mot said:
A mate has some 1/2" spacers fitted to her Turbo Diesel Nissan GQ Patrol ute bonnet hinges. I don't if it helps with the cooling or not but it looks tuff on the Patrol. I reckon it would look ghey on an 80 but.
An idea for added airflow in 1FZ engine
- Thread starter Romer
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A mate has some 1/2" spacers fitted to her Turbo Diesel Nissan GQ Patrol ute bonnet hinges. I don't if it helps with the cooling or not but it looks tuff on the Patrol. I reckon it would look ghey on an 80 but.
Romer said:
Ken:
A lot of opinions on airflow here, but my concern would be heat, not airflow yet (unless you are trying to clear the way towards hood vents). Airflow is related to heat management, but unless you have done something to add airflow, then it's just heat management.
Right now, we know airflow exits our 80's 'down', and by definition the battery box is 'up'. Just from the pictures you posted, moving the battery exposed more airbox surface area to radiator fan heat. That would indicate to me that your intake air temps will be higher than they were before. A temp measure of that postulation would be a better confirmation.
Ken, I would propose trying to identify the low pressure zone on the PS of the truck. Then take the mods necessary to clear the way to the low pressure zone/s. Or create the low pressure zone and clear the way to them (vents). Clearing the way for more heat at the airbox seems backwards to me.
It might also be interesting to compare the battery rotation to putting a heat shield from the stock location around the DS of the airbox. This 'directs' whatever airflow there is around the airbox toward the exhaust manifold, and then hopefully, down and out. Less than ideal, but water crossings shouldn't be affected this way...
Scott Justusson
94 FZJ80 Supercharged
Romer,
I would be concerned that w/ the tray open now, it will be easy for mud/dirt/splash to get to your 2nd battery. Also, it blocked heat from your battery too I bet.
Even stock, the tray doesn't block the radiator so I think you are ok.
Just from thinking about heat issues, improving radiator performance & evacuating underhood heat - can only be done by putting holes in strategic locations and/or forcibly moving air w/fans. moving stuff under the hood doesn't do anything, imo.
Also, is it really an issue or just a maintence issue or not at all?
Just my thoughts. I don't like to see you become a guniea pig at the cost of all your nice parts...
I would be concerned that w/ the tray open now, it will be easy for mud/dirt/splash to get to your 2nd battery. Also, it blocked heat from your battery too I bet.
Even stock, the tray doesn't block the radiator so I think you are ok.
Just from thinking about heat issues, improving radiator performance & evacuating underhood heat - can only be done by putting holes in strategic locations and/or forcibly moving air w/fans. moving stuff under the hood doesn't do anything, imo.
Also, is it really an issue or just a maintence issue or not at all?
Just my thoughts. I don't like to see you become a guniea pig at the cost of all your nice parts...
- Thread starter
- #44
I am planning on getting a supercharger. Several people told me that adding the 2nd battery tray will make the under hood temps higher because the second tray blocks the airflow. So, I tried to work that concern. What I am hearing is that the 2nd tray makes it cooler ??
Also, My 40 doesn't have a tray like that, I am not concermned about dirt. I can always add something on the side
Also, My 40 doesn't have a tray like that, I am not concermned about dirt. I can always add something on the side
Romer,
I was saying I thought the 2nd tray makes the battery cooler.
This is the most detailed I've found
http://www.oman4x4.com/hoodvents.htm#theory
The high pressure areas are the nose and base of windshield (why all cars have holes there for air)
At slow speed, the pressure zones are not a factor. attatched are my guess at where the hot zones are under hood borrowing the diagram from above site.
Green arrows suggest airflow going underbody and heat pooling up at the firewall.
At slow speed, I figure the headers are pumping out alot of heat into that empty zone.
Race cars are not, imo, fully applicable since much of a suv's performance is in idle/low speed trail work. That is where you don't want it to overheat, as well as freeway climbs/towing. So it's a mixed bag of controlling radiant heat and underhood air management.
Anyway, rambling a bit... sorry. Part of me questions if there really is a problem... for example, the 3 row rad seems to be a fix for many... or people just dont have a problem.
I was saying I thought the 2nd tray makes the battery cooler.
This is the most detailed I've found
http://www.oman4x4.com/hoodvents.htm#theory
The high pressure areas are the nose and base of windshield (why all cars have holes there for air)
At slow speed, the pressure zones are not a factor. attatched are my guess at where the hot zones are under hood borrowing the diagram from above site.
Green arrows suggest airflow going underbody and heat pooling up at the firewall.
At slow speed, I figure the headers are pumping out alot of heat into that empty zone.
Race cars are not, imo, fully applicable since much of a suv's performance is in idle/low speed trail work. That is where you don't want it to overheat, as well as freeway climbs/towing. So it's a mixed bag of controlling radiant heat and underhood air management.
Anyway, rambling a bit... sorry. Part of me questions if there really is a problem... for example, the 3 row rad seems to be a fix for many... or people just dont have a problem.
