Tuned the carbs

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Blair
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Tuned the carbs

Unread post by Blair » Tue Aug 08, 2017 6:42 pm

So I tuned my carburetors, i got a lot of the power back that I had. It's now able to idle on its own, with some difficulty still. Drove a few hundred yards and it stalled on me again. It started back up with still the same power with the assistance of some starting fluid. So at least I'm making progress. I have a 64 Monza. It's burning less oil but is it normal for the tube that comes from the engine and into the fuel filter to smoke? Still hard starting. Maybe spark plugs? Suggestions?

Jerry Whitt
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Re: Tuned the carbs

Unread post by Jerry Whitt » Tue Aug 08, 2017 8:12 pm

It is not normal for smoke to go into the fuel filter! Thinking you mean to say the air filter. Smoke is not something you want. Several items cause smoke, and burning of oil.

1. Piston rings
2. Valve guides
3. Oil leaks on to hot surfaces.

To isolate the issue, start with a compression test. All of the cylinders should be close in test results, usually in the 125 lb. range. When doing the test, do a visual note of the spark plugs. Are they all the same or does one or two show oil on the tip.

If some cylinders show low compression, the next test is a leak down test. Some auto parts stores will loan you the leak down test machine. In effect, air pressure is put through the machine, and it measures how much leakage in each cylinder. This test is done on each cylinder with the valves closed, and the piston near top dead center. Normal leakage is less than 20 percent. If leakage is higher than 20 percent, take a listen to the oil filler tube. Should the rings be bad, you will hear a distinct air rush noise. If leakage is high, but no air rush noise,
listen at the tail pipe. Should an exhaust valve be leaking, the air rush noise can be heard. Should you hear the air rush noise at a carburetor, with the throttle wide open, that would indicate an intake valve leaking.

Oil leaks are common and smoke sometimes can be deceiving. After a REALLY REALLY good cleaning, then with the engine running and with the rear of the car up enough to get under with a flash light, check and recheck for the leaks.
Jerry Whitt
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terribleted
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Re: Tuned the carbs

Unread post by terribleted » Tue Aug 08, 2017 8:31 pm

From another of your posts you seems to say the car has been sitting for 30 years. Have you rebuilt the carbs if not do so. Have you replaced basic ignition parts? Good idea to put plugs, points, rotor,cap, wires etc. Have you verified your fuel system (cleaned out sending unit and tank?) or are you using fuel from an external source? Any car that has been sitting that long really needs some baseline maintenance before any realistic result can be had. Yes it may run and yes you may be able to figure out the 5 things that are giving issues eventually but these basics are virtually always needed and can save a lot of head scratching and trouble.

You say you tuned your carbs. What does that mean? Adjusted the idle? The mixture? The balance?

There is no external fuel filter on a stock Corvair...there are only the filter stones in each carb and a filter sock on the fuel pickup in the tank. I am at a loss as to what tube out of the engine going to any fuel filter. Now there is a PCV tube that comes out the top of the engine shroud and goes to the air cleaner. On a 64 the system uses a PCV valve between the tube and the manifold balance pipe and also connects to the air filter. A very little smoke or mist from this system is normal a lot is not.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
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64powerglide
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Re: Tuned the carbs

Unread post by 64powerglide » Tue Aug 08, 2017 9:10 pm

My 64 sat for 22 years, I rebuilt the carbs, cleaned out the gas tank, new points & condenser, new plugs & wires & set the timing & put new oil cooler seals in. It smoked bad at first but I kept running it & the smoke finally went away. It has been my daily driver for 3 years. I might have been lucky but it doesn't burn oil & doesn't stall. I had to play with the carbs to finally get it to stay running in DRIVE when stopping at a light. Do a full tuneup & see what happens. I also did a cold & hot valve adjustment after I got it running pretty good, now it drives like a new one. GOOD LUCK WITH IT!!
64Powerglide, Jeff Phillips

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toytron
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Re: Tuned the carbs

Unread post by toytron » Wed Aug 09, 2017 6:23 am

Could it be smoke from mice and their nests? Lol

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Blair
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Re: Tuned the carbs

Unread post by Blair » Wed Aug 09, 2017 2:08 pm

I meant to say the air filter, not fuel filter. It doesn't make nearly as much smoke as it did before. But just a little bit out of the tube that it's into the air filter. It seems to run pretty healthy when I get it started but still leaks oil. I will continue to work on it till I figure it out. $1600 was still pretty decent price for it I think

