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Discussion Topic:
MACS rear hub bearings quality
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parrish |
10-31-2010 @ 10:40 AM
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Member
Posts: 349
Joined: Oct 2009
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Thanks for the comments. As a summary, I've tried to take a photo showing the respective finishes of the bearings: LEFT is original script, MIDDLE is MACS, RIGHT is non-script with black cage and supports from a 46 donor. The tape measure is simply used for reflection purposes...I'm very uneasy with the MACS.
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51f1 |
10-31-2010 @ 2:14 AM
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Senior
Posts: 573
Joined: Oct 2009
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An industrial bearing supplier such as Bearings and Drives does not sell inferior bearings. They cater to industry. They wouldn't stay in business very long selling an inferior product. And that's all I have to say on the matter.
Richard
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supereal |
10-30-2010 @ 10:19 AM
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Posts: 6819
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Be aware that all rear hub roller bearings are not the same. The original '36 bearings were 3.12" OD, and a switch was made that year to 2.78" OD during that year, and continued in thru '48, so a correct measurement must be made before ordering. Same was true for pickups. Quality of the roller hardening has a profound effect on the axle housings. A great deal of the problem with repro bearings stemmed from the cages, particularly the side plates. Any minor deviation from the spec of the originals can cause expensive damage. Being "close" doesn't count! And, yes, I was referring to the Sta-Lube Heavy Duty Drum Brake Grease" in my earlier post. There are a couple of other makers, but we prefer Sta-Lube, usually available at NAPA. Here is another tip: We have found that the wheel bearing grease seals that are not coated with the red sealer tend to be poor quality, and often collapse before they can be driven into place. When you buy seals for rear or front, ask the vendor if they are red or plain metal. If plain, try elsewhere, or buy plenty so you have enough to get at least what you need out of the batch.
This message was edited by supereal on 10-30-10 @ 11:01 AM
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kubes40 |
10-29-2010 @ 5:28 PM
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Senior
Posts: 3407
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Richard, I agree, you can get just about any brand you want. The problem remains that many of the after-market bearings are of poor quailty. I don't really care where the item was made. i do care if it's of poor quality. In the case of these bearings, I have no stake in the matter directly as I have perhaps a dozen NOS (Ford- OEM) bearings.
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51f1 |
10-29-2010 @ 3:30 PM
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Posts: 573
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kubes40: Bearing suppliers will sell you any brand of bearing that you want. Buy a reputable brand, and don't worry about where it was made.
Richard
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ford38v8 |
10-29-2010 @ 1:47 PM
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Posts: 2765
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Super brings up an excellent point that I hadn't thought of. The pumps vary their speed according to engine speed, and at idle, they move the coolant slowly. So while driving, most V8's are fine, but pull up to a stop sign and you get both less flow and less air movement through the radiator. Double trouble. This is one big advantage of the faster pumps. Mike, with regard to setting up an engine correctly, a large number of us are running engines that could really use a proper cleaning out of the water passages. As this cannot be done until it is dismantled, we run with accumulated deposits and sometimes even original casting sand because backflushing only accomplishes a limited cleaning.
