not to far from home.

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zabo
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Re: A Bad Day

Post by zabo » Fri Apr 20, 2018 7:17 pm

always better close to home. get better soon
60 beetle
78 bus

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wcfvw69
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Re: A Bad Day

Post by wcfvw69 » Fri Apr 20, 2018 8:48 pm

That's a bummer for sure. Sounds like you knew this engine's life span wasn't long based on your comments. I've always said VW's talk to us and provide a warning of an issue in some fashion. We just have to listen and act on what we're hearing. Sometimes my hearings great while other times my procrastination overrides my hearing.

You should share and post some autopsy photos when you get the engine opened up.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: A Bad Day

Post by bus71 » Sun Apr 22, 2018 5:51 pm

First I'd like to say thank you to Zabo for the kind words. I did know the engine was tired and thought as VW 69 suggested, perhaps I just didn't listen to what my bus was telling me and let spring fever get the best of me. The snow, ice and salt we're gone so......
It turned out that something very puzzling happened. I got the heads off and discovered brass shards in #4 and impact damage, and some in the other cylinders as well. I expected to find a broken valve guide, but, while worn, none show evidence of damage. I can see a mark which seems to show a brass object got past the intake valve. When I tore down the rest I found a typical worn engine with #4 rod and main bearing worn more than the rest and probably the source of what I heard in the lower end. No spun bearings, dowels and bearings still indexed correctly. Lots of shiny stuff in the oil and a very furry magnetic drain plug.
Im just not sure what got in there. I've driven the bus several times since it was back together and it was ok. I will post pics when I get things cleaned up. Maybe someone else will see something I don't.

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Amskeptic
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Re: A Bad Day

Post by Amskeptic » Mon Apr 23, 2018 8:56 am

bus71 wrote:
Sun Apr 22, 2018 5:51 pm
First I'd like to say thank you to Zabo for the kind words. I did know the engine was tired and thought as VW 69 suggested, perhaps I just didn't listen to what my bus was telling me and let spring fever get the best of me. The snow, ice and salt we're gone so......
It turned out that something very puzzling happened. I got the heads off and discovered brass shards in #4 and impact damage, and some in the other cylinders as well. I expected to find a broken valve guide, but, while worn, none show evidence of damage. I can see a mark which seems to show a brass object got past the intake valve. When I tore down the rest I found a typical worn engine with #4 rod and main bearing worn more than the rest and probably the source of what I heard in the lower end. No spun bearings, dowels and bearings still indexed correctly. Lots of shiny stuff in the oil and a very furry magnetic drain plug.
Im just not sure what got in there. I've driven the bus several times since it was back together and it was ok. I will post pics when I get things cleaned up. Maybe someone else will see something I don't.

Ouch ouch. Did you lose your accelerator pump nozzle? What carb do you have?
Colin
(these engines don't just throw a rod because they are feeling tired. With a factory-specified lubrication system, they *will* throw an oil pressure warning lamp at idle before the rods let go. But we like to monkey with pumps and pressure relief springs so the rods can open up past metal-breaking clearances and the oil lamp never gets wind of it)
2019 Annual Funding Drive!
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viewtopic.php?f=41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 97,179 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 77,717 miles

bus71
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Re: A Bad Day

Post by bus71 » Mon Apr 23, 2018 9:39 am

I realize my follow up post wasn't clear. I believe now there was a bit of panic in my assessment. Upon disassembly I found the crank and rods ok, just worn. The engine is stock other than 90.5 pistons and cylinders. Stock oil pump, relief springs, etc. It's a single carb stock 34-3 rebuilt by volksbitz and pump jet is fine. I think the rattle I heard was a combination of worn lifter bores and bearings accentuated by the rough idle from damaged heads. All I can think of is at some point I must have dropped something into the intake which lodged at the intake boot and then was sucked in. In other words, I must have made a dumb mistake at some point which came back later to bite me. I kept everything covered but maybe something from another project ended up in there somehow. At this point I need to start thinking of options. Get the case machined or new case? Another 1776? I have a set of 1600 p/ls that have been on the shelf for years, new Brazilian mahle vintage 2000 or so. New heads and cam/lifters are a must and of course pistons an cylinders.

