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a cooling idea thats brewing and needs a little input

Ben_Dyer

NAXJA Forum User
Location
Sterling
after my last horrable idea for a gas tank skid i hope this one has a little bit more ground to stand on.....


ok so after seeing Yellaheeps jeep in Moab. I wanted to do something similar to his boat vents on the side. i am wanting to do a pair of them one on each fender, using something like these vents....
whit-vent-louvered_5682fd453e05351e55d54cc674f894f2.jpg

I then had a spark of an idea to maybe add a blower to force air out of the engine bay using something like this little guy here.....
attw-bl0wer-3000-wht_0f8306f3781d8c6bcd16278745b4b050.jpg


a guy could create a cross breeze using two blowers one for intake and one for exhaust. throw these guys on a switch or dual switches and you could flip them on while wheeling for added air flow and cooling. or maybe toss a blower after a cone style filter for a forced air intake setup right in the engine bay or connect it to the vent for forced cold air intake.

thoughts, comments? i know this would help with cooling but would it have potential to cool too much?
 
Try it and let us know how it works. Those bilge blowers can be kind of loud, but other than that it should work out.
As far as the forced induction goes, don't use it for that. Most of those blowers have a less than spectacular durability and could come apart and leave debris in your engine.
 
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just another thought also.... an inspection hatch could be installed in the rear for easy fuel pump access should the need arise....
 
after my last horrable idea for a gas tank skid i hope this one has a little bit more ground to stand on.....

ok so after seeing Yellaheeps jeep in Moab. I wanted to do something similar to his boat vents on the side. i am wanting to do a pair of them one on each fender, using something like these vents....

Im liking the idea .... Guard vents will be much more practical than bonnet vents ;)

Knowing that a raised hood with padding / insulation in the firewall gap, at the centre rear of the hood, vents hot air at slow speeds and high speeds from the rear corners .......

I bought a couple of these a good while back, to put in the fenders .....

http://www.whitworths.com.au/main_itemdetail.asp?item=92320&search123=vent&intAbsolutePage=3

http://www.whitworths.com.au/main_itemdetail.asp?item=92313&search123=vent&intAbsolutePage=1

Idea was to remove brake booster and aircon/charcoal cannisters and holesaw through the panels as far back and as high up as possible.

Havent found a tidy way of getting through all the panel work yet .... but still hacking up the spare body shell for practice ... :laugh:

Decided on the smaller ones - as the ones in your pic need a lot of mounting space for the backing plate with the hose connections ....
.......................and I like "discreet" mods .... ;)

For the time being, and until I have enough parts and panels removed because of some other repair ... Im just running the raised hood with packing across the centre ... which provides the same effect as vents in the fenders .... Have engine bay / ambient comparison temps available if your interested.

Wouldnt mind seeing some close up pics of that Yellaheeps jeep fender vents tho ... to see what he did and how.

I then had a spark of an idea to maybe add a blower to force air out of the engine bay using something like this little guy here.....

a guy could create a cross breeze using two blowers one for intake and one for exhaust. throw these guys on a switch or dual switches and you could flip them on while wheeling for added air flow and cooling. or maybe toss a blower after a cone style filter for a forced air intake setup right in the engine bay or connect it to the vent for forced cold air intake.

thoughts, comments? i know this would help with cooling but would it have potential to cool too much?

The thinking is right but I figured there would be issues with too much additional air.

A lot of the slow speed overheating issues can be attributed to a lack of air flow through the radiator. The lack of air flow is not just the poor fan setup but a lack of escape routes for the radiator air intake ...

i.e. It cant get down the tranny tunnel quick enough. Common fix for that of course ... is chop holes in the hood :rolleyes:

Pump in additional air and it is competing for the same engine bay space the radiator airflow is .... and likely to slow/affect radiator airflow ... especially if the fans CFM is low.

Tis why I smile at XJ induction bonnets ..... vent nicely at slow speeds ... and then pump in back pressures at speeds over 20mph .... which probably means .... a need for a great big taurus fan, as compensation. ;)

My thoughts on using the bilge blower pump in your post, was to place angled cuts in a piece of poly pipe between the blower pump and the outlet aimed at the tranny tunnel / or fender vents .... The slot angle would allow the vent tube internal air to flow past the slots - but would draw engine bay air into the tube.

After making some phone calls ... I then found the blower pump is not designed for constant operation .... Its only intended for a short operating period to vent built up bilge fuel fumes in a bilge prior to starting the boat engine.

There are other blower pumps out there ... but they get big and bulky compared to the handy size of the one you showed.

