Porous cases?

[otis71]

My 56 FLH has leaks persistently around the front tappet block. I’ve checked the gasket surface, made sure holes in tappets face inward and replaced the gasket only to have a significant amount of oil to continue to leak and only from the front of the block. I’m starting to think the case is porous between the block and the timer. The metal in that area appears rough also. Do these cases spring leaks? Any way to slow it up short of splitting the cases?

[Rubone]

Do these cases spring leaks? Any way to slow it up short of splitting the cases?

Short answer, yes, and no.

[T. Cotten]

Its all about inspection, Otis,...

First I suggest removing the tappet block, and thoroughly de-greasing the suspected region, and although there are powder crack detection products for aluminum (a Magic Marker and Arrid Extra Dry?), often just a heat lamp will display oil released from anywhere it shouldn't be.

Is there a gallery welch plug in the case behind it? (#4 shown here..)

OVHGALRY.jpg

Capping that with a goober could save splitting the cases.

One such leak at the rear block turned out that the cylinder base studs had been severely over-torqued, and cracked the case. I wish you better luck!

....Cotten

[otis71]

I did clean and put new gasket on. It’s only oily on the front edge of the front block leading me to being it’s not the block. I’ll have to pull the block again and check for the Welch plug. Is it supposed to be plugged?

[T. Cotten]

I'm not an expert on welch plugs, Otis!

But I know they can leak.

Its all about observation: That's the same thing as inspection.

(I gotta put on my strongest magnifiers, which often makes the end of my nose get oiled.)

....Cotten

[larry]

Did you check the block for flatness?

[otis71]

Everything mates up nice and the gasket was replaced. Because oil is only visible from the front of the block, I really think the case is leaks. I’m wondering if anyone else has had this problem.

[T. Cotten]

By 'front', Otis,..

Do you mean relative to the machine?

That's downhill from the welch plug, of course.

Please spin a clean cotton swab on top of it to make sure its dry.

.....Cotten
PS: And I wasn't kidding about the Arrid Extra Dry.

PPS: And Larry!
I've got a welded block in my hand, and wonder how to check just that. Any tricks?

[larry]

I use a straightedge and a flashlight. If it passes that test, it's probably good.

[otis71]

Top of the block stays dry. Can you explain the arrid and marker trick? As far as a welded cast block, can you magnaflux it? When I worked in the trades QC would check welds with it though I’m not completely familiar with the technique.

[T. Cotten]

Magnafluxing in the traditional sense, Otis,..

Was applied to magnetic materials. But I've got an un-used two-decade-old Magnaflux brand "Spotcheck Jr." kit in front of me, a Christmas present from Ken Smith.

Its a real fancy gadget that accepts apparently four mini aerosol cans to shoot simultaneously or something. Actually, I can't figure it out.

The directions indicate two mini cans are a volatile cleaner, one a penetrating dye, and the other a 'developer'. The area is to be scrupulously cleaned, before penetrant dye is applied, soaked in, and then the surface wiped with the cleaner on a cloth. Then the developer is sprayed over it all, and trapped penetrant will bloom to the surface.

Just like if you really clean the area with Brakleen or something, then really ink everything with a red felt-tip marker moistened with a little Brakleen, and then allowed to dry. The surface can then be wiped with a paper towel moistened with Brakleen, and again allowed to dry.

Now comes the tricky part: I seriously don't know if "Arrid Extra Dry" is what it used to be, but the spray that left a layer of "powder" worked as a 'developer' to draw penetrated dye back to the surface for a readable display.

....Cotten

[larry]

Dye penetrant is a legitimate test for cracks and porosity. It will not reveal defects below the surface.

[T. Cotten]

Dye penetrant is a legitimate test for cracks and porosity. It will not reveal defects below the surface.

So how does the oil get out, Larry?

Its real hard to get the light behind my steel rule on this block.

Yet its all daylight when its only touching the corners.

Its going to be easier to bore a hole in a plate, and lap it for inspection. Then even an ant track will show.

....Cotten

[larry]

I use a flat file to straighten the corners.

[Jerry Wieland]

I use a flat file to straighten the corners.

Where can you buy a flat file anymore. Everyone I look at has a curve to it. Used to be able to buy good files at most farm/hardware stores but not any more. Jerry