Uggh...Thermoquad carb still leaking fuel. ---> FIXED!!!

[Super Blue 72]

Wife #1, Car #2, or life painful!

Happy wife, happy life... 


Yeah, my wife and kids can sniff out the fumes after I come inform working on the car... 


Good thing the lawn mower has a slightly similar oder.... 

[brads70]

I've heard of guys rebuilding their engines in the living room.
Of course, they were not married!

I rebuilt an automatic tranny once in the basement. I found an old table that spreads apart to add a leaf  to use as a workbench. Drilled a few holes to bolt the tranny down and it worked great!



That is until the tranny oil smell drifted upstairs and that "old table " was an antique?   Who knew? worked great but the wife was not exactly impressed?

Hey if you need it I have a fresh rebuilt Holley 750 here ,you could have it need be?

[Super Blue 72]

That is until the tranny oil smell drifted upstairs and that "old table " was an antique?   Who knew? worked great but the wife was not exactly impressed?

Hey if you need it I have a fresh rebuilt Holley 750 here ,you could have it need be?

Then the wife said, "Honey, have you seen the table that belonged to my great grandmother?  I wanted to bring it to the Antique Road Show to see if the value has increased from $10,000."   


Thanks for the offer, Brad.    It's a stock 340, 8.5:1 compression, stock internals.  I know the TQs were like 750-800cfm but when calculating it out and from what others suggest a 600-650 is adequate.  I have no idea. 

Also the stock intake is a spread bore set up.  Hoping not to change it out.  I think the only spread bore from Holley is a 4165 and 4175 and is rated at 650cfm.  Thanks!

[Super Blue 72]

I may have found the issue.  I think the air horn was dropped at one point in time, causing the O-ring on the passenger side not to seal.  I noticed it the first time I took the carb apart.  I think with small variances in the O-rings combined with the ethanol in the gas it caused the leak that was a little noticeable to be more pronounced.

I did a double gasket after filing the bottom of the air horn to make a better seal as the passenger side look a little mushed in. You could see that there was not a smooth mating surface.

We'll see what happens when I install it this weekend hopefully... 

[spamtank]

That sounds promising.

 

[Super Blue 72]

Ok, so here is my logic, or what little there of... 

I do not think it is the jet wells where the epoxy is prone to leak over time.

Reason:  Fuel bowls were full of gas.  If there was a leak from the jet well epoxy failing then the fuel bowl would be empty.  In theory... 

[Super Blue 72]

The needle seat assemblies close and open well.  I cannot blow air threw the fuel inlet when the air horn is inverted.  I lift the floats and air can pass.  Strong seal.

I do not think the floats are ill adjusted.

Reason:  Spec calls for 1" from gasket on air horn to top of float.  See pic.

[Super Blue 72]

Sooo... I'm thinking O-ring area.

Keep in mind the leak is on the passenger side.

Lookey at this pick of the part of the air horn that sits on the O-ring.  I noticed when I first took this apart years ago that it didn't look quite right.

The passenger side of the air horn looks squashed, like it was dropped at one point in time.

This pic is after I already took some sand paper to it.  You can see where dirt I embedded in it and those are areas where it is not smooth.

[Super Blue 72]

From this angle you can see a lip is a little mushed.

We'll see if adding the extra flat O-ring on top of the squared off one helps.  The top of the air horn had a had time fitting properly with 2 O-rings so I had to do some filing of the air horn.    No turning back now!

I found a guy in the next town that has some Thermoquads for $50 each.  Of course I got the call after I bought the Holley 4165 spread bore carb.    Oh well.  Might be fun to see the difference in the carbs once I get the car on the road.

Being Mother's Day weekend I don't think I'll have a chance to put it on until next week.  We'll see what happens... 

[Super Blue 72]

Woo-hoo!!! 

Got the carb on the car and started it up.  No more leaky!!! 

I think filing down the primary main jet area and the double O-rings were the ticket!

Thinking back at all the hard restarts after shut down, this problem has plagued this car for a long time. 

Thanks for all you input! 

[spamtank]

Woo-hoo!!! 

Got the carb on the car and started it up.  No more leaky!!! 

I think filing down the primary main jet area and the double O-rings were the ticket!

Thinking back at all the hard restarts after shut down, this problem has plagued this car for a long time. 

Thanks for all you input! 

Great news.  Now you'll be able to get it out and drive it around.  Did you put any miles on it today, or do you still need to get it registered?

[Bullitt-]

 

[Super Blue 72]

Great news.  Now you'll be able to get it out and drive it around.  Did you put any miles on it today, or do you still need to get it registered?

Thanks guys, no not registered so I did a couple runs in the driveway. 

I dunno.  Before it felt stronger.  I have to tune the carb some.  I noticed I hade the mixture adjustments were out like 4 turns.  I dropped them back to like 2.5 turns.  Car goes but it feels like it can't spin the tires as easily.  Will have to play with it a little. Feel like the secondaries opening late.  Maybe I was feathering it too just because I hadn't started it since like last October/November.  Maybe it was running rich with the leaking o-ring.  Might need to fatten up the mixture.

I dunno. Just happy that it isn't leaking...so far....

I just wanted to get the car running because it was moved during Hurricane Sandy and left on the grass since then.  Didn't want the under carriage messed up with the moisture from the ground.


"Ummm, yeah , honey.  I think it'll grow back..."   

[cudabob496]

Woo-hoo!!! 

Got the carb on the car and started it up.  No more leaky!!! 

I think filing down the primary main jet area and the double O-rings were the ticket!

Thinking back at all the hard restarts after shut down, this problem has plagued this car for a long time. 

Thanks for all you input! 

http://www.pond5.com/sound-effect/8664322/hallelujah-5-times.html

[Super Blue 72]

http://www.pond5.com/sound-effect/8664322/hallelujah-5-times.html

Indeed!