[wrea3_98]

Nope. I have the filters off when adjusting. I do think I am onto something with the #3 cylinder issue. Pulled #3 plug to check it. It was black but dry. Better than the others I checked wich were black and moist/cakey. Forgot to put the wire back on and fired the car. Fired right up and ran as good as it has. I saw the wire off and popped it on. No change to RPM, idle etc. NONE! I am going to replace that plug and wire before doing anything else. Seems weird it ran OK with it off. Still stumbled a bit but not what I would expect from a bad plug/wire.

Originally Posted by geeteeohguy

Another thing: are you doing the carb adjustments and getting black plugs with the air filter on? I've had issues with restricted center-carb air filters in the past if they are the pleated paper ones.....they get loaded up with crud easily, and act like a choke. I switched to K&N filters in the early '80's and no more problems.

[wrea3_98]

Just about ready to pull'em off and send them away.... Just when I thought I was getting somewhere... leaks , flooding, more of the same BS I started with. They ran nice for a week. Never fails.

[Sirrotica]

If the symptoms are the same and were okay for a week would be looking into rust or dirt in the tank. I know most people think a fuel filter will catch all the dirt and rust, believe me they won't.

I had someone pour crap into one of my cars fuel tank when it sat over the winter and the only thing that got my problems to stop was pull the tank and clean it as well as flush all the hard lines and replace all the rubber. When you take the cover off the top of the carb it was unbelievable how much dirt and rust made it through an inline filter and a stock style Q Jet filter. Just a thought concerning your circumstances, I may be wrong, but I would check it out....

[wrea3_98]

I'm pretty sure the tank was clean. But who knows. I drained the tank originally and had no dirt inside as I could see. I also rinsed it inside and blew the moisture out of it. I still may look into that. Very possible. My issue right now is after running it for a while, its fine with no leaks. After I shut it down, It takes about 2-3 minutes to see fuel start dripping into the carb. Then its so flooded it wont start again. I cracked the fuel line at the carb and released a little pressure and it stopped leaking. I thought that the pressure could have risen after shutdown (temp or whatever) and then it started leaking. Mike Wasson says on his site that Ethenol can cause this as it has a lower boiling point. He actually says exactly what mine is doing.... Still messing with it but I will have to check the gas like you said. Good idea.

[Sirrotica]

Put a fuel pressure gauge on it too and see where your at, Tri Power carbs don't like very much fuel pressure. You could have a pump with a defective regulator bypass over pressurizing the fuel. I had a mechanical pump do this once on a race car.

If the fuel pump eccentric has been removed and changed recently, sometimes they get installed incorrectly and stroke the pump excessively causing too much fuel pressure, I had this happen once too.

If you decide it's boil over/percolation problem there are some Jeep and Chrysler inline fuel filters that have a 1/4" return line. I believe these were used on A/C equipped vehicles and will return the heat soaked fuel back to tank after shutdown they are installed in the fuel line between the pump and the carb.

Fuel filter: http://shop.advanceautoparts.com/web...RPFILTAMS_____

The 77 T/As started using a foam pipe insulation on the fuel line from pump to carb to stop fuel percolation problems after shutdown. If your cars not a show car and more a driver you might also try foam insulation on the fuel line to help with heat absorption. Coincidentally this is about the same time oil companies were phasing in ethanol blends.

Something like this tubing insulation, you might have to slit it and cut a lengthwise slice out to make this small enough diameter to work on 3/8-5/16" tubing and maybe run duct tape on the outside to keep the slit together.

http://www.farmandfleet.com/products...e#.T58X59ljOt8

Just a couple suggestions you could try, I'd try them if I was having the problem like yours.

[wrea3_98]

Way ahead of you. I already have it regulated down to 3.5psi and have an inline gauge installed. My original tank sender only has one outlet and has no vapor return. A/C equipt cars had a return line. The filter you are talking about needs another line added back to the sender I believe. My sender was already restored back to original and would I hate to pull it and solder in another tube. Yes this is a restored show car. I cant afford to do much outside the box. I wonder if I could use a vented gas cap and run the return line into the vent tube on the filler neck. Could be hidden fairly easily. Just a thought.

