My 340 is running hot I think.. I need a sanity check.

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Well, has the gurgling gone away since you swapped the heater hose around?

When you filled the cooling system did you have the front of the car raised so it would 'burp'?

I would also suggest ditching the 160* stat for a 180* stat with the hole drilled in it. The last thing you want is for it to run too cool also, it creates excessive wear on the cylinder walls.
 
If you keep hearing gurgling, then the heater hoses aren't helping to get the air out properly. FWIW, it took more drives and heat cycles than usual to get all the air out of my /6 engine without a recovery system.

OK on the level in the rad; looks about right. And OK on the sensor locations; that sounds good. 2 temp gauges is a true 'belt & suspenders' approach LOL

So were your heads milled? I'm just trying to get to your CR numbers with that piston.

So when it does not want to start hot, what exactly happens? Does it turn over part of a turn and then stop, maybe with a knock? Or does it just turn over and over without firing? Any heat shield under the carb?
 
AlV said:
Yes, my engine builder did the machining and spec'ing. We're using Sealed power 428P pistons.
I'll drop him a line to confirm.
Click to expand...

I doubt with this build your engine builder cc'd the heads and measured piston top to deck distance. He would have charged you extra from a typical rebuild for those services.

But I'm guessing the head and deck were just minimal cut for clean up of .004 each and the 4 valve reliefs at 5cc total. And that X heads are typically 72cc measured. The Sealed Pro 428 has a compression distance of 1.829 in. with is theoretically .007" above a perfect 9.6" block deck height...With all that I get about 9.55:1.

If the 4 valve reliefs equal 10cc's it 9.06:1

Still, you could try backing of the timing a couple degrees and see what happens.
 
Bad Sport said:
Well, has the gurgling gone away since you swapped the heater hose around?

When you filled the cooling system did you have the front of the car raised so it would 'burp'?

I would also suggest ditching the 160* stat for a 180* stat with the hole drilled in it. The last thing you want is for it to run too cool also, it creates excessive wear on the cylinder walls.
Click to expand...

I haven't swapped the hoses yet but I will. Yes the front was raised and the stat was drilled. I filled the coolant with the upper hose removed so I could see the housing neck fill up.
 
nm9stheham said:
If you keep hearing gurgling, then the heater hoses aren't helping to get the air out properly. FWIW, it took more drives and heat cycles than usual to get all the air out of my /6 engine without a recovery system.

OK on the level in the rad; looks about right. And OK on the sensor locations; that sounds good. 2 temp gauges is a true 'belt & suspenders' approach LOL

So were your heads milled? I'm just trying to get to your CR numbers with that piston.

So when it does not want to start hot, what exactly happens? Does it turn over part of a turn and then stop, maybe with a knock? Or does it just turn over and over without firing? Any heat shield under the carb?
Click to expand...
Yes the heads were milled just to clean up.
When it doesn't start the motor will turn but not fire.
 
autoxcuda said:
I doubt with this build your engine builder cc'd the heads and measured piston top to deck distance. He would have charged you extra from a typical rebuild for those services.

But I'm guessing the head and deck were just minimal cut for clean up of .004 each and the 4 valve reliefs at 5cc total. And that X heads are typically 72cc measured. The Sealed Pro 428 has a compression distance of 1.829 in. with is theoretically .007" above a perfect 9.6" block deck height...With all that I get about 9.55:1.

If the 4 valve reliefs equal 10cc's it 9.06:1

Still, you could try backing of the timing a couple degrees and see what happens.
Click to expand...

Yeah it was a not a fancy build but it did receive attention. Here's what I know from notes.
I found some of the notes I took during the build, sorry I don't have some of the specifics and it was over a year and a half ago.

The block had been decked and line honed previously so as you say we just ran it through a deck and line hone to clean it up a bit.
The heads were milled for clean up also so good quess there too.
The rotating assembly was balanced.

Along with the 428P we installed the following bits
Hast rings 2m694 .040
Bearings CB-481P std/ms-963P std.
Lifters Comp 822-16
Pushrods SBI 190-1450
Stock rockers and shfts
Felpro 260-1121, .039 head gaskets
Flatop Piston 428P, .025 in the hole
Stock x Heads with cleanup, , 68 cc
Stock valley shield

Let me know if that helps with the calculation, let me know if that changes anything.
... he just texted me back and said he recalls it being closer to 10:1.

I will try to pull some timing after I swap the heater hoses and rig a recovery tank and change the cap. :)
 
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Yeah, backwards hoses just makes noise.And the trapped air can become an air-spring when you open a too-full rad.

I would prove the no-fire theory, cuz I suspect the real issue may not be ignition at all, but rather fuel related. As in; low fuel level due to gas boiling into intake and flooding engine.
You have the bulbous top tank. I see no reason to have to run a separate recovery tank.I also see no reason to not run one,as it is good practice.
I'm having trouble agreeing with the burping idea. With a drilled stat, I have never had to burp an A-body. Burping is for more modern cars that can trap air in areas higher than the top of the rad, where the filler is.

So let's recap; you seem to have everything needed to not get into overheat. The one thing nobody mentioned is the waterpump.
At slow speeds,usually around 30mph or less, Overheat is usually caused by insufficient heat transfer between the coolant and the airstream over the cooling fins of the rad, or insufficient coolant flow through the rad.There is a whole string of items to check to diagnose this problem.
Over 30mph, there is usually enough air being rammed through the rad, and the rpm is usually higher as well. The higher engine rpm, means a higher waterpump speed, which insinuates a faster waterflow through the rad. There is a different string of items to check to diagnose this issue.
A flooded intake due to heat-soak, may or may not point to an overly hot intake.
Puking coolant in the driveway, similarly does not prove overheat.
A water Temp over 200 does not prove overheat.
The IR gun can indicate overheat.It is the only way to know, where to go from here.
 