Since I have melted a couple of smaller fans I trialled using as puller fans for engine bay vents ... I wouldnt recommend the "puller" method ... :laugh:

Have been thinking about the factory fan shroud and putting a hose on the lower section of it to push some air around the top of the motor .... The shape of the shroud is so pathetic its actually restrictive compared to a proper cone shaped shroud ... so a hole in it, behind the fan, would probably be a good thing ...

Will keep an eye on your thread ... Might find just the info I'm looking for on this one.

:cheers:
 
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here is a link to his mods page. the first article is the one where he installed a single vent to replace the snorkle and has some good shots.
http://www.naxja.org/forum/showthread.php?t=1006537&highlight=snorkle

personally i think the vents i am thinking of using look a lot less like dryer vents and have the same look as hood style vents. i have also been able to find a few that only require a hole cut similarly to a snorkle set up.

i am unsure as to how far back and or forward i want to mount them. i am in the range of as far back as 1 inch from the back of the panel and as far forward as seven inches from the back of the panel. it would depend on the mounting location of the blower, as to where the holes could be cut.

you will have to share your secrets on cutting the body panel as i have never done such a thing.

i also was making a few phone calls, only to find something along the lines of what you said that bilge fans are not designed for constant duty. though it was suggested that a ventilation fan or heavy duty blower for cabins and engine bays would work much better as they can withstand much longer pulls and temps.

at the bottom of this page is an info box that gives some info close to what i was recieving...
http://www.marineengine.com/product...gine.com/products/jabsco-rule-pumps/index.htm

i was thinking of installing one of these (depending on price and fit)
http://www.jabsco.com/files/section_4_ventilation_blowers_07.pdf.pdf
directly next to the brake booster, or do a cone style filter and mount it farther forward where the old air box would have be. then do a custom washer bottle setup (mine is not there) to relocate the bottle. I think they would be able to handle blowing air out at low speeds like in rock crawling.

Are you refering to puller as sending air out or in? if you mean in i agree that it would not work very well. however if you mean to force air out i think it would work just fine and have to disagree.

just did a search on ebay and they can be had for around $100-$200.
 
I think that by the time you get everything wired up the extra draw on the alternator will be enough to cause it to run more and negate any advantage.


And that fan will never produce enough for a forced induction, I am willing to bet that at WOT your intake could pull air faster than that thing could push it. If electric blowers were an easy cheap solution they would be OEM.
 
After making some phone calls ... I then found the blower pump is not designed for constant operation .... Its only intended for a short operating period to vent built up bilge fuel fumes in a bilge prior to starting the boat engine.:cheers:

That is true but you are also supposed to have the blower running when the engine is running and the boat is below cruising speeds (not planing).
 
here is a link to his mods page. the first article is the one where he installed a single vent to replace the snorkle and has some good shots.

Thanks for that .... shame he was restricted by having to cover the snorkle hole .... Not a bad look on completion tho ....


i am unsure as to how far back and or forward i want to mount them. i am in the range of as far back as 1 inch from the back of the panel and as far forward as seven inches from the back of the panel. it would depend on the mounting location of the blower, as to where the holes could be cut.

When you open the bonnet and start to measure stuff ... you will find the engine bay stops well short of the rear of the fender ... When you get the outer fender skin off you will find lots of folded panels, that are part of the structural strength of the vehicle ..... some of those folds are the ones needed to be cut to get a snorkle fitted ... Im trying to avoid cutting those ... ;)

IMHO the XJ venting requirement is to release the trapped hot air lingering around the brake booster etc. The hot air above the engine will always be there ... as the engine is always generating it.

If you create a draft thru the stagnant areas under the bonnet, engine bay temps will be better, under all driving conditions ... just a matter of choosing a vent style that takes your fancy ... and mounting it somewhere beneficial.

I've proved it on my XJ's, ... Just by having 1/2" spacers on the bonnet and blocking the gap at the centre rear of the bonnet. Its something a lot of us have done on 70series toyotas in the past, especially after fitting aftermarket turbos. Just raising the bonnet on those caused coolant temp issues at highway speeds ... that we could only attribute to the induction effect.

The fender vents will look a lot better than my "badly fitted bonnet" tho :eek: ... :laugh: ......

Hood vents located as close as possible to the rear corners of the hood, will also be effective .... All just a matter of sticking some short lengths of wool on the body panels and seeing what happens to them at various speeds .... and doing it again after chopping any holes to note the variations.

If the wool telltails dont stream to the rear or sides of the vehicle, at all speeds, then that is not a good location for a vent. e.g. ..... telltails that stand vertical or flick back and forth, are in turbulent areas not ideal for siting a vent.

For slow speed operation with my bonnet arrangement ... A properly working XJ fanclutch and the e-fan provides enough CFM to make a difference - but theres no harm in improving fan CFM with something "proven" to be better.

