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View Full Version : Head Intake Threads and Seals ... Head Hog?



40 Nuck
08-16-2010, 11:51 AM
I have a couple of OEM heads that have been altered for O-Ring Intake and would like to go back to threaded so that I can mount the original brass intake and linkert. Any suggestions on whether this would be recommended, and if so, a good vendor. I've run across Head Hog (Don Sullivan), and wondering about feedback on them as a vendor. Also like their valve seat solution ... and was wondering if anyone had feedback on that. Also, I've noticed the articles in the AMCA mag on the new intake manifold seals that suggest that they eliminate the plumber intake seal problem, even on the brass 1940 intakes (mine is a 1940). Anyone had experience with those?

Thanks!

chibobber
08-16-2010, 03:38 PM
Vic,American Cycle Fabrication,Paul can fix you up.The stock brass seals work fine if done right. Some like the synthetic seals some don't. (ACF 570-752-8715 PA)
Good luck,Bob

Robert Luland
08-16-2010, 05:11 PM
I got no complaints against Don. He does great work and has always done right by me. I have read some to indifference but he’s always done good by me. His valve overlay process is incredible. He’s done four heads for me. The Peek ferule is the way to go. They cinch up at half the tork and this save putting a beating on the rivets. Bob L

Jerry Wieland
08-16-2010, 11:07 PM
Vic Brass intake manifolds are not 1940. 1940 uses a short steel manifold that has the number 428-40 on it. I believe that brass intakes are 1947.

Jerry

MJW
08-16-2010, 11:17 PM
I had Don re-thread my 51 pan heads, most of the original threads were gone so he welded them up and cut new ones. The only disappointment was my own error, I thought they would be air tight when I got them back with the new inserts already installed, turned out I needed to pull the intake and remove the inserts again. The skinny gasket that presses against the head had torn so I made new ones out of some gasket material, I know "goobers" are frowned upon, but I couldn't resist adding a dab of steam fitting sealer to the threads. I also made a special wrench to span the three holes in the perimeter of the inserts for tightening. No leaks yet after two years...Mike

Chris Haynes
08-16-2010, 11:49 PM
Vic Brass intake manifolds are not 1940. 1940 uses a short steel manifold that has the number 428-40 on it. I believe that brass intakes are 1947.

Jerry

Jerry,
Here is a 1947. Notice the Parkerized intake? Brass doesn't Parkerize.
http://i412.photobucket.com/albums/pp209/hd36knuck/16848.jpg

40 Nuck
08-17-2010, 12:09 AM
1940 was the first year for the large ports (1.5") and manifold. The brass was a one-year only (1940) part as it was found that the brass on brass (bushing on manifold) resulted in leaks, but apparently the brass manifold lasted most, if not all of the model year until it could be replaced. Thanks all for the feedback on vendors ... sounds like I have some solid options, and that there is hope for my O-ring heads.

koanes
08-17-2010, 07:59 AM
Chris, That prototype picture may have an iron manifold, but every original 47 knuck I have seen has a brass manifold. I always sneek a peek at the top of the manifold where the choke rod rubs, (they all do) and you can clearly see brass. Vic, the Peek seals are the way to go, far less torque on the nuts to get a good seal. I've never heard anyone speak poorly of them. Many thanks to Tom C. for bringing that material to my attention.

T. Cotten
08-17-2010, 08:37 AM
All bronze OHV manifolds that I have re-conditioned were long, not short like the '40.
They most often were found upon '47 EL's, and they are also prone to horrendous casting porosities, as shown in the attachments.

Moldthread's cast PEEK seals are ideal, if your manifold spigots are pristine and of the original diameter.
Bronze manifolds are more malleable than even steel, and have nearly all worn or distorted with use. Therefore, they require swaging before re-cutting to accept a fresh seal of any material.
PEEK seals have proven user-friendly and reliable when properly re-torqued, and in the decade of their use, nobody has worn any out. They are re-useable as long as the spigots were pristine in the first place. Blemished surfaces will make impressions that can be sanded out for re-use, but naturally shorten the seals' otherwise infinite lifetime.

The bottom line with any manifold seal is to properly test it before risking the motor.
This only requires air pressure, soapy water, and a little patience: http://virtualindian.org/11techleaktest.html

Beware that barnyard tests give barnyard results; The porosities shown below could not be detected by spraying it while the motor was running.

The greatest obstacle to restoring intakes is finding a sealer for the nipple thread that not only resists today's digestive fuels, but tomorrow's.

.....Cotten

Jerry Wieland
08-17-2010, 11:13 AM
Vic Here are pictures of knucklehead OHV intake manifolds and most of this you already know - from left, 1936 to 1939, 1940 only, 1941 to 46/maybe 47 and then the brass one.

My first knucklehead 30 years ago was a 1940. The second from the left (1940 only) has a casting number of 428-40 (all the rest have 428-401) and has the same distance from flange to port center as does the 1936 to 39. If you do not believe this is 40 only then try fitting your 7" air cleaner on a bike with this manifold - just make sure you have your hammer handy cuz you're gonna have to bend something. The 6" air cleaner that came stock on a 1940 has clearance but the 7" in 1941 necessiated lengthening of the throat of the manifold.

