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Old 20th March 2013, 11:43   #46
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Default Re: Hood Vents - Do they work in lowering temperature?

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Originally Posted by starter View Post
Hey Adi,
Strange, but that is exactly the problem i've faced with my Gypsy too.
I initially thought that it is some grounding issue. But it isn't.
Does this mean that, due to the lights on, the load from the alternator leads to the temp increase?
Cheers,
Deepak
Going OT but...
No Deepak. It was an electrical issue in my case as the temp-needle would drop down immediately on switching off the lights. If it was the alternator load, the temperature needle wouldn't drop immediately. Check what happens in your case.

Cheers,
Adi
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Old 20th March 2013, 14:20   #47
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Default Re: Hood Vents - Do they work in lowering temperature?

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Originally Posted by Tejas@perioimpl View Post
Why does it have openings at the firewall? My jeeps are sealed as tight as possible at the firewall. Why let warm engine air invade the cabin?
Hi Tejas, Sorry, I did not mean the firewall itself. As I have written, I was pointing out to the area/space available near the firewall. ie, from the engine to the firewall.
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Lol. But never do that even as a joke. The bonnet provides a lot of protection to the engine bay from rain, debris, etc.
Yeah, right!
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OT: Btw, how will removing the bonnet make the ride harsh?
I mean, remove the bonnet, and drive harshly.. so that the engine overheats!

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..........Have a feeling the habit of setting fuel pumps for "Maximum Mileage" is one of the major contributing factors to overheating here in India......Would like to know if any have altered settings and noticed any difference......
Hi gthang, even I have heard that overfueling leads to cooler combustion temps and underfuelling leads to hotter combustion temps.

However: What I have noticed in the XD3P/XDP 4.9 engines, is quite the opposite!

Effects of setting pump for max mileage: (1) two-three cranks with glow plugs needed for a start. (2) Less power, (3) Less temperature (4) Engine idles harsh.

Effects of setting pump for OTR events (2) Single crank start without glow plugs. (2) More power. (3) High temperature (4) Engine's a lil smoother.

P.S - I have absolutely no idea why this is happening as I have not personally done the same in my Jeep. This is just an observation and might be vehicle dependent too.
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Originally Posted by AVR View Post
I realized that if I switch off the headlights the temp needle would fall back to the 85-90 range . Unfortunately, this thread won't solve that problem!
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I initially thought that it is some grounding issue. But it isn't.
Sir, this IS infact a grounding issue. Try wiring one of the guages that shows this problem directly from the battery. It should disappear.
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Old 20th March 2013, 15:21   #48
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Default Re: Hood Vents - Do they work in lowering temperature?

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Originally Posted by dhanushs View Post
Sir, this IS infact a grounding issue. Try wiring one of the guages that shows this problem directly from the battery. It should disappear.
Hey Dhanush,
You are right, if the behaviour is as mentioned by Adi.
In my case however, the temperature guage is not dropping back to normal levels when i have the lights switched off.
Cheers,
Deepak
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Old 20th March 2013, 16:36   #49
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Default Re: Hood Vents - Do they work in lowering temperature?

over fueling causes higher EGT in diesels.. while in petrols, it drops temperature
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Old 21st March 2013, 10:52   #50
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Default Re: Hood Vents - Do they work in lowering temperature?

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Originally Posted by dhanushs View Post
Hi gthang, even I have heard that overfueling leads to cooler combustion temps and underfuelling leads to hotter combustion temps.

However: What I have noticed in the XD3P/XDP 4.9 engines, is quite the opposite!


P.S - I have absolutely no idea why this is happening as I have not personally done the same in my Jeep. This is just an observation and might be vehicle dependent too.
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over fueling causes higher EGT in diesels.. while in petrols, it drops temperature
Thanks for that information.

Diesel's preference to run lean was known, but did not know that running lean keeps it cool as well. Always assumed the opposite!!

Guess my assumption of "Max Mileage" was wrong!! But I'm guessing there should be a happy medium between mileage and power which should keep it going under all circumstances.

Cheers
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Old 22nd March 2013, 15:08   #51
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Default Re: Hood Vents - Do they work in lowering temperature?

