55blacktie wrote: ↑Tue Mar 28, 2023 7:27 pm
The spacer goes between the fan and the pulley, not between the pulley and the water pump. Look at a cooling-system diagram. You'll also find that all of the Tbird suppliers sell the fan spacer. Concours's part number is 8546.
Thundermax, if I can overcome the obstacles in my garage (don't ask) to get to my fan spacers when it stops raining, I'll measure a spacer. I seem to recall it's 1 1/2" inches, but I wouldn't swear to it (I have no trouble swearing, otherwise). If you call/email one of the suppliers, they should be able to tell you, if somebody else doesn't chime in. Fortunately, there's an easy solution to your problem.
Ooops! Concours says 1.18 inches (I didn't notice).
Well I have again learned something new. Apparently a 1/2" spacer was installed when my engine was rebuilt/replaced decades ago. I now see a 1+" spacer should be there and I never knew the difference. This will be corrected this spring.
Now I'm confused. Some say the fan should sit just outside the shroud and others say it should fit fully into the shroud. I have about a 1/2" fan spacer and the back edge of the blade sits about 1" outside the shroud. Maybe my spacer was for a Ford car and not the T-Bird. The shop that replaced my engine bought a long block from a Ford authorized rebuilder decades ago so I never knew the difference.
Ward, I think your confusion is justified. When Gil said that the edge of the fan should be 1/4-inch out from the shroud, he didn't specify whether it should be the front edge or back. If it's the back, the fan would be well within the shroud. I'll look into it.
55blacktie wrote: ↑Wed Mar 29, 2023 1:58 pm
Ward, I think your confusion is justified. When Gil said that the edge of the fan should be 1/4-inch out from the shroud, he didn't specify whether it should be the front edge or back. If it's the back, the fan would be well within the shroud. I'll look into it.
Thanks. I'll order the new spacer and install it this spring. I have had no issues so far but having the fan further into the shroud couldn't hurt. Especially Not having the blades so exposed. (Trust me been there when tinkering and catching things). Never knew there was anything different until I stumbled onto this thread.
Two CTCI members confirmed that no more than 1/4-inch to 1/3 of the fan should be sticking out of the shroud. How much difference does it actually make? There are so many variables to consider-air flow through the radiator, engine speed, fan size, etc. I'm not equipped to test all of the variables with absolute certainty. However, if your Bird runs hot, that might be an area worth checking.
55blacktie wrote: ↑Wed Mar 29, 2023 6:29 pm
Two CTCI members confirmed that no more than 1/4-inch to 1/3 of the fan should be sticking out of the shroud. How much difference does it actually make? There are so many variables to consider-air flow through the radiator, engine speed, fan size, etc. I'm not equipped to test all of the variables with absolute certainty. However, if your Bird runs hot, that might be an area worth checking.
My gut just tells me that it was assembled incorrectly and never knew. New spacer going in. A win-win piece of knowledge. Can only make things better and closer to correct. I think the better wind tunnel effect will no doubtly help.
Fact about the original TBird shroud. Basically, it does not work very well as a medium for cooling because of the open design of the lower part and the various small holes at the top. For a cooling shroud to work effectively, the entire radiator core must be covered with no holes except for the fan blade itself. This allows the fan to draw from the entire core surface. Any deviation, especially the early Tbird shroud, does very little for the purposes of cooling. Basically, it is a protective piece.
Because of this, the placement of the fan in the shroud probably does not make much of a difference for cooling purposes.
Not going to say the shroud does nothing, but is not the great cooling piece people make it out to be.
1956 Fiesta Red 312
1954 Ford Victoria 312
1948 Ford Convertible Street Rod 302
Casco has a lower fan shroud that is supposed to be more efficient than the original. I will probably use the Casco lower but retain the original upper shroud. I had considered getting a combination shroud and electric puller fan for my US Radiator, but I'm hoping that the Casco HO Pump, Paragon wp spacer, 4-row radiator, smaller pulley, and 180-degree wide-mouth thermostat will deem it unnecessary. Although my car will not be 100% original, it should be a better driver and, for the most part, still look period-correct.
paul2748 wrote: ↑Wed Mar 29, 2023 9:48 pm
Fact about the original TBird shroud. Basically, it does not work very well as a medium for cooling because of the open design of the lower part and the various small holes at the top. For a cooling shroud to work effectively, the entire radiator core must be covered with no holes except for the fan blade itself. This allows the fan to draw from the entire core surface. Any deviation, especially the early Tbird shroud, does very little for the purposes of cooling. Basically, it is a protective piece.
Because of this, the placement of the fan in the shroud probably does not make much of a difference for cooling purposes.
Not going to say the shroud does nothing, but is not the great cooling piece people make it out to be.
That being said, tucking it further into the shroud is a safety issue. If it cools better or not will be seen. Never really had an overheating issue to speak of once I got it properly tuned. Upon further review and looking at the spacer on line, I do have the correct spacer so this issue is now a non-issue.
Just measured and my fan is actually only 3/4" sticking out.
Last edited by ward 57 on Sat Apr 01, 2023 6:51 pm, edited 1 time in total.
Just to provide another data point. My 57 has an 18" 6 bladed flex fan with a 1.5" spacer. The back of the blades sit 1/2" outside of the shroud. There's an inch of clearance between the blade tips and the shroud.
Casco 8148XC lower fan shroud currently isn't available. They are working on getting a vacuum mold and hope to begin producing the lower shroud soon. Although the part number can be found in their latest catalog, it's not on their website.