[geeteeohguy]

While fuel return systems are a good idea, they should not be needed. It would only be a band aid solution to the real problem. I've been running the original tripower setup on my '65 for the 30 years I've owned the car, and I rebuilt it once, about 25 years ago. It has been on the car since the car was new. 47 years. No issues at all. Yeah, it's grimy and hardly show-worthy, but it's a driver, and the carbs don't leak. There is little if any ethanol in the fuels available around here at present, though....and that could be part of your problem. Mine does not have a fuel return system.

[Sirrotica]

I'm pretty tapped out for ideas if it's show worthy and needs to be original. I hardly ever own anything that I'd show, always put functionality over looks in my stuff. You could probably run a return to the neck if it had a 90 on the end to direct fuel into the tank instead of splashing when it hit the inside of the neck, my thoughts on that.

Return lines aren't a bandaid in my opinion, they worked for the factory engineers for many years in many applications and if your not dealing with blended fuel in your car how do you determine it's not necessary for his car? After all these cars never were built with any thoughts of running ethanol blended fuel when designed and obviously the original system is deficient in this car. Also Mike Wasson, who has probably seen and worked on more tri power systems than I'll ever see in my lifetime sees this problem fairly regularly. The fuel has changed and I believe the whole system may need re-engineered to contend with new age fuels, not just one persons opinion in this case, nor only one car having the problem. I doubt the OP has any choice of buying straight fuel where he's located.

Funny in ecological heaven CA that they don't have ethanol blend fuels, we've had them in this area for over 30 years. I doubt in the surrounding 300 miles from me you could even find a service station that sold straight gasoline. When I hauled gasoline we only had one customer that bought straight gasoline because of course blended fuel is cheaper because of the federal gov't subsidized ethanol program makes it cheaper to sell a blend than straight fuel, and when you sell fuel, price is foremost in the minds of the public and management. Also it's touted as home grown and less harmful to the environment, can't see the tree huggers in CA not forcing people to use it

[lust4speed]

I know you have checked it, but so much points to fuel pressure over powering the floats. Just for kicks take it from the 3.5 down to 1 or 1.5 if you can. Car is just sitting there so it won't need any more pressure while the testing is going on. Maybe borrow another gauge - for that matter many of the vacuum gauges will also work as a low pressure gauge, and you might take a back-up reading with that.

[wrea3_98]

Just talked with Mike Wasson. As fas as my initial idle problem, he is going to check out my venturi cluster and drill it out if needed. He is also going to sell me his new style needle and seats, some ethanol friendly accelerator pumps and a new power valve. He stated that a return line should not be an issue with 3.5psi of pressure and to not worry about it. Most of my issues seemed to him to be centered around possible needle and seat or power valve issues and I did mention the possible "dirt in the fuel" as we talked about here yesterday and he agreed that this could also be a problem. I removed the carbs to look inside are I didnt see too much dirt anywhere yet. There was a small piece of something in the center needle and seat and the front carb had some micro particles of dirt in the bowl. Hopefully I get somewhere. Mike is a very nice guy and extremely helpful. Anyone know the 65 jet sizes that I'm suppose to have? I forgot to ask him. I have 65s in the center and 74s on the ends and its in a 65 421. Thanks!

[geeteeohguy]

Sirrotica, as usual, you make a valid point, one I overlooked. The fuels of today are different than the fuels of the '60's, and an upgrade to the fuel system could be a necessity. Oddly enough, when I recently re-installed the original fuel/vapor return system onto my '67 ragtop ( I removed it on a cross country road trip in '88--long story!), I noticed that the car runs better on hot days. Smoother idle, no hesitation, no vapor lock type symptoms that it would sometimes suffer from. The cooler the fuel, the better!

[wrea3_98]

Yeah I only have one Ethanol free station in my town. Just found it yesterday. Also... when I cracked my fuel line open immediately after it started leaking, my fuel was cold. The fuel lines close to the hot block were definately not an issue as far as I can tell. As far as the ethanol, wish there was a pour in product to help things out.

