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Discussion Starter #1 (Edited)
So, a certain friend's Opel Ascona has been up and running for a little while now, but unfortunately the new engine creates enough heat to severely tax the stock cooling system. I came up with this 6.2 litre surge tank (and 2 litre overflow tank) to more than double the volume of coolant within the system, and to purge all air from the system at the same time. In addition, an aluminum radiator from Griffin has been adapted to fit into the standard location in the chassis, with no cutting or modifying of the bodyshell required.

I started by mocking up the general shape via cardboard.



I decided shortly thereafter to soften the appearance of the tank by radiusing the edges. Welding is also simplified by doing this, but of course fabrication time is increased. Prior to all bending, I drilled all the holes required for the AN fittings and the filler neck which would be welded on later. I also decided to use an offset-flange (stepped) bead roller die to add some decor to the surge tank, and stiffen the otherwise flat panels of the tank at the same time. Bending was done completely by hand over a piece of 3/4" steel bar stock. Material is 3003 series aluminum, .063" thick.



Fittings welded in place. I used a Canton Racing billet filler neck, and Summit Racing NPT fittings.



First test fitting. Radiator cap clears the underside of the hood, and all the lines clear other underhood accessories. Brass hose barbs will get nickel plated to prevent them from turning green from corrosion. Uppermost line at the filler neck gets routed to the overflow can, the two middle lines go to the highest points of the radiator and the engine (thermostat housing), and the larger 5/8" lower line is the return which 'T's' into the heater hose line at the water pump inlet.



A very simple hammerform allows for radiused ends.



After final fitting the first side, and bead forming it, it got tacked into place.



I then welded the side on fully. I should have filed the tack welds down, because they telegraphed through pretty badly.



Prior to welding the last side on, I made a simple internal gusset. This spreads the loading that the top of the tank will get from repeated opening and closing of the radiator cap (pushing down on the tank to compress the spring).



The other side cap after being formed...



With the main tank basically done, I started working on the mounting tabs. This tab fits a pre-existing bolt hole.



This side had no factory mounting holes to share, so it will get some nut-serts installed into the body shell instead.



Newly nickel-plated brass hose barbs are sealed up with teflon paste, and the socketless hoses are test fitted for routing clearance. Radiator cap is a 'Mr Gasket' cap with a 40°-270° degree thermometer built in. Perfect for goofy car owners who don't know better than trying to open a hot cooling system to the atmosphere!




Here's the custom overflow tank I built to work with the surge tank.



This is the approximate location of the overflow tank, and you can see also the air bleed at the top of the thermostat housing.



The larger hose at the bottom of the surge tank is the return line, which is 'T'd back into the water pump inlet (suction side). I made this T fitting from copper plumbing tubing, beaded the ends, and again had it nickel plated. I used high temp silver solder instead of tin/lead solder to hold it all together. I just have to cut the heater hose before the water pump and fit this in the line.



Lower radiator mount. I haven't taken any pics of the upper side mounts, but essentially they are just like the OEM Opel ones, using the rubber bumpers to locate the radiator fore and aft.

 

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Very nice work Bob.
Your attention to the little details shows your craftsmanship.
I'm surprised that you didn't add cooling fins on the surge tank:lmao:
Very nice work!
BTW did you cold roll or used heat?
 

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Discussion Starter #3
Very nice work Bob.
Your attention to the little details shows your craftsmanship.
I'm surprised that you didn't add cooling fins on the surge tank:lmao:
Very nice work!
BTW did you cold roll or used heat?
Thanks Dan. I ended up just bending it cold. It's pretty malleable stuff, and not too thick.
 

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Wow, the surge tank looks great! Do you have any additional pics of the radiator mounted in place? I have the same (or similar) Griffin radiator going into a 2.2 Manta but I can't imagine that I would need an additional surge tank. The Griffin radiator looks to have WAY more cooling capability than the stock radiator. Did you attach side mounts? Also, have you mounted a cooling fan yet? I'm planning to use the same radiator for my 2.5L application.
 

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Bob,
How much higher does the surge tank need to be than the rest of the cooling system? The location is probably the best but it seems to me that it still would'nt be the highest point.
 

