Author Topic: Project Rear Mounted Radiators  (Read 41160 times)

gtxdon

  • Trade Count: (0)
  • Jr. Member
  • **
  • Posts: 14
  • Liked: 0
  • Member Rating Points: +0/-0
Re: Project Rear Mounted Radiators
« Reply #44 on: July 10, 2013, 10:10:40 AM »
If you can engineer in an oil cooler that should help too. You can get them either with fans or without. We run deep sump oil pans with oil coolers on some nasty big blocks and they help a lot.

01Lambiero

  • Global Moderator
  • Trade Count: (+1)
  • Hero Member
  • *****
  • Posts: 1167
  • Liked: 404
  • Member Rating Points: +24/-3
  • "Using the skills that God gave me"
Re: Project Rear Mounted Radiators
« Reply #43 on: July 10, 2013, 09:50:14 AM »
AH, YES,YORICK, HOW TO COOL OUR ENGINES.  We have incorporated so many variables into our builds that it is almost possible for most everyone's advice to be correct.  Last time I checked:  the thermostat opens and closes to keep the temperature of the coolant in the engine block at a set temperature.  When all of the coolant has achieved the temp of the thermostat, the regulation of controlled temp moves to the efficiency of the radiators.  The efficiency of the radiators is regulated by numerous things such as: Surface area/size of the cooling tubes, capacity, construction material, and AIR FLOW.  Fans and ducting are next and hopefully the final addition.  One other overlooked culprit is the maker of all of this heat: OUR ENGINES.  More HP requires more cooling.  What works for one would not be sufficient for another.  I wish that I could have purchased a temp laser 30 years ago.  Jim 
20 yr. GM Niase certified Auto Mechanic (Tune-Up, Brakes, & Heavy Repair)
24 yr. GM Automated/Robotic Welding Systems
Retired

LamboJayso

  • Trade Count: (+6)
  • Sr. Member
  • ****
  • Posts: 303
  • Liked: 17
  • Member Rating Points: +6/-2
  • Experience is everything!
Re: Project Rear Mounted Radiators
« Reply #42 on: July 10, 2013, 08:12:04 AM »
Ahhh, Murci-me you didn't disappoint!
It is so nice to have an expert on EVERYTHING right here at Lamboclone.  What would we do without you?
You admit they give you additional cooling but go on to explain how heat from the first pass somehow heats the second pass. (?)  The two sections of the radiator are not one in front of the other.
You want to slow the water through the radiators to increase cooling.  That is what thermostats do BUT if you slow the water too much the engine will overheat.  That is why there are thermostats.  They control the amount of water based on temperature.  It is still up to the radiator to cool the water.  Larger radiator cores will help BUT, as every builder here knows, we are limited in the space available for our radiators and so must made the best of what space we have.  THAT is why we are discussing this!
As for dual fans, some have installed them and it has helped BUT it shouldn't be needed.  The two fans could end up fighting each other if they have different capacity.  If you install one EFFECTIVE fan, you will do well.  Besides, THAT it too complex and I am surprised you would suggest it.  You like to keep things simple.  Remember KISS?  Keep It Simple STUPID.  Calling your opinion science does not make it so.
If you use aluminum tubing for your water piping with the expectation it will help your cooling, it will dissipate the heat right back into your engine compartment where you will have to find a way to remove it. (Maybe more fans?  That would be simple, stupid. [KISS])  Is that 10 to 15 degree temperature drop proven scientifically?  If so, it MIGHT register on the water temperature gauge BUT it ends up back in the engine compartment!  You rely on Rube Goldberg too much.
Maybe the entire answer is back in your super-simple batwings.

RT

YES! The answer is in the batwings whenever you're putting radiators in the rear. The Diablo has vents that duct air at all times to the rads. On a Murcielago, you MUST have functioning batwings or the batwings must be affixed in the up position at all times to avoid overheating.

One can wire their batwings to open & close to the changing temperatures. I used 2 honda civic radiators in the rear with 10" fans on both on my first build. I never had any overheating problems except for when the batwings were closed. But, once they raised, the temp gauge never exceeded the 1/4 mark.
-Jayso

RT

  • Trade Count: (0)
  • Sr. Member
  • ****
  • Posts: 410
  • Liked: 308
  • Member Rating Points: +28/-0
Re: Project Rear Mounted Radiators
« Reply #41 on: July 10, 2013, 07:51:47 AM »
Dual pass radiators only cool slightly better (less than 5%) than single pass radiators. Don't believe the sales pitches and big claims, its just a way to sell more expensive radiators. More efficient cooling is achieved by slowing the flow of the water through the radiators, not by sending the water twice through the same radiator. Some heat expelled through the first pass is absorbed in the second pass, and the warm air flowing through the vanes reduces the cooling of both passes, lowering the efficiency of the radiator and making it not much better than a single pass radiator . Dual fans on a single pass radiator will cool better than a dual pass radiator with dual fans. Its not an opinion, it just science. If you want to cool better, slow the flow through the radiator by increasing the size of the core, and guarantee smooth airflow by adding dual fans. That's how Rube Goldberg would do it.