Originally Posted by geeteeohguy

Sirrotica, as usual, you make a valid point, one I overlooked. The fuels of today are different than the fuels of the '60's, and an upgrade to the fuel system could be a necessity. Oddly enough, when I recently re-installed the original fuel/vapor return system onto my '67 ragtop ( I removed it on a cross country road trip in '88--long story!), I noticed that the car runs better on hot days. Smoother idle, no hesitation, no vapor lock type symptoms that it would sometimes suffer from. The cooler the fuel, the better!

[Ragtop Man]

It's a long ball, but HPP ran a series many years ago that featured a Jim Taylor build up of a vintage tripower unit, and the peculiarities of the otherwise bolt-simple Rochester 2GC carbs.

You can find the articles on line, and look them up. I seem to recall some discussions about tripower peculiarities, one of them being an oiled leather diaphragm for the power valve (am I recalling this right -- help?) that had to soak in clean 30W for quite a while before re-installation.

I'm no tripower engineer (did have a good night's sleep, though) but if that's the case, I can't believe an alcohol compounded fuel would be doing the leather any good.

FWIW, modern fuels are blended for modern vehicles with alky compatible fuel tanks, lines and pumps, as well as fuel systems pressurized to anywhere from 30 to 30K psi at the pintle, and robust return systems to load unused fuel to the tank.

[Sirrotica]

The leather discussed is the accelerator pump cup, before neoprene many carbs used leather for accelerator pump cups. Before installation they need to be softened with oil to be pliable, same as work boot or a baseball mitt needs to be softened with neetsfoot oil before use, it also somewhat seals the grain against water fuel not so much.

[wrea3_98]

Yeah, I read that too. I know amimal skin is good for many things but who knew about carb parts...lol! Al least with my setup I can run the non-eth fuel in my town to see if it makes a huge difference in idle, drivabilty etc. We have 10 gas stations here and only 1 with no ethanol.

Originally Posted by Ragtop Man

It's a long ball, but HPP ran a series many years ago that featured a Jim Taylor build up of a vintage tripower unit, and the peculiarities of the otherwise bolt-simple Rochester 2GC carbs.

You can find the articles on line, and look them up. I seem to recall some discussions about tripower peculiarities, one of them being an oiled leather diaphragm for the power valve (am I recalling this right -- help?) that had to soak in clean 30W for quite a while before re-installation.

I'm no tripower engineer (did have a good night's sleep, though) but if that's the case, I can't believe an alcohol compounded fuel would be doing the leather any good.

FWIW, modern fuels are blended for modern vehicles with alky compatible fuel tanks, lines and pumps, as well as fuel systems pressurized to anywhere from 30 to 30K psi at the pintle, and robust return systems to load unused fuel to the tank.

[wrea3_98]

Well... I got my parts from Mike Wasson and have the car up and running. Im still having some minor issues. Mke opened up the venturi cluster to .035 (it was alrerady at .034) and he sold me 3 new ethanol resistant pumps, stock 63/73 jets (mine were 65 and 74), new style 2 piece needle and seats and a new power valve. I also bought the 1/4" phenolic spacer kit he offers to help with potential vaopr lock and boiling fuel issues with ethanol laced fuel. The car fires right up and the richness factor is better but I still have a little too much exhaust smoke (not nearly as bad as before) but alot more acceptable. I had the screws out at 2.0 turns each and when I fired it, I had a little idle issue so I turned the pass side out to 3 turns. Idle is now about perfect at all rpms. My only real issue is that when bumping the throttle from idle to WOT (2bbl only) I have a flat spot like its running out of fuel. It catches up with itself but is either lacking of fuel or has too much. I can slowy increase the RPMs with no issue, even when doing it a bit smoother and faster. If I just hit it in 2BBL mode it bogs/stumbles until it catches up with itself. I did change the jets from 65 to 63, added new needle and seats and I added the 1/4 inch spacer kit. I also adjusted the float to 21/32" with a 1 24/32" drop per Mikes video. I think they were right on originally as well but since I changed the needle and seats to a new style I had to make adjutments. Not sure which way to go yet. I also bumped the PSI up to 4 and 4.5psi from the original 3.5psi with no reslove. My opinion is float adjustment or jets. I can't see it dumping more fuel than before with smaller jetting. Mabey something to do with the new acc pump? Your thoughts?

