993GT

Hey guys,
For those who have removed their coolant fittings(vs. pinning without fitting removal) when doing the pinning, what epoxy have you used to replace the factory epoxy? Hard to find a trustable weld shop in my area so pinning is looking like the way to go for me...
Thanks in advance,
Rob

AudiOn19s

JB weld. Carries about the same stigma as duct tape but when you really dig into the details JB weld has one of the highest temperature ratings of any available epoxy. I found a couple with higher temp ratings when searching around and they were very hard to get ahold of. JB weld can be found anywhere.

I fixed one of my fittings with JB weld and ran it for a couple months and when I finally had my fittings welded the fabricator said the JB weld join was by far the most difficult to get apart.

993GT

Thanks! It seems like JB Weld is the way to go, already picked some up prior to posting-stuff just works!
Think the key is low shrink during cure/use, the structural portion now kept to the mechanical lock of pin/bolt, just need a filler to seal.
Cheers,

m42racer

I dont mean to bust your "*****" but dont understand the logic in JB weld over normal welding. If you think welding could leak, why do you think JB weld won't.

IMHO, this pining is not the way to go. As stated in earlier posts, welding is the only way to do it properely and finding a place that does certified welding is not difficult. You may have to ship them if they are not close, but pinning the nipples in and gouping on JB weld? Seriously? That is not engineering and certainly not at the level these cars deserve. I think whoever came up with that idea either doesn't have a welder or cannot weld.

993GT

There are pro's AND con's to BOTH welding and pinning methods. Ultimately both provide equal protection against rapid/'catastrophic' failure.

AEsco48

You have taken into consideration that from the factory the still come epoxy welded?

If you metal weld and in the future something happens to the fitting (low chance) the area has to be removed from the engine, the fitting cut off, the fitting machined off and then a custom fitting made, of course unless its less expensive to replace the component the fitting goes into.

I plan to pin my engine with out removing it to mitigate the risk of a catastrophic failure. I realize I may not be able to pin every fitting, but I am reducing the risk. If one of the fittings starts to leak bc the epoxy fail it wont be catastrophic and then I deal with the inconvenience of removing the engine and most importantly the cost associated with it. Since the car wont be entered in any prize money awarding races. Pinning with the engine in is IMO the best option.

As a mechanical engineer, I don't believe welding is the automatic and best solution. It may be the most profitable for shops...

m42racer

I may have come across a little strong, but the point is pinning is not good engineering. As a mechanical engineer, you have to admit that pinning and JB weld is "home depot" at its best.

993GT

sure it is good engineering, 'replaceable' sealing element with a mechanical lock.
Maybe we just need to agree to disagree here....
IMHO, what Porsche should have done is incorporate an internal Viton o-ring for a sealing element with external lock collar (ie. like the fuel return line). Or a threaded-in fitting with sealing ring.
Cheers,

cfjan

I had all my fittings welded a couple of months ago. The shop I used recommended welding. They feel confident enough to do a good job (based on their past experience with welding, making customized turbo plumbing, etc.). Fittings are removed and cleaned, welded and put under a water tank, pressurized for 24 hours+ to make sure that there's no leak, etc.

Who knows how they will hold up after using at the track with all the vibration, etc. But just providing one data point here.

AEsco48

Yup: 'replaceable' sealing element with a mechanical lock.

993GT

Thanks for the post/data point!
We are all 'learning' the long-term effects/benefits of all methods

m42racer

.Totally agree. What were they thinking?? All they needed to do was to have 0.002" interference fit and they would last forever. We rely on the main oil galley plugs to have this interference so why not the water pipes.

But don't replace bad engineering for more. Welding when done correctly will last forever.

Just because its easy doesn't make it right. Who ever thought of pinning has no engineering background. As an engineer would you have come up with that solution? I think not.

993GT

Porsche started thinking about their accountants and not their engineers
I very much disagree that pinning is bad engineering, has a sealing element with mechanical lock.
Believe Sharkwerks was the first to the pinning idea, I respect their stuff enough to give it a try on mine.
I'll leave it at that.
Regards,

Alan C.

Let's look at it another way. The factory includes fittings installed with epoxy as no charge. Fittings installed with epoxy and pinned for an additional $200.00 and fittings welded in for an additional $500.00. I'd pay the $500.00.

AEsco48

But being Porsche they would offer the welds matching the color of the car for 2500!