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Re: Tuned the carbs

Unread post by terribleted » Wed Aug 09, 2017 2:38 pm

Most all old Corvairs leak oil:) Worry about it if it doesn't leak!!
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
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Gregory_Miller
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Re: Tuned the carbs

Unread post by Gregory_Miller » Wed Aug 09, 2017 2:43 pm

Some folks say if a Corvair doesn't leak oil, it's because it's out. :P

Jerry Whitt
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Re: Tuned the carbs

Unread post by Jerry Whitt » Wed Aug 09, 2017 7:00 pm

I have had a Corvair since a new purchase in 1965. The true and only solution of 50 years plus of experience is to not put oil in them.
Jerry Whitt
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bbodie52
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Re: Tuned the carbs

Unread post by bbodie52 » Wed Aug 09, 2017 9:41 pm

My Corvairs have remained pretty dry and leak-free. One big change was VITON o-rings replacing the original rubber o-rings, which became brittle and hard as they "cooked" in normal air-cooled engine operating temperatures.



Corvairs are unique in that they have a flat pan that holds more than four quarts of liquid ABOVE the gasket mating surface. Most oil pans are simply a reservoir tank that contains the oil, and the gasket seal only has to seal against splashing oil. On a Corvair the oil is constantly trying to escape, even when the engine is not running, because it is above the gasket.

With the sheet metal pans the problem is usually over-tightening and crushing the sheet metal into the thick gasket material, so that the metal under each bolt distorts and pushes against the aluminum engine cases while leaving too-little pressure on the pan surface between adjacent bolts. In cases like that a little body work on the pan mating surface to flatten the pan contact area, and properly torqued bolts would solve the sealing problem.

With a cast aluminum pan, the mating surfaces should remain flat. A thin gasket as recommended by Clark's and proper torque should apply even pressure around the pan perimeter, to form a good seal.

You have to deal with nineteen small bolts that are easily damaged, or the threads in the aluminum can be easily damaged if the bolt is over-tightened. Too loose and it leaks — too tight and it could strip. If you invest a lot of money in the aluminum pan, why not invest $25 - $50 in an inch pound 3/8" drive torque wrench? Then you know for sure that the bolt pressure is correct and even, and you are not risking a stripped pan bolt thread. By the way, I have found that the beam-style design that uses a small 3/8" drive head also works well when torquing the connecting rods, as the small head can fit better than the more-bulky ratchet designs.

Interestingly, the 1961 Corvair shop manual specified 40-60 in-lbs. of torque for the ¼-20 bolts that secure the oil pan. However, the 1965 Corvair Chassis Shop Manual increased this torque specification to 85-105 in-lbs. even though the bolt sizes did not change. Apparently Chevrolet engineers increased the specification in an effort to provide for an improved seal.
Brad Bodie
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terribleted
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Re: Tuned the carbs

Unread post by terribleted » Wed Aug 09, 2017 9:48 pm

Mine have always leaked very little but then I put new seals...that area was not old any more:)
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toytron
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Re: Tuned the carbs

Unread post by toytron » Thu Aug 10, 2017 1:39 pm

Well the way my friends dad solved his Pintos oil leak problem was to fill the engine up until he saw the oil from the filler. He couldn't understand why it wouldn't start after that. I couldn't believe it if I didn't see it with my own eyes. I don't remember how much oil we ended up draining out of that engine but it smoked for a while after that and a few spark plug changes later. Lol

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66corsaguy
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Re: Tuned the carbs

Unread post by 66corsaguy » Tue Sep 26, 2017 7:29 pm

toytron wrote:Well the way my friends dad solved his Pintos oil leak problem was to fill the engine up until he saw the oil from the filler. He couldn't understand why it wouldn't start after that. I couldn't believe it if I didn't see it with my own eyes. I don't remember how much oil we ended up draining out of that engine but it smoked for a while after that and a few spark plug changes later. Lol

Ed Stevenson
To add to your funny story : when i was a kid my dad gave my great uncle our green Ford LTD. dad told uncle "it's a great daily driver and never needs oil." Uncle mis understood and thought he meant it never needed oil changes either. Car seized at some point. Grant it my great uncle was deaf and communication was thru sign language. So this truly was a "lost in translation" moment.


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toytron
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Re: Tuned the carbs

Unread post by toytron » Tue Sep 26, 2017 7:58 pm



Ed Stevenson

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65 corvair corsa convertible turbo
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