Slash five head gasket leak

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mattcfish
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Re: Slash five head gasket leak

Post by mattcfish »

Frog wrote:Work in progress....

Barrels back on, sealed and torqued. Studs seem okay.
That's great news. They probably needed a retorque a few 1000 miles ago.
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Duane Ausherman
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Re: Slash five head gasket leak

Post by Duane Ausherman »

Frog, were the valve adjustments fairly close to spec? If so, then the studs should be OK too.
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Frog
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Joined: Tue Aug 03, 2010 7:17 pm

Re: Slash five head gasket leak

Post by Frog »

Bad news.

But it all together....went for a heat cycle ride. Let it cool.

Opened it back up...checked the valve clearances....okay.

Retorque.....and 7 of the 8 went from about 21 lbs/ft to 25 lbs/ft and felt as they should.

The last one (left front upper) was at about 15lbs/ft....and felt mushy when tightening.

Dammit.

I think it is time to go over my top end.
Frog
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Re: Slash five head gasket leak

Post by Frog »

gspd wrote:
Frog wrote: I recently switched to synthetic oil.
I think you answered your own question.
Synthetic has more of a tendency to leak out of older engines.

If your head bolts seem to loosen and always require re-torquing,
you're pulling the studs out of the block. (VERY COMMON)
If they don't feel rock solid at 30lbs, they're pulling out.
The only permanent fix is case savers.http://vw.efi.tech.free.fr/catalog/engine.pdf
scroll down to page 13

Beware: Common heli-coils may also eventually pull out. Case savers never pull out.
GSPD,

Where can I get some more information about installing these. I have seen the heli coil jigs.

I imagine that I need a bottoming tap of the outer case saver thread, a tool to install the case saver and a means of keeping all of this square to the mating surface and in the right location.

Thanks,
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gspd
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It's easier to do than it is to explain

Post by gspd »

This will assure that the tap starts straight, use a base gasket as a template to fabricate a jig (1"-1.5" thick block of wood, metal, or plastic) so it slides down over the studs. (Remove the pistons and con rods)

You need a regular tap for all the holes, and a bottoming tap to finish the 2 left front and 2 right rear holes..
The case savers come with metric or standard outer threads, take your pick, just make sure the taps match.

You need to mill the outside end of each case saver so they're flat. (they come tapered)
The 2 right front and 2 left rear case savers have to be shortened to the same thickness as the case, if they stick in past the inside of the case, they will interfere with the crank counterweights.
If you don't have a machine shop, you can do the above mods by installing the case saver (with a short section of old stud to hold it) in a drill press and boring down on a piece of medium emery cloth.

The bottom ones have no oil feed, they just have to end up flush with the casing.
Use red loctite on the outer threads of case savers and screw them in using one of your studs (with a nut to prevent the stud from going right through the case saver); lock double nuts on the other end and use those to turn the case saver into the case.
Once the case saver is in flush, you can easily remove the stud by backing off the first lock nut.

Next, you have to carefully drill up through the top case savers at an angle to connect to the original oil feed passage in the case. Install one top case saver and drill it before installing the other one. that way you can put a drill bit in the adjacent oil feed hole to establish the correct angle. If you carefully mark the beginning of the hole with a center punch, it can be done with a hand held drill. Start the hole far enough in so when it's finished, the hole edge is just a bit below the case surface. Once the stud is re-installed, you shouldn't see the hole, the oil just pumps out past the first thread.

Once the case savers are installed and drilled, but before installing the studs, I put a tape and a hose clamp around the rod journal (to hold oil pressure) and crank the engine to confirm that oil is pulsing out all the top holes and to push out any crap that may have been left in there from drilling.

The studs aren't all the same length, so keep them in their original locations.

Phew! I hope this helps, some things are easier to do than to explain.
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
Deleted User 287

Re: Slash five head gasket leak

Post by Deleted User 287 »

Excellent post, gspd. Thanks for taking the time. I just hope I never have to use it!
Frog
Posts: 153
Joined: Tue Aug 03, 2010 7:17 pm

Re: It's easier to do than it is to explain

Post by Frog »

gspd wrote:This will assure that the tap starts straight, use a base gasket as a template to fabricate a jig (1"-1.5" thick block of wood, metal, or plastic) so it slides down over the studs. (Remove the pistons and con rods)

You need a regular tap for all the holes, and a bottoming tap to finish the 2 left front and 2 right rear holes..
The case savers come with metric or standard outer threads, take your pick, just make sure the taps match.

You need to mill the outside end of each case saver so they're flat. (they come tapered)
The 2 right front and 2 left rear case savers have to be shortened to the same thickness as the case, if they stick in past the inside of the case, they will interfere with the crank counterweights.
If you don't have a machine shop, you can do the above mods by installing the case saver (with a short section of old stud to hold it) in a drill press and boring down on a piece of medium emery cloth.

The bottom ones have no oil feed, they just have to end up flush with the casing.
Use red loctite on the outer threads of case savers and screw them in using one of your studs (with a nut to prevent the stud from going right through the case saver); lock double nuts on the other end and use those to turn the case saver into the case.
Once the case saver is in flush, you can easily remove the stud by backing off the first lock nut.

Next, you have to carefully drill up through the top case savers at an angle to connect to the original oil feed passage in the case. Install one top case saver and drill it before installing the other one. that way you can put a drill bit in the adjacent oil feed hole to establish the correct angle. If you carefully mark the beginning of the hole with a center punch, it can be done with a hand held drill. Start the hole far enough in so when it's finished, the hole edge is just a bit below the case surface. Once the stud is re-installed, you shouldn't see the hole, the oil just pumps out past the first thread.

Once the case savers are installed and drilled, but before installing the studs, I put a tape and a hose clamp around the rod journal (to hold oil pressure) and crank the engine to confirm that oil is pulsing out all the top holes and to push out any crap that may have been left in there from drilling.

The studs aren't all the same length, so keep them in their original locations.

Phew! I hope this helps, some things are easier to do than to explain.
THANK YOU KINDLY
Major Softie
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Joined: Tue Aug 03, 2010 1:46 pm

Re: Slash five head gasket leak

Post by Major Softie »

If you go with Helicoils, their outside threads are unique to the Helicoil product, so you have to use their taps.
MS - out
Jean
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Re: Slash five head gasket leak

Post by Jean »

Helicoils will eventually "walk" out. At least all mine have.
I think it has to do with us keeping our bikes for longer than the Helicoil people ever imagined.
AND my bikes are as old as some of yours!! The NEW one is 32 years+ and the OLD one is 39...and all still going.
Clemson, SC
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ME 109
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Re: Slash five head gasket leak

Post by ME 109 »

Has anyone tried welding and re-drilling and tapping stripped stud holes?
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