Custom vented hood for more cooling ?

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Mitevo7

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Mitevo7

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Dear All,

As some of you may know, i just converted a BMW E46 with 1jz engine, due to i am getting more and more familiar with the new characteristics of the car and i have been pushing it a lot. Now i've noticed, whenever i floor it hard and fast, the water temp will raise a little over the mid mark, upon slowing down, it will return to below middle. Have asked the mechanic that did the conversion, he said its very normal because its a turbo engine, when push hard thus will hot a little, plus recently the weather is crazily hot.

With skepticism, asked another mechanic which i never dealt with before, he mentioned the samething as he's thought its quite normal, however, he gave some suggestion on venting the hood and side fender for hot air to exit faster.

Therefore here comes this discussion, how effective is it to vent my car's body parts, or i should just get a low temperature thermostat and call it a day ?

Thanks,
Ken
 

gunnerzz

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gunnerzz

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Maybe...more hot air escapes thru the vent rather than recirculating back to the front of the radiator. But vent will help most when the vehicle is moving. During stationary it all depends on the radiator fan and the air temp the radiator is getting.

I rather seal the radiator area to prevent any chance of hot air from the engine bay getting recirculated to the front of the radiator.Very difficult to do but rewarding. I did that on the Kenari and aircond is much better too.
 

Mitevo7

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Mitevo7

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Maybe...more hot air escapes thru the vent rather than recirculating back to the front of the radiator. But vent will help most when the vehicle is moving. During stationary it all depends on the radiator fan and the air temp the radiator is getting.

I rather seal the radiator area to prevent any chance of hot air from the engine bay getting recirculated to the front of the radiator.Very difficult to do but rewarding. I did that on the Kenari and aircond is much better too.
My issue is when i am driving or racing it hard, the temp will creep a little higher, from what i read, 1JZ normally installed in larger Toyota cars. BMW E46 is not at the same league with Crown, may be that's why the hot air is kinda trapped in the engine bay.

Can you share some picture how you seal the radiator area ?

Thanks,
Ken
 

mADmAN

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mADmAN

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venting the hood if done properly can reduce the engine bay temperatures via the venturi effect. will minimize radiant heat being soaked up by ur engine components.

however, i would suggest a lower temp fan switch and thermostat. so that the fan will turn on at a lower temperature and cool the water earlier. a fan shroud would probably help as well.... after thats done, u can look into the venting.
 
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Mitevo7

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venting the hood if done properly can reduce the engine bay temperatures via the venturi effect. will minimize radiant heat being soaked up by ur engine components.

however, i would suggest a lower temp fan switch and thermostat. so that the fan will turn on at a lower temperature and cool the water earlier. a fan shroud would probably help as well.... after thats done, u can look into the venting.
Dude you foreseen my actual plans, indeed i am getting fan controller and lower temperature thermostat now. I don't want the modified body to attract any unwanted attention from authorities eventhough i am legal. My exhaust note is already quite a police magnet when i drive fast lol.

Thanks,
Ken
 

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Dear All,

As some of you may know, i just converted a BMW E46 with 1jz engine, due to i am getting more and more familiar with the new characteristics of the car and i have been pushing it a lot. Now i've noticed, whenever i floor it hard and fast, the water temp will raise a little over the mid mark, upon slowing down, it will return to below middle. Have asked the mechanic that did the conversion, he said its very normal because its a turbo engine, when push hard thus will hot a little, plus recently the weather is crazily hot.

With skepticism, asked another mechanic which i never dealt with before, he mentioned the samething as he's thought its quite normal, however, he gave some suggestion on venting the hood and side fender for hot air to exit faster.

Therefore here comes this discussion, how effective is it to vent my car's body parts, or i should just get a low temperature thermostat and call it a day ?

Thanks,
Ken
Ho ho ho... this was one of the things I mentioned to you right? The 1JZ runs hot. Uprate the radiator and fan and it's limited by the flow of the engine bay. I had the same problem with my 36 sometime back and my oil temp would touch 110 at time too with the water also reaching 100. I was looking for vents until I went for the old school mechanic way of raising the hood with some washers to test my theory of poor airflow and lo-and-behold, the temperature stabilized and although it still went up during spirited drives, the heating up wouldn't be as drastic. Perhaps you should try raising the hood as a temporary measure.
 

marsha1l_v6

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i just ordered spal last week..else can share shipping cost.

im working on reducing engine bay temp as well. using low temp thermostat..and raised front hood
 

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All turbo cars runs hot, especially when pushed. The turbine will be really hot, and water and oil sent there to cool that part will become very hot and when return to radiator and engine sump respectively, will spike up the temperature, that is why need engine oil cooler too.....
 

