The Tale of Buddy's Hot and Thrash-y Engine(s)

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Amskeptic
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Re: rod bearing clearance question

Post by Amskeptic » Wed Nov 26, 2014 8:39 am

asiab3 wrote: Last night gave me a *ping ping ping* up a hill in 3rd, so I'm anxiously doing this meticulous work as carefully as I can, all the while reminding myself that the current plant is on borrowed time.

Robbie

Pinging? Retard.

. . . the timing.

So, Robbie, very important to know what you are doing when you are escaping the realm of "acceptable practices" for OCD efforts at perfection. For example, filing rod caps *reduces* bearing clearances at the firing axis, but not at the mating line. So we are actually making a slightly oval hole, "FINE! IT GETS OVAL THE OTHER WAY WHEN IT WEARS, STUPID" that's what I scream at agog machinists.

Main bearing clearances, you need to do a full dry installation of all main bearings into a dry crankcase that has been torqued up to spec, and either wield your beautiful old-school micrometer or taking it to someone who has one. You want two readings per bearing hole - one across the firing axis and one across the parting line.
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

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Re: rod bearing clearance question

Post by asiab3 » Wed Nov 26, 2014 10:37 am

Amskeptic wrote:
asiab3 wrote: Last night gave me a *ping ping ping* up a hill in 3rd, so I'm anxiously doing this meticulous work as carefully as I can, all the while reminding myself that the current plant is on borrowed time.

Robbie

Pinging? Retard.

. . . the timing.
It's at 22* max mechanical advance, with three distributors all giving the same result. (German 009, Mallory SVDA, and 205Q dvda.) I'm pissed at this engine, and I want to rip it apart. I'm guessing at some massive carbon deposists, a high compression ratio, or both. But I need the bus to be on the road, if not to get to work, then just to appease my psyche.
So, Robbie, very important to know what you are doing when you are escaping the realm of "acceptable practices" for OCD efforts at perfection. For example, filing rod caps *reduces* bearing clearances at the firing axis, but not at the mating line. So we are actually making a slightly oval hole, "FINE! IT GETS OVAL THE OTHER WAY WHEN IT WEARS, STUPID" that's what I scream at agog machinists.
Ahhhhh this makes so much more sense. I was imagning sanding down the cap saddle, but the area on the caps where they mate to the rest of the rod is a much more logical place for this to happen.
Main bearing clearances, you need to do a full dry installation of all main bearings into a dry crankcase that has been torqued up to spec, and either wield your beautiful old-school micrometer or taking it to someone who has one. You want two readings per bearing hole - one across the firing axis and one across the parting line.
Colin
Ahhh ok. I don't remember reading this anywhere else, which is why I appreciate the help so much here! I've been skimming Bob Hoovers writings, both online and in old archives, and he measures so many things it makes my head spin. But measuring is free, and I have the tools so I'm happy to do it. Is this another case (pardon the pun) where we wouldn't mind a SLIGHT oval favoring tighness at the firing axis?

This is fun!

And happy travels for Thanksgiving... At 63mph?

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

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Re: rod bearing clearance question

Post by Amskeptic » Thu Nov 27, 2014 8:41 pm

asiab3 wrote:I don't remember reading this anywhere else,
we wouldn't mind a SLIGHT oval favoring tightness at the firing axis?

This is fun!

And happy travels for Thanksgiving... At 63mph?

Robbie
We don't talk about it anywhere else . . . I approach engine metal in an organic way, and sometimes you can just feel what the parts want. How do you explain that? So, for me, snugging up a rod clearance from .0025 to .002, with a now .0005 ovalized hole, yes, I maybe we now have a high speed flex as our tight firing axis opens up under stretch loads, but guess what? More high rpm oil supply then back to quiet clearances at lower speeds. Almost like the wonderful improvement in head studs by making them skinnier so they would stretch when necessary under heat expansion, but spring back as the engine cools back down. My rods in Chloe never seem to get above 4,000 rpm anyway, and I get to enjoy a nice quiet lower end for a little longer.

What a gorgeous little engine/generator shriek song today, 48* outside, cool running engine is tight in the lower end, no insulation or seats in there, it was just me, a white white headliner, and a slight rush from Pensacola to Decatur/Kirkwood, and I loved the immediacy of that loyal little engine locked in at 60 mph. I was only 15 minutes late.
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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by energyturtle » Fri Nov 28, 2014 7:20 am

SGKent has helped me a ton, Deep down I feel he wants to razor blade, JB Weld, tackle his own headliner etc. Either he thinks he knows better or is Skeered. Either way he is a great contributor who truly cares about our community. In the end though I found my money and time in the right hands. Driving is the goal......give it a massage and ask what it wants. It works....

