ej 22 underbelly rad design questions in a 1955 vw bus

AllenH Learner Dubber

15 posts · joined Aug 2014 · 23 Jul 2015, 2:31 pm

#1016939

Hi I am redesigning my shroud and need some advice Im enclosing the jeep cherokee rad . The rad dimensions are 27 1/4 inches long and 20.5 inches wide . Question 1 should i mount the slimline fan onto the top of the shroud or mount it right to the rad blowing down towards the ground . My reasoning is at highway speed the cooling surface will be unobstructed by the fan The effective rad cooling surface area is 21 inches long by 19 inches wide the lowest shroud closest to the ground is going to sealed to the rad with 3 inch holes for the hot air to escape.

Any advise would be appreciated thx Al

rocknrob Insano Dub Head

844 posts · joined Dec 2003 · 23 Jul 2015, 5:04 pm

#1016946

Hi there, i have offered to help a young friend fit a subaru to his split window van. We havnt even removed the sheeting under there yet but on my bay kombi there is a depth of 160mm between the chassis rails which allows a reasonable tilt up at the back to encourage airflow and the fan will fit underneath. I believe fans are either push or pull but we have the standard suby fan which is pull...do you have 27 1/4 between the chassis rails? Rob

AllenH Learner Dubber

15 posts · joined Aug 2014 · 29 Jul 2015, 2:50 pm

#1017169

After reading and researching pull vs push on an under belly rad setup on a bus there seems to be mixed reviews on what works best . I was planning on running a sealed rad underbelly with a push fan mounted on top of the rad blowing down through a mesh screen towards the ground After reading numerous posts it seems that the newer fans are pull through and are more efficient in displacing heat .

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 · 15 Aug 2015, 5:59 pm

#1017808

A few years back I climbed under the front of my brother's split window to see where a radiator would fit. I came to the conclusion there was ample room in FRONT of the front beam below the floor there. I'd have a look there and have a think. Have you seen the Race Taxi? They did this for that bus...

http://race-taxi.ch/gallery/album/slides/racetaxi%20(82).jpg

Whatever setup you use, you need to have a gurney flap or similar at the back the of radiator box to create a vacuum. This vacuum should pull the air through the radiator as you drive along. The outlet to the box should be totally open, or as much as possible.

Don't worry about how much the cooling fans restrict the airfllow. If the vacuum is enough, it will work well. This is how all modern cars now work. BTW, cooling fans should ONLY be used for traffic or similar. They should NOT run all the time.

"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

boof2332 Custom Title Time!

1,210 posts · joined May 2004 · 31 Aug 2015, 8:01 pm

#1018376

The race taxi is an air cooled 993 turbo motor.. I am pretty sure that that is for the oil cooler.
Set up would work the same but you need a long thin radiator with ample room behind it to create the low pressure required to draw the air through the radiator.
The race taxi is also strut front end as its on a late model t3 chassis, so there maybe more room at the front with no beam.

I have searched high and low for different radiators for bugs, bays and splitty's since we did the WRX bug conversions over 10 years ago and it makes the most sense and money in the long run, to have a custom alloy one made to fit exactly where you want it then build your shroud around it so it draws the air through. That way your pipes will be on the correct side also.

AllenH Learner Dubber

15 posts · joined Aug 2014 · 2 Sep 2015, 9:32 am

#1018420

Hi looks like my amended cooling system works quite well although it sits little low as the bus is quite low. The ecu turns the the fan relay on at 206 deg f and off at 199 deg f . I thought it was quite high but happy it takes the temp down in 2-3 min

Tonz Magonz Officially Full-On Dubber

201 posts · joined Apr 2005 · 2 Sep 2015, 5:02 pm

#1018428

Hi Allen
Do you have any pics of your mods to share..?

I have finally taken the plunge and commenced converting my '67 splitsceen Kombi to VR6 watercooled power.
Intending to locate radiator in a similar way.. Front edge lowest point and rear at highest with radiator on the underside.
I'm considering running some ducting from below front bumper to feed radiator shroud.

Tonz Magonz Officially Full-On Dubber

201 posts · joined Apr 2005 · 2 Sep 2015, 5:11 pm

#1018430

Good ground clearance so far..