If you have problems keeping the engine cool in traffic, the first thing I'd suggest is swapping out that water pump. It's the same design as CAT Performance and Edelbrock. Flow rate of that pump is OK on the highway but lousy at low RPM.
Yep, thats the one. Luckily, I live in a rural area with only 1 spotlight for 30 miles, but I will defintely keep an eye on it. Thanks for the heads up.
Joined: Sat Aug 19 2006, 05:03PM
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Fury Fan wrote ...
I've read somewhere that one of the aftermarket pumps is pretty good, and I think it's the Milodon?
MY memory isn't perfect, so anyone should research for themselves before buying.
I replaced it with the Milodon high volume pump with anti-cavitation plate and a high flow thermostat, which Milodon recommends for use with this pump. I am still using a cast iron housing, a good 3-row 22" copper rad, large Flex-a-lite fan and had already tried adding a shroud to no avail.
Joined: Wed Dec 21 2005, 07:34AM
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Did the Milodon fix it, then, Mike?
Cooling issues are always good for lots of theoretical discussion about some complex physics!
Adding a row to a radiator isn’t as effective as making it wider, so a 3-row 22” might not be as good as a 2-row 26” (although there are a lot more details involved in that equation)?
As I’m now learning a lot about engine fans at work, I’d be very leary about using an aftermarket fan (esp a flex fan), or at least I wouldn’t assume it would be part of the solution. You added a row to your radiator, which increased restriction, and if by ‘good 3-row’ you mean one with higher fin density, your flex fan might be a little flimsy to pull thru that higher restriction. In addition, a fan has its ideal immersion into a shroud, and with a flex fan you might not get that, certainly not as it starts flexing. Further, as the flex fan flattens out it’s becoming a larger blockage to airflow and decreasing its contribution. Who knows to what extent, but it’s happening.
I’m not suggesting these things are night/day differences, just that maybe they are cancelling each other out and making you think you’ve got an engine you can’t keep cool.
Personally I think finding the parts the factory used on an AC/copcar Fusey is the best starting point, esp if the car they are going on is a slabside and/or doesn’t have that AC condenser blocking the radiator (my slabs always ran cooler than my fuseys).
Joined: Tue Oct 11 2005, 01:33AM
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Check out the comparison testing, about half way down this page. It appears the stock Mopar pump beats most if not all the clones.
I'm having some heat problems which I suspect may be caused by the replacement pump I have. Finding a good Mopar pump may present more problems so I'm thinking Milodon high volume pump with anti-cavitation plate and a high flow thermostat.
Joined: Sat Aug 19 2006, 05:03PM
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The test that Bill linked to is the same one I found online which convinced me to change water pumps from Edelbrock-style to the Milodon. Yes, changing water pump and thermostat fixed the problem.
I say my 3-row rad is "good" because it was clean inside and not fouled-up with deposits, and had no problems at all keeping my original 383 cool, and it had a 4-blade fan and no shroud. Didn't have cooling problems until I dropped-in my 451 stroker. I don't know the fin density of the rad. I had it recored by a local shop over a decade ago, before I knew to inquire about such things. At the time, the guy had a hard time finding any core still in production that would accommodate my end tanks, so I was happy to get what I could get.
Flex fans flatten-out at higher RPM, which is typically higher road speed, when you don't need them to help with cooling anyhow. Not as good as a thermostatic clutch-driven fan, but supposedly an improvement over a direct-driven rigid fan. I know there was some discussion on here recently about flex fans being bad and coming apart. First I've ever heard of that. I must admit that I've ignored all of it.
My fan is a Flex-a-lite stainless steel flex fan, 18" diameter I think. I am using my original spacer which I'd say puts the fan at a good depth from the rad / inside the shroud. I would not use an aluminum flex fan, and many cheaper flex fans don't have enough pitch on the blades to pull enough air at low RPM. Maybe those are OK for a race car but not a street car. I was just looking at some pics online, and the Derale stainless flex fans look to have even more reinforcement of the blades than the Flex-a-lite does, if one is worried about failure due to metal fatigue.
