double pass radiators

348tripower · June 30, 2008, 05:12:10 AM

Quote from: "2rods"What year Stude and what engine?

1951 and a stock 454 chevrolet.

348tripower · June 30, 2008, 08:31:43 AM

Quote from: "348tripower"
Quote from: "2rods"What year Stude and what engine?

1951 and a stock 454 chevrolet.

I should of added an update with this post.

Yesterday I added the electric fan back into the system. I let the car idle until it reached 210 degrees and took a ride. Moving down the road, with the air on, the temperature dropped to under 180 again. No air flow restriction from the electric fan.

I parked inside the garage in a warmer and less air moving area and turned on the electric fan. The temperature stayed constant at about 195 degrees with the air on.

Soooooo,
I am going to stop here. I can't get a shroud in this without a bunch of work and it is still very iffy. I think that I am close here. We are going to Columbus for the Good Guys Saturday the 12. ( my pal Red is in the final drawing for the 33) This will be a good test. I know the car will cool without the air on so heat is not a concern now. I can always turn the air off and cruise. One more addition will be wrapping the exhaust pipes this week.

I did notice one strange thing. When i turned the lights on the temperature gauge rose from 190 to 210 degrees. I turned the lights off and it went back down. Next, I turned off the dash lights. The gauge went back down. :? Then I check the temperature with the infrared thermometer. Matched the gauge reading with the lights off. Something going on here.

Don

phat rat · June 30, 2008, 10:27:39 AM

If the exhaust is steel I'd think twice about wrapping it. The wrap promotes rust. Have you looked into the plastic aftermarket schrouds?

348tripower · June 30, 2008, 11:52:08 AM

Quote from: "phat rat"If the exhaust is steel I'd think twice about wrapping it. The wrap promotes rust. Have you looked into the plastic aftermarket schrouds?

Yes I have. The problem is a typical one. Small bag lots of stuff

Leon · June 30, 2008, 01:02:39 PM

Quote from: "348tripower"
I did notice one strange thing. When i turned the lights on the temperature gauge rose from 190 to 210 degrees. I turned the lights off and it went back down. Next, I turned off the dash lights. The gauge went back down. :? Then I check the temperature with the infrared thermometer. Matched the gauge reading with the lights off. Something going on here.

Don

I had that happen with a car and added a ground from the engine to the gauges and it went away.

348tripower · June 30, 2008, 01:44:56 PM

Quote from: "Leon"
Quote from: "348tripower"
I did notice one strange thing. When i turned the lights on the temperature gauge rose from 190 to 210 degrees. I turned the lights off and it went back down. Next, I turned off the dash lights. The gauge went back down. :? Then I check the temperature with the infrared thermometer. Matched the gauge reading with the lights off. Something going on here.

Don
I had that happen with a car and added a ground from the engine to the gauges and it went away.

I was thinking a ground problem. I just haven't forged ahead on that trail.

river1 · November 22, 2008, 02:45:52 AM

bump with a personal experience with a double pass.

i was visiting elpolacko (HAMBer) at his shop(industrial chassis) when he was starting for the first time a 56ish ford pichup. it has a monster motor but i don't remember the size :oops: as we were listening to it run, checking for leaks etc i happened to touch near the top of the radiator YOUCHH it was hot. then i tried near the bottom of the radiator and it was practically cold. it was a ron davis radiator and while it wasn't on the road experience, i WAS impressed.

later jim

348tripower · November 22, 2008, 05:11:06 AM

Right before winter set in I finished the install of the new fan shroud on the double pass radiator I put in the Stude. I haven't had a chance to see how well it works because the weather changed. I am keeping my fingers crossed on this one. One thing I really hate is a hot running car.
Don

HOTRODSRJ · November 25, 2008, 07:27:18 AM

I hate to burst bubbles here... but there are several misunderstandings in this thread that I would like to comment on for future reference.

Multi-pass radiators are very good for "constant RPMs" situations such as racing applications etc. But, for the street they are NOT the most efficient. That does NOT mean they won't work or improve YOUR situation per se. ....just that they are not the best technology for street applications.

