http://www.mtfca.com/discus/messages...tml?1284480432

http://www.fordbarn.com/forum/showthread.php?t=73662

and then there is this...

http://www.arrowheadradiator.com/14_...utomobiles.htm

Bill

Doesn't this suggest that moving water slowly does not allow it to pick up heat when steam forms an insulating layer? I'm thinking that the quart of water floating on top of the molten lead wasn't moving very quickly.

Fast moving coolant (or turbulent) might prevent the steam pockets from forming, no?

:cheers:
Gerry

In the 1990's we used to manufacture Carter Water Pumps then we picked up Sealed Power and TRW Water pump business so we had a lot of water pump exposure.
Things I saw pump related that caused overheat issues.
1. Pump with impeller that did not have enough interference fit on the shaft, the belt turned the WP pulley but did not turn the impeller inside. NO Flow.
2. Pump with reverse rotation impeller installed by mistake No Flow
3. Pump with OEM Design that required a Positive displacement plate on the impeller sold without the positive displacement plate installed causing low flow overheat issues.
Heavy Duty engine Water Pumps usually had a Positive displacement pump, these did not pump more water but pumped with more pressure so they could maintain flow in high heat environments. Like a 327 in a Dump Truck pulling a hill that takes several minutes at wide open throttle, these work engines expose the block to more heat for extended periods and positive displacement pumps worked, change that engine to an automotive water pump and they would burn up the engine doing the same work.

5. Most automotive pumps use a simple paddle wheel impeller, it slaps at the coolant as it rotates keeping it flowing, in low demand applications this works fine.
Some aftermarket companies add a disc to the back of the impeller making it function more like a positive displacement pump without adding the extra weight and mass of a true heavy duty pump. These actually improve flow considerably, not faster flow but positive displacement flow so the pressure stays more uniform cold or very hot and this helps.
Water Pump sales in the late 90's were all exiting the USA and moving to China and we chose to exit the business in the late 90's so all this info is old but may still apply.
Let us know what you finally find.

I'd remove the block drain plugs, power flush it then replace the pump with the stock cast iron pump. This is a cheap next step to remove potential blockage then rule out the pump. Check your heater hose configuration as well. I'm running with a similar replacement radiator, the Bosch stock style pump, 50/50 mix, 180 thermostat, and the bypass from manifold to pump top. 327/365 bored .040 over. Never overheats even in the garage on a hot day.

Good morning everyone. I was able to get a few things done last night and left with some more items eliminated and some more questions.

First, the Block Engine Test came back negative (Image 1), so that's a relief. Ran the motor up to 190 deg so the thermostat was open and flowing. Checked fluid levels and then temps in the rad hoses to verify circulation. Set the tester in place of the rad cap and pumped the bulb for a minute. Glad to see it remained blue.

Second, I replaced the vacuum advance mechanism (Image 2). It matches the one spec'd out in one of Lars' articles and was the recommended replacement from Napa as well. After getting everything back together I still have no vacuum advance on my timing. 34 total and 16 at idle regardless of whether the vacuum is attched or not. The arm on the advance seems to take a significant amount of suction to move. I tried testing it with my mouth (as one YouTube vid demonstrated. guess I don't have 16-18 in. Hg in me. Insert joke here) and it wouldn't budge. It makes me question if the vacuum from the carb (Image 3) has enough to move it. More questions.

This weekend I plan to replace the water pump with a cheap unit (if there is one in town) to see if the current one is the issue. I'll also go through the rad with the I.R. gun to map out the temp differential across it.

Thanks again for all the great input.

Image 1: Block Test Results
http://s17.postimg.org/6kleb86xb/20130710_202616.jpg

Image 2: Vacuum Advance Mechanism
http://s22.postimg.org/527qdla29/20130710_202015.jpg

Image 3: Vacuum line from carb to advance
http://s15.postimg.org/3sk5x7gnf/20130710_174307.jpg

If vacuum to the dist continues to be an issue, remove the plug at the back of the manifold as seen in you pic, and adapt a fitting for attaching the dist vacuum. It will be the most direct you can get. :cheers: Dennis

:iagree: try it...; if that doesn't move it there is something wrong with your distributor
Bill

OK, you got a 2818 Holley Carb so disconnect the rubber vacuum line from the vacuum advance and connect a vacuum gauge to the steel line coming out of the carb and post the reading you get at idle.

If you have a Mityvac you can connect it to the vacuum advance and see how many inches of vacuum (Hg) you need to pull the canister to full advance.

You might have a stuck or jamming breaker points plate in the Dist.

Agree. He said he applied oral vacuum and he couldn't move it. Oral vacuum should easily move that plate. It shouldn't take but about 3" vacuum to make it start to move.

As a side note, make sure someone hasn't stuck a ball bearing inside the hose to block vacuum from going to the can.

Oral vacuum didn't move the arm on the vacuum advance (new and old) at all when applied directly to the vacuum advance mechanism.

Did you suck on the vacuum advance with it uninstalled? You should see the arm move.

Yea. It was done on both while they were uninstalled.

Maybe it's already been mentioned but in case it hasn't...the #2818 carb has the vacuum advance connection up on the metering plate, above the throttle plates, so there won't be any vacuum signal coming through at idle to the vacuum advance canister. You'll only see vacuum when the rpm increases . If you're actually testing at an elevated rpm and still no signal, there is a blockage somewhere, or maybe the canister is defective?
Mike T.

Use a Mityvac, can't imagine you have 2 bad vacuum advances.

2818 vacuum port
 

Mike are you saying that the vacuum port on the Holley 2818 is "ported" vacuum instead of full vacuum?

I came across an older post from another website where BarryK was discussing this very topic.

Seems that while the original 2818-1 carbs were full vacuum ports the later service replacement units were changed to ported vacuum.

If true could explain why there is no vacuum at idle.

just depends if the port is above the throttle plate(ported) or below the throttle plate (full vacum)

Unless the #2818 is built different than all the other Holleys I've seen (and that is a possibility), any time I see the vacuum port being used is not located on the baseplate or at least the lowest portion of the carb body, then I usually assume the connection is intended as a 'ported vacuum'. I expect the guys with the #2818 will chime in soon and let us know for sure.
Mike T.

Attached is a picture of a 65 327/350hp I restored a few years ago, the 2818 carb on this car was a correct dated (1965) carb and the vacuum line is hooked up the same.

This car NEVER ran over 180 degrees while I owned it.