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This is what happens when I'm bored, I don't even know why I did it. It kinda looks cool, and it has a relocated heater hose fitting plus ports for an OEM temp sender and an aftermarket sender.
 

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RallyBob said:
This is what happens when I'm bored, I don't even know why I did it.
Bob, if you get REALLY bored, theres a perfectly good heated workshop attached to my house, with attendant tools (not quite up to your standards, but it has a MIG, sand blaster, ox-acetylene torch, etc.) that could keep you entertained for, oh say, the winter. And maybe a bit of work might get done on the GT that occupies the space.

Yea, I am never THAT bored either!
 

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That does look cool. And a 1/2" NPT port or two will come in very handy!
I plan to do something different with mine, too. It will look quite different, I think I won't use a thermostat at all. It just needs to be a housing that bolts to the head and has five 1/2" ports. One for the Autometer temp gauge, one for the idiot light, and three fittings for heater hoses that will go to the top radiator tank. At the top of the radiator tank one hose will go on the far left side, one just left of the center, and one a bit to the right of the middle one.
My thinking here is that the Honda Accordian radiator will flow more than the pump will, thus if I'm dumping all the water in at one spot it just falls straight down to the bottom tank.
Does this make any sense to you, or should I quit wasting time and concentrate on how to get the right rear axle ratio? It's gonna be a long winter, I can't wait to run Speedway GT again!!
 

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Jeff, Cooling systems are an area of consideration for me and I have made it almost a plea to not remove the thermostats, but rather make sure they are functioning correctly. They do serve a pupose other than getting the engine up to temp quickly, they regulate to coolant flow to maintain a predetermined temp. One thing overlooked by a lot of folks is that by regulating coolant flow through the radiator, the coolant in the radiator has sufficient time to cool. I've said it before and I'll say it again, I have seen cooling systems overheat because the thermostat was removed. As far as having the coolant enter the top of the radiator in three different locations, I feel once the coolant enters the top tank of the radiator, it will seek it's own level, thereby flowing across the top tank and using all the coolant tubes for the descent to the bottom tank. Just a little bit of basic laws of physics. But it's your call to do what you want with your radiator.
 

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boomerang opeler
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jeff you may want to think of your radiator the same as a household 1 the whole system is full there is no where for water to fall through(air gaps mean bangs and rattles). As the pump will only pull it out the botton at the same rate it puts it in the top you will only get a flow not a fall
this flow is at a rate to match your pump and best cool the water
the thermostat is used to match this and is the ristriction that ron has said in his post.
to remove is to kill on a high rev use like your as it can not get the time to drop the temp;)
 

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You are absolutely right, Ron, there is a science to it, and generally it is a BAD IDEA to remove the thermostat. In a typical street driven car. What I'm talking about is my race car, a car that is built to do horrible things to yet must survive each flogging. Hopefully even cross the finish line in front of twenty other cars. I constantly strive to make changes to it to be strong, fast, and reliable.
As I live in an area of severe winter weather and my occupation involves diesel engines from small to huge, I despise starting an engine cold and revving it before it has warmed up. Ditto on my race car. It hasn't been fired up yet without being pre-heated. The fans come on when the temp is 180. Then it runs full throttle at 7000 rpm in a hard left turn with such G-forces that it hurts my body where the seat holds me in. We address these G-forces very carefully in the oilpan, why not in the radiator tank?
Could there be anything to it?
In the compact class we built Speedway GT for, a common problem is overheating. Recently the rules were changed from "stock radiator located in stock mounts" to "any radiator located in front of the engine." HOORAY!
I put a Honda Accordian radiator in, slanted like a Stingray Vette. Everybody said it won't work, you won't get airflow. I said, hey, it works in a Vette, and this is a baby vette.
With some sheet plastic ducting work from the opening under the Bumper to the bottom of the radiator, it works like a charm. But it has yet to be really proven in an actual race with traffic trying to kill it.
I can't wait till spring!
 

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Discussion Starter · #8 ·
While I don't agree with using a thermostat on a racing engine, I also don't like using a fully open thermostat housing either. After a lot of testing, I settled on a 7/8" ID restrictor working best for my particular conditions (your results will vary with ambient temp, altitude, RPM's, humidity, etc). Fully open we used to run 205-210 degrees water temp. With the restrictor we ran 190 degrees. Bear in mind, this was with a set of reduction pulleys dropping the water pump rpms by 34%. Prior to the pulleys, it also ran hot....the water spent too little time in the radiator, therefore it did not cool enough. Slowing things down dropped the temps.

HTH
Bob
 

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A good point about the "G"-loads Jeff, but, and this is not really rocket science, but if the radiator is full, and also the cooling system, water being a non compressible fluid, where can it go to? The oil pan baffling is completely understandable, lotsa room for the oil to move around in the crankcase. Even with Rally Bob's suggestion of a restrictor instead of a thermostat, the restricted flow would not allow sloshing around of coolant if the radiator is full. JMTCW.
 