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Discussion Starter #6 (Edited)
Wow, the surge tank looks great! Do you have any additional pics of the radiator mounted in place? I have the same (or similar) Griffin radiator going into a 2.2 Manta but I can't imagine that I would need an additional surge tank. The Griffin radiator looks to have WAY more cooling capability than the stock radiator. Did you attach side mounts? Also, have you mounted a cooling fan yet? I'm planning to use the same radiator for my 2.5L application.
Todd, you're typing faster than you're reading....:haha:

Lower radiator mount. I haven't taken any pics of the upper side mounts, but essentially they are just like the OEM Opel ones, using the rubber bumpers to locate the radiator fore and aft.

http://farm2.static.flickr.com/1143/...c1b9671e_b.jpg
Gregg's car was running *at least* 210-220 degrees with his 2.2 engine. And while just the radiator alone might have been enough for the current engine, eventually the car will get a header, 2.5" exhaust, twin EFI throttle bodies, and a much bigger camshaft. Which will put even more thermal loading into it. If the car is ever to be run hard at the track (or even the road) in hot weather, I'd rather have 'too much' cooling than too little.

As it is, it was hitting crazy temps just cruising at 50-60 mph in 85-90 degree heat. It was bad enough the camshaft got wiped out and had to be replaced at 1700 miles, and we had to inspect the head to be sure the valve guides didn't seize on the valves and start pulling out of the head. They were okay thankfully. The valve springs lost a little bit of spring rate however (Rick removed them and tested them).
 

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Discussion Starter #7
Bob,
How much higher does the surge tank need to be than the rest of the cooling system? The location is probably the best but it seems to me that it still would'nt be the highest point.
It just needs to be higher than the highest point where air could accumulate in the system...meaning the thermostat housing and the top of the radiator.

As far as my chosen location, it is the highest point under the hood that does not interfere with the heater core. The radiator cap is about 1/4" below the surface of the hood, and the rear of the engine compartment is considerably higher than the front of the engine compartment. Unless I removed the heater and put the surge tank in the middle of the hood (as the hood is slightly crowned in the middle), the only place higher is outside the car!
 

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Todd, you're typing faster than you're reading....:haha:
Actually, my question is legitimate but I should explain. I know you don't have pictures yet but I'm wondering if you have attached the side mounts yet. The reason I ask is that my radiator is currently at a shop to be modified, but the guy is a little concerned about welding the mounts to the side because the reservoirs are on the sides. For my bottom mount, he fitted an aluminum block (with either a threaded hole or a stud, I haven't seen it yet) so that the installed height is like the original. Basically I took him the old radiator and the new one and asked him to match it up so that it would fit like the original. I'm just hoping his TIG capabilities are good enough that he can get the side mounts welded on there without hurting the tanks.

Now you have me worried that this radiator won't be sufficient for my 2.5. However, I'm sure I will never drive the car as hard as Gregg.

Todd
 

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Discussion Starter #9
Actually, my question is legitimate but I should explain. I know you don't have pictures yet but I'm wondering if you have attached the side mounts yet. The reason I ask is that my radiator is currently at a shop to be modified, but the guy is a little concerned about welding the mounts to the side because the reservoirs are on the sides.
I have fabricated the mounts, but not welded them in place yet. I had to push my 'mockup' car outside the shop to let something else on my lift, which stopped the radiator fitting dead in it's tracks.

As far as your car's cooling, you will probably be fine. A surge tank is a good idea always, to eliminate all air. It doesn't need to be like the one I built (as you know I torture myself by making everything from scratch). A $60 1 or 2 quart off the shelf Moroso or Canton tank would be fine, and gives you a high point to fill the cooling system. I ended up removing the radiator fill cap from the radiator for Gregg's car, since it interferes with the hood closing...but it's an Ascona, which has less room than a Manta. The system will be filled entirely from the surge tank.
 

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Discussion Starter #10

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Lazy solution.

More nice work Bob!
But I'm partial to my auxiliary radiator solution. Adds at least 15% to the capacity of the radiator
heat transfer area and really pulled down the temps. In parallel with stock heater core.
:veryhappy
Ford Econoline heater core $20 new in custom fabricated mount.
 

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But I'm partial to my auxiliary radiator solution. Adds at least 15% to the capacity of the radiator
heat transfer area and really pulled down the temps. In parallel with stock heater core.
Ding the little light bulb just lit up. Thanks Mark!
Bob do you mind If we wonder off subject...kind of.
There's a company(internet) that sells intercoolers cheap. There air/air and there junk for moving good quantities of air. I'm wondering if I could buy back the unit at a lower price from a dissatisfied customer and reuse it for additional cooling. I've got just the place in mind for the reconfigured cooler, right under the stock radiator.

