Horn hole cover modification.

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Duke Mk1a

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I really believe that the engine compartment can benefit with the extra air that flows through the horn holes at freeway speeds.

Problem is, the cooling system does not like the hot air circulating into the radiator from the horn holes at idle and slow speeds.

Solution - install a spring loaded flap door in the horn hole covers. This flap door will be spring loaded shut at low speed and then be pushed open at higher speeds by the force of the air flow.

I just ordered some spring loaded shut hinges from McMaster Carr. Will let you know how it works out.

Thoughts?
 
michael-king

michael-king

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Duke,

Audi used a similar system on the rally quattros in the 80's.. until they got some photos of them doing that and got pinned for cheating.

I gather you are figuring having some fresh air in the engine bay stop their being a pool of still warm air heating the base of the carb etc.. did you end up making a sealed box for the carb from your LAT bonnet?

Another solution might be to run some ducting from the horn holes, it would stop the air flowing back out in traffic and would direct it where you want to at speed.
 
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Duke Mk1a

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michael-king said:
I gather you are figuring having some fresh air in the engine bay stop their being a pool of still warm air heating the base of the carb etc.. did you end up making a sealed box for the carb from your LAT bonnet?

Another solution might be to run some ducting from the horn holes, it would stop the air flowing back out in traffic and would direct it where you want to at speed.
Click to expand...

They only time my temp rises is when I am at freeway speed. I figure the horn holes being blocked and the DeRale fan flattening out does not help. Have not made the box yet.

Ducking is ugly and is more clutter in the engine compartment. For front brakes is a different story.
 
65beam

65beam

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hole

duke,
you need to go to the TE/AE site and read up on tiger tom's testing.
 
Bryan

Bryan

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just put some T-28 cowl flaps- you should really be flying now---
 
TigerBlue

TigerBlue

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What

Fix something that needs fixin. If the temps are within the normal range? In your inviornment? Find another project that needs fixing.

Rick
 
cobrakidz

cobrakidz

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My temps are good so I still have not covered the holes---but I can sure tell how much air goes through them when I put a fan in front of the car in the garage--surprising.:eek:
 
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Duke Mk1a

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ramseyt said:
Does anyone sell those horn hole covers or is everyone just making their own?
Click to expand...

Yep - piece of cake. Get a sheet of .025 aluminum from your local Ace Hardware, make a template with cardboard, transfer to aluminum, cut - bend - drill, paint and then install.

008-4.jpg

001-40.jpg

Made these yesterday as my old ones would not work with the new Hella horns. Took a couple of beers and an hour or so.


TigerBlue said:
Fix something that needs fixin. If the temps are within the normal range? In your inviornment? Find another project that needs fixing.

Rick
Click to expand...

When I drove to Canada in July and the FAT was in the high 90's, I had an issue with my AFR going rich. I figured it was due to sucking super hot air into the carb. Been meaning to build a cold air box for the top of the carb that will seal with the air scoop. This is just another idea I have to get cooler air into the engine compartment at speed.
 
X

XTIGERX

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Duke: If you think the spring flap door at speed is a solution if you were to make and mount as you've shown with thiner material your cover would spring open as speed increases and close again as you slow down.

ramseyt: There is a template with simple instructions in my "Special Parts" album pics in my profile.
 
R

ramseyt

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Thanks! I just saw three great ideas!

I've been struggling with the lack of a cup holder. Who sells the water valve? It looks close to the correct one and I like it tucked away with the heater core.
 
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cadreamn67

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608
From the peanut gallery

Duke,

I think your idea would be particularly good in conjunction with a cold air box incorporating the front scoop.

As we all know, the LAT hood is designed to bring in cool air and direct it over the exhaust manifolds and it exits at the two rear ports. If you steal the air coming in the front scoop for the carb, it seems you could replace it somewhat at least with the air coming in from the horn holes.

Gene
 
M

Moondoggie

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Duke,

I assume you are using the high volume Edelbrock water pump ??? I used to
have heating issues and installed the horn vent blocking plates but since then
in the new motor build I went with the high volume pump and that eliminated
the blocking plates. Another neat feature of Dale's front end is it allows for bigger diameter fan since the rack is not in the way. The Kirkham brothers make a slick turkey pan for their Cobras (see picture) when the dust settles
this winter I may have them make a Tpan to fit my Tiger...just need to spend
some time getting the demensions together.

Moondoggie
 
D

Duke Mk1a

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Moondoggie said:
I assume you are using the high volume Edelbrock water pump ??? ........The Kirkham brothers make a slick turkey pan for their Cobras
Click to expand...

The article on Tiger cooling did tests and determined that the HV pump did not help with cooling but hurt. The water was not spending enough time in the radiator to be cooled properly.

I looked into the turkey pan but am leaning away from it due to difficulty adjusting carb and amount of space it takes up....also, still have to fab something so it seals with the hood. I really do like the ability to keep the whole carb to include fuel manifold cool with it though.
 
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cadreamn67

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608
FWIW

Duke,

Like you, I have read that cooling article several times. I think the difference between that article and the success reported by others with the Edelbrock high volume pump is that the Edelbrock was not available and part of the tests done at the time. It could also be that their interpretation of why the ones tested had a negative impact was incorrect.

There was a nice article done for the CAT Tales newsletter by Tim Ronak a year or so ago (time flies) in which he also installed this pump for another club member. Along with being sure a lot of the air gaps around the radiator were sealed, the results turned out quite successful. In the article he discusses some of the features of the pump. As I recall, one of the advertised features is that it balances the water flow between each cylinder bank. Maybe that is enough of a difference along with its low cavitation design to help differentiate it from the HV pumps tested in that article. Anyway, Moondoggie and that CAT Tales article at two real life examples of it apparently making a very positive difference. This is going to be my next improvement try next year if I can ever get my new motor installed and it runs hot even with my Griffin radiator.

Gene
 
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