Radiator Air Flow

[steveg]

There are a couple of guys that have done it and published articles.
https://www.stevesaustinhealey.com/blog/9-ac-installation?showall=
Also September 2015 Healey Marque

The Healey version of the Manhattan Project!

 

[John Turney]

....

I bring this up because if I were to address your issue, I would favor installing a similar low mounted scoop under a few inches behind the bottom of the shroud with 2 upward facing fans. This would allow uninhibited air flow through the grill to allow cooling at speed (as apposed to many who have found the constant running of an electric pusher fan mounted on the cross braces that block grill air flow at speed).

Just my thoughts,
Ray(64BJ8P1)

Thanks for the input, I've given that some thought. What my initial test makes me think though, is that when fans are not against the radiator the air would take the path of least resistance and be deflected by the radiator and perhaps out the grill if not moving.

I have spent a bit of time thinking how an engine fan shroud could be constructed and installed in the tight Healey space without having to have someone fabricate one at great expense. As I noted in an earlier post, I have a Texas Cooler fan, it is offset to the left side of the radiator and there isn't much room. The attached drawings are based on my car (BN4 body, 3000 engine, stock radiator and NTAHC fan). I use simple aluminum shapes readily available at the local hardware store and no complex forming. One shows the shroud with the radiator and one without. Hopefully these show up. Comments are welcome:

 

[steveg]

John,
Would it be possible to repost them at a larger size? I click on them to read them and they don't blow up at all.

 

[Bob_Spidell]

John,

Why is your fan offset to the left? I don't have my BJ8 here, but it's always appeared to be directly behind the radiator.

Many moons ago, I bought a 'kit' from BCS that included a 7-bladed flex fan and a shroud that doesn't enclose as well as this appears to. The flex fan was one of the most effective temperature control additions I've done, but it was too noisy at idle--where it worked best--and I replaced it with a Texas Cooler. The shroud bolts to the lower radiator mounts, and as far a i can tell it's symmetrical.

 

[steveg]

Bob - the water pump center is left of center. The fan overhangs the driver-side edge of the radiator by around 1". Passenger side it's about 1/2" inside of the radiator edge.

 

[John Turney]

John,
Would it be possible to repost them at a larger size? I click on them to read them and they don't blow up at all.

The attachments have been superseded and removed. Please see my post of Dec 4th.

 

[steveg]

John - thanks for uploading the pdfs - they work for me.

Wonderful work!

One minor comment - what about pop-riveting the side assemblies together?

Not quite clear from the drawings - does the rear piece fold over for the two top pieces on either side of the curved fan guard?

 

[John Turney]

...
One minor comment - what about pop-riveting the side assemblies together?

Not quite clear from the drawings - does the rear piece fold over for the two top pieces on either side of the curved fan guard?

I suppose the side assemblies could be pop-riveted if one has the proper tools and rivets.

Yes, the rear piece does fold over the for the two top pieces on either side of the curved fan guard.

 

[Deleted member 21878]

can upper radiator hose get thru?

 

[ScottM]

The best solution we have found up here in the high desert. Is to install pusher electric fan in front of radiator, and add a 15 inch stainless steel 5 blade fan. /And space it as close as you dare to radiator! Works well, and maintains oem looks.

 

[John Turney]

can upper radiator hose get thru?

Good Catch!!

I have to revise that side.

Thanks!

 

[John Turney]

The best solution we have found up here in the high desert. Is to install pusher electric fan in front of radiator, and add a 15 inch stainless steel 5 blade fan. /And space it as close as you dare to radiator! Works well, and maintains oem looks.

My Texas Kooler fan has worked fine up to 105F. Beyond that the people overheat. I just noticed that although the fan blows a lot of air, very little of that air comes through the radiator at idle.

 

[RAC68]

Hi John,

Your observation of low through-radiator air flow at idle is telling and I would expect you are either drawing air from openings under the shroud or loosing fan draw at the end of the blades.

Does your shroud incorporate panels blocking off radiator areas outside the circumference of the fan opening? I bring this up because of your comment about observing little or no radiator flow-through at engine idle. Forcing all air to flow through the area covered by the fan would give greater air flow and, even with some radiator air recirculation, would result in greater fan pull. As I understand, good fan draw also requires the fan have a tight fit with the surrounding shroud and a loos fit will allow functional efficiency and loose draw.

