• 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
Tips
Tips

Cold Air Bilge Blower update

Share this page

RAC68

RAC68

Darth Vader
Offline
Hi All,

UPDATE

A while back I installed a bilge blower within my Cold Air Duct to bring additional air into the foot well of the cabin. After my initial install of a variable speed control and downward footwell air diverter in front of the cabin vent, an April testing within cool weather seemed to prove the concept. However, testing later showed that the unit was NOT a Success as hot radiator air recirculation was also brought into the foot well when running very slow as in traffic or stopped.

To help eliminate hot radiator recirculation, I created closed ducting between duct and grill as well as radiator and grill to help eliminate hot air draw. Although this effort was more extensive then expected, it did not do resolve the total problem as much of the issue depended upon air flow through the engine compartment.

Not wanting to install hood louvers or fender vents, Dougie indicated some very positive results for improving engine compartment flow from adding (4) 3" sets louvers to each inner fender well. Additionally, I added an on/off polarity switch to the variable speed switch in order to push air out of the Cold Air Duct when going slow or stopped. Although this polarity switch is now manual, it would be nice if I could figure a way to have it automatically and safely switch as sook as the car slows to a stop. Any ideas would be appreciated.

By the way, these additions have improved cooling and at some point this summer hope to change back to my original 4-bladded fan to see how it functions.

Ray(64Baj8P1)
 
From the MG fender vents thread:

"... the wheelwell is a low pressure area and will suck the hot air out of the engine bay when moving. And yes, quite a few owners have reported very significant improvements in cooling with the holes. Incidentally, the airflow out of the engine compartement is generally enough to prevent splash from the tires from entering the engine bay. "

Note at the end of the thread this link to louvered panels:

http://rodlouvers.com/Default.aspx
 
Ray
i would also like to see your vents.

i was thinking i might take a house soffit vent, since it is louvered and screened already. cut it to the length i want.

you say this helps with temps. do you mean cabin temp or engine temp?

thanks
 
Hi Guys,

I hate to say it but this is the second time I seem to have misplaced Dougies louver-installed pictures. The louvers are composed of two steel sheets of (4) louvers, placed in the inner wheel well reasonably close to the suspension opening with the louver extending out of the engine compartment and down on an angle consistent with the inner fender edge. As Steve indicated, the low pressure created by the wheel well, brakes the air bubble that forms in the engine compartment around the fire wall and draws the air to flow into the wheel well and exhaust area. As I see it, this difference in pressure allows for more effective engine compartment air flow from the radiator and through the engine compartment when the car is moving and also provides an outward exit when the car is stopped.

s-l225.webp
15416135_t.jpg


Dougie, I hate to ask you again but could you post your picture again,

Thanks,
Ray(64BJ8P1)
 
Last edited:
Ray,
Better sealing would be needed between the grille opening and wheel well in the tie rod area - or the vents would be pulling cool air from the front as well.

Maybe some sort of canvas gaiter could be made that would close off the opening and accommodate the movement of the tie rods.

Blocking the airflow on either side of the radiator would allow the upper suspension openings to function as such an exit.

BaffleRtRadAlternator.jpg


BaffleLtRad.jpg
 
Last edited:
I did two things to help with the vent duct:
  • my radiator side baffles come all the way to the grille. I have the 100-6/early 3000 horizontal grille and the baffles end at the vertical supports about 2/3 of the way toward each side.
  • I wrapped 3" aluminum dryer duct with 1/4" foam insulation and slid it inside the 4" black hose. It's not visible and keeps the air from picking up engine bay heat.

The resulting air is relatively cool.
 
I also added insulated 3 inch ducting inside the original. It does help. But then air conditioning helped more!
 
RAC68 said:
Hi Guys,

I hate to say it but this is the second time I seem to have misplaced Dougies louver-installed pictures. The louvers are composed of two steel sheets of (4) louvers, placed in the inner wheel well reasonably close to the suspension opening with the louver extending out of the engine compartment and down on an angle consistent with the inner fender edge. As Steve indicated, the low pressure created by the wheel well, brakes the air bubble that forms in the engine compartment around the fire wall and draws the air to flow into the wheel well and exhaust area. As I see it, this difference in pressure allows for more effective engine compartment air flow from the radiator and through the engine compartment when the car is moving and also provides an outward exit when the car is stopped.

s-l225.webp
15416135_t.jpg


Dougie, I hate to ask you again but could you post your picture again,

Thanks,
Ray(64BJ8P1)
Click to expand...

Ray, where did you get those louver panels?...

Thanks,
Steve
 
steve
look at Steve's post above on hot rod louvers. there is a link. post #4
 
Looking at the MG louvers on the V8 site, the MGs normally don't have an opening down there, so if the wheel well is a low pressure area, the louvers make sense on an MG.

On a Healey, I'm wondering what these louvers will do that the front suspension opening isn't already doing.

If one hasn't blocked off the area on either side of the radiator, maybe a rearward facing scoop over the suspension opening would help exhaust hot engine-compartment air and not just air that's bypassed the radiator.

Science project idea: place some kind of temperature pickup on the rear edge of the wheel well and see which version gives the most heat in that area - that would show whether the vents were working.
 
Last edited:
Hi All,

Sorry for my slow response. The panels were selected from a number available in ebay. Although the panel pricing seems reasonable, the shipping, even from ebay, seem quite high.

Ray(64BJ8P1)
 
Back
Top