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Re: A Bad Day

Post by Amskeptic » Mon Apr 23, 2018 6:35 pm

bus71 wrote:
Mon Apr 23, 2018 9:39 am
I realize my follow up post wasn't clear. I believe now there was a bit of panic in my assessment. Upon disassembly I found the crank and rods ok, just worn. The engine is stock other than 90.5 pistons and cylinders. Stock oil pump, relief springs, etc. It's a single carb stock 34-3 rebuilt by volksbitz and pump jet is fine. I think the rattle I heard was a combination of worn lifter bores and bearings accentuated by the rough idle from damaged heads. All I can think of is at some point I must have dropped something into the intake which lodged at the intake boot and then was sucked in. In other words, I must have made a dumb mistake at some point which came back later to bite me. I kept everything covered but maybe something from another project ended up in there somehow. At this point I need to start thinking of options. Get the case machined or new case? Another 1776? I have a set of 1600 p/ls that have been on the shelf for years, new Brazilian mahle vintage 2000 or so. New heads and cam/lifters are a must and of course pistons an cylinders.
I was commenting for the readership (all eight of them!) about rods and oil lights and etc.

So you did not lose any brass bit from the carburetor, yet you had brass shards embedded in the pistons? Combustion chamber ceilings? You have checked every guide both under the valve springs and in each port? Sometimes, a guide will lose just a partial wall and it almost looks like maybe the guide was clearanced for more airflow.

I have never heard my lifters make noise. Loose oil pump tangs in the camshaft, yes.
Colin
2019 Annual Funding Drive!
**********************************
viewtopic.php?f=41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 97,179 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 77,717 miles

bus71
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Re: A Bad Day

Post by bus71 » Mon Apr 30, 2018 4:35 pm

Thanks for the tips Colin. On closer examination it looks like I did lose a piece of valve guide. I have heard lifters rattle when a engine is idling rough and slow, however, there is wear on the oil pump tang. This has become more of a puzzle as it appears the cam gear bolts have been hitting the oil pump. There is definitely damage to the pump on the boss which holds the driven gear. I am also wondering if this was the correct pump. I measure the gears at 30mm. It is curious that things went so long without noise. There wasn't exessive endplay at the flywheel. The case will need lifter bores sleeved as the lifters rock in the bores. Anybody have recommendations on machine work? Any tips would be appreciated. Will machine work equal the cost of a new case? I have to factor in shipping also.
Thanks!

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asiab3
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Re: A Bad Day

Post by asiab3 » Mon Apr 30, 2018 7:41 pm

Where are you located, bus71? A good machine shop close by will be worth the cost. Shipping a Type 1 case can be cost prohibitive when new cases are available and seem to be decent quality.

Good luck,
Robbie
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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Amskeptic
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Re: A Bad Day

Post by Amskeptic » Sun May 06, 2018 6:40 am

bus71 wrote:
Mon Apr 30, 2018 4:35 pm
it looks like I did lose a piece of valve guide.
it appears the cam gear bolts have been hitting the oil pump.

I do not yet know the reasons why valve guides may break off.

If you still have the camshaft and the thrust bearing (that fits closest to the gear), check the clearance and let us know what it is.

A new bearing can start life at a clearance of .001". Let's say you check for bolt clearance at the gear/pump with a feeler blade and push the camshaft towards the front of the engine and decide that it clears by .012". Then, ten thousand miles later, your CrapORama brazilian cam bearing has opened up to a thrust clearance of .011". Then, because you are learning fast here, you realize that you checked the cam bolt clearance *without pre-loading the camshaft play towards the pump* and your actual clearance was only .009" and the bearing has opened up past contact.
Details, details.
Check cam bearing clearance between the thrust surface of the bearing and camshaft on the gear side. Then you will be guaranteed that you have taken into consideration all possible movement of the camshaft. I like double-thrust bearings for the simple reason that I need ultimate longevity, and keeping the camshaft end play within specifications is important.