However, although the addition of panels, as you describe, that focuses all air flow through the fan-surrounding shroud would make the modification purposely effective at all speeds (including idle). Even if the original modification would present an obvious appearance quite counter to the original, I believe once solved, its presentation could be modified to be consistent with traditional Healey themes of presentation

Ray(64BJ8P1)

 

[John Turney]

Hi John,

Does your shroud incorporate panels blocking off radiator areas outside the circumference of the fan opening? I bring this up because of your comment about observing little or no radiator flow-through at engine idle. Forcing all air to flow through the area covered by the revolving fan would give greater air flow and even with some radiator air recircl

No, it only stops air from the sides being drawn through the fan. If I block off radiator areas outside the circumference of the fan opening, then I wouldn't get increased flow when moving.

 

[RAC68]

John,

You may be right but here is an example of an enclosing radiator fan shroud that seems to provide substantially better flow over the full radiator. The difficulty I see is the area needed to allow full under-shroud flow across the radiator core. Additionally, it definitely looks non-standard.

Dale Spooner's 1977 MGB with Ford V8.
According to Dale, "Fan shroud improves idle and low speed cooling".

Just my thoughts,
Ray(64BJ8P1)

 

[Patrick67BJ8]

John,

You may be right but here is an example of an enclosing radiator fan shroud that seems to provide substantially better flow over the full radiator. The difficulty I see is the area needed to allow full under-shroud flow across the radiator core. Additionally, it definitely looks non-standard.

Dale Spooner's 1977 MGB with Ford V8.
According to Dale, "Fan shroud improves idle and low speed cooling".

Just my thoughts,
Ray(64BJ8P1)

I’ve been told that it’s important for the fan blade to stick out from the shroud like this, half way out or there’s problems with turbulence which decreases the cooling performance.

 

[John Turney]

John,

You may be right but here is an example of an enclosing radiator fan shroud that seems to provide substantially better flow over the full radiator. The difficulty I see is the area needed to allow full under-shroud flow across the radiator core. Additionally, it definitely looks non-standard.

Dale Spooner's 1977 MGB with Ford V8.
According to Dale, "Fan shroud improves idle and low speed cooling".

Just my thoughts,
Ray(64BJ8P1)

Ray,

I may have misunderstood what you said. I thought you meant blocking off the radiator in front of the fan. Yes, my design blocks off air flow so that all air coming through the radiator above the upper cross member goes through the fan opening.

 

[John Turney]

I’ve been told that it’s important for the fan blade to stick out from the shroud like this, half way out or there’s problems with turbulence which decreases the cooling performance.

I've seen that the fan blades need to stick out either half way or 2/3 of the way depending on the shroud manufacturer.

 

[HealeyRick]

Not sure if any of this is transferable to a stock Healey as the measurements of engine placement will be different than with a stock motor.

First off. I'm using a 14" Maradyne fan installed as a puller: https://www.thewedgeshopstore.com/products/Maradyne-14in-Electric-Fan.html

The first iteration was the fan installed on an uprated stock Healey radiator with a shroud made from cookie baking sheets:

It provided some benefits but not as much as I wished, so my present set up is a Wizard aluminum radiator with an integral shroud:

This was a custom build in order to position the back of the fan motor clear of the V8 pulleys and also involved removing the cross brace and mounting the radiator as close to the hood locking mechanism as it could go. Clearance is still tight after all the modifications, but it does fit and cools the motor sufficiently,

I'm still hoping to drop underhood temperatures a bit with my hood louvering (but have to admit this is more an appearance than mechanical necessity)

I was very happy with the work done by Wizard. They were willing to work with me to design a radiator that would fit in the limited confines of the Healey and the fab work on the radiator is very nice. I don't think an aluminum radiator is a one-stop cure-all to Healey overheating but has to be combined with all the methods that have been discussed to maximize airflow through the radiator.

 

[turtle]

Here's my custom Wizard setup. My mechanic just finished the installation today. He was very impressed with the build quality and it dropped right in.

It's Wizard's 100/4 radiator, upgraded to 1.25" tube, Spal 14" brushless 500w puller fan with shroud, modified for Chevy V8 (swap in/out locations).

Only snag was the lower hose not wanting to fit with the new shroud but a little customizing was expected. I have high hopes that I won't need to replace the bonnet with a louvered one... since the solid bonnet 100s are so "rare" now and I want to keep the "stock" look... well except for the giant side pipes that always give me away.