340 heads or gasket leaking?

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ChrisRom

ChrisRom

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Hello,

I have a 73 340 installed in my 65 dart. It is a low compression motor .030 rebuilt with headers, airgap intake and a 242/248 cam. The heads are from an earlier 340 with 2.02 intake valves and little porting (got a good deal on them).

I did a compression test and all the cylinders are all in the 130-135 psi range with very little variation.

The motor runs good, no issues other than condensate coming out of one of the pipe. There is no H or X connectors, each bank runs independently to the back.

So, when the engine is at the operating temperature there is a quite a bit of water coming out of one of the tailpipe but not the other. First time I thought it is just condensate, but when the engine is hot.....????
There is no contamination of the oil or coolant whatsoever.

What can it be? Is it normal?

Thank you.
 
Do a compression test and at the end of the test see if the cylinder holds pressure or looses it...
 
ChrisRom said:
Hello,

I have a 73 340 installed in my 65 dart. It is a low compression motor .030 rebuilt with headers, airgap intake and a 242/248 cam. The heads are from an earlier 340 with 2.02 intake valves and little porting (got a good deal on them).

I did a compression test and all the cylinders are all in the 130-135 psi range with very little variation.

The motor runs good, no issues other than condensate coming out of one of the pipe. There is no H or X connectors, each bank runs independently to the back.

So, when the engine is at the operating temperature there is a quite a bit of water coming out of one of the tailpipe but not the other. First time I thought it is just condensate, but when the engine is hot.....????
There is no contamination of the oil or coolant whatsoever.

What can it be? Is it normal?

Thank you.
Click to expand...
How much and how long does it come out. With manifolds and a working heat riser, you won't get much from the passenger side when started cold. Condensation will build up in the exhaust and settle in the mufflers. Once the pressure get's to it it will spit out of the tail pipe until the engine warms it up. If enough is in there it will turn to vapor which just looks like exhaust smoke. Is it using coolant. If you don't have to keep adding coolant it is probably just condensation.
 
Also take off the radiator cap when it begins to warm up and the thermostat is cycling watch for bubbles percolating from the engine another good sign of a head gasket leak
 
Thank you guys. The strange thing is that it happens when the engine is hot and only on one side (driver side). It is not a lot. Ignore the white stuff on the concrete - it is just black water, one side only.
I am going to do a leak down test and see if I can pinpoint a leaky valve or small crack/break in the head gasket.
Like I said the coolant looks good and I didn't see any bubbles in the radiator. But maybe I didn't wait until the engine was fully warmed.

exhaust.jpg
 
ChrisRom said:
Thank you guys. The strange thing is that it happens when the engine is hot and only on one side (driver side). It is not a lot. Ignore the white stuff on the concrete - it is just black water, one side only.
I am going to do a leak down test and see if I can pinpoint a leaky valve or small crack/break in the head gasket.
Like I said the coolant looks good and I didn't see any bubbles in the radiator. But maybe I didn't wait until the engine was fully warmed.

View attachment 1715571279
Click to expand...
Headers or manifolds? The black is carbon from a rich mixture. It mixes with the condensation. I will ask again, is it using coolant?
 
ChrisRom said:
Thank you guys. The strange thing is that it happens when the engine is hot and only on one side (driver side). It is not a lot. Ignore the white stuff on the concrete - it is just black water, one side only.
I am going to do a leak down test and see if I can pinpoint a leaky valve or small crack/break in the head gasket.
Like I said the coolant looks good and I didn't see any bubbles in the radiator. But maybe I didn't wait until the engine was fully warmed.

View attachment 1715571279
Click to expand...


A little bit of condensation is a normal product of combustion..
 
toolmanmike said:
Headers or manifolds? The black is carbon from a rich mixture. It mixes with the condensation. I will ask again, is it using coolant?
Click to expand...

Headers.
It is not using coolant to my knowledge. I didn't have to add any coolant this year, since May. It looks at the same level in the radiator.
 
ChrisRom said:
Headers.
It is not using coolant to my knowledge. I didn't have to add any coolant this year, since May. It looks at the same level in the radiator.
Click to expand...
No cracks or head gasket leaks then.
 
Punch it in neutral a few times to blow out the mufflers, then wait and see. I bet it stops for a while.
Then look under the car; I bet the other side has a hole in it somewhere and the steam is exiting there.

In the end you need to drill a 3/32 inch drain hole in each muffler at the lowest point to let the water out, else it will form hydrochloric acid in there and eat it it's way out, and then it sounds sucky.
On another note;
If you are running 3.55s or less, AND
Have a 4-speed; OR
do not have at least a 2800TC; THEN;
You would absolutely benefit from a crossover in that exhaust system. That cam is killing your cylinder pressure, and with a low-stall/3.55s your bottom-end is more than likely quite soft. A crossover will pull up that low-rpm torque quite a bit.
If you haven't noticed it, ignore me on this,lol.
When I cut mine out to fit a GVod, I had to install 16% more starter gear to compensate. That's a lot of compensation.
 
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