Yes John! That’s what I was thinking about! Hmmm.
Now you’ve got me thinking. Although the idea of using a silicone adhesive/ sealant seems like it may offer some benefits.
Loctite Form-A-Thread is available on Amazon.
Epoxy (JB Weld) is the surer bet. As to permanence and removing the nipple fifty years from now, heating up the area sufficiently will soften the epoxy sufficiently to remove the nipple with little effort.
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It’s on Amazon but will take a week to get here, and I’m not sure I feel like waiting…
I’d consider tapping the hole for the Helicoil, coating the side of the threads that contact the manifold with “The Right Stuff”, let that cure overnight and then install the nipple with a thread sealant and a sealing washer.
So if I went with JB Weld, is there a particular version that is recommended? I was looking and there seems to be all types now…
JB Quick will work.
…
Do you have a local Pepboys? Mine carry the thread repair product. TBH, I tried it once and it didn’t hold up well, but I might have messed up the application. You can also cut threads into JB Weld. You have to be careful with the application so that it doesn’t extend much above the existing threads otherwise you have to bore a hole to clean it up before running the tap through it.
Remember it’s very nominal pressure, like you could probably block it with your thumb. If you can run the fitting in and you can’t pull it straight out again, then that’s strong enough and you can seal it with just about any sealant. You could probably even use old fashioned plumber’s pipe dope.
I went there yesterday, and they didn’t have it… interesting to hear your experience, as I’ve heard or read others didn’t have the best results with the form a thread, and found myself hesitant about putting something in that ultimately doesn’t work, forcing me to take it all apart again.
Now I’m thinking about using the Right Stuff with the brass fitting. Should be close to a permanent, but reversible, solution
What about araldite? That stuff sticks like the proverbial (to a blanket)
Its the black one you need. US part number 25229. Its the best gasket sealer I have found in over 40 years. Do not use it on oil pans and intake manifolds. It will never leak, but It sticks too well, and you will struggle to get them apart in the future. Keep it off your fingers. Leave it for a couple of hours to fully cure.
Leave the clear plastic spout on the can after you use it.
Colin,
Why the black one? I bought the grey… do I need to do something different?
Robert,
Have you given any thought about asking someone who rebuilds these engines for a living ,like Dick Maury, how they would properly repair the threads so you can use the proper supplied parts? Shipping costs should be minimal.
That would be my approach for a proper repair and piece of mind.
Marco
Marco, in general I am not a fan of bypass type/ hack job fixes, and I confess there is a part of me that is a bit uncomfortable taking this non-factory approach. I’m fairly certain I know what the proper repair is. Weld up the hole with new aluminum, then drill and tap a new BSP 3/8”-19 threaded opening.
But I think that’s more expense and effort than is required.:
- My car is a driver, not a show car.
- My car is a 68, so while a series 1 car, if it has a triple SU manifold on it, it’s not “”correct” since it left the factory with dual strombergs
3)The “correct” adapter is steel, which I think is a material spec flaw, probably done to save money. So I think this approach is, functionally, better than original. The combination of brass and sealant will outlive the factory steel piece.
And since all resources are finite, I would rather spend my $$ on something that is either more mission critical, or something that provides some enhanced esthetic. I see this adapter as being neither. (actually the brass adapter is one less piece that will rust under the hood, and if idleness gets a serious grip on me, I’ll have one more piece of brass to polish! 
)
Robert
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After just reading the unending blather about what constitutes “concours” wrt 120 tires… it’s refreshing to read the above.
Sane. Pragmatic. Reasoned.
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Robert,
My point was not about originality (which by the way I’m an anal fanatic) but exactly the same as yours. The “critical mission” in this case was avoiding a failure and breaking down on the road.
Granted the pressures are low but if your luck is anything like mine with any questionable repairs the chances of failures are high.
Best of luck with whichever path you choose.
Marco
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If strict originality is psychologically important then the only solution is to plug weld the hole, drill it out and tap the casting making it essentially as original. If that’s what it takes to sleep well at night.
If functionality is important then using an epoxy based solution is more practical, and the repair will be equally invisible and functional - only you will know. If you want to strike a compromise then consider Devcon 10610 aluminum putty. It’s expensive, but specifically designed to repair aluminum castings to as good or better than original specification and can be machined and tapped just like a plug weld repair and will be entirely invisible. I’ve used it and can vouch for its efficacy. Given the relatively low pressure application under discussion and how a lesser epoxy compound like JB Weld would function equally as well then the Devcon or plug welding solutions are overkill. But ymmv. End of free advice.
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So, it’s done. I installed the brass fitting, using JB Weld. I applied the JB like it was a thread sealant, coating the full depth of the threads on the brass fitting, and then “screwed” it in. In quotes because the thread engagement was limited. I opted to include the copper washer for two reasons, first is the esthetic of it being expected. Second is that it offered an additional sealing surface, as it does in its normal function. This was a bit different as the backside of the washer also has a a bit of JB on it.
So now there’s not much to do but wait for it to set up, and then assemble and pressurize the system and see what happens…
Congrats, onto the next nightmare!
Lol. That is sort of the world of old cars…
thanks for your help with this one Erica! 