I think if you really want to help increase cooling, use aluminum tubing as the plumbing. Aluminum disapates heat very quickly, and acts as a heatsink before and after the radiators. Just in the tubing alone you can expect about a 10 to 15 degree temperature drop overall. Rubber hose is an insulator, use as little as possible.

Ahhh, Murci-me you didn't disappoint!
It is so nice to have an expert on EVERYTHING right here at Lamboclone.  What would we do without you?
You admit they give you additional cooling but go on to explain how heat from the first pass somehow heats the second pass. (?)  The two sections of the radiator are not one in front of the other.
You want to slow the water through the radiators to increase cooling.  That is what thermostats do BUT if you slow the water too much the engine will overheat.  That is why there are thermostats.  They control the amount of water based on temperature.  It is still up to the radiator to cool the water.  Larger radiator cores will help BUT, as every builder here knows, we are limited in the space available for our radiators and so must made the best of what space we have.  THAT is why we are discussing this!
As for dual fans, some have installed them and it has helped BUT it shouldn't be needed.  The two fans could end up fighting each other if they have different capacity.  If you install one EFFECTIVE fan, you will do well.  Besides, THAT it too complex and I am surprised you would suggest it.  You like to keep things simple.  Remember KISS?  Keep It Simple STUPID.  Calling your opinion science does not make it so.
If you use aluminum tubing for your water piping with the expectation it will help your cooling, it will dissipate the heat right back into your engine compartment where you will have to find a way to remove it. (Maybe more fans?  That would be simple, stupid. [KISS])  Is that 10 to 15 degree temperature drop proven scientifically?  If so, it MIGHT register on the water temperature gauge BUT it ends up back in the engine compartment!  You rely on Rube Goldberg too much.
Maybe the entire answer is back in your super-simple batwings.

RT
It isn't enough to want a Lambo, you have to want to BUILD A CAR.

Murci-Me

  • Guest
  • Trade Count: (0)
Re: Project Rear Mounted Radiators
« Reply #40 on: July 09, 2013, 11:59:27 PM »
Dual pass radiators only cool slightly better (less than 5%) than single pass radiators. Don't believe the sales pitches and big claims, its just a way to sell more expensive radiators. More efficient cooling is achieved by slowing the flow of the water through the radiators, not by sending the water twice through the same radiator. Some heat expelled through the first pass is absorbed in the second pass, and the warm air flowing through the vanes reduces the cooling of both passes, lowering the efficiency of the radiator and making it not much better than a single pass radiator . Dual fans on a single pass radiator will cool better than a dual pass radiator with a single fan. Its not an opinion, it just science. If you want to cool better, slow the flow through the radiator by increasing the size of the core, and guarantee smooth airflow by adding dual fans. That's how Rube Goldberg would do it.

I think if you really want to help increase cooling, use aluminum tubing as the plumbing. Aluminum disapates heat very quickly, and acts as a heatsink before and after the radiators. Just in the tubing alone you can expect about a 10 to 15 degree temperature drop overall. Rubber hose is an insulator, use as little as possible.
« Last Edit: July 14, 2013, 03:38:41 PM by Murci-Me »

RT

  • Trade Count: (0)
  • Sr. Member
  • ****
  • Posts: 410
  • Liked: 308
  • Member Rating Points: +28/-0
Re: Project Rear Mounted Radiators
« Reply #39 on: July 09, 2013, 10:34:48 PM »
If you do not have your radiators yet consider dual pass radiators.  You can find them at www.summitracing.com.  Just do a search.
Dual pass means the water goes through the radiator twice by-way-of both inlet and outlet being on the same end of the radiator.  The water goes in the inlet and has to pass through once to get to the other end tank and then back through once more to get to the outlet.  They claim to offer better cooling per radiator size.  I am using dual pass and find them effective.
I just can't wait to see how wrong I am about this.  Murci-me, are you there?  Maybe we need another Rube Goldberg solution.

RT
It isn't enough to want a Lambo, you have to want to BUILD A CAR.