FirstToy, Is that your drawing? Hmm…. very impressive, its really good…
- Thread starter
- #49
Thanks james,
I have the third row 94 Rad and I have no cooling issues. I was just trying to optimize things ahead of the TRD. I was told I needed to move the 2nd battery before installing the TRD due to heat issues.
Don't know if thats true now?????
I have the third row 94 Rad and I have no cooling issues. I was just trying to optimize things ahead of the TRD. I was told I needed to move the 2nd battery before installing the TRD due to heat issues.
Don't know if thats true now?????
SUMOTOY said:
how about we.....
electric fan in front of condenser
wrap the exhaust to keep its heat in
insulate / wrap the intake (can, hose, manifold) to keep heat out
vent the hood in a low pressure zone to allow heat out the top
passenger fenderwellectomy to allow heat out the side
run a line from your windshield washer pump to spray water onto the front of the AC condensor / radiator....... or pipe CO2 from your powertank to in front of the radiator for extra cooling
if it still gets too hot then maybe you need to relocate the rear heater from under the passenger seat back to outside the truck where the spare tire used to be and rig it so it runs all the time
after having said all that - Im having trouble remembering..... why are we doing this again?
FirstToy said:
First Toy:
I like the drawings. I also posted up a jeep site that a guy did a lot of work on identifying heat and low pressure zones.
Race cars and trucks are no different. It's airflow. You create the airflow from ram air, or from radiator fans, getting it out is the same principle. Since the 80 has no radiant heat, it's identical, since with an engine fan, by definition you are speaking to convection.
I can share that it's a problem when the underhood temps are higher than the radiator temps. This creates brittle wires, high intake air temps, and trapped convective heat at low vehicle speeds. This is a problem with forcing airflow 'down' to vent it, you need vehicle speed and low pressure zones present to optimize it.
Heat wants to rise, and it will get trapped at the firewall, and create a barrier of high heat. The only real way to solve this is by venting at the hood, or venting out the sides of the fenders (ala rover SC).
Radiant heat from the exhaust will find it's way out a properly vented 80 hood. By definition if you aren't trapping it, it will find it's way out. Superchargers add quite a lot of heat generation under the hood as well, compounded by the fact they are very close to touching the hood itself.
Airflow management is the key here. If the easiest way out is a low pressure zone in the hood, it's a no brainer. Trying to force hot air down under a truck during wheeling sounds and is counter intuitive.
There really aren't downsides to hood vents, other than improper mounting them in a high pressure zone. On the 80 hood, that's gonna be tough to do.
Scott Justusson
yup.Rusty Phillips said:
Not with you. IME exhaust wraps tend to trap heat and moisture, turning mild steel pipe to rotting steel pipe very quickly. Ceramic coat if you want, but I found it does very little compared to heat shields and vents.
yup
yup
I really like this one, there are already ports in the rear of the engine bay for this.
I've used water sprayers on intercoolers for improved efficiency, I suppose that would work, but the duty cycle has to be pretty high. I used to do this for turbo dyno runs (to simulate faster vehicle speeds on the dyno) and found that it takes a lot of water to cool the IC down (similar temps btw as the condenser sees) and it was only good for 1 20 second dyno run, then the temp was right back up there.
Why not just an aux rad under the truck?
Because we want to have cold a/c at idle on hot days? Me, I just look at the underhood temps of an 80, and just can't believe that's 'normal'. It's massive, and it can cause some serious problems. I think going after the radiator fan 'output' is doing the exercise backwards to your good suggestions above.
Scott Justusson
Scott,
I think you misunderstood what I said, as we are saying the same thing.
In stock configuration, the air has only one way to go- down. It goes down or it stays in the engine bay, heating up just under the hood as per my dwgs.
I believe most of the hood is a low pressure area (leading edge & base of windscreen being the high pressure) and airflow "spilling" over the sides.
easy to verify by placing pieces of string on the hood to see how the air flows.
As for this being a problem on a stock 80... I am 50/50 on. This is life under the hood of 99% of production cars & trucks. I think it would help a blown motor-turbos create alot of heat... but not my area of knowledge.
I think you misunderstood what I said, as we are saying the same thing.
In stock configuration, the air has only one way to go- down. It goes down or it stays in the engine bay, heating up just under the hood as per my dwgs.
I believe most of the hood is a low pressure area (leading edge & base of windscreen being the high pressure) and airflow "spilling" over the sides.
easy to verify by placing pieces of string on the hood to see how the air flows.
As for this being a problem on a stock 80... I am 50/50 on. This is life under the hood of 99% of production cars & trucks. I think it would help a blown motor-turbos create alot of heat... but not my area of knowledge.
FirstToy said:
From my post on 2-21-06
http://jeepsunlimited.com/forums/showthread.php?threadid=413088&perpage=20&highlight=cooling&pagenumber=1
Turbos are my area of knowledge, but the principles of heat management and airflow are the same. Landtank and others are going after the radiator fan. I think that's trading off more airflow thru the core, with more heat after the core. Open up the airflow, then measure the gains. I suspect doing nothing else, this will prove to be *the* mod to additioinal 80's cooling. No electric, no silicone fluid, just a sawsall blade and some pontiac parts.