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AJ/FormS said:
Yeah, backwards hoses just makes noise.And the trapped air can become an air-spring when you open a too-full rad.

I would prove the no-fire theory, cuz I suspect the real issue may not be ignition at all, but rather fuel related. As in; low fuel level due to gas boiling into intake and flooding engine.
You have the bulbous top tank. I see no reason to have to run a separate recovery tank.I also see no reason to not run one,as it is good practice.
I'm having trouble agreeing with the burping idea. With a drilled stat, I have never had to burp an A-body. Burping is for more modern cars that can trap air in areas higher than the top of the rad, where the filler is.
Click to expand...

I don't think its an ignition issue either and agree that it could be heat/fuel related. The car normally starts no problem but after a drive and the temp is up that's when I have trouble starting it. Keep in mind this is an early production 69 which I don't think came with external reservoirs. In my initial post I used the term burping but I think another poster used the word gulping which seems a more accurate description of the noise it made pulling into the drive while spewing from the drain tube.

My fuel filter sits next to the fuel pump not on top of the engine. I can see clear liquid in there but the issue could be in the intake. What should I be checking for to diagnose boiling into the intake?
 
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AlV said:
What should I be checking for to diagnose boiling into the intake?
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When it's warm, engine off, open the throttle up with butterflies open and see if you can see puddling on the floor of the intake.
 
Like I need a reason to take the car out :) LOL! I'll do it now and see what I see.
I'm trying to see what I can turn into a coolant resevoir.
 
It's nice if the reservoir is semi-transparent. The 73Dart tank fits real nice with just a drilling of a few holes.

If it's boiling the gas in the carb after shut-down, you should be able to see the vapors coming out of the filter house, with the top removed, and the main nozzles should be dripping.This will usually begin within 1 to 3 minutes of shut-down.The tops of the butterflies will be wet.Grab a Coke,sit down,and Wait for it.
 
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Since you say it will crank and not fire, then likely it is heat in the carb. Any heat shield under the carb?

Take of the air cleaner right after you stop and look down the throat for dripping fuel, and also look for vapor rising out of the carb air vents. If you see vapor, don't be lighting up a Lucky Strike!

Also, when you start it hot, hold the throttle about 1/4-1/2 way open; don't pump it. See if that helps it to fire faster.
 
I have not once ever had to raise the front of the car to fill it with coolant.
The air bleed in the thermostat makes filling them soooo much simpler and safer because the engine doesn't have to get up to temp so the thermostat opens to circulate the air out.
It gets most of the air out before the engine ever warms up.
 
AlV said:
Along with the 428P we installed the following bits

Felpro 260-1121, .039 head gaskets
Flatop Piston 428P, .025 in the hole
Stock x Heads with cleanup, , 68 cc
Click to expand...
Best I can come up with is
around 9.8:1, ignoring the '.025 in the hole' above. These pistons should be .007" OUT of the hole with a stock deck, rods, etc., and decking would only make that more. Maybe it is .025" OUT of the hole? Then I get around 10.2.
 
TrailBeast said:
I have not once ever had to raise the front of the car to fill it with coolant.
Click to expand...
Try filling a 4.7L Dakota; they really take some work to burp, and filling uphill helps. For everything else, a few heat cycles usually does it fine.
 
nm9stheham said:
Best I can come up with is
around 9.8:1, ignoring the '.025 in the hole' above. These pistons should be .007" OUT of the hole with a stock deck, rods, etc., and decking would only make that more. Maybe it is .025" OUT of the hole? Then I get around 10.2.
Click to expand...
yes... OUT. ugh I often read what I write after I post and correct my mistakes. :) digital white out.
 
nm9stheham said:
Try filling a 4.7L Dakota; they really take some work to burp, and filling uphill helps. For everything else, a few heat cycles usually does it fine.
Click to expand...

First off I would never intentionally own a pickup with a 4.7, and second the Ram v8's can even be a PIA because of the heater location and hose routing.
Looks full, acts full but there is a huge air bubble in it so the heater doesn't work.
My Brother's truck did this in the winter and he had some cold rides to work before he mentioned it to me.
 
nm9stheham said:
Best I can come up with is
around 9.8:1, ignoring the '.025 in the hole' above. These pistons should be .007" OUT of the hole with a stock deck, rods, etc., and decking would only make that more. Maybe it is .025" OUT of the hole? Then I get around 10.2.
Click to expand...

What cc's are you using for his X-heads?

Even though books and literature list them at 68cc, they are never that unless heavily milled.
 
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Yeah 4.7's have their issues. But my son has 270k miles plus on his. If the valve seats hold in, they go alright.
 
autoxcuda said:
What cc's are you using for his C-heads?

Even though books and literature list them at 68cc, they are never that unless heavily milled.
Click to expand...
Yeah I had to use 68 cc's to get those numbers: I assume the 68 cc is a real number after milling. I agree; normally I'll start with 74 cc's. IIRC the 68 cc is the IHRA number which is the MINIMUM. With 74 cc's, I am at 9.5:1 CR, assuming 6 cc's in the reliefs.
 
nm9stheham said:
Yeah I had to use 68 cc's to get those numbers: I assume the 68 cc is a real number after milling. I agree; normally I'll start with 74 cc's. IIRC the 68 cc is the IHRA number which is the MINIMUM. With 74 cc's, I am at 9.5:1 CR, assuming 6 cc's in the reliefs.
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wish I had the exact numbers for you.. but I suspect that even with a compression ration of 9.8:1 I should consider taking out some timing.
 
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