01Lambiero

  • Global Moderator
  • Trade Count: (+1)
  • Hero Member
  • *****
  • Posts: 1167
  • Liked: 404
  • Member Rating Points: +24/-3
  • "Using the skills that God gave me"
Re: Project Rear Mounted Radiators
« Reply #38 on: July 09, 2013, 09:35:54 AM »
I like series flow myself too because you will have equal flow through each radiator.  We covered this in the "Heating Cooling" Topic post.  Your "best friend" should be a laser temp gun.  It will nail down how warm things are getting.  Jim 
20 yr. GM Niase certified Auto Mechanic (Tune-Up, Brakes, & Heavy Repair)
24 yr. GM Automated/Robotic Welding Systems
Retired

jdinner

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 202
  • Liked: 25
  • Member Rating Points: +6/-0
    • KwikerCars
Re: Project Rear Mounted Radiators
« Reply #37 on: July 09, 2013, 06:39:29 AM »
My suggestion, connect the rads in series not parallel (unless the tubing is equal lengths from the Y's on the supply AND return).
Use Spal fans that run at around 20 amps each. (Measure fans by amps not CFM - some manufacturers have strange criteria)
I ran 2 fans per rad like Mike suggested. It does make a big difference and works but the Spal fans actually pushed more air.
My yellow 6.0 is now running cool at an outside temp of 105* in traffic. Engine stays at 200*(fan off) to 205*(fan on). 

My experience...
http://www.kitcentral.com/index.php?name=PNphpBB2&file=viewtopic&t=4055&postdays=0&postorder=asc&start=120&sid=b5dc3597ec7074f1cd9347b9bf0ff1ad

Dale VanBlokland's experience...
http://kitcentral.com/index.php?name=PNphpBB2&file=viewtopic&t=3444

pkovgolf

  • Trade Count: (+2)
  • Full Member
  • ***
  • Posts: 194
  • Liked: 0
  • Member Rating Points: +2/-2
Re: Project Rear Mounted Radiators
« Reply #36 on: July 08, 2013, 05:54:46 PM »
Thank you again Jim!
Sure looks like a tight fit :)

01Lambiero

  • Global Moderator
  • Trade Count: (+1)
  • Hero Member
  • *****
  • Posts: 1167
  • Liked: 404
  • Member Rating Points: +24/-3
  • "Using the skills that God gave me"
Re: Project Rear Mounted Radiators
« Reply #35 on: July 07, 2013, 09:35:41 PM »
pkovgolf / Peter:  I don't think that there is a cut & dried blueprint for installing rear radiators.  When I got to mounting my rear radiators, I made a frame for each radiator with mounting tabs for holding the radiators.  You have to allow clearance for the rear mounted fan on each radiator which will be covered with metal mesh/screen.  With your body positioned on your chassis, slide the radiator up inside to the correct position that you want in front of the rear opening.  You may have to trim the metal on your chassis for clearance for each radiator.  Once it looks good, weld brackets from your radiator frame to your chassis and strengthen as necessary.  Hose routing is also a builder's choice.  You can choose in series or parallel flow.  Jim
20 yr. GM Niase certified Auto Mechanic (Tune-Up, Brakes, & Heavy Repair)
24 yr. GM Automated/Robotic Welding Systems
Retired

Murci-Me

  • Guest
  • Trade Count: (0)
Re: Project Rear Mounted Radiators
« Reply #34 on: July 05, 2013, 06:23:26 PM »
Use dual fans on each radiator also, 1 in the push and 1 in the pull positions on each radiator. It makes a WORLD of difference!

Tusabes

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 613
  • Liked: 127
  • Member Rating Points: +8/-2
Re: Project Rear Mounted Radiators
« Reply #33 on: July 05, 2013, 12:47:51 AM »
Use spal fans
You will overheat with the cheap china fans and its 100x easier to do it right now vs fixing it later

pkovgolf

  • Trade Count: (+2)
  • Full Member
  • ***
  • Posts: 194
  • Liked: 0
  • Member Rating Points: +2/-2
Re: Project Rear Mounted Radiators
« Reply #32 on: July 04, 2013, 11:55:22 PM »
Can you please point me to a build diary or two that show this info - e.g. the details on plumbing and additionally mounting the radiators (especially for a Murcie)

Thanks!
Peter

Nitemare

  • Guest
  • Trade Count: (0)
Re: Project Rear Mounted Radiators
« Reply #31 on: June 13, 2013, 12:18:05 PM »
People show how they did it in their build diaries, check 'em out

lamboman

  • Trade Count: (0)
  • Jr. Member
  • **
  • Posts: 46
  • Liked: 0
  • Member Rating Points: +1/-0
Re: Project Rear Mounted Radiators
« Reply #30 on: June 13, 2013, 10:30:36 AM »
 ::LAMBO Any photos and info on how to run the hose from the engine to radiators, and did you use the pipes from the fiero motor? I am installing my dual radiators and removing the front oem fiero.
1, will I have to remove the rear bumper? In my case it will need to be cut off it I have to remove it.
2, will I have to make a cage to hold the two radiators in place or can it be made out of fiberglass.
 ::beers ::beersThank you all and help will help.