Lotus Elan

Griffin Scirocco radiator install

PostPost by: garyeanderson » Tue Aug 28, 2007 11:01 pm

Thiis is a list of parts that I have used to swap out the Elan Radiator in some of my Elans. It has worked well for me and is a relitively inexpensive swap.
The following paragraph is from Elanmods yahoo group, I wrote it 4 years ago but its still says the same as it did when I wrote it.

The following items were used an my S4 coupe to upgrade the cooling system
MOROSO-63730 Cast aluminum, 1 1/2 in. hose to 1 1/2 in. hose, radiator hose
filler neck
1 1/2" I.D. section 3" to 6" long to connect thermostat housing to Moroso -
63730
Napa 8661 Lower Radiator hose
Napa 8726 Upper radiator hose
Griffin 2-58185-H Scirocco double pass Right 1.25 #4 (no filler neck on the
radiator)this has two 1 1/4" rows of cooling tubes verses the cheaper
2-28185-x that uses two rows of 1" tubes.
2 - 16" length's of 1" aluminum angle for brackets to support radiator
(length will depend on how much the radiator is moved forward) front to
rear and is does have to be moved forward to fit in front of the stock
horns. This is the last step in the install and will mount to the top stock
Scirocco mounts to the body to frame bolt that goes into the shock tower.

Summit racing has this radiator in stock (part # GRI-2-58185-x) but with
a filler neck, it does fit in the Elan nose but limits how far forward you
can place the radiator. The mounting ears on the bottom of the radiator
need to be trimmed to fit slightly (about 1 1/4" off of each end to reduce
the overall width). I drilled a 5/16" hole in each mounting ear and
connected the lower hose(Napa 8661) to both radiator and the water pump
intake to locate the radiator front to rear and then used around a 1" to 1
1/8" of rubber spacers to locate it vertically. The upper radiator hose is
cut at one end (the end with the 90 degree bend, not the end with the 45
degree bend) and the cut off section is used (cut off the 90 degree bend
and you are left with around 3" of 1 1/2" straight hose to connect the
thermostat gooseneck to the moroso filler neck. Finally drilling through
and the fiberglass in the bottom of the Elan nose for the bottom mounts
when I was satisfied with the location. 2 - 1 3/4" bolts through the holes
drilled in the radiator, rubber spacers, and fiberglass complete the
install. Total cost last week was $320 to summit for the radiator and
filler neck, and around $36 to Napa auto parts for the two hoses and 6 hose
clamps. I will install a electric fan at a later date, but the $180 for the
duel fan and shroud was just not in the budget.
Attachments
70_coupe_griffin.JPG and
under construction
Elan_radiator_conversion.jpg and
hose_routing.jpg and
griffin_radiator_under_nose.jpg and
yellow_coupe_radiator_hoses.jpg and
Last edited by garyeanderson on Sat Sep 01, 2007 12:06 pm, edited 1 time in total.
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PostPost by: msd1107 » Tue Aug 28, 2007 11:52 pm

I'm with Gary on this one.

I got a Scirroco radiator off of Ebay. It is not the same quality as Garys', but will work. Since everything was out of the nose of the car, I pushed the radiator all the way forward to just behind the air inlet. The radiator is actually a little too wide to allow clean air inlet past it, but some ducting to the air cleaner solves that. Otherwise, it is like it was designed for that mounting. I also rotated the radiator so both pipes are on the left and used Cliveyboys radiator filler cap. Routing the bottom hose across the body is easier that routing the top hose

On the stock Elan and radiator, when air comes in at the nose of the car, it immediately spills into the front cavity of the body, turning into turbulent flow and losing most of its ability to cool. Then it meanders through the radiator and eventually stalls at the back of the engine bay where it bleeds up and down. No wonder Elans have over heating problems.

Simulations show that the Cd of the air inlet to the radiator is around 1.36, considerably worse than a flat plate. Aircraft practice has shown that you can actually get a small negative Cd from a properly ducted radiator system.

There have been some posts recently on helping this air exhaust situation. The factory workshop manual recommends cutting holes in the front fender. Cliveboys sponsored Elan has shown up with two holes cut in the left back of the hood. Another post had one hole cut there. And another post had louvers cut along the sides of the hood. Some people just run with the hood raised proud. All of these will improve the airflow through the radiator, improve the cooling capability of the radiator, and decrease aerodynamic drag.