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nah.. get a fan with a higher CFM. More blades doesn't mean anything la.
I think it should. Just compare ceiling fans with 3 vs 5 blades. Replacing the motor with more powerful one of course is even better.
 

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I think it should. Just compare ceiling fans with 3 vs 5 blades. Replacing the motor with more powerful one of course is even better.
Reading your reply, made me google, then saw this......lol

Fewer Blades Mean Less Drag. Many believe that the more blades your fan has, the cooler it is, but it isn't secret that industrial style and commercial fans usually only have two or three blades. ... When a fan has fewer blades, there is less drag on the motor and it can go faster and move more air more efficiently.

Looks like stronger motor is better.....
 
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6UE5t

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6UE5t

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Reading your reply, made me google, then saw this......lol

Fewer Blades Mean Less Drag. Many believe that the more blades your fan has, the cooler it is, but it isn't secret that industrial style and commercial fans usually only have two or three blades. ... When a fan has fewer blades, there is less drag on the motor and it can go faster and move more air more efficiently.

Looks like stronger motor is better.....
Makes sense so need to pair with stronger motor as well.
 

Mitevo7

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Ho ho ho... this was one of the things I mentioned to you right? The 1JZ runs hot. Uprate the radiator and fan and it's limited by the flow of the engine bay. I had the same problem with my 36 sometime back and my oil temp would touch 110 at time too with the water also reaching 100. I was looking for vents until I went for the old school mechanic way of raising the hood with some washers to test my theory of poor airflow and lo-and-behold, the temperature stabilized and although it still went up during spirited drives, the heating up wouldn't be as drastic. Perhaps you should try raising the hood as a temporary measure.
We will try with cooler temp and fan controller at lower temp, but that will mean work the fan quite regularly. I might need to look an M3 side fender with stock air vents that can let the hot air escape from the side. It's more stealthy and low profile.

Thanks,
Ken
 

Mitevo7

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All turbo cars runs hot, especially when pushed. The turbine will be really hot, and water and oil sent there to cool that part will become very hot and when return to radiator and engine sump respectively, will spike up the temperature, that is why need engine oil cooler too.....
Well said, lots of coolers need to be installed then if i want to drive like i stole it. For now i only able to drive it hard for short period of time before seeing the temperature creeps over mid point.

Thanks,
Ken
 

Mitevo7

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Folks, anyone got contact where i can get reasonable vented hood for the E46 ? If i have to, i will need a fabricator to fabricator one from a spare hood i bought.

Thanks,
Ken
 

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Folks, anyone got contact where i can get reasonable vented hood for the E46 ? If i have to, i will need a fabricator to fabricator one from a spare hood i bought.

Thanks,
Ken
I thought you wanted low profile? hahaha.. buy the vents off Lazada and give to the fab guy to cut a hole in the hood and mould it in. But before you commit to cutting holes, why not just lift the hood for testing purposes and see if that works. If it works then you know for sure it's just a venting issue and start chopping that hood.
 

Mitevo7

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I thought you wanted low profile? hahaha.. buy the vents off Lazada and give to the fab guy to cut a hole in the hood and mould it in. But before you commit to cutting holes, why not just lift the hood for testing purposes and see if that works. If it works then you know for sure it's just a venting issue and start chopping that hood.
Hehehe, i am going for low profile and functional venting. I can go with another style of venting as long as i can draw the hot air out. We actually drove without hood once at very fast RPMs, temperature stays still ! Therefore can quite confirm we need some vents on the hood.

Thanks,
Ken
 
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vr2turbo

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Well said, lots of coolers need to be installed then if i want to drive like i stole it. For now i only able to drive it hard for short period of time before seeing the temperature creeps over mid point.

Thanks,
Ken
Turbo engine need oil cooler, my stock VR engine already equip with one......
 

vr2turbo

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Hehehe, i am going for low profile and functional venting. I can go with another style of venting as long as i can draw the hot air out. We actually drove without hood once at very fast RPMs, temperature stays still ! Therefore can quite confirm we need some vents on the hood.