Interesting point about the flex fan becoming a restriction when it flattens out, Chris. That may help to explain something I noticed. Before changing water pumps, I added a shroud which helped a little in low speed driving. The temp still climbed but more slowly. However, when I got out on the highway the temp didn't fall as quickly as it did without the shroud, so there was more restriction to airflow through the rad at high speed. Would have been an interesting exercise to swap-in a rigid fan to see if it had any effect on the highway.
Joined: Tue Oct 11 2005, 01:33AM
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Mike66Chryslers wrote ...
.... Interesting point about the flex fan becoming a restriction when it flattens out, Chris. That may help to explain something I noticed. Before changing water pumps, I added a shroud which helped a little in low speed driving. The temp still climbed but more slowly. However, when I got out on the highway the temp didn't fall as quickly as it did without the shroud, so there was more restriction to airflow through the rad at high speed. Would have been an interesting exercise to swap-in a rigid fan to see if it had any effect on the highway.
Now that is an interesting point. It's been nearly 50 years since my studies of flow mechanics so the math escapes me, but a spinning disc in the center of a rectangular air column has got to produce some really interesting flow anomalies. Brings to mind newer aircraft wings with "winglets" to reduce drag caused by wing tip turbulence.
Thinking a little deeper, I suppose it may be fair to say anything in the airflow will cause turbulence which greatly reduces the air column's ability to draw heat from radiator surfaces. I don't think anyone gave much thought to the aerodynamic characteristics of grills, grill supports and all the other "stuff" in the air-stream feeding the rad. The down stream side is even worse, a hulking great hot block of iron with the aerodynamic characteristic of a brick. Then a shroud is introduced with it's own turbulence and flow restriction problems. Then came the flex-fan advertised to save fuel while cruising the highways.
Having the flex-fan transform itself into a flat disc probably does save fuel, especially when the car is parked at the side of the road while the rad boils over! A thermostatic clutch fan might produce less turbulence since it does leave "holes" for the air flow.
Myself, I like my 7 blade beater, moves lots of air and to perfectly honest, I couldn't care less if it increases my fuel cost.
Joined: Wed Dec 21 2005, 07:34AM
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this is an interesting hijack we’re doing, and hopefully it keep the thread active so that we hear more about Glenville’s progress. And we need the skinny on that '62, also!
Turbulence is a funny thing – sometimes it helps, sometimes it hampers. The dimples on a golf ball create turbulence which adds yardage.
Actually, the engine location helps the fan, although I’m not knowledgable enough to explain the physics behind that. For a fan pulling thru no restriction, the exhaust flow is basically axial (inline with the fan) but as restriction increases the flow becomes more radial (slinging off the OD of the fan). When we flowtest fans with a restriction, if we mount an engine-profile piece of plywood on the drive dyne the flow and efficiency curves will increase a bit.
The shroud does add some restriction, due to the area of the circle is generally less than the area of the radiator core. However, the shroud’s main purpose is to prevent recirculation of air – air that comes off the blade tips in a radial manner and then re-enters the inlet side of the fan (like the dustcloud that follows Linus from the Peanuts). For a fan that blows thru a radiator, teh shroud adds another function – it helps pressurize the exhaust from the fan so that it flows thru the core better.
Each fan/shoud/radiator combination would have in ideal immersion distance, too.
Joined: Tue Oct 11 2005, 01:33AM
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Sorry also for the hijack, it's just that some of this stuff is so damn interesting! I'm afraid I'm one of those people who buys some new gizmo and immediately take it apart to see how it works. LOL
No worries on the hijack guys, lots of good info being discussed.
As for the 1962 300, its owner in the mopar guru I mentioned in another thread. Its got a 440 with dual 4 barrel carbs. When he stopped by the garage it was making the a horrible racket. Come to find out the torque converter bolts weren't tight enough.
I have made great progress on my 66. The motor is all plugged in and I drove it to the gas station yesterday. I'm taking it to the muffler shop tomorrow to install cut outs, X-pipe, and 2.5 exhaust from the headers back.