Replacement Airhorn
 

Hi Everyone,

I have one badly mangled airhorn on a tri-power end carb for my 64 GTO. In looking around for a replacement I have found that prices vary considerably.

Which replacement is the best?

Oh Yeah - for your viewing pleasure...
http://i1284.photobucket.com/albums/...psmdxywojt.jpg

Nice right? Idiots are powerful forces of destruction...

All the repros I've seen are the same--from Thailand, I believe. They are very high quality, only distinguishable from the originals by the thinner air cleaner web toward the front of the opening. All the Pontiac vendors, including Ames, has them and they are often listed on eBay. Usually sell for about $90.

Early ones had too large a bore for the accelerator pump shaft/lever, but that's been corrected now. Those early ones needed to bushed to fit the pump shaft correctily.

I seem to remember an old hpp issue on how the did a make shift fix

Another solution (which helps the balance of trade deficit):

(1) Find a common non-tripower carb with the same "spider"
(2) Mill ALL of the spider from the existing tripower airhorn
(3) Mill ALL of the airhorn away from the spider on the donor airhorn
(4) Fit the donor spider into the tripower airhorn with a couple of drops of red loctite on each side.
(5) Clamp in place until dry
(6) Remove the clamps
(7) Drill 2 holes from the outside of the airhorn into the new spider on each side.
(8) Countersink the holes
(9) Tap the holes for a number 3x48 screw
(10) Install flat-head steel screws into the spider with a drop of red loctite on each.

Original airhorn saved.

Don't let anyone use a "cheater bar" when finger-tighting the wing nut on the air cleaner ;)

Jon.

Dick - how well do the new repros take the chromate?

The repros I remember were done using a powder in a rubber mold. They looked good until one tried to have them chromated, but would not take the chromate color as they were a different material, AND they had no structural rigidity. After a year or so, they warped, badly.

Jon.

Jon,

I think those were the first repros that were made in the USA about 10 years ago. The castings were very rough. The screw holes don't line up with the ones on the original float bowls. The surface that sets on the float bowl top edge is not flat--whether warped with age or not flat to begin with? I have one left of the half-dozen I bought years ago. I don't think they are available any longer.

The imported repros are much better--good casting detail, good fit to airhorn, and they DO take dichromate similar to the OEM airhorns. Actually, the casting detail is better than OEM ones I've had. As I said, the downside is the thin airhorn web and with the early ones, too big a hole for the accelerator pump lever. On some of these I've had, the two towers that hold the float swivel pin are drilled too far from the floatbowl gasket surface which requires two gaskets under the needle/seat instead of one to allow proper float settings.

The first picture is of the poor-quality repro made in the USA. The second is of a decent OEM airhorn. The third picture is also of the poor quality repro showing the bottom of the airhorn. The last picture is of the imported repro tops on a Tripower I recently restored. Note the dichromate looks the same as the OEM center carb (None of these three carbs are correct Tripower carbs.)

Dick - thank you.

Jon.

Thanks everyone for the help. Actually, I should post the other end carb - it has a less major problem with the air horn. Possibly it could be fixed instead of replaced??

Dick - do you sell parts, or exclusively restore tri-power set-ups?

I have quite a lot of original and repro Tripower parts. PM me with your needs and I'll let you know if I have what you need.

Thanks Dick - I will hit you up when I know what I have and what I need. I am still finding parts scattered through the boxes (basket case).

BTW - I have enjoyed your youtube videos...quite informative.

Jon, Are you using only the cross piece? What about the bar that goes to the front?

I only used the cross piece.

The steel screws give sufficient rigidity to hold the piece.

Of course, if the end-user uses a breaker bar to tighten the wing-nut on the air cleaner, the repair will fail. ;)

Over the years, we have had to develop techniques to repair items that just will never be reproduced. Even made a complete carburetor for an exotic import of the 1920's when one of our competitors dropped and broke one of the only pair of carbs known to exist.

Have in the past fixed several airhorns in the manner listed.

Jon.