I think I will install this tomorrow. The idea is to give me extra cooling and move some of the heat out of the engine compartment.

I'm confused....do you have a rear end in your engine compartment?

Seriously, how's that gonna help?

I am gonna run some half inch copper lines from the heater box hoses with some Tees and valves through the tunnel and to that heater core back there to radiate some heat out back there.

If you have excess heat why not fix the cooling system so it works optimally instead of doing all that work?

backflush engine
replace water pump
boil/clean/recore radiator & heater core
replace hoses & heater control valve
make sure air is flowing through radiator not over & under

Plus, install an oil cooler

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I don't understand the WHY of extra cooling. Does your car overheat? In my rather limited experience with Sprites, they don't NEED anything more than what the factory provided. That is you don't need and oil cooler, you don't need an extra fan, (tho using an electric and removing the engine fan will provide extra horses) and you most likely don't need an extra radiator! Its all cool to have (until you try to change your oil and mix the dirty oil from the cooler with the clean oil you just added).. I've run in 98 degree weather, stuck in traffic jams for over an hour, and climbed the Rockies at 4000 rpm in third gear and NEVER overheated.... but then my engine is a MOSTLY stock 1098. ....


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New water pump, hoses, I went through the heater control valve. Radiator was a used one that looked better than the one I had. I just hate to tear all that stuff back out again. It has an oil cooler too that I flushed out and cleaned up as well as the hoses. I wanted to find a way to keep it on the road this summer. I don't know what is causing it. It seems to run nice and cool for the first 1/2 hour or so and then if I shut it off, it runs hot after that.

Well, before I started running lines through the underside, I'd pull that radiator &, while you're at ir, backflush the engine.

How do you say, "DPO"? hehehehe

Think I would try a nice new thermostat. Then would have the radiator cored along with a back flush.

I'm thinking about doing the same fix. Moving some of the heat out of the engine bay is a good idea.I will be adding a small fan on a relay with temp. sending unit combined with my main rad.elec. fan to cool this aux. rad. I have cooling problems that won,t go away no matter what I do and I,ve spent alot of time on this.

It seems to me, in days of yor, some race cars had very large water tanks attached to their systems.

Maybe Hap can weigh in here about finding the correct high quality water pump. I suspect there are some water pumps causing overheating problems due to low flow and cavitation.

Was that for colling down the fuel?
I had cooling problems too Kim, that trip back and forth to the Ozarks this time, I never went over 1/3 on the gauge.
I had the radiator out and flushed by a radiator shop, head flushed, new water pump and the heater by-passed, new t'stat and hosing; whichever one of those things worked a treat, but I suspect the water pump, as it was the last to go on.

Maybe, just maybe we have some bad water pumps floating around. By that I mean the wrong pump for the vehicle.

Lookie two pumps Moss 434-540 948 thru 1275 12CD/H1745 and 1275 12CD/H1746 and up Moss 434-545. Moss catalog page 14 by the way. The latter seems to be standard radiator and cross flow as well.

I bet the wrong one even fits.

Long ago on a 3/4 race ford I had to have the impellers shortened on the water pump to slow down the water through the radiator so it had time to cool. Shrug, it worked.

So, I have no idea what the difference is but it could be larger or smaller and still be interchangeable in the head.

Guess I would check the pump part number.

Must be a reason.

Some impellers are made of stamped steel and some are cast, and the depth of the impellers vary.

Well, guys. This was something I figured I could hook up in a day without tearing the car back apart. I am not going to do anything that cannot be undone. Only going to cut the heater hoses and install some Tees and run those lines back there and see what it does. I probably do have a bad radiator but I want to keep driving the car for the season and then work on it this winter when off the road. I thought this might be a quick fix for now so I can keep on driving it. The lines going back as well as the heater core will all radiate some heat. I figure I am not far from keeping it cool right now as it takes 1/2 hour or so for it to get hot right now. It is a weird condition that I have. I can fill the radiator and drive in stop and go traffic and it might overheat but it takes a long time. If I run 70 on the interstate for a few miles, I can watch the heat hand steadily rise and when I stop after that it goes to boiling point. (I know where 212 is on my gauge because I calibrated it when out of the car) after that is might cool off a bit but still is near boiling and goes to boiling easily. I have not yet heated it up to where it blows steam, I usually shut it off and let it cool down before that.

Intresting Trevor, and I bet they cool different as well.

OK, did not work on this today. My kitty cat of 15 years and friend through thick and thin took a bad turn for the worse and we had to make the hard decision and have her put down today. Spent the afternoon making a wooden box and digging a hole in some dry ground as it has been drought here. We do get attached to those little critters. Not a good day for me. Tony and jack, I hear what you are saying and I know ya'll are right. I am just trying to get by till I can get it fixed right. Its been forever on this car and I just need a little extra cooling to keep it going.

Sorry about your loss. It's tough, no question about it.

Do what you need to do Kim, your work is of excellent quality and it is fun to follow your efforts.