Having done the maths .... I dont think the blower / pusher fan is a better arrangement as it is competition to the air drawn thru the radiator .... hence my thoughts that just boosting / maintaining quality radiator airflow is more beneficial.

Drawing / pulling air out of the engine bay would be effective but is fan motor quality dependant, for operational life ... and have yet to find a solution to that issue. Its not that important to me at the moment anyway ... as my current setup is fine.


you will have to share your secrets on cutting the body panel as i have never done such a thing.

heh heh .......... 4" discs, holesaws, air nibbler tool, tin snips, the grace of god .... and lots of silicon / body putty .... :laugh:


i also was making a few phone calls, only to find something along the lines of what you said that bilge fans are not designed for constant duty. though it was suggested that a ventilation fan or heavy duty blower for cabins and engine bays would work much better as they can withstand much longer pulls and temps.

The fans in your links are similiar to alternatives I looked ... Just a matter of finding the space to fit them.


Are you refering to puller as sending air out or in? if you mean in i agree that it would not work very well. however if you mean to force air out i think it would work just fine and have to disagree.

Dont suck the engine bay air thru a cheap fan to a vent .... They dont like the heat ... must dry the bearing grease out quickly or something.


That is true but you are also supposed to have the blower running when the engine is running and the boat is below cruising speeds (not planing).

Ahhhh .... that makes sense for an engine in a bilge .... bit like needing the e-fan on when crawlin in the XJ then ....

Marine accessory counter sales staff obviously have as little idea about product info these days, as what most auto parts stores staff do .... :banghead:


:cheers:
 
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i guess some vital info on my rig would be to point out that i do have a cowl hood that is functional....

ill drop the fan idea as it appears to have way more cons than first thought.

When you open the bonnet and start to measure stuff ... you will find the engine bay stops well short of the rear of the fender.

this is very true and i realised this after i went out and actually compared measurments from the engine bay to the exterior of the fender. i think it would be best to cut out as much as you can with out cutting threw the folded panels. im in the process of finding the vent i like the most and trying to fit it with out actually having it in my hands to make sure i like the placement and size before i order.

i think i am going to go with this style vent....
http://www.boating.com/boat-store/whit-vent-louvered.html
they are cheap and platic so if i brake one i wont be pissed.

would these vents be more beneficial facing forward or towards the rear? at speed you would get a forced air effect with them forward. would this forced air cause a jaming effect for the air in the bay?

facing the rear would it allow for a suction to occur as air passes past the vent at speed and also allowing the air to vent freely as the rad fans suck it in at slower speeds?

to me facing the rear would be better......

i wish i could find the pic of that jeep a company did that was all grey and had vents on the sides. so i could drop them some questions.....
 
Ahhhh .... that makes sense for an engine in a bilge .... bit like needing the e-fan on when crawlin in the XJ then ....
:cheers:

No, not exactly. Boat engines are cooled by the water that they are floating in, the purpose of the bilge blower is because there is not adequate ventilation for fuel vapors unless the boat is cruising. It's purpose is NOT to provide cooling air or air for the engine.
 
not really a need i just liked the look of Yellaheeps vent and wanted to copy him lol. and i figure why not make them actually do something
 
No, not exactly. Boat engines are cooled by the water that they are floating in, the purpose of the bilge blower is because there is not adequate ventilation for fuel vapors unless the boat is cruising. It's purpose is NOT to provide cooling air or air for the engine.

heh heh ... bit of confusion ... sorry about that ...

I wasnt suggesting the e-fan in its capacity as part of a cooling procedure ..... but it in its role as part of a venting procedure in the XJ at slow speeds.


not really a need i just liked the look of Yellaheeps vent and wanted to copy him lol. and i figure why not make them actually do something

Welllll ... in that case ... just bang em in. :)

I would have them extracting air rather than forcing more in from another direction ... but thats me ;)
 
would these vents be more beneficial facing forward or towards the rear? at speed you would get a forced air effect with them forward. would this forced air cause a jaming effect for the air in the bay?

facing the rear would it allow for a suction to occur as air passes past the vent at speed and also allowing the air to vent freely as the rad fans suck it in at slower speeds?

You will never achieve a "forced air effect" from any sort of vent like that until you begin to reach speed approaching that of the speed of sound. Think of it as trying to Force more water into a bucket with a garden hose, you can turn the hose up full blast but once it is full you will never get any more in with the given equipment.

rear facing would be better, it really does not matter though.
 
If you are trying to keep the motor cooler, you would be money ahead to put a fan in front of the radiator to increase cooling. Remember that a cooler engine is not necessarily a more efficienct engine, hence the need for a thermostat.
 
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