55blacktie wrote: ↑Fri Apr 14, 2023 8:52 pm
Casco 8148XC lower fan shroud currently isn't available. They are working on getting a vacuum mold and hope to begin producing the lower shroud soon. Although the part number can be found in their latest catalog, it's not on their website.
Are you missing the OEM lower shroud or just thinking you might benefit from a different one? I thought about getting the plastic one from CASCO but did some measurements of how much of the radiator was not already covered and I calculated that the plastic lower shroud would only add around 6% more coverage, and it would be "cooling" the cool part of the radiator at the bottom. At the time I was putting in a AC system and to manage increased temperatures from the AC I put in a high flow water pump, the Ames spacer, and wide mouth thermostat. I decided to gamble on the 6% not being enough of a difference to be worth it. The car runs cooler now with the AC on, on a 90 degree day then it did before I added the AC and other stuff on an 80 degree day.
Thanks, Jim. I have the original upper and lower shrouds, but I've read that the lower shroud is not very efficient.
Dick Shaw has a Youtube video of the installation of a Flex-A-Lite electric puller fan on his 56. In the video, he shows how much of the radiator core is outside the original shroud. He added material to the upper shroud and made a replacement shroud to provide better coverage. His lower shroud looks similar to Casco's 8148XC, which he recommended to someone inquiring about Dick's making a lower shroud for him.
I do have Chris Ames's (Paragon Industries) wp spacer, 1-inch smaller pulley, 4-row copper & brass US radiator, 6-blade fan, just placed order for Casco HO wp, and will buy an EMP Stewart 385 180-degree thermostat. I do not have a/c and don't intend to install it. Based on your experience, it sounds like I don't need the 8148XC lower shroud.
If necessary, I would consider using a pusher fan in front of the radiator; Gil Baumgartner recommends a pusher fan, when needed, but others have commented that putting a fan in front of the radiator restricts air flow. If so, to what extent?
When my engine is rebuilt, attention will be given to the possible rust build-up in the water jackets that could contribute to overheating.
I like originality so I'm not a big fan of electric fans as a solution to general overheating problems, esp on these tbirds UNLESS the specific issue is long slow parade driving. I think in many cases they just mask problems that could have been solved more properly and without the need to add stuff and add a huge electric draw that requires an alternator. A decent electric fan is probably going to draw 15 to 20 amps, I've heard of some that draw 30+ on high speed.
People who have done instrumented tests on how the stock system works and how possible "fixes" performed found that the stock system has very very poor water flow thru the engine at idle speeds. In one of the test setups they were getting ZERO water flow!!! You can be sure the engine is going to run hot when no water is flowing. Also, when no, or little, water is flowing it's not going to make much difference what radiator and what fan you have cooling the radiator, the engine is going to heat up.
That suggests to me that the place to start with overheating concerns is the water flow issue and there are three solutions available. The Ames spacer, high flow water pumps (Casco and FlowKooler) and the wide mouth thermostat (about twice as large an opening as the stock style). The thermostat is a no-brainer since it's so inexpensive. Next in cost is a high flow WP, about $170, then the Ames spacer, $260. I did all three while I had things apart.
This assumes all your existing parts are good. If you've got a leaky radiator that you are going to have to replace anyway perhaps the first place to spend money is on a GOOD replacement radiator, maybe that would be all you need to do. The original radiator in these cars had around 110 tubes. The commonly sold OEM *style* (not real OEM) radiators only had 93 tubes. That means a lot of people have subpar radiators who think they have OEM capacity. You can get replacement radiators with 100+ to as high as 200 tubes. So if you need a radiator anyway that might be the place to start and throw in a large opening thermostat.
Another thing if you are only having a mild problem and you still have the original 4 blade fan is to go to a 6-blade flex fan or if you want to go crazy fit a fluid clutch 6-blade fan to it. The cooling power of the flex and fluid is similar, but the fluid will have less parasitic power losses when you are at speed and the clutch can disconnect. The flex is likely to be noisier too. These fans can consume as much as 40 hp at high rpm and probably never less than 5.
If you've done those things and still are running hot or just want an electric for whatever reason, the electric, with upgraded alternator almost mandatory, can be a good way to cool things down - but don't cheap out on the electric fan choice. If you are going to go electric, you would want at least as much air flow as a good engine fan system has so that would be about 2200 cfm and up. But.. there's always a but... the kind of shroud on the electric is important to whether or not you really get the claimed cfm. You can find relatively cheap low-profile ones (called basket fans by some) which might only move half their rated capacity because they sit so close to the radiator and are poorly shrouded. You want full shroud and the fan motor sitting a few inches back from the fan blades and the blades a couple inches from the radiator. You can find ones that go as high as 3000 cfm. You also should avoid putting them on the front of the radiator, that blocks airflow and is likely to be the basket fan style. I've heard of people doing that (front side fans) and leaving the engine fan in place and using it only as a parade fan but when its off it's going to still be blocking the radiator.
More personal choice => If you are going to go thru the trouble of putting a parade fan on why not go all the way and be done..Get a GOOD electric, add alternator, and just replace the whole engine driven system. That will also save you the 10 or 20 hp that was used to drive the engine driven fan. Oddly enough, and I don't understand how, in one report I saw a 65 amp drain on the alternator only created a 2 hp power loss on a dyno run at 4500 rpm. That alone would make me want to switch to a good electric.. it frees up 20 hp!!