What if an exhaust fan (electrically driven) is mounted near the vent to drive out hot air? it could be internal in the hood and drive out air (something like the CPU unit fan in a desktop computer). This way RAM air is not needed at low speeds during mud plugging or rock crawling. Also if the exhaust fan is controlled via a switch in the cabin, once the speeds exceed 40-50kmph and RAM air is in effect, the fan can be switched off...
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Old 22nd March 2013, 15:45   #52
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Default Re: Hood Vents - Do they work in lowering temperature?

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What if an exhaust fan (electrically driven) is mounted near the vent to drive out hot air? it could be internal in the hood and drive out air (something like the CPU unit fan in a desktop computer). This way RAM air is not needed at low speeds during mud plugging or rock crawling. Also if the exhaust fan is controlled via a switch in the cabin, once the speeds exceed 40-50kmph and RAM air is in effect, the fan can be switched off...
The biggest issue with this is actually switching it on and off appropriately. What happens if you leave it on full time or if you forget to switch it on at all
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Old 22nd March 2013, 15:49   #53
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Default Re: Hood Vents - Do they work in lowering temperature?

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What if an exhaust fan (electrically driven) is mounted near the vent to drive out hot air? it could be internal in the hood and drive out air (something like the CPU unit fan in a desktop computer). This way RAM air is not needed at low speeds during mud plugging or rock crawling. Also if the exhaust fan is controlled via a switch in the cabin, once the speeds exceed 40-50kmph and RAM air is in effect, the fan can be switched off...
Interesting concept. One consideration. Electrical fans take quite a bit of power. So adding a fan that really moves a good amount of air is really going to put a noticeable load on the electrical system and thus the engine. A good size fan could easily draw upwards of 5HP. So in order to bring in cool air, or per your suggestion extract hot air, you are actually increasing the loading on the engine as well. In this case via the electrical system.

On some cars it might work, on others it will not. On the older Alfa Romeo Spider this was a known problem. Cars equipped with AC had an additional electric fan to work in parallel with the engine belt driven standard fan. The electrical fan would kick in trough a temperature sensor. Somehow they did not get the dimensioning correct. Because when the electric fan kicked in the engine very quickly started overheating.

So really need to dimension this carefully, because the nett effect might be little or worse negative.

Little anorak fact: On my old VW beetle I had an electrical clutch installed on the engine fan. As you probably know the original beetle engines were air cooled and the engine drove a huge fan that took some 10-12% of the engine power. These were not particularly powerfull engine to start with.

With a little switch you could disengage the fan from the engine. That meant it did not get any cooling, but you did get 10-12 extra HP. So you shouldn't disengage for too long. But it was great for a bit of acceleration boost.

I don't know but maybe offroad enthusiast know whether they use this technique as well. If you're stuck in the mud, you could use extra HP for 5-7 seconds.

Jeroen

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Old 22nd March 2013, 16:09   #54
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Default Re: Hood Vents - Do they work in lowering temperature?

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The biggest issue with this is actually switching it on and off appropriately. What happens if you leave it on full time or if you forget to switch it on at all
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Originally Posted by Jeroen View Post
Interesting concept. One consideration. Electrical fans take quite a bit of power. So adding a fan that really moves a good amount of air is really going to put a noticeable load on the electrical system and thus the engine. A good size fan could easily draw upwards of 5HP. So in order to bring in cool air, or per your suggestion extract hot air, you are actually increasing the loading on the engine as well. In this case via the electrical system.
Jeroen
Pganapathy: leaving the fan on might not be a big issue, if it is wired with the ignition. At max removing the keys will stop the fan running. Or a temperature sensor can automatically start/stop the fan based on engine temperature, or a speed sensor can stop the fan when RAM air is in effect. There are many solutions possible.

Jeroen: interesting observation regarding the Beetle fan, instant bhp when needed.
Using a centrifugual fan http://en.wikipedia.org/wiki/Centrifugal_fan one can reduce the size of the fan, and mostly the power requirements. Remember this fan is not used to cool the engine, it is used to vent out excess hot air inside the engine bay. The radiator still cools the engine, this is a supplementary system to remove hot air.
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Old 22nd March 2013, 21:47   #55
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Default Re: Hood Vents - Do they work in lowering temperature?