For example physics dictate that double pass radiators require 16x more pressure to flow the same volume of coolant through them, as compared to a single pass radiator. Triple pass radiators require 32x more pressure to maintain the same volume. Automotive water pumps are a centrifugal design, not positive displacement, so with a double pass radiator, the pressure is doubled and flow is reduced by approximately 33% and we all know flow is king! Modern radiator designs, using wide/thin cross sections tubes, seldom benefit from multiple pass configuration. The decrease in flow caused by multiple passes offsets any benefits of a high-flow water pump also. Common double or triple-row big tube aluminum radiators are king when it comes to shear cooling efficiency.

Quote from: "348tripower"
I should of added an update with this post.

No air flow restriction from the electric fan.

This is a myth! Electric fans will NOT block airflow to any significant degree. There are plenty of new OE cooling designs (such as a BMW X5) that use front electric "pusher" fans as primary cooling fans and are very efficient.

Quote from: "348tripower"I did notice one strange thing. When i turned the lights on the temperature gauge rose from 190 to 210 degrees. I turned the lights off and it went back down. Next, I turned off the dash lights. The gauge went back down. :? Then I check the temperature with the infrared thermometer. Matched the gauge reading with the lights off. Something going on here.

Don

What is going on here could be a ground.... but my money is on voltage drops occuring at the dashboard power buss. This is very common. What happens is the source is paralleled at the same point where the lights are being source. The wire length or size is not sufficient to carry all the load and therefore voltage drops to the temperature sensor which uses the voltage as reference for a reading. When the voltage dips at the meter then the meter is affected. I have seen this time and time again. I would suggest that you put the headlights on a relay sourced from a breaker protected lead from the battery bus to aleviate this phenom.

phat rat · November 25, 2008, 09:30:42 AM

Well I'll stick with my triple pass as it's proven to work for me on the street.

HOTRODSRJ · November 25, 2008, 09:58:15 AM

Quote from: "phat rat"Well I'll stick with my triple pass as it's proven to work for me on the street.

I agree! This is not about changing your multi-pass series out unless they are NOT doing the job! My statement here was to make everyone aware that single-pass, large-tubed aluminum radiators are the most efficient.

I would tell you that if you are NOT running a high flow water pump with your multi-pass (or any new application for that matter) that would be a good upgrade and certainly more insurance for higher flow numbers meaning higher cooling capacity!

phat rat · November 25, 2008, 01:21:08 PM

Well after 50,000+ mi all over the country in all kinds of temps and conditions without a problem, I'm not going to fix what's NOT broke. My son always had a cooling problem with his 406 powered Jeep he built for off-roading until he went with a double pass. Again not broke needn't fix. Both of these radiators are aluminum 2 core with big tubes. Neither car runs a high flow water pump either

348tripower · November 26, 2008, 06:49:34 AM

To add to this thread, I think I may have found the voltage problem. The battery went south so I replaced it.

HOTRODSRJ · November 30, 2008, 08:13:04 PM

Quote from: "phat rat"Well after 50,000+ mi all over the country in all kinds of temps and conditions without a problem, I'm not going to fix what's NOT broke. My son always had a cooling problem with his 406 powered Jeep he built for off-roading until he went with a double pass. Again not broke needn't fix. Both of these radiators are aluminum 2 core with big tubes. Neither car runs a high flow water pump either

I like the "if it's not broke.. don't fix it" addage for sure. Also, let's not confuse double-pass with double-row. Not the same and I think it can get confused sometimes.

But, in case you are interested, high volume/flow pumps are a great insurance policy for both cylinder temperature differential and hotspots (some hotspotting can occur without you knowing it! They improve flow throughout the cooling manifold and especially in the rear cyclinders regardless of radiator construction. I think they are a great bang for their cost these days.

phat rat · November 30, 2008, 08:18:15 PM

I understand about the high flow pumps. But I like to keep my car as much "off the shelf" as I can. Always easier to get a replacement in BFIowa