mild engine refresh

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TrollFromDownBelow
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mild engine refresh

Post by TrollFromDownBelow » Thu Oct 29, 2015 11:33 am

She runs great, good power, not over heating, however......

Why I feel the need to refresh:
- oil consumption is kinda high .... about a quart every 250-300 miles if I am freeway flying. running 20w50 dino.
- think an oil galley plug is weeping.....will get a spot of oil underneath the engine after extended (over an hour) of highway driving
- Now the worst part...I have happy valves; check 'em every 2-3k miles and they are all just a tinch looser than spec...just the way i would expect. However, I have a broken stud boss on the left bank (and ergo a noisy exhaust leak) and helicoil on the right bank that has a death grip on the spark plug which I've put about 15k miles on. Therefore, the heads are toast.


Why I am hesitant to do a full-blown engine rebuild:
- Did I mention it runs really well?
- last time Colin checked about 6k miles ago, end play was in spec, and consensus is the case has never been split.
- yes, there is the budget thing....with a daughter in college, I don't have the $2k-$3k to spend on quality parts. I have about $1k to play with.
- net/net: Hate to mess with a good thing: so want to be as minimally invasive as possible but still fix most of the issues without breaking the bank.

Goals of the refresh:
- securely hookup exhaust without leaks
- adjust end play correctly (want to keep the bottom end as tight as possible for as long as possible)
- fix oil galley plug weep
- be able to replace all four spark plugs
- slow down oil consumption
- piece of mind that exhaust system won't fall off
- solid, reliable engine for the next 15k-30k miles when I can afford a complete rebuild.
- like some piece of mind that the engine is reliable enough to drive 400 miles up north and back to do some camping

Plan of attack:
- Bus Boy rebuilt heads ~ $600. They have a 12k mile warranty, and figure i will have good cores to have a competent rebuilder to start with as both my heads are not rebuild-able.
- New rings ~ $100
- Reset end play
- fix galley plug weep

Leaves me about $300 left for miscellany. Not enough for good pistons and jugs, and to be frank, am concerned that a completely rebuilt top end would put too much stress on the bottom end and make it wear out quicker. last time I checked compression on the three cylinders that i could check they were all in the 110-115 lb range so appears that they should have a decent amount of life left.

Interested in thoughts/opinions.
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.
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asiab3
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Re: mild engine refresh

Post by asiab3 » Thu Oct 29, 2015 12:27 pm

It's clear that you've thought about this, which is good. I hate to see someone rush into an overhaul like this without solid grounds for the work. Exhaust leaks are a big one, CO is odorless and dangerous. The oil consumption is interesting, do any of (your three good) plugs show carbon fouling or buildup?

Some people in other forums recommend replacing the rod bearings if you have the cylinders off. I've always wanted to know if this was actually an accepted practice.

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

TrollFromDownBelow
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Re: mild engine refresh

Post by TrollFromDownBelow » Thu Oct 29, 2015 12:43 pm

asiab3 wrote: The oil consumption is interesting, do any of (your three good) plugs show carbon fouling or buildup?

Some people in other forums recommend replacing the rod bearings if you have the cylinders off. I've always wanted to know if this was actually an accepted practice.

Robbie
It's been a while since i checked, but they weren't the last time. If the suspected galley plug is weeping, it can explain some of the oi loss, but would think I would see more than a silver dollar sized spot if it was leaking enough to leak a whole quart that way. I don't have any oil drips with around town driving, or highway driving less than one hour.

Oil consumption drops to about a qt every 500 miles if it's round town driving.
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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wcfvw69
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Re: mild engine refresh

Post by wcfvw69 » Thu Oct 29, 2015 1:38 pm

What's the cost these days to have your existing heads overhauled? Is it half the price of buying new ones? Could you apply those savings towards new pistons/cylinders? Robbie makes a good point on replacing or at least inspecting one of the rod bearings to see how much is left. Do you know how many miles are on the bottom end?

IDK, every time I've had an engine apart down to the short block and didn't know the miles on it, my OCD kicked in and I split the case to inspect it. Both times, my little voice was right to do so. On one engine, the main bearings had worn thru the bearing material and showed brass. I ended up mic'ing everything and everything passed, including the case. I installed rebuilt rods, bearings, cam and had the heads overhauled. I also installed new P/C's. I think I had under $500 in parts and head work, total. The other engine was worn as well and I did the same to it though it did need a line bore and I had everything balanced as well.