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Being an auto tech and a radiator repairman for too many years I have seen my share of overheating troubles. The points about physics and flow are well taken, but due to the many different designs what applies to one may not apply to the next. One example. the first Dodge pickups with the Cummings engine had a huge radiator, but the inlet and outlet were on the same side(downflow, tanks on top and bottom) in hot weather and severe usage the engines would overheat. The coolant would go in the top, right down and out the bottom hose. Only 1/4 to 1/3 of the rad was trying to cool the engine. Before they redesigned the rad and moved the outlet to the oppisite side, they installed baffels in the top tank to make the coolant flow all the way accross the top tank, it worked. In my opel over the years I have tried several things, a mild street engine never over 5000 RPM. NO t-stat, engine runs too COLD, biggest difference, fuel mileage dropped 7MPG. Modified t-stat, guts removed, 180F even on the hottest of days, but takes awhile to reach this temp, and too long in the winter. 180 degree t-stat works great most of the time,the engine will run hotter than I care for during the peak summer heat season, then I use the modified t-stat.

DAN
 

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Thanks Dan! Your cummins experience describes exactly what's going on in my radiator, after a hard run it just felt like only one area of my radiator was warm, just the rows under the top water neck. I think my plan to put the coolant into the top tank in three different places equals the Dodge pickup's new baffles in the tank, and those hard G-forces will be put to use here, too!
I want an electric water pump. High tech in the new auto world is there, it's been common in drag racing for a while, and you see it on lots of hot rods now. That pump could vary its flow according to need. Isn't that simple...
To open a new can of worms, has anybody studied coolant flow rates through the Opel engine? Is there any need for improvement there to reduce hot spots, or did the Germans have it together that day, too? Just think how an electric pump could be plumbed in to inject the coolant into the block in any area you want!
 

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Jeff, I read that you are using a honda radiator, a few questions, was it brand new? Is it copper/brass or aluminum? If less than new did you have a tank removed to make sure all tubes are flowing at 100%? I have not seen an electric water pump that has a variable flow. I have seen small electric water pumps (factory installed) on audi turbo motors, BMW and Mercedes. These are called booster pumps(at least on the Audi), I have seen some of these used in the heater lines to boost heater output. Have read where some MFGs are using or planning to use a reverse flow coolant system, coolant returning from the rad goes to the heads first.

DAN
 

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Use an Infrared Thermometer

If you've got some extra cash laying around, consider purchasing a RayTech infrared thermometer gun. Besides using it as a marital aid, you can scan your radiator to definitively evaluate the flow (or blockage).

It's also handy to determine which fuel injector or spark plug is fouled, which cylinder is running rich, etc.

I've never used the inexpensive models, but RayTech's technology is tried & true. The Extech 42500 lists for $79.00, while the Extech 42510 costs $99.00.

You can buy direct, order through JC Whitney, or an auto parts store.
 

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The radiator is brass, the Honda was an 85 Accord although I call it an accordian, it was very rear-ended but otherwise intact when I removed it's radiator which was full of coolant. I don't at all question its integrity but you have a good idea there. I will have the top tank removed and then make some more changes to it before putting it back on.
Yes the temp gun is great! I use my Blue Point version practically every day.
As for the electric water pump, I would experiment with some heater fan motor resistors to get somewhat variable flow rates. The ones used on heavy equipment with multiple blowers may be heavy duty enough. Just something to play with...
I just like the "all electric" idea. So far we have electric fans and fuel pump, next will be electric water pump, and I ponder the possibility of an electric lube oil pump. Anything to reduce horsepower-robbing of poor little 1.9 liter Speedway GT...
Thanks for all the input. Our combined minds seem to work well!
 

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Oh yeah, and the reverse cooling trick! I'm pretty sure it was another innovation of the late great Smokey Yunick (my stock car racing hero) way back in the sixties. It is factory stock on the second generation Chevy LT1.
The only time I've dealt with it is on a couple Mastercraft ski boats around here that have that LT1 engine aboard.
Jeg's catalog shows an inline electric water pump that flows 20 gpm. I wonder what the stock Opel pump flows. Anyone?
And then I wonder, at what rpm (rpm of the water pump impeller itself) does the Opel pump flow the most? I had started modifying pulleys to slow mine down (as Bob suggests) but didn't get that done before track testing. I was running a stock crank pulley and stock pump pulley. At up to 7200 rpm.
By the way, I'm not complaining that Speedway GT was running hot, it was perfect (190) but that was on a September evening in northern Montana, not quite t-shirt weather... What will happen next summer when we race in July and it's 102 in the shade? Just want to be ready. I hate overheating even worse than an oil leak...
 

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jeff denton said:
Oh yeah, and the reverse cooling trick! I'm pretty sure it was another innovation of the late great Smokey Yunick (my stock car racing hero) way back in the sixties.
One of the most indespensible reference books I have is Smokey's "Power Secrets" Deals mainly with Chevy V8s and V6s but lots of the stuff in there can be directly applicable - just a pity he did not race Opel CIH motors!
 

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jeff its just a thought but if the electric pump is too fast(its bound to be for a large V8) could you put an industrial ball valve in the line to the rad and mount it in the cab so you could start partialy closed and then open it as you go round, if its too hot, close more if its too cold!!
 
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