underhood heat

[moparnation74]

I agree with you regarding the timing and carb focus. I was wondering what the effect of timing has on engine heat and what other factors come into play, such as cam specs, manifolds, etc. I can only imagine how much heat is trapped under the hood in 90F+ weather while idle. This is likely what is causing the sputtering, etc. This is the only time it has happened since putting a spacer and sock on it. The temperature has been fairly mild this summer however.

You have HP manifolds...ZERO effect...they are cast iron headers...

Cam affects timing.....

Yes, you ran better on a cool day but I think that problem was there then and benefited from the outside temps...

 

[oldbee]

Also retarded timing makes engine run hotter. Don't worry about what vac.advance adds to timing until you get the aforementioned fx'd. Vac advance usually shows problems when steady state cruising like a little bucking,etc. Yeah those plugs look rich.

 

[Glenwood]

You need a shroud definitely, ur running a direct drive fan & not channeling the air correctly. Total timing oughta be 34-38* range revved up w/vac advance unhooked. Forgot the t-stat ur using, if u said, nothing higher than 180*. Do u have the hood-radiator rubber seal that seals on the rad.support? That helps too.

I am aware of the shroud benefits. Unfortunately, this rad does not have mounting ears for one. I think I'll have to come up with a custom one. It is a 180 stat, but no rubber seal.

To Justin's point, perhaps in an idle situation with only a portion of the fluid getting cooled, the hot fluid is returning to the motor and keeping it on edge? All of this makes sense, but it doesn't explain why so much heat is being thrown off of the rad that actually feels like it is so intense as when you reach into an oven to pull out the roast and your arms above the mitts are burning. I assume the rad is doing its job the best it can under the circumstances but wow.

 

[oldbee]

You still could be "breaking in" the engine also; my estimation is anything under 1000-1500miles is break-in,at least on a street engine.IMHO

 

[Glenwood]

so, how does one determine how much initial timing the engine wants? I have not been able to get it to ping, but I haven't pushed the timing above 25* yet.
maybe my hearing is worse than I thought lol.

 

[Glenwood]

could inadequate spark contribute? Wondering if the coil and ecu are inadequate for this combo.

 

[Dennis H]

Shroud is essential. Make sure clutch fan working, replace with low profile Hayden if not. Not easy to diagnose. The ceramic coated TTI headers reduce overall under hood temps by 100 degrees on the Coronet. More peace of mind at long red lights. Spacer etc too.

 

[Mike67]

Well I'm not an air flow specialist but have dealt with it enough in my career to form opinions... and you know what every one says about those!
If you had a shroud you would be pulling probably 95% through the radiator, here comes the opinion, which effectively makes your engine compartment pressurized which pushes the air out of the bottom.... without the shroud there is no balance, you are essential recirculating the air in the engine bay.
Would your ac blower work without a steel cage around the blower or would it just short cycle the air around the pitched blades? Ya it will move a little air but not enough to cool your home...
Again it's just my theory and opinion...

 

[moparnation74]

so, how does one determine how much initial timing the engine wants? I have not been able to get it to ping, but I haven't pushed the timing above 25* yet.
maybe my hearing is worse than I thought lol.

10-15 initial....stay around 36 total if you can...

I have never been a fan of the mopar units and I have ran many of them......Always erratic and poor spark...but before going that route try to normalize things first....

 

[Glenwood]

Well I'm not an air flow specialist but have dealt with it enough in my career to form opinions... and you know what every one says about those!
If you had a shroud you would be pulling probably 95% through the radiator, here comes the opinion, which effectively makes your engine compartment pressurized which pushes the air out of the bottom.... without the shroud there is no balance, you are essential recirculating the air in the engine bay.
Would your ac blower work without a steel cage around the blower or would it just short cycle the air around the pitched blades? Ya it will move a little air but not enough to cool your home...
Again it's just my theory and opinion...

That's an interesting thought Mike. The thing is, the hood is open and I'm trying to adjust the timing, etc., and my hands are getting cooked! Just trying to understand the dynamics I guess, as best as this old electrician can!

 

[moparnation74]

That's an interesting thought Mike. The thing is, the hood is open and I'm trying to adjust the timing, etc., and my hands are getting cooked! Just trying to understand the dynamics I guess, as best as this old electrician can!

Dumb question are you using a timing light?

 

[Glenwood]

10-15 initial....stay around 36 total if you can...

I have never been a fan of the mopar units and I have ran many of them......Always erratic and poor spark...but before going that route try to normalize things first....

It seemed to like it at about 13*. Easy to start and ran well, but my carb may not have been set up properly. The car with a 2400 stall and 3.55s does not seem to make as much power as I expected though. I figured the timing wasn't quite right either.

 

[Glenwood]

Dumb question are you using a timing light?

I flick a lighter as fast as I can lol.

I have a timing light on it that connects over #1 cable.

 

[moparnation74]

It seemed to like it at about 13*. Easy to start and ran well, but my carb may not have been set up properly. The car with a 2400 stall and 3.55s does not seem to make as much power as I expected though. I figured the timing wasn't quite right either.

I flick a lighter as fast as I can lol.

