Case like butter.

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BumbleBus
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Case like butter.

Post by BumbleBus » Mon Sep 15, 2014 8:47 am

Quick question if I may:

I have two intake manifold bolts that sheared when removing my carb awhile back (didn't even force them.. they just plain sheared off). I recently successfully drilled out the remnants with copious shop-vac sucking. I was very careful. I then went to the local hardware store and matched up two new bolts. I made sure the pitch was correct etc. Upon threading them as they seated even just a bit they started to spin in the case and the case threads just disintegrated and came out like butter. Like butter. Shavings all over. Oh no!

I'm curious if my poor CB case has had it or can it be saved? I'm in the [slow] process of pulling poor venerable CB000076 for a rebuild by local VW guru Klaus this winter/spring (a real German!), but I've read that if a case overheats one too many times over the years the metal can deteriorate to the point of being unsalvageable (I suppose heads might butterize whilst the bottom end is still fine... I just don't know). I don't have the resources to be throwing bad money after bad money, but poor old Bumblebus deserves a new heart & not some bastardized Suby swap... as tempting as that is this early VIN '72 deserves more respect than that.

Thanks for advice.
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

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Amskeptic
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Re: Case like butter.

Post by Amskeptic » Tue Sep 16, 2014 6:23 am

BumbleBus wrote:Quick question if I may:

I have two intake manifold bolts that sheared when removing my carb awhile back (didn't even force them.. they just plain sheared off). I recently successfully drilled out the remnants with copious shop-vac sucking. I was very careful. I then went to the local hardware store and matched up two new bolts. I made sure the pitch was correct etc. Upon threading them as they seated even just a bit they started to spin in the case and the case threads just disintegrated and came out like butter. Like butter. Shavings all over. Oh no!

I'm curious if my poor CB case has had it or can it be saved? I'm in the [slow] process of pulling poor venerable CB000076 for a rebuild by local VW guru Klaus this winter/spring (a real German!), but I've read that if a case overheats one too many times over the years the metal can deteriorate to the point of being unsalvageable (I suppose heads might butterize whilst the bottom end is still fine... I just don't know). I don't have the resources to be throwing bad money after bad money, but poor old Bumblebus deserves a new heart & not some bastardized Suby swap... as tempting as that is this early VIN '72 deserves more respect than that.

Thanks for advice.

There are so many questions here.
a) there are no intake manifold "bolts" on the case.
Did you mean "intake manifold studs in the cylinder head?

b) CB cases are aluminum and do not suffer from the age-related work-hardening and cracking of magnesium cases.
Have you been reading about Type 1 magnesium cases?

If you would like to fix up your engine, read specifically for your engine so you don't get overwhelmed by the discovered engineering weaknesses of all Volkswagens since 1949 needlessly.
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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BumbleBus
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Re: Case like butter.

Post by BumbleBus » Tue Sep 16, 2014 9:51 am

Amskeptic wrote: a) Did you mean "intake manifold studs in the cylinder head?
Yes, sorry the studs in the head that the intake manifolds bolt onto heh, heh. My bad. Upon threading new replacement studs they just spun the head threads right into shavings and I was barely more than hand tight when doing it. The head stud holes are essentially just smooth now internally. I know I could re-tap a larger size, but wouldn't want to spend that money if the head metal is that fatigued. Just get new heads?
Amskeptic wrote: b) CB cases are aluminum and do not suffer from the age-related work-hardening and cracking of magnesium cases.
Have you been reading about Type 1 magnesium cases?
I suppose it was probably regarding Type I cases then yes. And I'm sure my short block is still ok then probably, but just my heads that need love. Thanks Colin for helping me clarify what I was talking about.
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

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Amskeptic
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Re: Case like butter.

Post by Amskeptic » Wed Sep 17, 2014 6:34 am

BumbleBus wrote: Just get new heads?
I'm sure my short block is still ok then probably
Naw. If the heads otherwise check out, drill and tap some helicoils or timeserts, easy.
If you use a machinist to do the job, tell him to pilot the damn hole with a fixture or your manifold !&@!*.
If you do it yourself, pilot the damn hole with your manifold so you drill straight, !&@!*.
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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