Down here in Johannesburg

On the Spridget tour I was constantly concerned with overheating, watching the gauge is not conducive to relaxed driving. Anyway the water pump packed up and I was trailered for about 100 miles. Next day a new water pump and I noticed the diameter of the pulley was significantly larger than the old pump's pulley. The rest of the trip was amazing the temp gauge must have dropped by half. As opposed to just under the H mark, it never approached the N mark. The smaller pulley rotates too fast so it either churns the water or pumps it too quickly through the radiator. The larger pulley turns less giving the water time to cool through the radiator.

So out with your radiator back flush every and anything and make sure your water pump is the larger diameter kind, about 5 inches as opposed to about 4 inches.

what about the radiator cap. If its not sealing boiling temp is going to come on you pretty quick.maybe your not running pressurized? could be the wrong lenght spring under the cap and your sealing on the secondary ring.

Kim - if its a temporary thing to get through the driving season & it doesn't become a permanent bandaid - its your car, go for it!

But, during the winter - were it my car - I'd go through the entire cooling system & refresh everything....the little car should keep itself cool regardless of the outside temperature - just like it was designed!

Yeah, that is the plan Tony. I just know it will take a while and I will go through everything this winter. Does anyone know what degree thermostat was supposed to be in there original? I can't recal what was in mine or if I tested it in a pot on the stove. Could be that it is not opening enough. What really gets me is that how the temperature starts out fine on the highway and then slowly creeps up. You would think there would be plenty of airflow going down the highway even with no fan at all. I could see it heating up at an idle after a hard run when all that heat catches up and the fan is not going that fast and the car is not moving. I will get to the bottom of this one. Meanwhile will try the temp fix because it seems like cutting the heater on helps a lot but I don't want my feet to cook. Also, would appreciate any more info on the waterpump size thing. Are there different size impeller pumps through the years??

180 Degrees is optiomal.

1) I'm not convinced that you'll get enough airflow down there to make a lot of difference.

2) I wouldn't want a rad down there where it could get hit by stones thrown up from the wheels and therefore let all the water go - that would make it overheat!

I think that I would start with
- make sure as much air as poss goes through the radiator - fill any gaps at the sides or above with ali sheet for instance.
- is it a 2 or 4 blade fan? - if 2 make it 4 or take it off and put an electric fan in
- put water wetter in the cooling system
-put an air scoop to pick up air from under the 'chin' of the bonnet - i know this has been done sucesfully with middle sized Healeys (3000s etc) and they do suffer form overheating!

As a longer term thing look at a bigger capacity and/or ali radiator.

John

As I recall there is a difference in water pumps and impeller sizes / wear in the vanes could also be an issue. Pumping rusty / chunky water through a water pump, as done by a P.O. could definitely weat out the vanes. Hey try changing out hte waterpump first and foremost. That and flush the radiator. Spridgets don't necessarily always overheat. Usually some external condition / wear causes the issue. You might not have the correct water pump for your engine or it could be worn. Try simple stuff first before reengineering

Down here with 95 or so heat and lots of humidity Miss Agatha has never gone over 180 and that includes the Loto as well come to think of it.

Just goes to show what clean inards will do for you.

I put a brand new pump on it when I rebuild the motor. I never realized there was a difference in them. Does anyone have any info on this deal about too much circulation and running hot? I know that my pully is not stock the stock pulley was plastic and broke years ago and I am not sure if the replacement is the same size. I kept on with the project. The heater core I am using is out of a subaru (because I have one laying around) and I also used the heater control valve out of the subaru, so I can cut this extra cooling off or on or shut off if I should develope a leak down there. I bought the copper line and have them bent and installed and the valve too. Started making a frame for the heater core and ran out of energy yesterday. Hopefully get it put in this evening and then Tuesday hook up all the heater hose Tees and test it out. I think it will help. I have had sevral cars the would overheat and cutting the heater on would act as an extra radiator and help cool it back down. This core is totally open so there should be plenty of air flow under there at speed, more than the heater fan I hope, plus 8 feet of copper line through the tunnel which should have air flowing through it as well.

Everything installed underneath. Had to make a few parts and took some time. Got to hook hoses up tomorrow under the hood and test it out. Hopefully this with help at least till fall when I take it off the road and put my Sportage back on the insurance. Then in the winter I will work on it. Already got an electric fan coming that I bought off of Ebay. Will probably install that one right away as time allows.

So, how long has it taken to put htis modification under the car - in lost driving hours?

I don't know Tony, I still go the top down on the car in the basement/garage and its poured the rain the last couple evenings so I might not have driven it anyways. It might all be a big waste but its experimentation and interesting to me.

I remember back when I was setting up my carb jetting that tuning it with just a little to advance on the timming really warmed it up and not much performance differance just a thought. hate to see you go through to many motions if you dont need to .
Too many miles not enough time.....

Well, its done. Tested it out but it is only 71 degrees outside and I ran it hard and could not get it even up to the N mark. the hotest it got was when I shut it off in the basement. Still just over the N. Time will tell. Here are some pics of the final thing. I could put my hand on it and feel it was scalding hot and at speed must have been removing a lot of heat. I could see the needle drop pretty quick after pulling away from a light.

Looks like nice work.

Electric fan came today. It won't fit as a puller unless I do some serious stuff with the water pump shaft and pulley to give room for it.