I have a timing light on it that connects over #1 cable.

I figured but had to ask...like the lighter joke!

 

[Mike67]

That's an interesting thought Mike. The thing is, the hood is open and I'm trying to adjust the timing, etc., and my hands are getting cooked! Just trying to understand the dynamics I guess, as best as this old electrician can!

I'm an electrician too but cross trained in the world of HVAC and Instrumentation as well.
Several microchip plants and a lot of healthcare which rely heavily on proper air flow characteristics ...
It could be a combination of both timing and the lack of a shroud... Timing is the easiest like Justin and others are saying. You may have to fab you a shroud which will take a little time... look on the internet I'm sure there are some retrofit kits for those radiators without mounting tabs...
I wish you the best buddy! Nothing worse than a car you don't trust...

 

[Glenwood]

Shroud is essential. Make sure clutch fan working, replace with low profile Hayden if not. Not easy to diagnose. The ceramic coated TTI headers reduce overall under hood temps by 100 degrees on the Coronet. More peace of mind at long red lights. Spacer etc too.

No clutch fan yet, didn't think I have enough room in this 64. Does a clutch fan really cool better that a 7 blade mech fan? I thought the only advantage was reduced drag and engine load until needed. I'd love a set of TTI's on this old girl. I've not been impressed with the manifolds so far.

 

[Mike67]

The lack of a shroud might be why your hands are getting cooked, the fan isnt building positive pressure in the bay so all the heat is just rising up from the motor....It kinda confirms my theory if you think about it..
The fan is just chopping the air there's no real movement to get the heat out....

 

[threewood]

so, how does one determine how much initial timing the engine wants? I have not been able to get it to ping, but I haven't pushed the timing above 25* yet.
maybe my hearing is worse than I thought lol.

You can do it with a vacuum gauge and tach. I advance mine until I just about peak at max vacuum. Adjust rpms down as you go, say 850-900 rpms. More timing is not really worth a few more psi vacuum. Then back it off a bit and make sure it doesn't kick the starter. By doing this you also ensure you are on the Eddy idle circuit and the metering rods stay in the hole. Then throw a timing light on it to see what the initial is. Final step is setting total at about 34°.
You look rich. To see if your metering rods are working properly, rotate the rod covers over and tighten down. You are uncovering the rods but the edge of the covers keep them in place. Start the motor and at idle they should be stuck down. Rev the motor and they should pop up. If they are bouncing you either need to get more vac at idle or softer springs on the rods because they are giving you more fuel than needed.

Do you have a good hood to radiator support gasket? Without a shroud you will be circulating hot air around the radiator and engine compartment instead of pulling outside air. If there are gaps around the radiator it will also recirculate hot air.

How does your coolant look? Radiator tubes inside? If your block wasn't cleaned well (like mine) crud will migrate from the block to the cooling tubes and restrict flow.

What temp plug are you using? It could be too cold and not burning off residue on the plugs effectively.

 

[oldbee]

Shroud, shroud like we keep saying. Also know that heat is relative, I mean if your skin/hands are used to it, it doesn't seem so hot. After 'mechanizing' for 40+ I notice the heat gets to me quicker since retiring, softer skin,etc. Anyway with a shroud & direct drive can you oughta be able to cool anything!

 

[Glenwood]

Shroud, shroud like we keep saying. Also know that heat is relative, I mean if your skin/hands are used to it, it doesn't seem so hot. After 'mechanizing' for 40+ I notice the heat gets to me quicker since retiring, softer skin,etc. Anyway with a shroud & direct drive can you oughta be able to cool anything!

well I haven't welded anything for a while, but I don't think my hands softened that much yet.

You can do it with a vacuum gauge and tach. I advance mine until I just about peak at max vacuum. Adjust rpms down as you go, say 850-900 rpms. More timing is not really worth a few more psi vacuum. Then back it off a bit and make sure it doesn't kick the starter. By doing this you also ensure you are on the Eddy idle circuit and the metering rods stay in the hole. Then throw a timing light on it to see what the initial is. Final step is setting total at about 34°.
You look rich. To see if your metering rods are working properly, rotate the rod covers over and tighten down. You are uncovering the rods but the edge of the covers keep them in place. Start the motor and at idle they should be stuck down. Rev the motor and they should pop up. If they are bouncing you either need to get more vac at idle or softer springs on the rods because they are giving you more fuel than needed.

Do you have a good hood to radiator support gasket? Without a shroud you will be circulating hot air around the radiator and engine compartment instead of pulling outside air. If there are gaps around the radiator it will also recirculate hot air.

How does your coolant look? Radiator tubes inside? If your block wasn't cleaned well (like mine) crud will migrate from the block to the cooling tubes and restrict flow.

What temp plug are you using? It could be too cold and not burning off residue on the plugs effectively.

I'll clean up the plugs and have another go at the timing. I was thinking I would have to replace the counter weights in it to get the mechanical in range. How do you know if vac advance is needed or not?

Maybe there's something to the poor recirculating without a shroud. I'll address that after the tuning is right.

Coolant looks clean still. The plugs are 12YC. Not sure if they are an issue. I'll check out the metering rods as suggested.