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Rear mount radiators.

Posted: Tue Jul 22, 2008 8:23 pm
by mikesmith
hey guys

am going to mount my radiator in the back of my truck under the tray.

i was wondering what setups ppl use to bleed the system??

i have a new mq diesel radiator with twin el thermos on it.

should i leave the radiator cap on it blocked off and run a line up to a overflow\surge tank on the roll bars and use that tank to control the amount of coolant in the system and the bleeding of air???

oh its for the cooling of a 350 chev and the radiator will be under the highest point of the engine hence the questions about bleed points.

will i need a bleed point in the engine bay at all???

sorry about all the questions i just want to get this done once and done properly.

the car is going to be a daily driver and used for 4wd comp work.

thanks

Posted: Tue Jul 22, 2008 8:29 pm
by joeblow
a daily driver?....rear radiators are illegal.

Posted: Tue Jul 22, 2008 8:55 pm
by mikesmith
why are they illegal??

i spoke to my engineer and he said he had no problems!

Posted: Tue Jul 22, 2008 9:43 pm
by tt6_lux
My radiator is rear mount and was engineered, blue slipped and registered this way (NSW).

Posted: Tue Jul 22, 2008 10:13 pm
by BOGAN V8
joeblow wrote:a daily driver?....rear radiators are illegal.
Negative they are completely legal well in nsw they are mate has one done and 2 others that i know off..

Posted: Tue Jul 22, 2008 10:48 pm
by joeblow
don't know of a VICTORIAN engineer that will pass them.

Posted: Tue Jul 22, 2008 10:54 pm
by Gwagensteve
I do....

Steve.

Posted: Wed Jul 23, 2008 12:13 am
by joeblow
then speak up boy.

Posted: Wed Jul 23, 2008 7:52 am
by Gwagensteve
They're no more or less illegal than a front mounted radiator. AFAIK there's no ADR that covers where a radiator has to be. EG - Toyota MR2's have a rear mounted radiator stock, but a lotus elise has a front mount radiator - both cars are mid engined. Engineers don't like them because they don't think they'll cool the car properly being in a low pressure area behind the cab. If you an ovecome that problem, then they have no reason to deny it.

Obiviously, there has to be no chance of a coolant leak showering the occupants of the car in boiling coolant.

No need to name the engineer on here - an engineer needs to be involved in a whole project no just one aspect of it so you would need to discuss the whole build with any engineer, but he was happy to approve a rear mount radiator on a full bodied ute (i.e not a cut down soft top) so long as the car passed a test drive and remained cool.

I have found that some engineers won't even look at some mods and others are fine with them.

Steve.

Posted: Wed Jul 23, 2008 5:51 pm
by cooki_monsta
i know of a few vic engineers that pass them, if they didnt most of vic's comp trucks wouldnt be racing due to not being rwc due to having a rear mounted radiator on the tray ...

Posted: Wed Jul 23, 2008 5:55 pm
by Gutless
Engineer had No probs with my rear mounted radiator in QLD either.

Posted: Wed Jul 23, 2008 6:17 pm
by sierrajim
joeblow wrote:don't know of a VICTORIAN engineer that will pass them.
Mike also lives in melbourne (not too far from where you used to have your shop Joe) so i'd assume that he is also using a Victorian Engineer.

Posted: Wed Jul 23, 2008 7:07 pm
by mikesmith
my engineer has said its no worries so thats all i care about.

can i get some info on if guys just used the water pump from the engine or they also used a davies craig setup or both pumps???

i am using an AU radiator and thermo fan setup and its going to be under the tray level but is a fair bit back from the cab so should still get reasonable airflow. can only try it and see how it goes.

Posted: Wed Jul 23, 2008 9:07 pm
by cj
mikesmith wrote:

can i get some info on if guys just used the water pump from the engine or they also used a davies craig setup or both pumps???
Have a look at the Bosch electric water pumps instead of the Davies Craig ones.

Posted: Wed Jul 23, 2008 9:11 pm
by BushTuckerNed
cj wrote:
mikesmith wrote:

can i get some info on if guys just used the water pump from the engine or they also used a davies craig setup or both pumps???
Have a look at the Bosch electric water pumps instead of the Davies Craig ones.
why is this?

