Gary The Grün

Bus, Microbus, Transporter, Station Wagon, Vanagon, Camper, Pick-Up.

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tommu
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Re: Gary The Grün

Post by tommu » Sat May 04, 2019 11:21 pm

I pressurized the vacuum system with smoke:
Image

And found that the intake manifold had a surprisingly bad leak. I realized I'd never retorqued the intake manifolds on both sides and they were both far too loose. 3/4 side still leaked after torquing up so I needed to replace the gasket entirely. And now back to normal.

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Amskeptic
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Re: Gary The Grün

Post by Amskeptic » Mon May 06, 2019 8:56 pm

tommu wrote:
Sat May 04, 2019 11:21 pm
I realized I'd never retorqued the intake manifolds on both sides and they were both far too loose.

Preach it brother, I try.
Engine rebuilds must be retorqued after several heat cycles.
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: Gary The Grün

Post by tommu » Mon May 06, 2019 10:21 pm

Amskeptic wrote:
Mon May 06, 2019 8:56 pm
tommu wrote:
Sat May 04, 2019 11:21 pm
I realized I'd never retorqued the intake manifolds on both sides and they were both far too loose.

Preach it brother, I try.
Engine rebuilds must be retorqued after several heat cycles.
Colin
Good practice to retorque the heads? Wondering if I need to be dropping the engine in preparation for your visit..

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Amskeptic
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Re: Gary The Grün

Post by Amskeptic » Tue May 07, 2019 1:24 pm

tommu wrote:
Mon May 06, 2019 10:21 pm
Amskeptic wrote:
Mon May 06, 2019 8:56 pm
tommu wrote:
Sat May 04, 2019 11:21 pm
I realized I'd never retorqued the intake manifolds on both sides and they were both far too loose.

Preach it brother, I try.
Engine rebuilds must be retorqued after several heat cycles.
Colin
Good practice to retorque the heads? Wondering if I need to be dropping the engine in preparation for your visit..
No, if you follow my roundly-ridiculed heat cycle facsimile (overnight 40 or whatever, then re-torque to factory 23 in the morning), the head studs are designed to hold torque through the bedding in. BUT, if you ever get an overheat, then yes, re-torque heads. The manifolds are more prone to relaxing because of those paper/phenolic/copper gaskets that compress to seat, their torque values are lower to begin with, so relaxing takes away the clamping force quickly.
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: Gary The Grün

Post by tommu » Tue May 07, 2019 7:51 pm

Amskeptic wrote:
Tue May 07, 2019 1:24 pm
BUT, if you ever get an overheat, then yes, re-torque heads.
Colin
Got it. Kind of. What counts as an overheat? A few minutes of head temps at 420* - or something more dramatic?

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Amskeptic
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Re: Gary The Grün

Post by Amskeptic » Wed May 08, 2019 7:00 am

tommu wrote:
Tue May 07, 2019 7:51 pm
Amskeptic wrote:
Tue May 07, 2019 1:24 pm
BUT, if you ever get an overheat, then yes, re-torque heads.
Colin
Got it. Kind of. What counts as an overheat? A few minutes of head temps at 420* - or something more dramatic?
420*? That's just barely warming up for some cylinder head carbon-cleaning!
Overheats are characterized by the smell of oil burning off the engine and the smoke of oil burning off the inside surfaces of the heat exchangers. Have you used a self-cleaning oven feature? That smell. I did a brief 535* plastic bag on BobD's engine, and I should have done a re-torque. I lost a lot of clamping force, and I see the oil ooze between the heads and cylinders ...
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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