Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Offline
The Healey version of the Manhattan Project!
-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
Radiator Air Flow
- Thread starter John Turney
- Start date
Share this page
The Healey version of the Manhattan Project!
OP
Offline
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:
Bob_Spidell
Yoda
Offline
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.
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.
OP
Offline
The attachments have been superseded and removed. Please see my post of Dec 4th.
Last edited:
Offline
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?
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?
OP
Offline
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.
D
Deleted member 21878
Guest
Guest
Offline
can upper radiator hose get thru?
OP
Offline
Last edited:
OP
Offline
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
Darth Vader
Offline
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)
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)
Last edited:
OP
Offline
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
Darth Vader
Offline
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)
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)
Offline
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,
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)
OP
Offline
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.
OP
Offline
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.
Offline
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.
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
Senior Member
Offline
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.
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.