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by Amskeptic » Tue Dec 02, 2014 8:53 am

energyturtle wrote:SGKent Deep down I feel he wants to razor blade, JB Weld, tackle his own headliner etc.
I'll keep that in mind. We have had a tradition of crashing a mexican restaurant when I visit him outside Sacramento, and he is appreciated for his wealth of experience and desperately necessary standards of high quality.
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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Mon Dec 22, 2014 7:08 pm

I'm back with more measuring, swapping of bearings, swapping of rods, and plasti-gauge-ing than I ever thought I would be doing…

After many rounds, I was able to find a combination of bearings, rods, and journals to get exactly the same .002" clearance on each rod bearing. Is it more important to have matching clearances, or smaller clearances? Sanding down rod mating surfaces sounds fun, but I won't if I don't have to now that they're consistent.

My current engine began chirping when cold this week, so the new engine will be taking more of a priority now.

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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by Bleyseng » Tue Dec 23, 2014 10:02 am

Now get the rods, pistons and wristpins to weight the same....
Geoff
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70 Ghia vert, black, stock 1600SP,- 139,000 miles,
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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Tue Dec 23, 2014 12:27 pm

I want to make sure my bearing clearances are cleared for takeoff before I commit. I feel like balancing the rods WITH the bearings on them will be more realistic, seeing as the bearings are rotating mass too.
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by Amskeptic » Wed Dec 24, 2014 7:11 am

asiab3 wrote:I want to make sure my bearing clearances are cleared for takeoff before I commit. I feel like balancing the rods WITH the bearings on them will be more realistic, seeing as the bearings are rotating mass too.
Don't worry about matching the bearing clearances too much. If they are all in the low .002s yer good to match weights.
ColinMyEngine'sNext
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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Sun Jan 11, 2015 10:08 pm

Well well… I have access to a medical scale accurate to the hundredth of a gram on Tuesday for my balancing needs. Except my second set of NOS pistons and cylinders aren't here yet…… :pale: I'm hoping I'll be able to go back in a few days when my pistons get here to nail them down too.

I heated up my crank and distributor gear tonight on the back patio and had a fun time sliding them on the crank. I got goosebumps when they slid on perfect and burned my fingers on the oil through my gloves at the same time.

My main bearing clearances are in an acceptable range…
Measured: | Bentley Specs:
1- .002" | .0016" - .004"
2- .0025" | .001" - .0035"
3- .003" | .0016" - .004"
4- .0025" | .002" - .004"

I'm missing one bearing dowel pin and one secondary case stud, (down by the cam plug,) so I'm visiting my old German friend to get them tomorrow. He also has quite a few gently used camshafts to try in my case with my crank if I'd like. Am I better off finding a good used cam with perfect gear mesh, or buying a few new ones and picking the least bad? I can't afford to buy ten new cams to swap around and sell at a slight loss.

Cylinder heads are dropped off at Adrian's, and I've acquired my new Porsche swivel-foot adjusters.

One or two of my crankshaft dowels are loose. How big of an issue is this, and what can I do about it?

My distributor drive pinion will not fit into my case. It hangs up about an inch and a half from being seated. Is there something I'm missing here?

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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by Amskeptic » Wed Jan 14, 2015 10:14 am

asiab3 wrote: main bearing clearances
1- .002"
2- .0025"
3- .003"
4- .0025"
If you are a nutcase, please join me in a moment of sheer insanity.
#2 is supposed to be .0005" tighter than the other big bearings along the crank. This is the whip journal. While its overall clearances are mostly within the same range as the others, VW had a reason for tightening #2 down a smidge.

The insanity is to razor blade the mating surfaces of the saddles at #2. You have machining marks as reference. Go down evenly just enough to almost obliterate them, both case halves. Now grab a #2 main bearing half. It is coated with a dull lead grey. The edge, the edge that butts the other bearing half, you can carefully rake with a fresh clean razor blade. Do one bearing at the bottom, the other at the top. Just enough to see that the razor blade indeed has visited. We want the #2 clearance at least down to #1's clearance. I would probably also razor #3 down a tad.

Beyond the horrified expressions of revulsion from the Color Inside The Lines Brigade, we are trying to reduce the hammering and vibration that occurs inside the magnesium crankcase. Every bit of help we provide now when the engine is new, extends the day that the hockey stick graph catches up with you. That means, as clearances open up, the resultant damage goes up exponentially. If you should choose to embark upon this insanity, the need for cleanliness goes up commensurately.
Less clearance = greater damage from debris.
asiab3 wrote: I'm missing one bearing dowel pin and one secondary case stud, (down by the cam plug,) so I'm visiting my old German friend to get them tomorrow. He also has quite a few gently used camshafts to try in my case with my crank if I'd like.
Dowels should be secure in the case. People will often blow this off because they cannot see the cure, "it doesn't matter!" The problem with loose dowels, is the bearings can move/fret in the case when the engine is hot, and this causes wear on the backsides of the bearings, which then reduces the "crush" which then opens up the clearances, which then allows more movement still, which allows more fretting, which reduces the crush still further, and eventually you have bearings that are ovalizing at the dowel hole and banging around in there destroying your case and eventually the dowel leaves the case hole and all hell breaks loose.

