Tri-Power registry

Damn, two years since anyone posted in this section. Who on this forum has Tri-Power beside me?.....John

Wish I had !!, but i am looking forward to trying a AFB

Mine was originally a tri power. I hope to put it back someday

Doesn't seem like there are too many bonnies on this site. Mosty star chiefs and Cats

ya , my tri power sits in the corner waiting to be rebuilt!! tham dam end carbs $$$$$ but i will get there eventually.

on the subject of carbs< I saw on your car ,robert, that you have dual quads! i have an offy intake and gonna try to use some edelbrock 500 cfms. have you heard anything about an electronic ignition not fitting because of the back carb?? guess i could try a petronics inside a smaller cap??

I'm using the pro billet distributor from MSD. It's a tight fit but it does fit. No way an HEI would work

Yes, the end carbs can be problematic. Rebuild kits are available for all three, but the main problem seems to be vacuum leaks caused by throttle plates that don't seal well when they get old. I adjusted mine countless times, but when I would hold them up to the light, I'd still see light around the edges. Gave up and bought new throttle bases with shafts and plates already fitted. There is a teflon based material called DAG213 that is made to seal the plates and bores. Pontiac used it with Tri-Powers in later years. I remember that the service manual for my 1965 GTO had a caution to not use the regular parts cleaner on the throttle bases when rebuilding the carbs. One other problem is that if you don't get on it every once in a while, the gas in the bowls gets stale and gums things up.

Finding a good center carb can be a problem, but the small Rochester 2bbl from the 420E engine is basically the same carb with smaller primary jets, and a different throttle shaft......John

Catbird: Please add my '59 Bonneville 2d h/t to the registry. Car originally had Carter AFB 4bl when I acquired it some 35 years ago. Began a frame off restoration in 2002 and completed it in 2006. Car is now exactly like the one I ordered from dealer in 1959 when i was a senior at Auburn and that one had Tri-Power so the current car had to have it too. Thanks, 4896

I also have tri-power on my 59 Bonneville coupe. I purchased it on Craig's list and rebuilt it myself except for the bases which I sent to Mike Wasson for professional rebuilding and adaption for mechanical linkage.

Add my 59 Cat to the list. Bought the intake and carbs used in '86. I had to rebuild them again last year. Bent the fuel lines myself. No vacuum leaks but it doesn't idle right after the engine warms up. I think I'm off on the idle mixture. Michael

Another tri power owner here. Castle blue Catalina 2 dr. While I am sure my car is not a factory tri power car, I just checked the casting on the intake and it is 532422. Interesting as the motor numbers match.

At any rate, glad to be a part of the club!

Getting my Tripower to idle smoothly was not a trivial problem.   There are lots of places for vacuum leaks.   Adjusting the fuel/air mixture is also important of course but not hard to do.    I installed the center carb only first and then bolted blank plates on top of the gaskets for the other two carbs.  I then adjusted the fuel/air mixture and ran the car for awhile using only the center carb.   Once I was satisfied the engine was running smoothly I added the other carbs one at a time.  

I immediately found problems with vacuum leaks and eliminated them one at a time.   The throttle plates did not leak thanks to Mike Wasson's professional rebuilt job on the bases with the use of DAG-215 sealant.   Once all the leaks were fixed it idled smoothly most of the time but not always.   Very frustrating.

Remember rough idle can be caused by many factors and you should not automatically assume the problem is with your tripower.  Like everyone my car sits most of the time with gas that is many months old.   Over Christmas I put a fresh tank of premium Chevron gas in my car and added a can of octane booster.   This helped a lot but it still was hard starting with intermittent rough idle.    So I installed new R45 AC Delco spark plugs and a points-free ignition module in my distributor.  The old plugs looked OK but were an off brand put in by the guy who rebuilt my engine six years ago.   The points free lobe sensing ignition module was not hard to install and does not show.   No more need to set the dwell either.

The combination of these minor changes to the fuel and ignition systems has resulted in much easier starting.   The engine idle is also extremely smooth with no intermittent rough idle problems so far.

I also cheated a little as the linkage to the end carbs is not hooked up which means the throttle plates on these carbs remain seated properly with good vacuum integrity.   I consider the end carbs to be only "eye candy" which look good but since they are rarely used I would prefer not to take any chances with fires.  More than one person has warned me about tripower fires caused by end carb flooding problems.

I got a bit of education on tripowers last week at a car show here in the LA area.  There was guy there with a 60 Pontiac which had tripower.  He had a hose going from where the tripower vacuum control switch on the front of the intake manifold was suppose to be to the water bypass inlet on the timing chain cover.   Rick Gozer (POCI tech advisor) was there and confirmed this hook up was wrong. The correct routing is from a hose connection right next to the therostat to the inlet on the timing chain cover.   This hose is a thermostat bypass to allow water circulation even when the thermostat is closed.

 Rick says he has seen all kinds of weird setups on tripowers being a POCI judge.   I also learned that the 60 Tripower, as well as the 2 or 4 BBL intake manifolds, came in two series.  The earlier series had the hot water outlet hose (to the heater) on the intake manifold same as on 59s.  The later series intake manifold eliminated this hose connection and moved the heater hose connection from the intake manifold to the front of the passanger side cylinder head.  This was done to eliminate complaints of water noise problems on the new 1960 direct flow cooling system design.   The dealers had upgrade kits to convert from the old style to the new style 1960 Pontiac heater hose connections, but both styles are correct for judging purposes.