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Lets ask experts on board ( BHP ) , I know few people will certainly know & help , Arka ,Sutripta Da , SS Da , Ken , DB Sir ??
Come back and see this thread. And someone asks for me by name! So here goes, my top of the head thoughts:
A) Will look cool. Or weird. Or wacky. All these lie in the eye of the beholder.
B) Will have no effect on the engines running temperature.
C) If intelligently done, might have a very slight beneficial effect on
1) Vapour Lock problems. (Petrols only)
2) Might (pure speculation on my part) slightly extend life of alternator electronics.

Regards
Sutripta
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Old 22nd March 2013, 21:56   #56
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Default Re: Hood Vents - Do they work in lowering temperature?

Doesn't this Jeep use a similar engine? are they overheating too? How do they deal with it?
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Old 22nd March 2013, 22:30   #57
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Default Re: Hood Vents - Do they work in lowering temperature?

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Doesn't this Jeep use a similar engine? are they overheating too? How do they deal with it?
A: Most of these are 'dee-ayi eenjin' sir. They are tractor derived engines, which are very crude, less rpm, very low NVH, BUT very rugged. I'm yet to hear a Di overheat, unless the cooling system is messed with.

Also, 'I' think, most of the off-road engines overheat, when we revv it to the max to extract whatever they can give in those inclines, OTR events, and of course slush....

Last edited by dhanushs : 22nd March 2013 at 22:33.
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Old 22nd March 2013, 22:56   #58
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Default Re: Hood Vents - Do they work in lowering temperature?

Maybe but look at the number of people its pulling !!!

DI -> non-DI is not 500% difference is engine efficiency is it?

Do they use the same radiator?

Last edited by Mpower : 26th March 2013 at 07:51.
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Old 22nd March 2013, 23:29   #59
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Default Re: Hood Vents - Do they work in lowering temperature?

Mpower has raised a very valid question.

Somehow, I do not buy this idea of Peugeot engines overheating. At our R&D centre, we had a XD3P Bolero which was used to visit vendors located all around Maharashtra. It was literally r**ed by all and sundry, including me. It ran AC on full blast mode, had 4.88 ratio, went like a rocket, was a 2WD, top end was poor though. The manner in which it came up the Kasara ghats would put most new cars to shame. It was not cared either, just regular service like oil change and brake checkups, nothing else.

I had sometimes seen the temperature reading hover slightly above the normal temperature mark. That's it. It had no other mods done on it, only thing is, the guy who had overseen the build, knew what he was doing. Everything was from Bolero parts bin. It never overheated.

Spike
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Old 23rd March 2013, 08:26   #60
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Originally Posted by dhanushs View Post
A: Most of these are 'dee-ayi eenjin' sir. They are tractor derived engines, which are very crude, less rpm, very low NVH, BUT very rugged. I'm yet to hear a Di overheat, unless the cooling system is messed with.
Dhanushs Sir , Peugeot ( locally called as pizots ) were there since ages . The first one , the 2112 cc was on many models .If I am not wrong they are here for nearly 30 ( 28 ?? ) years . The Jeeps were mostly used by the village people ,the village Taxi & all kinds of stuff . These were in long chassis commander ,NC ,Armada ,540 & what not .All these vehicles were used by drivers who were less informed than the educated class like us ( thats what the assumption about them is )

BUT these people exactly knew how to treat engines . Oil & water checks were mandatory every day , at least they checked water levels every day & they always inspected the water levels frequently .

In short they knew about their engine's tendencies & lived with it .


Quote:
Also, 'I' think, most of the off-road engines overheat, when we revv it to the max to extract whatever they can give in those inclines, OTR events, and of course slush....
So whats wrong with the 4x4 Jeeps in particular ? Nothing .

we need to take care of the water-oil levels more frequently if the 4x4 load is more .

BTW , how many times you see people doing it at a Lunch Break in a OTR ??

Hood wood / vent bent== is just killing symptoms , our habits need to change IMO

But yes such accessories Look KOOL

Sudarshan

Last edited by Sudarshan : 23rd March 2013 at 08:35.
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