I know that many people have suffered movement of the driven gear "axle" inside the pump. I have never had to deal with that with my original VW pumps. Chloe has a 30mm pump currently, and I do not know if the aftermarket manufacturer managed a correct interference fit of that driven gear shaft/axle in the pump.
I, like you, have to be alert with an oversized pump to bearing clearances opening up and not signalling the oil pressure idiot light.
Colin
2019 Annual Funding Drive!
**********************************
viewtopic.php?f=41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 97,179 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 77,717 miles

bus71
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Re: A Bad Day

Post by bus71 » Fri Jun 22, 2018 11:41 am

Thanks for all the help. I'm finally getting back to this. I have determined that the problem with the bottom end was caused by an ill fitting oil pump and too tall cam bolts. I had about 50k on a low budget refresh. As the cam bearings wore, crunch! My plan is to take things to Seattle for machine work to someone I trust. Don't know of anyone here familiar with air-cooled work. It's about a 5 hour drive but can combine with family visits so "shipping" costs won't be a loss. It looks like I'll be using the AA p/ls and heads. Heads will be reworked with better valves etc. Not sure what brand cam and lifters to use so am open to advice. Not planning on non stock grind or head mods as I'm happy with "stock" 1776.

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Re: A Bad Day

Post by Amskeptic » Sat Jun 23, 2018 9:33 pm

bus71 wrote:
Fri Jun 22, 2018 11:41 am
Thanks for all the help. I'm finally getting back to this. I have determined that the problem with the bottom end was caused by an ill fitting oil pump and too tall cam bolts. I had about 50k on a low budget refresh. As the cam bearings wore, crunch! My plan is to take things to Seattle for machine work to someone I trust. Don't know of anyone here familiar with air-cooled work. It's about a 5 hour drive but can combine with family visits so "shipping" costs won't be a loss. It looks like I'll be using the AA p/ls and heads. Heads will be reworked with better valves etc. Not sure what brand cam and lifters to use so am open to advice. Not planning on non stock grind or head mods as I'm happy with "stock" 1776.
I bought off-the-shelf "Whatever Stock Cam/Lifters" from Air-Cooled.net. Work good at 27,000 miles thus far.
Colin
2019 Annual Funding Drive!
**********************************
viewtopic.php?f=41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 97,179 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 77,717 miles

bus71
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Re: A Bad Day

Post by bus71 » Thu Jan 03, 2019 6:12 pm

Well. Finally back to update. Bus is back on the road! Just in time for snow and salt (sigh). I did not get pics but my cam gear is on the machinists wall of shame. Heads are Chinese with valves, seats and springs,etc replaced. AA 90.5 pistons and cylinders. I had the shop do the rebuild because time and health issues got in the way. We had lengthy talks and I assisted a bit on final assembly.
.Very satisfied with the results. I had forgotten how smooth an engine could be. It is fully balanced. I'm running stock Engle cam and exhaust. Carb is German 34-3 rebuilt by Volksbitz. Stock Bosch 034(mex.). Runs fine, and with the trans nose cone I rebuilt a while ago, Very smooth shifting. Thanks for the support on that evil day.!

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tommu
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Re: A Bad Day

Post by tommu » Fri Jan 04, 2019 12:12 am

Excellent news. Do you have a video of it running?

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Re: A Bad Day

Post by bus71 » Wed Jan 09, 2019 6:06 am

I don't have any video. I would need to pull the bus out to film and it's cold and snowy here. Perhaps if we get some clear weather and the yard gets plowed.

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