48 pan threaded intake spigot replacement information needed

[MarkLindyHugo]

Hello all,
I have a 1948 panhead with under 25k original miles.
I am in the process of waking it up after a 20+ year slumber.
When last run, it was thought to have an intake leak. Bubble testing confirmed a very minor leak on the front spigot past the head threads
The rear spigot was more of a mystery. When I removed the intake manifold, I noticed the rear spigot was able to rotate a few degrees.
Closer inspection showed that the rivet is able to move in and out about 1/8 inch.
There does not seem to be any slop in the threads trying to pull/push the spigot.
I have tried to review the other posts about this subject in this forum and others, and I still have some questions I need answers to.
My service manual does not address this repair.

Assumption - the rear spigot needs to be replaced.

• Are the V-Twin spigots and rivets the right source or is there a better one?
• Is a thread sealant recommended when installing - if so, which one?

I plan on using green and draw a vacuum to seal up the leak on the front.

• Is there a torque spec for installing the spigot? How tight?
• Is the hole for the rivet drilled once the spigot is tightened in place?
• Is any sealant used when installing and peening the rivet?
• Is the rivet peened cold or heated?
• Can this repair be done with the head on the motor and the motor in the frame?

In conversation with other club members, I have been pointed to making an anvil from a bolt and coupling nut profiled to match the inside face of the spigot.
Is there any issue with this style of anvil?
Any other recommendations?

My dad owned this bike from new, and I have all the receipts. The heads have never been off. It almost 'looks' like it was never fully peened at the factory, but that seems unbelievable.

As always, I appreciate the thoughts and advice here.
Thanks
Mark

[PaulCDF]

48 pan threaded intake spigot replacement information needed



Mark;

Here is a link to a previous discussion on topic:

Chief nipple removal tool - AMCA Forum

NOW the thing of it is IN THAT DISCUSSION is a Link Tom Cotton provided to Virtual Indian 2002 (Why that link is still working I don't know but the article is PURE GOLD)
Discusses manifold leak testing AND nipple rivets.

There are many other post on forum on point as well IMO the above is the best.
In the search box just use keyword "nipple"

Good luck. Please keep us posted.

[dukekleman]

Hello all,
I have a 1948 panhead with under 25k original miles.
I am in the process of waking it up after a 20+ year slumber.
When last run, it was thought to have an intake leak. Bubble testing confirmed a very minor leak on the front spigot past the head threads
The rear spigot was more of a mystery. When I removed the intake manifold, I noticed the rear spigot was able to rotate a few degrees.
Closer inspection showed that the rivet is able to move in and out about 1/8 inch.
There does not seem to be any slop in the threads trying to pull/push the spigot.
I have tried to review the other posts about this subject in this forum and others, and I still have some questions I need answers to.
My service manual does not address this repair.

Assumption - the rear spigot needs to be replaced.

• Are the V-Twin spigots and rivets the right source or is there a better one?
• Is a thread sealant recommended when installing - if so, which one?

I plan on using green and draw a vacuum to seal up the leak on the front.

• Is there a torque spec for installing the spigot? How tight?
• Is the hole for the rivet drilled once the spigot is tightened in place?
• Is any sealant used when installing and peening the rivet?
• Is the rivet peened cold or heated?
• Can this repair be done with the head on the motor and the motor in the frame?

In conversation with other club members, I have been pointed to making an anvil from a bolt and coupling nut profiled to match the inside face of the spigot.
Is there any issue with this style of anvil?
Any other recommendations?

My dad owned this bike from new, and I have all the receipts. The heads have never been off. It almost 'looks' like it was never fully peened at the factory, but that seems unbelievable.

As always, I appreciate the thoughts and advice here.
Thanks
Mark

Mark,

I typically use Colony spigots, however on occasion, I find myself making a custom spigot.

I torque the spigot on aluminum cylinder heads to 40 Ft lbs.
Keep in mind this torque value is NOT a dry torque. It is a lubricated torque as I use Loctite 565 thread sealant on the threaded portion.
After torquing the insert, I then drill the assembly in place for a proper rivet fitment.
I have special tooling I designed/adapted and built for cold pressing the rivet. My tooling allows me to perform this entire process on the motorcycle, fuel tanks installed.
I allow a full cure of 24 hours for good measure and long success.

I hope this helps,

Duke Kleman

[MarkLindyHugo]

Thanks for the link to the Indian write-up by Cotton. I had not seen that in my previous searches.
Mark

[otis71]

Personally I forgo the thread sealant because the nipple is straight thread and not tapered. I do use JB Weld where the nipple meets the head. Often the rivet hole is wallowed out and an oversized rivet is needed. I redrill the hole the least amount necessary to make it round and then turn a rivet to have a slight interference to the hole. Softening the rivet with heat and slow cooling helps too.

[marksg]

Mark,

I typically use Colony spigots, however on occasion, I find myself making a custom spigot.

I torque the spigot on aluminum cylinder heads to 40 Ft lbs.
Keep in mind this torque value is NOT a dry torque. It is a lubricated torque as I use Loctite 565 thread sealant on the threaded portion.
After torquing the insert, I then drill the assembly in place for a proper rivet fitment.
I have special tooling I designed/adapted and built for cold pressing the rivet. My tooling allows me to perform this entire process on the motorcycle, fuel tanks installed.
I allow a full cure of 24 hours for good measure and long success.

I hope this helps,

Duke Kleman

Any chance you would want to share a picture of your tooling. I enjoy the process of learning and doing for myself.
Cotten shared a picture of his Linkert throttle disk arbor and I had to go out and by a lathe.
It is great when those with knowledge pass it down to those of us learning. I appreciate this forum.

[joe fxs fxr]

Cotten shared a picture of his Linkert throttle disk arbor and I had to go out and by a lathe..

Classic!!!
Keep up the good work

[T. Cotten]

Again for reference, Folks,..

https://web.archive.org/web/20250615...hleaktest.html

Please note that was a quarter-century ago, and the question of a sealer is still up for grabs.
'Seal-Lock' has its limits; 'J-BWeld' can be successful, but it needs extended cure to resist fuels.
Beware of any 'Loctite' that tastes like saccharine, as it will wash out.
(We desire a sealer of course, even if it is 'suspenders and a belt'; Since the Factory achieved a seal without one, we must question if so many of the fuel-digestible goobers reported to succeed wouldn't have achieved a seal without them.)

Please also note that the sealing surfaces for Pan nipples are painfully wide, with nothing to bite into each other for a mechanical seal, even though the Factory apparently never used a sealer (as Indian did). Both the face of the nipple and seating face upon the head must be dressed of all blemishes.
(Parkerizing on nipples can also interfere with sealers, particularly 'Seal-Lock'.)

The greatest problem with Pan nipples is that the heads were often stripped out by callous disassembly.

....Cotten