For that matter there's other cooler's that could be reused. One that comes to mind is the 7.3l intercooler. Yes I'm cheap!!!!!
 

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Discussion Starter #13
Ding the little light bulb just lit up. Thanks Mark!
Bob do you mind If we wonder off subject...kind of.
There's a company(internet) that sells intercoolers cheap. There air/air and there junk for moving good quantities of air. I'm wondering if I could buy back the unit at a lower price from a dissatisfied customer and reuse it for additional cooling. I've got just the place in mind for the reconfigured cooler, right under the stock radiator.

For that matter there's other cooler's that could be reused. One that comes to mind is the 7.3l intercooler. Yes I'm cheap!!!!!
Dan, I'd think that if the tanks are welded (as opposed to crimped on and sealed with foam gasketing), an intercooler would work fine as a radiator.
 

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More nice work Bob!
But I'm partial to my auxiliary radiator solution. Adds at least 15% to the capacity of the radiator
heat transfer area and really pulled down the temps. In parallel with stock heater core.
:veryhappy
Ford Econoline heater core $20 new in custom fabricated mount.
Just did measurements and checked my installation notes for the record if anyone cares.
The 1973-1992 Ford HD Econoline van front heater core 6"x9"x2" thick adds 28% to the heat transfer area over the stock '75 Manta 14"x18"x1.5" thick rad. Also increase coolant capacity by about one quart with the extra hoses and all. New ford cores sell at advance for about $28 currently, Part No. 399026 that I used. :p
 

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Sounds like a great deal! Just one quart though? Seems like, with those long lines, it would add at least two. :confused:

I might try this with my GT.

Jim :cool:
Since only a small amount was lost when I cut into the two existing heater hoses, and most of it was caught, I was able to measure how much more was needed to fill the reconfigured system and it came to about a quart, give or take a couple of oz.
Those new hoses are 5/8 ID and about four feet long each. Not much volume. :no: The increase in heat transfer area counts for far more then the added coolant volume. BTW. There are many heater cores to chose from for different mounting. Some are long and narrow and could be tucked up beneath the rad as Dan has mentioned. Just want it to be in the air flow. I was looking to use only one large heater core, but two or more in series is another way to do it. This was just the way I settled on. Most people think it's an oil cooler if they notice it.
 

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Discussion Starter #17
A surge tank is a good idea always, to eliminate all air. It doesn't need to be like the one I built (as you know I torture myself by making everything from scratch). A $60 1 or 2 quart off the shelf Moroso or Canton tank would be fine, and gives you a high point to fill the cooling system.
Okay, some of them are a little more expensive than I remembered, but here are some off the shelf alternatives for a surge/expansion tank.

www.cantonracingproducts.com

Moroso : Category Display

Speedway Coolant Expansion Tank

AFCO: RADIATOR SURGE TANK

JOES Racing Products designs items to meet the demands of the racing market. Check out our full line of high quality items and browse our website to find great products that track tested and simple to use. - JOES Racing Products

Forge Motorsport | Alloy Fabrication
 

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Wow!

Nice work!!

I have used AFCO cooling stuff (aluminum radiators) in the past and found them very good at a very reasonable price. Their shocks, on the other hand, were a big disappointment, but that's another story.

Keep up the good work and the information flow!

jtb
 

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Discussion Starter #19 (Edited)
Gregg's Ascona has come and gone from my shop, the new cooling system upgrades have been installed with excellent results. Unfortunately I was not able to utililize an electric fan for this car, as there was simply no room. With the thicker radiator core, there was only 2.25" clearance between the outermost part of the water pump pulley and the radiator core. And the aftermarket tranny cooler meant no room in front either!

So I fitted a stock Opel 7-blade fan instead, but I had to shim it out 3/16" to clear the 2.2's lower crank pulley attachment bolt. No shroud was fitted.

The leak-test involved starting the car while on my lift and letting it run for 20 minutes with no airflow passing through the radiator. Before the upgrades, it would run at 200-210° minimum, spiking to 230°+ in slow traffic. Now it warms up to 170-175° and stays there regardless of whether the car is idling or being run hard in traffic. There is a 180° thermostat installed, and it appears to be opening, but I can't get any more heat out of the engine now!

I'll post pics of the completed installation when I have a chance to download them.

Bob
 

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Discussion Starter #20
As promised, here are the pics of the completed installation.

















 
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