Don't quote Palmer on this one - he's been educated now but when he wrote his book both he and Chris were should we say - uninformed on this matter.

http://i243.photobucket.com/albums/ff187/JerryWieland/OHV%20intakes/OHVintake3647-1.jpg

http://i243.photobucket.com/albums/ff187/JerryWieland/OHV%20intakes/OHVintake3647-2.jpg

Chris next time you get around an original 47 look real close at the intake like Kyle said. Brass almost always shows thru by the choke rod.

Jerry

Jerry Wieland
08-17-2010, 11:58 AM
It is not uncommon to find an original 47 that does not have a brass intake but I assume that this brass intake problem reared its' ugly head fairly quick. So was the brass intake in 1947 just part of a year or were they replaced with steel. Probably will never know unless blueprints exist somewhere.

Jerry

T. Cotten
08-18-2010, 09:08 PM
For what it's worth,
I re-fitted a bronze UL manifold today, and it was from a '46.


....Cotten

Neil74
08-19-2010, 10:25 PM
I'll check my 47EL in the morning, I think it is the bronze intake on mine. Cotton any word on this sealer for the intake threads
http://www.cylinderheadsupply.com/kl1379.html

T. Cotten
08-20-2010, 08:39 AM
I'll check my 47EL in the morning, I think it is the bronze intake on mine. Cotton any word on this sealer for the intake threads
http://www.cylinderheadsupply.com/kl1379.html

Neil!

Seal-Lock again survives this year's summer-blend of local P4gas (Shell),
but it has its limitations: It is not a structural adhesive. It bonds on a molecular level, but is not great for filling voids.
It is ideal for the sealing and peening of the rivet, however. But at thirty bucks a bottle, its extreme medicine (unless you have other uses for it, such as valve seats, guides, crack pinning, etc.)

J-BWeld has held up better this year than last.
It would be my choice for the threads and shoulder.

It is a shame that we do not know what Indian used.

....Cotten

Neil74
08-20-2010, 01:33 PM
Cotten if we need to remove the nipples or rivets again, can this be done with J-B weld? Also any idea what they used on the early aircraft intakes?

T. Cotten
08-20-2010, 07:35 PM
Cotten if we need to remove the nipples or rivets again, can this be done with J-B weld? Also any idea what they used on the early aircraft intakes?

Neil!

Sorry for another late reply,
but since the new forum format takes several minutes to open, at 2 cents a minute to my lan line provider, I may have to dismiss this forum to only view when I have borrowed time on other peoples computers.

This has been pushed further to be a genuinely a rich man's hobby.

JBWeld dissolves in methylene chloride strippers.
The fear is that it will in modern fuels as well.

I have no information about aircraft assemblies at all.
But I do know that modern aircraft fuels are not nearly as digestive as pump gas.
To me, that makes aircraft techniques somewhat irrelevant.

....Cotten

Chris Haynes
08-20-2010, 09:30 PM
[QUOTE=T. Cotten;99830]Neil!

Sorry for another late reply,
but since the new forum format takes several minutes to open, at 2 cents a minute to my lan line provider, I may have to dismiss this forum to only view when I have borrowed time on other peoples computers.

This has been pushed further to be a genuinely a rich man's hobby.

Cotten,
AOL is FREE.

Rubone
08-20-2010, 11:58 PM
Chris,
AOL may be free in a populous area, but in the hinterlands where I live there is no such thing. I depend on a local service provider. A small price to pay to stay away from civilization!
Robbie

T. Cotten
08-21-2010, 08:17 AM
And AOL was anything but free when I first started out on it back in the '90s.
(But it did let me publish a website with common MS software, and not need to fathom FTPs.)

Back again to topic,
I failed to mention my favorite goober that has gotten me out of trouble so many times:
Tnemec's Omnithane Series 530 isocyanate urethane aluminum primer.

It has proven P4gas-proof, so far.

...Cotten

Neil74
08-27-2010, 03:35 PM
Tnemec's Omnithane Series 530 isocyanate urethane aluminum primer,now thats a mouthful:) I tried JB weld on an old mustang gas tank once, two months latter a slimmy gob came off and I was leaking again.:)) 47th post had to edit an mention my Knuckle and Chief:) just seemed fitting.

T. Cotten
08-27-2010, 04:57 PM
Tnemec's Omnithane Series 530 isocyanate urethane aluminum primer,now thats a mouthful:) I tried JB weld on an old mustang gas tank once, two months latter a slimmy gob came off and I was leaking again.:)) 47th post had to edit an mention my Knuckle and Chief:) just seemed fitting.
Neil!

It wasn't the "Kwik-Set" variety of JBWeld was it?

Last year's testing in Shell's summer "nitrogenated" fuel was the first time I observed any softening at all of the original formula. It was a minor change, but it still indicated a digestive effect.

This year, I sandwiched JBWeld between two blasted sheets of air duct scrap.
Not only has it remained intact in this summer's blend, the surplus drool hasn't softened like last summer.

Although we never know what might come out of the next pump, original JBWeld is still the best we got.

It is most likely that there are other brands of epoxies such as Devcon that work as well, maybe better, but they will never be as convenient.

....Cotten

Neil74
09-03-2010, 07:13 AM
Cotten, my turn for being late on response:) sorry. I'm not really sure what kind of JB weld I used that day, I was at a friends shop and he said here use this JBweld. In all fairness the car was jacked up with the tank emptied enough there was no steady flow of fuel. Maybe enough still leaked or the fumes were enough to contaminate it. My biggest complaint as I get older is never having a good pair of reading glasses when I need them most. I used a borrowed pair of shop reading glasses that day so most of the job was just a blur:)