now what ....

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TrollFromDownBelow
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now what ....

Post by TrollFromDownBelow » Sun Jul 08, 2018 4:59 pm

Have the heads off.

Outside of cleaning and painting, what should be my next steps before I can successfully attach the new heads? Do I need to cc the old and compare to the new? Do I need to pull off the jugs and clean the base for a clean install? Do I need to check deck height...if so how would I do that? I've got new heads from Len, and just placed a big order from busdepot - should be here by the end of the week...


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https://drive.google.com/open?id=0B6n1i ... NkVGE1bzNV

https://drive.google.com/file/d/0B6n1ie ... sp=sharing
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

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Amskeptic
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Re: now what ....

Post by Amskeptic » Sun Jul 08, 2018 10:07 pm

TrollFromDownBelow wrote:
Sun Jul 08, 2018 4:59 pm
Have the heads off.

Outside of cleaning and painting, what should be my next steps before I can successfully attach the new heads? Do I need to cc the old and compare to the new? Do I need to pull off the jugs and clean the base for a clean install? Do I need to check deck height...if so how would I do that? I've got new heads from Len, and just placed a big order from busdepot - should be here by the end of the week...

I see oil drenching your pistons, it looks like the bottoms of the pistons have actually had their carbon washed off? Is that true? I'd suggest new pistons and cylinders of course. But if you keep those pistons and cylinders, new rings and honing of the cylinders is in your immediate future.
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

TrollFromDownBelow
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Re: now what ....

Post by TrollFromDownBelow » Mon Jul 09, 2018 9:57 am

Amskeptic wrote:
Sun Jul 08, 2018 10:07 pm


I see oil drenching your pistons, it looks like the bottoms of the pistons have actually had their carbon washed off? Is that true? I'd suggest new pistons and cylinders of course. But if you keep those pistons and cylinders, new rings and honing of the cylinders is in your immediate future.
Colin
It looks like it. It burns about a qt every 300-400 miles on the highway, 600ish around town.

We've had a lot of unexpected expenses this spring/summer, so the budget is a bit tight. However, more importantly, I'm thinking that if I keep the original pistons and cylinders and go with new rings and a hone job, it will keep at least the majority of the happy running state this engine is in. I'm figuring if I can get another 20k miles (about 7-10 years of driving for me) then will do a complete tear down and rebuild.

Thoughts? Is my logic sound? Also, do I need to order new shims or gaskets for the jugs?
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

cegammel
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Re: now what ....

Post by cegammel » Mon Jul 09, 2018 5:15 pm

I would do it all now...after the heads, everything else is pretty cheap.

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Re: now what ....

Post by Jivermo » Mon Jul 09, 2018 5:38 pm

Yes, scrape it together, and do it all now. This is one of those things that, if you don’t, it may just start bugging the hell out of you that you didn’t do it when you had everything all apart. Think of the satisfaction, and knowledge that all those new parts are pushing you down the road.

TrollFromDownBelow
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Re: now what ....

Post by TrollFromDownBelow » Mon Jul 09, 2018 6:45 pm

"Doing it all now" means to me, a complete engine tear down, splitting the cases, new mains, balancing, etc. I really don't want to have the bus non operable for that long. That's a winter project that needs to be done with love and unhurried concentration.

If "doing it all now" means in addition to replacing the heads, to also replace the jugs and pistons and leaving the case un-split, then I'm concerned that the new pistons will change the balance of the spinning mass inside the engine that will in-turn beat the rest of the internals into a state where I would have to rebuild the entire thing much sooner than if I left the harmony of the spinning mass of crank,mains, rods, wrist pins alone.

Despite all of its flaws, this engine runs really well. I don't have to flog it to keep up with traffic around town, and she hums along nicely at 65 on the freeway all day long. If it wasn't for the loud exhaust due to broken exhaust stud, I would have been happy feeding it's oil habit.

My theory is that if I simply replace the rings and hone the jugs I will keep most of the happy homeostasis the engine has, and will be more likely to make it another 20k - 25k miles, and then I will have to replace everything (except the heads). If I replace the jugs and pistons without doing a thorough rebuild, it may run phenomenally for 10k - 15k miles, but then I will be in the same place anyways. The jugs and pistons will be newer, so may only have to replace the rings, but I will be in the same place of a total engine teardown...only sooner.

So if we remove the "doing it all now" option of a complete engine tear down, rebuild and balance, and doing what we can "right now" of either, rings with hone, or, to add new jugs and pistons to the mix, which is more likely to last longer before a total engine rebuild with the knowledge that the engine is currently well balanced...just needs heads and some rings to slow down oil consumption (btw, I checked compression about 10k ago and the three cylinders I could check - one has a helicoil in it - all tested between 112 and 118 lbs.- Oil consumption has stayed very consistent the whole time I've been running it the past 20k miles).
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

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Amskeptic
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Re: now what ....

Post by Amskeptic » Mon Jul 09, 2018 8:16 pm

TrollFromDownBelow wrote:
Mon Jul 09, 2018 9:57 am
Amskeptic wrote:
Sun Jul 08, 2018 10:07 pm


I see oil drenching your pistons, it looks like the bottoms of the pistons have actually had their carbon washed off? Is that true? I'd suggest new pistons and cylinders of course. But if you keep those pistons and cylinders, new rings and honing of the cylinders is in your immediate future.
Colin
It looks like it. It burns about a qt every 300-400 miles on the highway, 600ish around town.