Ill be setting my rear mount up soon. Was thinking of running the davis craig 110 and a electronic control unit.

Posted: Wed Jul 23, 2008 9:59 pm
by cj
BushTuckerNed wrote:
cj wrote:
mikesmith wrote:

can i get some info on if guys just used the water pump from the engine or they also used a davies craig setup or both pumps???
Have a look at the Bosch electric water pumps instead of the Davies Craig ones.
why is this?

Ill be setting my rear mount up soon. Was thinking of running the davis craig 110 and a electronic control unit.
Reliability, longevity and flow.

Rear Radiator

Posted: Wed Jul 23, 2008 10:06 pm
by XTREME MMM
Radiator under tray is going to get zero air flow (in my opinion). Mine is at the rear of cab and I also use the Ford thermo fans fully sealed in radiator shroud. I use standard water pump as fitted tro my TB 4.8 and David Craig electric water pump with fan which are wired into computer set at xDegs, so when fans come on David Craig water pump starts up and it then cycles between set computer tempertures.

Make sure that you drill a 1/4" hole in outer of thermostat to enable water flow if thermostat is closed, this will happen if you have an override switch and leave on, after an SS. This set up is good to help eliminate heat soak after you have done a very hard stage, you can shut down motor and have fan and electric pump still going to cool down a very hot motor.

Hope that has been of some help.

This system has worked very well on my Nissan GQ 4.8

Cheers
David

Posted: Wed Jul 23, 2008 10:16 pm
by 5lt Patrol
Im looking for an engineer in vic that will pass a rear mount radiator, holden 5lt, and a rear chassie chop. if you know of any could you please pm me their details.
Thanks.

Posted: Wed Jul 23, 2008 10:45 pm
by mikesmith
how would u get air flow at the rear of your cab???

mine is mounted half way down the tray so i will be able to pipe air into it.

rear mount

Posted: Thu Jul 24, 2008 8:04 pm
by 60_series_united
anyone ever put one in the back of a wagon? cause i really wanna move mine

Posted: Thu Jul 24, 2008 9:19 pm
by tt6_lux
I've never put one in a wagon, thought I do have one behind a Hilux dual cab.

Bleed: from all the high points that have low points either side I have bleed hoses that run to the radiator overflow.

My radiator sits twenty centimetres from the back of the cab. It's a late model commodore auto radiator, and I use a electronic controller to turn on the thermo fans when the temperature his 92, off again at 86.

Also have a Davies Craig pump in-line in the plumbing, but rarely ever use it. Testing it I've found that running the pump it takes a lot longer to get to temperature, and cools down a lot quicker.

Posted: Thu Jul 24, 2008 11:12 pm
by jessie928
joeblow wrote:a daily driver?....rear radiators are illegal.
they are not illegal at all.

JEs

Posted: Fri Jul 25, 2008 5:48 pm
by cooki_monsta
hey smiff, so long as you have good thermos then you dont need any airflow going through the radiator as the fans will take care of it for you, if you need a hand with it drop in at ftg auto salvage and ask daz how he did his, some very useful information comes out of his chops at times, if not its usually, ah i dunno ask andrew at ontrack 4x4 :P

Posted: Fri Jul 25, 2008 6:26 pm
by mikesmith
lol thanks gerg i spoke to them down there and had a look at there truck.

i am still trying to fit it in the front but if worst comes to worst then under the tray it goes.

most guys mount them up high on the tray and the ones i have seen have also had turbo 6's so with the V8 there is not much clearance to sneak hoses or steel pipe down to the rear out of the engine bay.

Posted: Sat Jul 26, 2008 10:21 am
by cooki_monsta
thats what ya get for puttin a chev in :D:D :armsup:

Posted: Sat Jul 26, 2008 10:28 am
by mikesmith
lol u will love it once its finished!! nothing better than a v8 at full noise!!! :armsup: :cool:

Posted: Tue Sep 02, 2008 8:51 pm
by REVNGQ
hi just looking for an engineer in vic around shepp or bendigo way.. i all so want to put the radiator behind the cab.... any name or numbers would be great...