You mentioned that you're concerned about rod knock with a fresh top end. To me, if you tore this down now, you may get away with changing the main bearings, rebuilt cam, rods, etc.. and have a fresh engine for not too much $ over your budget.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

TrollFromDownBelow
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Re: mild engine refresh

Post by TrollFromDownBelow » Thu Oct 29, 2015 2:04 pm

wcfvw69 wrote:What's the cost these days to have your existing heads overhauled? Is it half the price of buying new ones?
heads are toast ... broken exhaust boss on one head, and helicoil in the other. Hence the need to buy reman heads, which will give me good cores that I can have rebuilt by a competent rebuilder.
wcfvw69 wrote:On one engine, the main bearings had worn thru the bearing material and showed brass. I ended up mic'ing everything and everything passed, including the case. I installed rebuilt rods, bearings, cam and had the heads overhauled. I also installed new P/C's. I think I had under $500 in parts and head work, total.
Budget is part of it, but really hate disrupting a nicely running engine. Engine runs smooth, cool as a cucumber, and whenever i drop the oil screen, it's relatively clean of stuff. If it wasn't for the fact that I only have 2 studs holding up the left side of the exhaust system, and a exhaust leak to go with, I would probably continue to roll it and feed it oil.

I'm trying to be minimally invasive to maximize homeostasis. Even if I got a paltry 8k-10k miles out of my McGuyver rebulid that would be 3-4 seasons of driving....I'll be ready for the full Monty then. When I do rebuild, want to do with the best quality parts I can .... have a bucket list dream of driving it to Alaska...
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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asiab3
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Re: mild engine refresh

Post by asiab3 » Thu Oct 29, 2015 3:05 pm

TrollFromDownBelow wrote:I'm trying to be minimally invasive to maximize homeostasis. Even if I got a paltry 8k-10k miles out of my McGuyver rebulid that would be 3-4 seasons of driving....I'll be ready for the full Monty then. When I do rebuild, want to do with the best quality parts I can .... have a bucket list dream of driving it to Alaska...
If this is the case, I would source some heads, and get them to the same combustion chamber volume of your current setup. Then enjoy it. Are you 1700, 1800, or a 2L setup? If 1.7 or 1.8, you could use the compression sealing rings instead of opening your combustion chamber IF you need it. I follow VW's orders to not use them on a 2.0 T4 bus engine, but your setup will require math that can only be done once the heads are off.

I don't think you need to tear into a T4 short block if it runs well and you only need 10k miles before a quality rebuild. But start gathering parts now. If it were me, I would buy the best heads possible now so minimal work is required down the road. Perhaps just a cleaning before the new engine build?
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Amskeptic
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Re: mild engine refresh

Post by Amskeptic » Thu Oct 29, 2015 5:16 pm

TrollFromDownBelow wrote: heads are toast ... broken exhaust boss on one head, and helicoil in the other.
Hence the need to buy reman heads,

really hate disrupting a nicely running engine. Engine runs smooth, cool as a cucumber,

If it wasn't for the fact that I only have 2 studs holding up the left side of the exhaust system,
and a exhaust leak to go with, I would probably continue to roll it and feed it oil.

Even if I got a paltry 8k-10k miles out of my McGuyver rebulid that would be 3-4 seasons of driving....
I was surprised that the left side exhaust studs lasted longer than the expected month.

My recommendation now is to pull the heads and look at the pistons *before* you disrupt the piston-to-cylinder wall relationships currently in place. For all you know, the oil consumption is coming from the valve guides. If you see pools of oil and wet pistons, then perhaps new rings are called-for. I recommend pulling the piston/cylinders via the wrist pins if you are saving the pistons for another go.

Be conservative here. Do not worry about that bullsh*t of "fresh heads might overwhelm the lower end", that is nonsense. I would try to get away with merely sticking on a combustion-chamber-CC-equalized set of replacement heads, and enjoy quiet exhaust FOR ONCE.
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: mild engine refresh

Post by TrollFromDownBelow » Fri Oct 30, 2015 7:18 am

Thanks Folks - Don't all 2.0 liter Type IV heads have the same combustion chamber volume; or are you saying that i need to match the old heads with the new ?
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: mild engine refresh

Post by Amskeptic » Fri Oct 30, 2015 12:38 pm

TrollFromDownBelow wrote:Thanks Folks - Don't all 2.0 liter Type IV heads have the same combustion chamber volume; or are you saying that i need to match the old heads with the new ?
Ha . . . ha, ha . . . haHAHAHAHAHAAAHAHAAAA, no. We cannot say with any certainty that your new/reconditioned head cc's are matched to each other. Just the variations in positions of the valves on the seats can vary enough to tangle up CC's.
YOU check, carefully.
Because your engine is a happy little three-legged mutt most days, you DO want to match the averaged out reading of each of your old combustion chamber's CC's.
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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