The 80 is known to run cool (too cool IMO) most of the time. However, when it gets hot, the temps are where I see turbo car application temps. That's a trapped heat problem. The tallter the hood and the deeper the engine bay, the more of a problem it can become.
I believe we do agree on most of it. I just don't see low speed operation with a mechanical fan any different in terms of heat or airflow management.
My next set of ABC's of 80's cooling is mounting up the Z34 hood vents to my truck, with a measuring tool of it's effectiveness. I have no doubt that any of the guys that have already done them, are chuckling at all the postulation.
I've used really small vents on several of my own turbo cars, and the heat coming out those vents could bake bread. The theory is solid and well proven, a lot of unfounded concern from many of the swimmers of the group regarding water crossings. My own thinking is that if water gets to the vents at the back of the hood, it's only an inch from drowning the HVAC....
Scott Justusson
'95 FZJ80 Supercharged
sleeoffroad
Supporting Vendor
Ken, when we discussed it I said we will not do a SC with dual batteries because I believe it caused restricted airlfow. Remember it is not just the battery, it is also the relocated washer bottle. Having owned a dual battery with SC truck and also experience with a SC with out dual batteries, the engine bay was a lot cooler on the latter. Never measured it, but all the parts added for the dual battery, plus the SC on top of the manifold pretty much filled up the whole PS side of the engine bay.
SUMOTOY said:
I'm going after the clutch because my almost new one wasn't doing anything to help cool the engine.
It's starting to look like a small advancement to the clutch's timing and some slightly thicker oil will get the job done. Not strong arming the thing by any means.
I'm only interested in a properly running engine. My AC at idle has always been ok with me and with 200k on the engine that has been running hot for most likely it's entire life with no wiring or other issues, I don't think a little the extra airflow through the rad is a problem.
I also don't see the difference of air flow under the hood when comparing a modded clutch/fan and a stock clutch/fan with a pusher fan. If the two setups provide the same cooling through the radiator then I'm thinking their air flows pretty much match and the under hood temps are going to be close.
If someone can tell me where the danger zone is for under hood temps I'll be happy to post mine here. I have a digital thermometer that records the max temp and I can reset it and go for a drive and see what they are.
landtank said:
Misunderstanding. I don't believe you are strongarming at all LT, in fact, you are taking it slowly and documenting it pretty well. I hope we don't find catastrophic failure because of it. I've btdt, and really hope I'm a special case of 1
Can't hurt, but does it help? And if that is at the expense of high rpm risk (lcoked clutch and engine speed), it might be a problem.
LT, if you read my ABC's carefully, there is no reference to radiator temps. I believe if anyone is putting on an aux fan to help radiator temps, they probably are netting some pretty low gains (read: better to just do your mod). That said, if you do the aux fan with the purpose of *cooling the condenser* to optimize dash vent temps, it's a good mod. Just about every production automobile and truck that has a pusher fan has that goal. Otherwise it wouldn't be A/C activated.
Firewall, back of head,
Airbox
Firewall PS
Firewall DS
I think vents are inexpensive and proven additions to airflow and heat management. Tall crowded engine bays and massive hood expanse will yield higher benefits.
Scott Justusson
Sumotoy, I wasn't referring to the ABC trilogy, it has been discussed that a pusher fan will help with engine temps and a few have documented that here on the site. I was only making a point that regaurdless of how the air flow is generated at idle the hood temps for any amount of flow would be close.
Today is not a very warm day and I'm leaving for Kentucky in the morning which is the start of another heat wave here. So I'll see what things look like when I'm back which could be during the heat wave.
Today is not a very warm day and I'm leaving for Kentucky in the morning which is the start of another heat wave here. So I'll see what things look like when I'm back which could be during the heat wave.
sleeoffroad said:
Christo:
Obviously some measures might have helped here. The hot air will find the easiest path to get out. Before exposing a battery to the engine bay, which toyota isolates pretty well, I would think hood vent before clearing the airflow river of rocks. That specific one of which actually did a better job of blocking the airbox from direct airflow than it does in modded trim. I look at it more that it may have more clearance to go backwards, but where's it goingand what's it convection baking in the process?
The only reason I posted on it, was I was actually considering *adding* the PS battery (with heat shield) as one of the methods to decrease intake air temps. Using Density Ratio as my guide, if I can increase the pre-compressor air temp, I have effectively increased the corrected PR.
This also applies to N/A trucks as well. If the intake air temp is lower, air density in the cylinder is higher.
I'm pretty sure I can just mount the 2 temp probes I have in the upper rear of the truck and take some measures. As I've just finisthed the Aux Cooling Fan for the Condenser, it might take a bit before I can start cutting my hood for vents. Any data of underhood temps might be a good start to that comparo.
Scott Justusson
94 FZJ80 Supercharged