[carbking]

I just read this entire thread twice to make sure I think I understand what has been written.

I believe the key to the thread is "freshly rebuilt engine".

Several years ago (yes, before ethanol), I completely rebuilt my tripower engine. Replaced everything but the castings and the crank and rods. And I built the carbs. As I always do, I blocked the end carbs upon start-up.

Upon firing engine:

Fired on second revolution, and ran for thirty minutes to break in cam (cam manufacturers recommendation).

After 30 minutes, set idle mixture control screws to 1 1/2 turns, and curb idle screw to 900 RPM in drive (it simply would NOT idle lower). Rough idle.

Took the car for a 220 mile trip. Upon return, reset idle to 750 RPM in drive. MUCH improved idle.

Over a period of time drove another roughly 400 miles. Readjusted idle mixture control screws to 1 1/4 turns, and curb idle to 550 in drive. Good idle, no hesitation, no engine heating, no issues.

Of course the ethanol fuel means this scenario is history, but by opening the idle tubes as you have, and using 0.001~.002 richer jets, you should take care of the difference in caloric content of the fuel.

Bottom line: I think your engine parts just need to get to know each other better!

I would suggest again blocking the ends as you correctly did in the beginning, start with +.001 jets and go drive the car! Watch for heating issues. If it doesn't heat, drive it. the blocked crossover is not helping your symptoms; but since it is done, run the engine long enough (perhaps as long as 30 minutes) for the engine to properly warm. If I had a dollar for every prospective customer with a carburetor problem AND blocked crossover, I could BUY Hawaii and retire!

Jon.

[wrea3_98]

@carbking
Thanks for the info. I do not have a blocked crossover but I'm sure alot of what your saying is very valid. It idles/runs fine now. I had the center cluster drilled to .035 and jetted down to .063 from .065 on the center carb. I had a bad power valve and the cluster on the front carb was not tight creating a vacuum leak. The center cluster had no fiber washer under the center bolt and it leaked air into the bowl. Thats where the flat spot was coming from. All problems fixed and it runs great. Idle is 850rpm. Vac is 19 inches, temp gets no higher than 185 and and I'm very happy.

[wrea3_98]

Just to reflect on my 65 tripower tuning issues and my road to satisfaction. If you have any issues with getting your tripower to fuction properly here are some good places to check. Remember, these were completely restored before I got them and now I know that means diddly squat. I had all of these issues:

Problem: Flooding during running. Then hard or no starting.
Cure: Needle and seats sticking open with debris. Clean or replace needle and seat.

Problem: Flooding 1-3 minutes after warm shutdown
Cure: Used Mike Wassons 1/4" phenolic spacers. Keeps Ethanol fuel from boiling into carb

Problem: Way too rich, air / fuel screws don't help.
Cure: Bad power valve in center carb

Problem: Unstable idle quality
Cure: Loose venturi cluster screws on front carb, caused huge vacuum leak.

Problem: Good idle, starving for fuel on hard acceleration only (center 2bbl only).
Smooth acceleration was fine.
Cure: Used split washer under center carb venturi screw which causes it to push
more air than fuel. I added the correct fiber washer to seal off any air from
passing.

Problem: New accelerator pump sticking (won't spring back). New pump elbow made too
fat in bend area.
Cure: Open hanger bracket hole slightly with round file to free up elbow. Also did the
same to all of the upper and lower pump rod bracket holes outside of carbs.

Problem: Wide open throttle with all 3 cars, throttle sticks open, wont return to zero.
Cure: Front pump rod was installed from the inside out, instead of outside in. Rubbed carb body.

Now I have super running carbs, great idle, great vacuum and I'm very happy with them. When your an idiot on Tripowers (like me) it's frustrating to work on them. I hope this helps anyone who experiences the same types of issues.

[carbking]

Glad you now have your issues solved; but WOW, is that ever a bunch of issues with "completely restored" carburetors!

Jon.