If you think cooling down only about 25% means the "radiator is doing its job" you are sadly mistaken. I believe you found your problem without knowing it.
340 with edelbrock heads overheating
- Thread starter Early a body
- Start date
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I’ve had to redrill the dowel holes a hair to fit on Speedmaster heads, not on Edelbrocks or TF’s.
Wonder what the car temp would be if he put the X Heads back on?
Would not be the first time the aftermarket was wrong, especially when you add in the Chineseium factor.
Ma Mopar had it right from the start.
Thinking the earlier post about how the aluminum heads have less coolant circulating volume is spot on. Turning Up the Heat.
Also aluminum heads conduct the heat out of the block and send it to the radiator at a higher temp than the block actually is.
Get out that IR temp gun and check the block temps at the frost plugs, then go up to the front and rear faces of the aluminum heads, watch that temp rise by 60°.
Aluminum Heads are not all what they are cracked up to be.
Lots of 360s overheat, after being modded. What is the common denominator?
Aluminum Heads, sure it's more performance but they can't dump the heat.
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Would not be the first time the aftermarket was wrong, especially when you add in the Chineseium factor.
Ma Mopar had it right from the start.
Thinking the earlier post about how the aluminum heads have less coolant circulating volume is spot on. Turning Up the Heat.
Also aluminum heads conduct the heat out of the block and send it to the radiator at a higher temp than the block actually is.
Get out that IR temp gun and check the block temps at the frost plugs, then go up to the front and rear faces of the aluminum heads, watch that temp rise by 60°.
Aluminum Heads are not all what they are cracked up to be.
Lots of 360s overheat, after being modded. What is the common denominator?
Aluminum Heads, sure it's more performance but they can't dump the heat.
☆☆☆☆☆
Early a body
Well-Known Member
took thermostat out . ran the car with out radiator cap. heated up again over 210 and rising. Coolant flow looked great, i did see lots of bubbles. I am thinking I have exhaust in the coolant. Cant think of what else it could be at this point.
btw, its not the radiator, it was doing the same with the radiator i had in it before the cam and head swap. i only changed radiators after the problem persisted.
btw, its not the radiator, it was doing the same with the radiator i had in it before the cam and head swap. i only changed radiators after the problem persisted.
Your local auto parts store should the little deal that you put on the radiator that detects combustion gasses in the coolant. When I worked at oreilly, we rented it out all the time. That would at least verify before you tear it apart possibly for nuthin.
Early a body
Well-Known Member
yeah no around me has one. I spoke toa buddy of mine that owns a shop he said to bring it in next week and heel test it.
I did pull the #1 spark plug it is brownish. Not suprised since i have been messing with the af mixture and timing
Forgive me if you answered this, but does the highest temp on the IR gun coincide with the temperature gauge? In other words are you SURE da beeotch is really runnin hot?
replicaracer43
Grumpy Old Man
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It wont be anything with the heads themselves, but it very likely IS related to the installation. Head gasket, improper bolt torque, bolts bottoming out before clamping, dowels too tall ect
Early a body
Well-Known Member
the ir gun actually reads higher. so if the gauge is at 210, the gun is at about 220-240 where the sender goes in at the intake
I think I would trust the gun at this point. But you say this has been a problem with the iron heads too? Is that right?
Early a body
Well-Known Member
ok, i found a combustion leak tester at harbor freight. I tested it and the blue fluid in the tester turned green. looks like the head gaskets have failed or something. What head gasket do you all recommend. I am using the felpro 1008
Try a new set of head gaskets, the same ones will do, just make sure you use a lube (oil/ARP) and a good torque wrench to the proper settings for the actual lube you’re using. Everything should be fine. The only other reason why a head gasket would fail would be irregular surfaces on the deck and the head.
1WildRT
Well-Known Member
If you flip the head gasket upside down and end for end they can be installed wrong...
I would use whatever the cylinder head manufacturer recommends.
StreetSleeper
Well-Known Member
Rusty I have a couple of questions about this.
Generically, would 12 degrees of initial timing be about right?
Second, if he has closed chambered heads, wouldn’t those be more efficient and need less timing? Initial or total?
He didn’t mention if he has 340-specific-edelbrock open chamber heads.
Does the aluminum affect timing?
I would have thought more efficient heads need less timing. Thanks for your wisdom!!
Generically, would 12 degrees of initial timing be about right?
Second, if he has closed chambered heads, wouldn’t those be more efficient and need less timing? Initial or total?
He didn’t mention if he has 340-specific-edelbrock open chamber heads.
Does the aluminum affect timing?
I would have thought more efficient heads need less timing. Thanks for your wisdom!!
@RustyRatRod
Early a body
Well-Known Member
3
340 specific heads
More "efficient" heads don't necessarily need less timing. An engine that has a high cylinder pressure is the one that will require less timing. There may be "some" truth to the more efficient head, but all in all it's more linked to cylinder pressure. Notice I did not say compression ratio. Cylinder pressure and compression ratio are not the same.
Oh and as for the 12 degrees, I would consider that low initial timing for any type of performance engine. Generally speaking, you concern yourself more with total and WHEN (at what RPM) you achieve total. I would consider "around" 16 degrees initial a "starting point" for any type of performance build, regardless of compression or cylinder pressure.
dano
Evil Handy Man
That sucks to hear. My 1008 needed a retorque after a few heat cycles. They would lightly weep coolant on both sides after warning the engine up. No other leaks. It happened out of the blue after driving the new motor 6-7 times. I've never had to re-torque the head bolts but read it not uncommon sometimes with aluminum heads.
Are you using bolts or studs?
Early a body
Well-Known Member
ok, took off the heads, what i found was very discouraging. Appears some of the valves hit the pistons. Not sure after i checked and rechecked clearance. Well this motor is toast.
Does explain why the idle mixture screws would not do anything. Likely bent the vales too.
Does explain why the idle mixture screws would not do anything. Likely bent the vales too.
Pictures please
Early a body
Well-Known Member
picture attached . top shows where the valve hit the piston. I actually cannot say if this happened with the edelbrock heads or the iron heads as I was not looking for a problem when i took the iron heads off.
Read post #14 again. I spoke to a mechanic friend today with 40+ yrs experience who fitted Edel heads. [ Not a Mopar, but V8 ]. Nothing else was done, but temp increased 10*.
A new water pump may do nothing to fix the problem if the gap between the impeller blades & housing is large. It just churns up water but doesn't capture water. Same deal with high flow pump, it just churns up more water! The gap needs to be closed up so that pressure is increased to force the water through the restricted passages in the alum heads.
A new water pump may do nothing to fix the problem if the gap between the impeller blades & housing is large. It just churns up water but doesn't capture water. Same deal with high flow pump, it just churns up more water! The gap needs to be closed up so that pressure is increased to force the water through the restricted passages in the alum heads.
Once again, put the Iron heads back on to what you have there. No that engine is not toast, just the aluminum heads are.
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