Would my dual snorkel scoop be affecting my cooling at highway speed?

[famous bob]

The fan blade should be 2/3 into the shroud, I don't think distance from radiator matters as much as the fan position/location??

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agree w / this . I have never seen an unsealed scoop that didn`t affect the in coming air flow, but have seen a few cars that it didn`t hurt real bad. Usually shows up on the hi way, overheating.

 

[Clelan]

I have Thursday and Friday to work on this so I hope to have some answers after that.

Cley

 

[Clelan]

No answers after the weekend. I might as well have pissed up a rope as done what I did. I need some car time!

Cley

 

[Clelan]

I finally got around to testing this. No changes to the motor at all for this test. 30* C day and I took a 40 mile cruise with the AC on high. Temp hit 210 and was confirmed by my IR temp gun. I taped off the openings in the dual snorkel hood and drove the same 40 miles home at the same speed with the AC on. I saw a 25* drop in operating temp and the AC was noticeably colder on the trip home. The unsealed scoop definitely has a negative affect on airflow through the Rad.

Cley

 

[Treblig]

I finally got around to testing this. No changes to the motor at all for this test. 30* C day and I took a 40 mile cruise with the AC on high. Temp hit 210 and was confirmed by my IR temp gun. I taped off the openings in the dual snorkel hood and drove the same 40 miles home at the same speed with the AC on. I saw a 25* drop in operating temp and the AC was noticeably colder on the trip home. The unsealed scoop definitely has a negative affect on airflow through the Rad.

Cley

It would only make sense!! The amount of air that passes through the radiator is determined by a pressure differential, that is to say that the more pressure you have in front of the radiator and the less pressure you have behind the radiator will determine how much air actually passes through the radiator fins. So if you have these scoops pushing air into the engine bay it creates pressure that interferes with the air that's trying to pass from the front of the radiator into the engine bay/??? That may be why Mopar "factory" hood scoops were always sealed off from the engine bay??

treblig

 

[Clelan]

I guess so! I always thought the air would flow out the bottom of the car toward the back, but I guess I proved that wrong. Now I just need to build a block off plate of some kind.

Cley

 

[TF360]

Yea, but the Dusters came with the Dual Snorkel scoop from the factory unsealed. Do you have the two 4 inch holes cut out in the back of the scoop, or do you have the triangle part cut out?

 

[Clelan]

I have the triangle cut out.

Cley

 

[Treblig]

Yea, but the Dusters came with the Dual Snorkel scoop from the factory unsealed. Do you have the two 4 inch holes cut out in the back of the scoop, or do you have the triangle part cut out?

The open scoop concept might work just fine on a factory /6 or 318 but this guy has a 360 that probably produces more power and heat!!

Treblig

 

[TF360]

I hear you Treblig. They came from the factory on the 340 cars. Two four inch holes cut out at the back of the scoop

 

[Treblig]

I hear you Treblig. They came from the factory on the 340 cars. Two four inch holes cut out at the back of the scoop

During a rainstorm how did the factory set-up keep water from getting all over the engine and electronics as you drove down the road?? Just wondering.

Treblig

 

[AJ/FormS]

During a rainstorm how did the factory set-up keep water from getting all over the engine and electronics as you drove down the road?? Just wondering.

Treblig

What a great question! I drove a 70 Swinger340 from fall of 70 to spring of 75, and that thought never occurred to me. 'course I was a DA kid at 17 when I got it.

 

[mderoy340]

During a rainstorm how did the factory set-up keep water from getting all over the engine and electronics as you drove down the road?? Just wondering.

Treblig

They didn't do much. The two rubber boots have a raised lip.

 

[Jimacuda]

I finally got around to testing this. No changes to the motor at all for this test. 30* C day and I took a 40 mile cruise with the AC on high. Temp hit 210 and was confirmed by my IR temp gun. I taped off the openings in the dual snorkel hood and drove the same 40 miles home at the same speed with the AC on. I saw a 25* drop in operating temp and the AC was noticeably colder on the trip home. The unsealed scoop definitely has a negative affect on airflow through the Rad.

Cley

Excellent, awesome.

air entering the engine bay thru the unconnected scoop displaces air that SHOULD be entering the engine bay thru the radiator.
Less air equals less cooling ability.

Physics still rules.

 

[famous bob]

Block off the scoop opening and take it for a ride. Question answered.

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[Clelan]

Well, let's see what this does for me. It took a while but I am finally going to give this a try. It's a stainless bowl attached to the bottom of my air cleaner. I cut a foam gasket for the top and I think it should be good. Ill report back on how it works in a while.

Cley

 

[oldkimmer]

I can say that whatever scoop/scoops i had on any of my cars not 1 of them ever ran hot. I never had 1 with a/c though. I know a/c can make a big difference on the airflow that passes thru the rad. Have u added a chin spoiler? They help huge. Kim

 

[Clelan]

I'd like to add a chin spoiler but have not done it yet.

Cley

 

[Jimacuda]

Nice work Cley...
Nothing like prototyping with an eye to what's in front of you for "raw materials"!
Always makes me feel better about my (very slight) hoarding tendencies

 

[crackedback]

Nice work and this is a COMMON issue with hood scoops that open to the engine compartment.

You are packing air into the compartment that fights the air coming in from the grille.

 

[krazykuda]

The fan blade should be 2/3 into the shroud, I don't think distance from radiator matters as much as the fan position/location??

treblig

Mine is about 1/2 to 2/3 into the shroud if I remember. I'll check that.

Cley

A good starting point for fan to shroud overlap is half of the fan should be inside the shroud and half outside...

 

[krazykuda]

last Friday at the strip, it was started, stopped and idled between my 10 passes with no AC on for a few hours and the temp never topped 160*F. In traffic with the AC on, it does not go past 180*F. On the highway with the AC running 70ish MPH at 2000 rpm the temp goes just past 200*F and drops back to 180 once you are back in traffic.

From these symptoms, I would suspect that your radiator is not sealed to the radiator support and air is going AROUND the radiator and not THROUGH it... Especially since it's happening at highway speeds and not in traffic....

Make sure that the radiator is sealed to the radiator support... You can put some of that adhesive strip foam in there to block any air gaps... This way all the air going in the radiator opening will come through the radiator and not around it....

 

[Jimacuda]

From these symptoms, I would suspect that your radiator is not sealed to the radiator support and air is going AROUND the radiator and not THROUGH it... Especially since it's happening at highway speeds and not in traffic....

No, it was an open scoop issue

 

[Clelan]

I will seal up the rad support as best as I can, but I am sure it was the open scoop that was the problem. As mentioned before, I taped off the scoop and the problem went away.

Cley