273 Commando smokes terribly

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Kevin74

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Hey Guys,

I bought a 66 Cuda that had been sitting since 1991. I installed a new fuel pump, Edelbrock carb, distributor, spark plugs, and gas tank.

She started up just great and idled with 40 lbs of oil pressure, but the engine smoke was insane! Smoke billowed out of the tailpipe, and lots of smoke poured out of the open element valve cover breather.

Would you suspect worn piston rings or worn out heads? Would it be worth having the heads rebuilt and giving it another try with the same unrebuilt short block?

Thanks,
Kevin
 
Could be valve seals
Could be rings
Could be PO put oil in the cylinders prior to storage.
Could be gasket leak (intake or head)
Could be crack
Could be warn out engine
 
Kevin74 said:
Hey Guys,

I bought a 66 Cuda that had been sitting since 1991. I installed a new fuel pump, Edelbrock carb, distributor, spark plugs, and gas tank.

She started up just great and idled with 40 lbs of oil pressure, but the engine smoke was insane! Smoke billowed out of the tailpipe, and lots of smoke poured out of the open element valve cover breather.

Would you suspect worn piston rings or worn out heads? Would it be worth having the heads rebuilt and giving it another try with the same unrebuilt short block?

Thanks,
Kevin
Click to expand...
Where in Phoenix? Let me know if you need a hand with anything, I’m in downtown Phoenix.

Jake
 
Hi Dana67Dart,

Actually, you reminded me of something!
I myself put a ton of PB blaster in the spark plug holes before turning the engine with a breaker bar.

Maybe I gave up too soon. When I smoked out the neighborhood, I turned the engine off fairly quickly.
 
Hey Jake!
That’s a very generous offer. I’m out in Gilbert. I’ll try a few more things first but I might take you up on your offer. And I would definitely pay you for your time to drive out here.
 
Kevin74 said:
Hi Dana67Dart,

Actually, you reminded me of something!
I myself put a ton of PB blaster in the spark plug holes before turning the engine with a breaker bar.

Maybe I gave up too soon. When I smoked out the neighborhood, I turned the engine off fairly quickly.
Click to expand...
My guess is that it’s going to take time to burn all the pb blaster all out. Start it again and let it run for 15 minutes.

Jake
 
KISS method (keep it simple stupid). Is crankase overfull? Is PCV working? Run it at fast idle for a while to see if it clears up.
 
IMHO-

it may be nothing and it could be something- let’s face it... it’s 54 years old.
Do a compression check and a leak down check. That will help with diagnosis. Take Jake up on his offer. A second set of eyes that know well is always a good thing.
Good luck,
Joe
 
Sitting that long, rings could be stuck in the pistons. I'd run it a while and see if they break loose. Take the valve covers off and observe the operation of valves/rocker arms.
 
Run it. It will get better. Mine sat for years, we started it by dribbling gas down the carb and jumping it with a tractor battery. I overhauled the carb, flushed the tank and fuel lines, (it was nasty and I soon bought a new tank and lines) tuned it up and adjusted the valves. It ran better the further I drove.
 
txas2step said:
Sitting that long, rings could be stuck in the pistons. I'd run it a while and see if they break loose. Take the valve covers off and observe the operation of valves/rocker arms.
Click to expand...
Go get a can of Rislone.... rev the engine and slooowly dribble half the can down the carb. Enjoy even more massive amounts of smoke. Put the rest in the gas tank. It will help to loosen up sticking rings and clean deposits off of intake valves and stems. It may help.. or may not.. but the smoke is a lot of fun LOL
 
Kevin74 said:
Hey Guys,

I bought a 66 Cuda that had been sitting since 1991. I installed a new fuel pump, Edelbrock carb, distributor, spark plugs, and gas tank.

She started up just great and idled with 40 lbs of oil pressure, but the engine smoke was insane! Smoke billowed out of the tailpipe, and lots of smoke poured out of the open element valve cover breather.

Would you suspect worn piston rings or worn out heads? Would it be worth having the heads rebuilt and giving it another try with the same unrebuilt short block?

Thanks,
Kevin
Click to expand...



Do a compression and leak down test...

Those will tell if the engine is sound or needs repair... If it needs repair, it will tell you what the problem is...
 
nm9stheham said:
Go get a can of Rislone.... rev the engine and slooowly dribble half the can down the carb. Enjoy even more massive amounts of smoke. Put the rest in the gas tank. It will help to loosen up sticking rings and clean deposits off of intake valves and stems. It may help.. or may not.. but the smoke is a lot of fun LOL
Click to expand...
I carbon blasted by trickling a pop bottle full of water down the carb. Disclaimer though, Warm engine and TRICKLE not pour! LOL
 
Used to work for a dealer that installed "water injection". It was adjustable. The purpose was to keep the valves clean by increasing the cylinder temp.
 
LOL.... Water injection kits that I knew of were for fuel mileage... a lot of that was tried and sold in the 70's. Then they showed up on turbo rally cars in the 90's....so you could push the boost up a bit more.
 
nm9stheham said:
LOL.... Water injection kits that I knew of were for fuel mileage... a lot of that was tried and sold in the 70's. Then they showed up on turbo rally cars in the 90's....so you could push the boost up a bit more.
Click to expand...

So you want to switch to vaping to stop the smoking habit ?
 
Dump a can of Seafoam in the gas tank and one can in the crankcase and run it.
 
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