Thanks,
Ken
Not only the hood, even my forester comes without the plastic engine cover. Seems it keeps the heat in......lol
 

Mitevo7

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Turbo engine need oil cooler, my stock VR engine already equip with one......
That is effectively bringing the engine oil down right ? Just curious, how come stock 1JZ didn't equip with oil coolers in the Crown halfcut i bought.

Not only the hood, even my forester comes without the plastic engine cover. Seems it keeps the heat in......lol
LOL stock 1JZ has no cover or whatsoever, not even heatshield on the turbo manifold. Imagine the heat dispersed during high speed runs ...

Thanks,
Ken
 

^pomen_GTR^

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^pomen_GTR^

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Dear All,

As some of you may know, i just converted a BMW E46 with 1jz engine, due to i am getting more and more familiar with the new characteristics of the car and i have been pushing it a lot. Now i've noticed, whenever i floor it hard and fast, the water temp will raise a little over the mid mark, upon slowing down, it will return to below middle. Have asked the mechanic that did the conversion, he said its very normal because its a turbo engine, when push hard thus will hot a little, plus recently the weather is crazily hot.

With skepticism, asked another mechanic which i never dealt with before, he mentioned the samething as he's thought its quite normal, however, he gave some suggestion on venting the hood and side fender for hot air to exit faster.

Therefore here comes this discussion, how effective is it to vent my car's body parts, or i should just get a low temperature thermostat and call it a day ?

Thanks,
Ken

1- do you still have fully stock radiator and bumper ventipation shroud?(the cover that channel all air straight into radiator)
Usually looks like some plastic plate and shapes that can throw away that have great effect in cooling...
Adding a radiator cooling plate on top of its also help (if there is gaps between radiator and the body frame)

2- does the temp kept climbing all the way to redline? Or it just hover above middle mark?

This is good reason people installing aftermarket water temp gauge to read exact number of water temp.. anything below 98 degree C while travelling at high boost and high speed is ok ish...

As comparison, my car when climbing genting a few time reaching temp 102degree C due to enough speed (short acceleration burst and stuck behind slow traffic)

Another view is..during summer heatwave like nowadays where ambient temp reaching 40degree C, crusing at highways following slow moving traffic in middle lane on hot afternoon also my water temp reaching 96-98degree C... Only when i switch into faster lane to get better air cooling wth open roads, the water temp dropping back to sub 90degree during cruising...


Then my additional effort to reduce that heat management inside engine bay... More ventilation holes! Especially when car is stationary during idle in traffic..the theory is hot air moving up.. instead of forced going down (in stock car air management)...

Opening vents hole up in the bonet is the oreferred method anyway...

But just make sure your thermostat, better coolant, fan and radiator condition is perfect as well as your thermostat...
PicsArt_03-26-05.45.30.jpg
 

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That is effectively bringing the engine oil down right ? Just curious, how come stock 1JZ didn't equip with oil coolers in the Crown halfcut i bought.



Thanks,
Ken

Stock oil cooler got 2 types..

1- the usual small radiator type design (air to oil cooler)

2- something does not look like a radiator..but is still the oil cooler... Like the atf cooler that sitting at the bottom of radistor in automatic cars..

3- a cylinder type of thing that usually sandwiched between oil filter and engine block that have small coolant pipe running through it... This is more common on oem turbo car method for cooling the engine oil... As well as continental method of cooling their gearbox oil (sandwiched onto gearbox instead)
 

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That is effectively bringing the engine oil down right ? Just curious, how come stock 1JZ didn't equip with oil coolers in the Crown halfcut i bought.



LOL stock 1JZ has no cover or whatsoever, not even heatshield on the turbo manifold. Imagine the heat dispersed during high speed runs ...

Thanks,
Ken
Yup, cool the engine oil.

Older car no engine cover, only the newer ones but seems for forester they removed it, the turbo model stilll have engine cover but it is small and are vented.....lol
 

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one noob questions, vented hood prone to heavy rain or heavy splash to the hood ?

usually if the vent location is directly under sensitive item like coil plug and such, there is some blocking panel to avoid water dropping directly onto that...

on my scooby it just falls through the chassis rail... so no problem let it vent directly open