We've had a lot of unexpected expenses this spring/summer, so the budget is a bit tight. However, more importantly, I'm thinking that if I keep the original pistons and cylinders and go with new rings and a hone job, it will keep at least the majority of the happy running state this engine is in. I'm figuring if I can get another 20k miles (about 7-10 years of driving for me) then will do a complete tear down and rebuild.

Thoughts? Is my logic sound? Also, do I need to order new shims or gaskets for the jugs?
For the record, new rings and a hone means a whole new order of friction and heat, just be prepared for that. Also, we don't know why oil is coming past. You need to find out the actual piston/cylinder clearance measured by a really good machinist.
.002" is new.
.008" yer done gittin new ones.
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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tommu
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Re: now what ....

Post by tommu » Mon Jul 09, 2018 9:05 pm

You should be able to peek at the cam now you have the heads off. How does it look?
Have you thought about the rings you'd run? I think Goetze are available and seem to be the OEM choice.
Oh - be *very* careful about dropping any dirt or grit inside the case!

cegammel
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Re: now what ....

Post by cegammel » Tue Jul 10, 2018 4:34 am

So...a question from the uninformed:. If you hone the cylinders and ramp up your compression, would that affect the rod bearings, which now have as much wear as your current tired pistons?

Would you be accelerating wear to the crankshaft, then, which in the type 4 is a marvel of engineering?

Ditto on the camshaft. Then the decision is easy.

TrollFromDownBelow
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Re: now what ....

Post by TrollFromDownBelow » Tue Jul 10, 2018 4:43 am

Reading between the lines here, I'm getting the impression that whether I simply hone the walls and replace the rings, or I get new jugs and pistons it will substantially change happy homeostasis the engine currently has. Yes, or No?
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

TrollFromDownBelow
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Re: now what ....

Post by TrollFromDownBelow » Fri Jul 13, 2018 9:32 am

I sucked it up and bought a new Mahle piston set.
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

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Re: now what ....

Post by Jivermo » Fri Jul 13, 2018 6:57 pm

Now we talkin’.

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Amskeptic
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Re: now what ....

Post by Amskeptic » Fri Jul 13, 2018 8:25 pm

cegammel wrote:
Tue Jul 10, 2018 4:34 am
If you hone the cylinders and ramp up your compression, would that affect the rod bearings, which now have as much wear as your current tired pistons?
Would you be accelerating wear to the crankshaft, then, which in the type 4 is a marvel of engineering?
No.
No.

Compression is a function of architecture + parts condition. If it was 135 new, then 110 old, and you clean up the rings, it is going only back to 135.
These crankshafts and rods are friggen stout. They could run a big block Chevy's pistons and compression ratio and do it with half the oil pressure of the Chevy.
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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Amskeptic
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Re: now what ....

Post by Amskeptic » Fri Jul 13, 2018 8:26 pm

TrollFromDownBelow wrote:
Fri Jul 13, 2018 9:32 am
I sucked it up and bought a new Mahle piston set.
Good good good.
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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SlowLane
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Re: now what ....

Post by SlowLane » Sat Jul 14, 2018 4:48 pm

Hi Mike.

I see you are teetering on the edge of the "as-long-as" engine-building rabbit-hole.

You know:
"as-long-as" I have the heads off, maybe I should look at the pistons...
"as-long-as" I have the pistons off, maybe I should check the connecting rods...
"as-long-as" I have the pushrods out, maybe I should check the lifters...
"as-long-as' I have the lifters out, I should peek at the camshaft wear pattern...

and so on and so forth, to where you end up at:
"as-long-as" I have my rotating assembly out being race-balanced to 9000 RPM, the piston crowns getting ceramic coated, the camshaft and lifters being cryogenically treated, maybe I should have the head studs deep-chrome plated... :geek:

But let's step back from the precipice a bit. How far down the rabbit hole you decide to go should be informed by forensic analysis of the state of your engine now, as well as your tolerance for risk and the impact to your budgets, both financial and temporal.

Before you remove the old cylinders, take a moment to lightly clamp them down to the case with the head nuts and a few short pieces of tube or pipe (PVC would do). Make sure they are seated squarely against the case, then lay a flat-edge across the tops of each pair of cylinders to confirm that their head sealing surfaces are in the same plane. This will inform you whether your new HAM heads will have a good chance of sealing. If they are not co-planar, then the job of head sealing will be harder, if not impossible, and this would need to be corrected by having the case re-decked (which of course entails splitting the case).

Next, while you have the cylinders clamped down, you can again use the straight-edge and some feeler gauges to measure the existing deck height. This is somewhat academic, since you have new pistons, but it's good to know what you started with. Then you can compare it to what your new pistons give you.

Getting new pistons is probably a good move (new cylinders too, I assume), because there's a good chance that your old pistons may be too worn out in the ring groove to seat new rings adequately. You can inspect them when you remove the old pistons for interest's sake.

Once the pistons are off you will be asking yourself whether it's worth unbolting the rods and sending them out to be measured, re-bushed (small end) and re-sized (big-end). Personally I think it would be good insurance, as it can be done without splitting the case, but I believe that new connecting rod nuts are no longer available (at least from AC.net. Right, Colin?), and you would have to balance the risk of re-using the old nuts (opinions seem to be divided on this practice) versus continuing to use con rods that may be out of spec. I believe that taking the rods out and making sure they are in spec is worth the peace of mind knowing that you may have avoided a thrown rod. As a bonus, the rods can then be modified with the notches to squirt oil at the undersides of the pistons while they are out ( this was recommended by a VW bulletin that is often mentioned here and on TS).

Best of luck. Those new heads deserve some support from the engine they are being bolted to.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
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