Find a good mesh amongst any of the camshafts available to you with your crank and your cam bearings.
Now read the number on the gear that has the best mesh.
A lightly worn camshaft with the gear of your choice may be able to have additional hardening treatment, or you can regrind the lobes to factory specs on a slightly smaller base circle (followed by hardening treatment). Camshafts work too hard to use off the floor used ones. You want new lifters that match the camshaft hardening numbers. If the gear of your choice is not available on the camshaft of your choice, you will need to grind off and bolt on. It is critical to do this job more than carefully.
asiab3 wrote: My distributor drive pinion will not fit into my case. It hangs up about an inch and a half from being seated. Is there something I'm missing here?
Yes. This is not a new case is it? If it is, there have been reports of incorrect diameter down at the thrust washer end, which seems too low down for your 1 1/2" hang-up.

Crank is nowhere near, right? If crank is in, you MUST carefully wobble the crank back and forth and try to get the distributor drive gear tooth to slip past the brass ramp of the crankshaft gear. Really babysit this one. I have had to razor blade every entrance to the brass gear . . .
Itinerant Scissorhands

The Razor-Bored Crankcase (I did have to rake the entire saddles to make them larger)

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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Wed Jan 14, 2015 12:52 pm

I'm feeling very much like a nutcase. I'll get on this schnell.

What engine is that you razor-bored?

Current engine gave up the ghost last night as cylinder 4 showed 30psi, and decided to let all the spark plug threads have a permanent vacation on the compression tester. Now the shavings have collected nicely in the combustion chamber, and I'm going to tear it down for parts. I was hoping to be able to limp it to my dad's garage where I can have a clean open space to install the new one, but this engine just didn't want to go any farther.

In the unlikely event that my house catches on fire (again) and I need to move the bus ASAP, should I remove the pushrods and ground the plug wire to prevent any more damages?

From my phone, apologies for grammar,
Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Wed Jan 14, 2015 5:45 pm

VW factory bagged and tagged "reconditioned" connecting rod weights in grams:

638
634
654
636

I got 1, 2, and 4 within half a gram. I don't think these rods have enough meat on them to even attempt #3.

Does ANYONE out there give a shit anymore????? I can't afford to keep buying mediocre parts to replace allegedly better parts that don't check out. I've put well over a grand into wasted parts on this engine that have all been ruined at the hands of a human that doesn't care. I can't "care" a crank back straight. I can't "care" 20g off a rod with no balance pads. I can't "care" the fins back on to NOS cylinders.

Pardon my rambling I have grinding to do.
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by Amskeptic » Thu Jan 22, 2015 9:58 am

asiab3 wrote:VW factory bagged and tagged "reconditioned" connecting rod weights in grams:

638
634
654
636

I got 1, 2, and 4 within half a gram. I don't think these rods have enough meat on them to even attempt #3.
Does ANYONE out there give a sh*t anymore?????
I can't "care" 20g off a rod with no balance pads. I can't "care" the fins back on to NOS cylinders.

Pardon my rambling I have grinding to do.
The board has been reset 6 days prior, so we have lost some narrative and information.

Please add all wrist pins to all rods. Check overall weight between the rods. Now ream the inside diameter of the #3 wristpin (equal cuts on each side to a similar depth, make very very smooth when you are done. Then check the top-to-bottom respective weights of the rods using an identical fulcrum point. You'll have to keep the wristpins in. While you have been grinding rods, feel free to smooth off the burrs and round sharp edges all over the rod that you are trying to lighten. Smoother is stronger.
ColinAhhhhhhhhhWhoGivesASh*t
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

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Re: The Tale of Buddy's Hot and Thrash-y Engine(s)

Post by asiab3 » Fri Jan 30, 2015 7:08 pm

I've been feeling pretty dang depressed about everything on this engine that other people need to touch. I got my rotating assembly back from the balancer, with the crank pulley in a ziplock bag. This is the actual conversation I had with the monkey at the front counter.

"But isn't the pulley part of the rotating assembly?"
"Well yeah!"
"Then why didn't you balance it?"
"We don't balance the pulley."
"But didn't you charge me to balance the complete rotating assembly?"
"Well yeah!"
"So then why don't you balance the pulley"?
"It isn't part of the rotating assembly."

I prayed to every deity whose name I could muster to grant me the strength to avoid mauling this man with a flywheel.

So I'm going to remove the transaxle to replace shift bushings and paint the rear shift rod. Making it match the front will give me the confidence to continue. And repacking the CVs will give my mind the serenity it needs to track down an oil cooler not made in China.
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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