Inlet packing bushing

Next step for me is to re-install the intake. I've read a lot about all the intake issues on the WLA, and trying to prevent whatever problems I can. Looking at 45parts depot I see original metallic replacement Inlet packing bushings, and then another listing for Inlet packing bushings made from PEET. Any thoughts on advantages/disadvantages of either one? Any tips on how to best R&R the Inlet packing bushings?

Thanks,

Mark Robinson

Mark!

Brass seals are certainly the least expensive, if you can get them to seal.
A simple bubble-test will tell if you are successful: http://virtualindian.org/11techleaktest.html

The material PEEK is an ideal replacement for the unforgiving brass.
If your manifold is pristine and un-blemished, then a set of molded seals from http://www.enfieldracing.com/8.html may save you time and money.
Beware however, that if there is wear or blemishes upon the spigots, the seal's fit may be compromised, and its re-useability as well.
Worn manifolds are reconditioned and custom-fitted by many sources, but at greater expense.

Beware that leaks can occur between the nipples and the headcastings as well, where the seals do not apply.

....Cotten

Cotten,

Thanks for the good advice on the bushings. Sounds like I need to spring for the PEEK bushings. Are the bushings a press fit, and if so, any recommendations on removing the existing bushing?

Thanks,

Mark

Mark!

For stuck seals that will not release by smacking the nut with a small wooden mallet, I welded an old BigTwin shift fork to a block that could be held firmly in a vise. With the manifold spigot within the fork, and the nut resting upon it, a drift that is just slightly smaller than the seal' inside diameter can be used to tap squarely upon the end of the spigot, pushing the manifold out the bottom.
Penetrant helps of course, and heat if need be.

Seals that have been crimped that tightly have usually marred the spigot.

Good luck!

....Cotten

[Pa]

My issue with the seal design is how it butts up against the cylinder nipples. The compression part of the design, where it compresses around the manifold and against the taper in the nut, is ok but the butting up is my main concern. A product such as Permatex Ultra Copper, which is good to 700 degrees F, solves the butt up issue when using the original brass seals.

Pa!

The PEEK has incredble tensile strength, but it is still compliant.
The nipple makes an amazingly detailed impression into its face as it seals.

IMPRESS.jpg

This is also why you want a pristine spigot if you wish to re-use the expensive seals.
And obviously retorques are prudent, as with any seal.

...Cotten

I have just fitted some PEEK seals, after many many attempts to get the brass ones to work. I noticed the PEEK ones were hard to push on to the manifold, and the manifold surface was marred slightly, and out of round by a couple of thou. I managed to dress the manifold surfaces up true.
I inspected the spigot faces closely, and determined that they were OK. Likewise the threads on the spigots and in the nuts.
I smeered some Hermetite Blue on the spigot faces, but I found it smudged everywhere, when trying to align the manifold, and getting the plumbers nuts started on their threads.
I didn't find it neccessay to loosen the cylinder base nuts.
The front plumbers nut done up firm, but the rear one felt a bit mushy.
I made up a fitting for the end of the carb, and put about 5 or 6 PSI air into the intake.
I had very very fine bubbles develope around the gasket between the carb and the manifold, course bubbles from around the rear plumbers nut, and also course bubbles from around a small bolt that screws in to hold the rear spigot in place.
(My other motor has what looks like peened over plugs, holding the spigots)
I tightened the rear nut a bit more, three manifolt bolts, and also the spigot bolt, and viola, no more leaks. Unbelievable.
I found a NOS condensor #1629-30, and put that in, in place of the no brand aftermarket condensor I had in there.
My second hand D16 plugs were not firing, so I fitted a new set, gapped to 30 thou.
I have the M88 carb fitted after the good advise I got recently from the forum, regards the orientation of the fixed jet and stem plug.
I have the low speed out about 2 1/2 turns.
I was able to get the motor to start and run really well, but the starting ritual is still unknown.
I've dicked around with this new restoration project off and on, close on three years, and finally, I have a result.
So, I have a PEEK float, PEEK seals, new float needle and seat, carb rebuilt correctly, good throttle bushes, unmarred maniflold, new plugs and condensor, tappets and ignition timing set as per the manual.
I hope this is a help to some-one.
Cheers Keith

[Pa]

Sounds like you are in business now Keith.

[Pa]

Pa!

The PEEK has incredble tensile strength, but it is still compliant.
The nipple makes an amazingly detailed impression into its face as it seals.

IMPRESS.jpg

This is also why you want a pristine spigot if you wish to re-use the expensive seals.
And obviously retorques are prudent, as with any seal.

...Cotten

Nice evidence there Cotten !! Undoubtably true.

Keith!

PEEK seals should indeed be a squeeze-on fit, as tight as possible.

(PEEK is not used for floats however.)

Thorough bubble-testing requires at least 10-12psi, with 15psi maximum, and it must be a constant, regulated supply to display microfissures that may take several seconds to appear as blisters of foam.

These leaks may form anywhere, even casting porosities invisible to the eye.

POROSITY.jpg

MANBLSTR.jpg

....Cotten

[Pa]

Cotten....What is your technic for sealing up casting porosities ?

Pa!

Silver solder usually, except upon aluminum, of course.

....Cotten

[Pa]

Thanks Cotten.

Thanks for pointing that out. Yes the float is a rubber ducky, not PEEK.
This is what I made up to pressurize the inlet. Constant supply from the compressor.
I'll consider increasing the pressure a bit.
Keith

Just some more about how the seal contacts the nipple,.. Folks,

Here is a photo that shows the impression of the nipple into the face of the seal, upon a set with ~2000 miles of duty.

IMPRESS2.jpg

The nuts must be snugged as the seals comply.

...Cotten