Tried the timing thing once again with no difference. The only thing that is going to make this radiator cool this engine is more airflow.......and that's iffy. I'll probably try a fixed fan.
Absolutely. Two different times. I done with timing guys. This is not the problem. Fixed blade fan - Derale 17317 ordered. Test next weekend. If that don't work, I'll be changing radiators.
Hey rock, did they give you the dimensions of that fan? I realize it is 17 inch across, but is there an offset? howm uch of the blade is in front and behind the mount surface?
To be honest, I didn't think of that. It appears to have no offset. I will space it to be half in/half out of the shroud, as the present flex fan is positioned.
I am looking at speedway motors part # 910-1575-17, the fan blades are 3/4 inch behind the mounting surface, and 1 3/8 in front. I worry about the howl from the fan. SO please post how you like yours, and is it effective. Thanks
I'm disgusted. The new fan definitely moves more air. The engine runs about 190 in hot weather, as long as its moving. When it's sitting still, it's a different deal. The temp starts climbing after a few minutes and once it starts, the only way to make it stop is to get moving. Once you're moving, it cools right back down in just a few minutes. This tells me that the air is not exiting the engine bay while the car is parked. When you raise the hood, there is a lot of hot air trapped there. Tomorrow, I am going to try letting it idle with the hood open. Any ideas for moving that air out from the engine compartment?
I'm subscribed to the thread. I've thought the same thing... Like why not mount a fan somewhere to draw air out, say to the passenger side. Then again if you are moving the air would be moving under the car I think. Seems like you still need a radiator?
thanks for the update, 1 more thing, how far behind the mounting point and how far in front does the blades sit? 3/4 behind and 1 3/8. forward. Is that the same?
Otay, I'm a little lexdysic ; ) The part has a misleading****le. Guess it acts like putting your thumb over the end of a hose and increasing the pressure. However much the glass is full, it works.
Can you post a picture of your pulley setup? I would go with a smaller water pump pulley, there are a few different sizes depending on what crank pulley is used. Normally the crank pulley is much larger than the water pump pulley and not 1:1. I have a bunch of sets here from long water pump setups if you need a setup to try out.<p> Also I know it has already been mentioned but I would be pulling the water pump off and replacing it with a good stock GM one if the pulley swap doesnt help. Could have the wrong impeller for a serpentine setup or could just have a cheap impeller. There are stamped steel ones that dont move much coolant and there are cast iron ones that do. Sometimes the wrong part gets put into a box, I would buy a water pump for a 70s SB (assuming you have a long nose water pump) and swap it out. You can open up the back of your chrome pump and check the impeller design if you want. <p>I do not have a very big radiator in my 37 buick and I can hardly get the SB to 190 degrees unless stuck in traffic, and then the electric fan cools it right down again. Good luck!
I do believe it is a fine-line...... can't circulate the water too fast or it will not be cooled enough while in the radiator or..... If the coolant circulates too slow and spends to much time in the engine it'll never cool down. I think the most frustrating thing is some cars have old beat up undersized radiators, no shroud or special water pumps or fans, etc, etc, etc..... and the engines NEVER run even run "warm" let alone "hot". Practically everyone I know (including myself) who has had (or has) a cooling problem has a tough time tracking down the problem. Most of the time it NEVER comes easy!!!! What adds confusion to the confusion is very often the problem cannot be "pin-pointed" to just one thing or two things. Also something that needs to be taken into consideration is some engines tend to run warmer than others especially in stop & go traffic. Running 190-200 for those engines might be is good as it gets.
Since the fan did not fix the problem try a slightly smaller water pump pulley to speed up the pump a little,I have found a/c equipped cars have a slightly smaller water pump pulley.
A bigger crank pulley will turn fan and water pump faster,late model cars have a very large crank pulley and a small water pump pulley.In was in the tech info from Howard Stewart.
Crank pulley is 6" and fan pulley is about 5". It's overdriven. I took the edelbrock water pump off today and was going to put an OEM water pump on it. Actually, I did put an OEM water pump on it only to find out that the shaft extension won't work with my pulleys. I took the rear cover off the edelbrock. Their tech told me it would have a R stamped on it for reverse rotation. It does not have an R on it. Also, there is no sign of corrosion. I doubt seriously there is anything wrong with this pump. I may put it back on. Does anyone know of a relatively inexpensive water pump (short style) for a SBC that has a longer shaft extension on it? OEM is 3/8" and the edelbrock is almost 5/8". I am not installing a fan on this water pump without it being properly piloted. Question. If I had an air pocket, would it still run at acceptable temps at speed but overheat at idle? Or would it overheat all the time?
I just measured one of my LWP setups, has a 7" crank pulley with a 5" WP. Not sure what is available but I think a smaller WP pulley or larger crank pulley would help. As for air pockets I always drill a 1/8" hole in my thermostats to allow a small amount of coolant and any trapped air to get by the thermostat at all times, works well for me. Sounds like you pulleys are aluminum or for some reason extra thick, I would go with an OEM water pump and pulleys, but I have learned the hard way to use OEM stuff whenever possible.
It has been my experience, that an air pocket will only last till the thermostat opens. Then it burps out. Its the same principle as drilling an 1/8 hole, which I do on WIndsor setups, or LT1 setups. Once the thermo opens, then it should be gone. That*****s, your heat issue. Man that*****s. I was hopin it was cured with the fan.
I really don't want to start changing pulleys. I dont really believe it will make a big difference either. That is going to get really aggravating to get right. I didn't build this car. At this point, I'm just trying to make chicken salad out of*************.
I've only had 2 air pockets, one on an OT SBC truck, and once on my current motor in its previous life. The first time I had the air pocket it wasn't apparent till about a week after I had the car, its almost like it finally got caught on top of the thermostat and just kinda hung out there. I know it was an air pocket, because I was able to bounce the car up and down till I saw the bubble pop out of the hose. Started the car up and never looked back! The second time It ran hot all the time, till I let it sit and run with the rad open and repeatedly bounce the car up and down. I've seen those thermostat housings that have a bleader in them, but if your rad cap is high enough its not really necessary! Good luck man!
a friend of mine had the same problem with his plymouth.. he evean bought another crate 350.. and had the same problem.. so he sold it.. the guy who bought it moved the electric fan down 3 inches... solve the problem.. it was airflow.. sometimes it's the simple things..
I have a shroud, a 3 row radiator, and have put a rigid blade fan on it. Air should not be the problem.
Put some "over the road" miles on it & see what happens."thirtycoupe" had the same problem with his crate motor till he got alot of miles on it. JimV
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