David
1968 36/7988
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PostPost by: cliveyboy » Wed Aug 29, 2007 7:12 am

Hello David.
Fascinating reading about air flow in the engine bay.
I keep wondering how to vent the air from the engine bay without cutting holes in the external bodywork.
On the later Elans the mod was to cut the two holes in the inner wing on the exhaust side but I wonder why its never mentioned about doing it both sides. The other thought I had was seeing if it is feasible to break into the vent that sits in front of the windscreen. that way you can vent air upwards from the back of the engine bay and over the windscreen.
Any thoughts
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PostPost by: john.p.clegg » Wed Aug 29, 2007 12:06 pm

.....and get engine fumes in the cockpit.....

John :wink:
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PostPost by: steveww » Wed Aug 29, 2007 12:30 pm

cliveyboy wrote:Hello David.
Fascinating reading about air flow in the engine bay.
I keep wondering how to vent the air from the engine bay without cutting holes in the external bodywork.
On the later Elans the mod was to cut the two holes in the inner wing on the exhaust side but I wonder why its never mentioned about doing it both sides. The other thought I had was seeing if it is feasible to break into the vent that sits in front of the windscreen. that way you can vent air upwards from the back of the engine bay and over the windscreen.
Any thoughts
Clive


That would not work as the base of the windscreen is a high pressure area, that is why the cabin heater inlet is there. You need a spot where the air is flowing passed dast and smooth to create a low pressure area. The wheel wells are low pressure and the holes cut on the exhaust side as this is the hottest due to the manifold.
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PostPost by: steveww » Wed Aug 29, 2007 12:33 pm

msd1107 wrote: Otherwise, it is like it was designed for that mounting.
David
1968 36/7988


I have also installed the radiator right down in the nose. I am sure this gives better air flow though the radiator not to mention much easier access to the engine for general maintenance. See my site http://www.steveww.org/ for more details.
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PostPost by: msd1107 » Wed Aug 29, 2007 2:45 pm

Yes, the question of how to exhaust the hot radiator air is a vexing one.

Steveww is correct that the pressure is positive at the base of the windshield. In most cars, there is a high pressure stagnaton point at the front of the car, and then a low pressure gradient as air curves up and around the nose and hood (the Elan is not optimum here). Then there is a high pressure spike as the air is deflected up the windshield, turning negative again at the top and back over the passenger roof. With the windshield grommets top and bottom, the flow is pretty thoroughly turbulent by the time it reaches the roof, and gets worse going down the rear window and away from the car.

Holes in the front fender are a good idea. The front wheel well is a known low pressure area. I wonder, like Clive, why we can't vent both sides. But even 4 2.5" holes is a far sight from the 22X13 area of the radiator, so, in theory, more exhaust area is needed.

This gets in the way of authenticity (although with the Sirroco radiator in the nose you are not that terribly authentic already) and asthetics. The holes at the rear of the bonnet have already been mentioned, but their small size is far from optimum. That they improve the cooling situation shows just how bad the situation really is.

One post mentioned putting louvers on each side of the bonnet. That would be much better. Possibly, instead of louvers, body coloured wire mesh would be less visually disruptive. Key here is to mount it flush to the body.

Once the radiator is mounted far down in the nose, another option becomes available. That is to put the exit duct in the nose just forward of the bonnet. Here again, possibly using body coloured mesh would be a way of maintaining a consistant body colour and line. And clever people could construct a duct from the radiator to the duct so that all hot air is exhausted efficiently, leaving the engine compartment only to deal with the heat of the exhaust pipes. Pulling the back of the radiator back and up so the radiator leans forward would assist this process. Studies I have seen seem to indicate that this form of ducted cooling to be the most efficient in a car.

So lets get out our tin snips and go to work.

David
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PostPost by: elansprint71 » Wed Aug 29, 2007 8:40 pm

cliveyboy wrote:On the later Elans the mod was to cut the two holes in the inner wing on the exhaust side but I wonder why its never mentioned about doing it both sides.


Clive,
My 72 Sprint has original pairs of holes both sides, with mesh grilles to keep most of the muck out.

TT 26r ally rad in "normal" position works for me, no overheating even in traffic at 35 Centigrade. I've also got sealed expansion tank.
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PostPost by: types26/36 » Thu Aug 30, 2007 3:22 pm

elansprint71 wrote:My 72 Sprint has original pairs of holes both sides,


How about a pic of the right side Pete?
Brian
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PostPost by: Tonyw » Fri Aug 31, 2007 1:29 pm

Hi this question may be directed to Rohan or some of the other Aussie forum contributors, I notice many of you seem to have overheating problems and quote ambient temps of 35c I get regular ambients of 40c + so I am wondering if I have the wider radiator, a good electric fan and vent the engine bay if I will have enough cooling?? as my car is still in a zillion bits it is going to be easier for me to factor mods in now rather than wait until I decide to go to a wine tasting on a 40c + day, staying home is not an option!!!............

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