Fuel Percolation
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
Fuel Percolation
WARNING TO OTHER IF THIS HAPPENS...DONT TRY TO START THE CAR, REMOVE PLUGS, LET SIT FOR DAYS, TURN OVER BY HAND, THEN AIR OUT SOME MORE AND ONLY THEN, REINSTALL PLUGS.
I went for a drive earlier, then came home and shut the car off and lifted the hood so the engine would cool down quicker. It's warm outside today, around 82, but not hot and the car ran consistently at 185 degrees with no overheating. 30-45 minutes after the car was parked, i went back in the garage and heard a bubbling noise coming from the engine. I lifted the hood and the below video is what i observed. This wasn't occurring previously and I am wondering what caused it to start? The carburetor was hot to the touch when I discovered the fuel percolating, but I could not locate my IR gun to take its temp.
The crossover at the top of the intake is blocked off, but the heat passage for the original style carburetor choke is still open.
The floats are set correctly and are dead center while the car idles.
Thoughts?
I went for a drive earlier, then came home and shut the car off and lifted the hood so the engine would cool down quicker. It's warm outside today, around 82, but not hot and the car ran consistently at 185 degrees with no overheating. 30-45 minutes after the car was parked, i went back in the garage and heard a bubbling noise coming from the engine. I lifted the hood and the below video is what i observed. This wasn't occurring previously and I am wondering what caused it to start? The carburetor was hot to the touch when I discovered the fuel percolating, but I could not locate my IR gun to take its temp.
The crossover at the top of the intake is blocked off, but the heat passage for the original style carburetor choke is still open.
The floats are set correctly and are dead center while the car idles.
Thoughts?
Last edited by 65silververt; May 5, 2014 at 11:07 AM.
Safety Car
Joined: Jan 2004
Posts: 4,270
Likes: 561
From: Macedonia Ohio
I had that problem when I installed a new SBC 400 motor. It would always happen on a hot day. I had to route the fuel lines up higher off the manifold and install a 1" phenolic spacer. That solved the problem.
Drifting
Joined: Jan 2013
Posts: 1,772
Likes: 196
From: Asheville NC
Carb Temp
I went for a drive earlier, then came home and shut the car off and lifted the hood so the engine would cool down quicker. It's warm outside today, around 82, but not hot and the car ran consistently at 185 degrees with no overheating. 30-45 minutes after the car was parked, i went back in the garage and heard a bubbling noise coming from the engine. I lifted the hood and the below video is what i observed. This wasn't occurring previously and I am wondering what caused it to start? The carburetor was hot to the touch when I discovered the fuel percolating, but I could not locate my IR gun to take its temp.
The crossover at the top of the intake is blocked off, but the heat passage for the original style carburetor choke is still open.
The floats are set correctly and are dead center while the car idles.
Thoughts?
Quick Fuel Carburetor percolating 30-45 minutes after driving. - YouTube
The crossover at the top of the intake is blocked off, but the heat passage for the original style carburetor choke is still open.
The floats are set correctly and are dead center while the car idles.
Thoughts?
Quick Fuel Carburetor percolating 30-45 minutes after driving. - YouTube
If this is new:
Verify the carb temperature then go after the heat source
Heat riser stuck closed?
I put FI gaskets on my L79 to resolve the same issue.
phil
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
The car will not turn over now....just clanks once when i turn the key and then nothing. This happened a few months ago also after running the car, but hasnt occurred since. I thought there was an issue with the starter, so i removed it and then reinstalled it only to find that didn't help, so then i thought it had a dead battery and I let it sit for another day and the next time i went to start it, it cranked slowly then blew out a bunch of smoke from being too rich.
My question is, why does it lock up the engine?
Oh, and I did confirm that the heat riser is hanging up.
Thanks
My question is, why does it lock up the engine?
Oh, and I did confirm that the heat riser is hanging up.
Thanks
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
Yup, number 8 was full. However, now that the car has fully cooled off, the heat riser is moving around freely. I guess the metal is expanding when it gets hot and just that little be of expansion is allowing it to hang up.
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
I hope your engine is OK.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
Engine is screwed. Just put the plugs back in and started it and it is knocking like crazy.
The newly rebuilt 427 only had about 800 miles on it, max! Bad way to start a Monday! I just hope the block isnt damaged.
The newly rebuilt 427 only had about 800 miles on it, max! Bad way to start a Monday! I just hope the block isnt damaged.
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
That's a shame. On my 65 they replaced the rod and piston assembly without removing the engine from the car. No block work was required BUT they didn't start the car once it hydralocked.
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
I spoke to the previous owner of my 65, he's also a coworker. He confirmed the rod was bent by the starter and that the head was removed but block left in place for the rod and piston replacement.
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
Unbelievable! I wonder if the stock 390hp rods are really weak? It's not like I have a high torque starter on the car....just a standard over the counter replacement.
I imagine the entire engine needs to come out to be inspected. If one bent, then there is the possibility that others were bent slightly the last time this happened.
I imagine the entire engine needs to come out to be inspected. If one bent, then there is the possibility that others were bent slightly the last time this happened.
Team Owner
Joined: Sep 2002
Posts: 38,348
Likes: 2,076
From: California
Nice souvenir! If you put that up on EBAY
If I could get 3 more, then I would probably weld together a parts animal sculpture using the bent rods as legs!
Usually if I am smelling gas because of a condition (rare), pull the plugs and pull the coil wire and spin it on the starter. As was said above, definitely want to check the oil level also to make sure you don't have a Corvette grenade with the pan full of gas! I would rather pump it out of the cylinder with the compression. Darn put it in the headers and then start it, and have the U-tube camera ready for the impressive flame out the pipes. Sounds like a lot of fun!
It doesn't hurt to employ all of the tricks on a V-8 to insulate the carb, the lines, etc. and trick out the cooling system.
PS or put those rods back in for an effectively shorter stroke!
Or maybe that is the special low deck height connecting rod setup?
Last edited by TCracingCA; May 5, 2014 at 05:57 PM.
Thread Starter
Safety Car
Joined: Dec 2009
Posts: 4,171
Likes: 335
From: Homewood Alabama
Not yet, I am currently working almost non-stop attempting to get the split window restomod ready to go back to the paint shop for it's doors, hood, and headlamp buckets.
Someone told me that it could just be a valve, but I don't see how that is possible since if the valve was open, the gas would have just sprayed back up into the intake or out the exhaust port. I suppose maybe it could have a bottle neck effect where only so much fluid could escape at one time under so much pressure and that could cause it???
I'll do a leak down check anyway, then pull the pan, then most likely be depressed for a little while after seeing a bent rod, then have a or two, then somehow manage to find the time to pull the engine out to send it off to have new rods installed and be balanced again. 
Someone told me that it could just be a valve, but I don't see how that is possible since if the valve was open, the gas would have just sprayed back up into the intake or out the exhaust port. I suppose maybe it could have a bottle neck effect where only so much fluid could escape at one time under so much pressure and that could cause it???
I'll do a leak down check anyway, then pull the pan, then most likely be depressed for a little while after seeing a bent rod, then have a
or two, then somehow manage to find the time to pull the engine out to send it off to have new rods installed and be balanced again.