Alan
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supereal |
10-29-2010 @ 9:48 AM
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There are a number of factors bearing on the ability of the cooling system to function properly. Some are variable, others are not. Among the fixed are the flow capacity of the radiator (how much fluid can actually move thru the core at peak) and the surface area of the tubes and fins. These bear on the ability of the radiator to transfer heat from the coolant to the air, and establish a maximum rate of heat transfer. Variables include the ability of the coolant mixture to absorb heat as it passes thru the system. Generally, plain water is a better medium than an antifreeze solution due to higher density. Air flow is also variable, whether from the engine fan or the movement of the vehicle, as is ambient temperature. The other variable is the pumping rate of the engine driven water pumps, directly linked to the rpms of the engine. If the rate of pumping drops, as in the case of idling or slow moving traffic, the coolant stays longer in the water jacket and arrives at the radiator considerably hotter than at highway speed, causing a higher load on the radiator, and a hotter returned coolant to the engine. In effect, a "zero sum" situation. Hotter coolant does not increase radiator efficiency. I agree that the stock pumps, at speed, are adequate. The advanced style increases pumping rate at low speeds, where most overheating occurs. If all other parts of the system are in good operating condition, only the pumping rate can be addressed by a design change. As engines age, the water jacket becomes coated with materials that form an insulator, reducing efficiency. It is unrealistic to expect engines that are decades old to be as efficient as newer ones. To compensate, you must address the variable parts of the system outlined above. To maintain the originality of the vehicle, a bigger radiator or fan is usually off the table, as is abandoning the belt driven pumps, leaving flow rate as the bottom line. I hold no financial interest in the new pumps. In fact, my '47 has the original style, but it also has a new radiator and the block was boiled clean when it was rebuilt. We I bought it, you couldn't go around the block without pegging the gauge. Street rods, old style cars with huge engines, often incorporate electric water pumps and non engine driven fans to produce adequate cooling. For the rest of us, these are impractical and we can only change the parts that address the factors that preserve appearance, while compensating for age and design problems. The number one complaint we hear from owners of old Fords is overheating. Some blame the design, but it should be kept in mind that millions of these cars and trucks were made and ran well, as long as they were properly maintained. These improvements in water pump design give an added meaning to the phrase "go with the flow".
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kubes40 |
10-29-2010 @ 6:47 AM
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Senior
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SUMMARY REPLIES TO THE LATEST RESPONSES: * I know where to get brake grease. My comment in regard to a lot of guys NOT knowing what it is was to reflect the idea that brake grease is 'old school'. You know, from my days * Although bearings are one of the most easily acquired items, the caged roller bearings for the rear drums is not one of them. They are in fact, as one member states, available at the local bearing supply house. However, you will no doubt get a BCA brand (Mexico). The quality of those is poor. I tested the hardness of the cage years ago and they were dead soft. The assembly would have failed QUICKLY in application. * I was never at the top of my physics classes. Darn close, but not at the top. A 'young' fellow with very long hair and earings was in fact at the top. He made me understand that guys can be okay with long hair and earings. * I agree that most engines are not set up properly. That leads me to another members response. That is: Why not fix the problem (he referred to 12v vs. 6v) instead of simply 'masking' the problem (my words). * We all know there are numerous methods to get our engines to cool. I eluded to that right away. Still, the necessity to remove thermostats, add faster pumps, etc. is ONLY one of them. One that is a 'mask'. See above comment. To reiterate: There are NUMEROUS methods to get the cooling we desire in our vehicles. Yes, I agree! Really I do! However, to suggest that faster pumps, etc,. is THE way is patently false. I have never had cooling problems and do not use 'fast' pumps, pressurized systems and oh yes, I DO install thermostats. Possibly, just maybe it is because I choose to set my engines up correctly. Yes that takes additional time and yes, may cost a few more dollars. Like 'brake grease' I'm from the old school. The place where I was taught to do it once - do it correctly. * In many situations moving coolant quicker will indeed allow it to dissipate heat quicker. That's in a 'perfect world' where all mitigating factors are constant and in tune with one another. (I think it was 51F1 and Alan that seem to have a pretty decent grasp on thermal mass retention / transfer)...In reality moving the coolant TOO quickly through the radiator will not allow enough exposure time to the cooling fins for the heat to dissipate (to take full advantage of the radiators 'job'). There's a definite design engineered into each and every radiator application. Total surface area of the cooling fins is critical as is capacity (amongst others). EX: Back when I raced (big block Chevies) there were no 'fast pumps'. What there was were larger capacity radiators. That's all it took to keep the 500+ cubic inches cool - a larger radiator. I still ran thermostats and didn't change anything else.
This message was edited by kubes40 on 10-29-10 @ 6:53 AM
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51f1 |
10-29-2010 @ 5:07 AM
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Senior
Posts: 573
Joined: Oct 2009
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Higher coolant flow will always result in higher heat transfer. Coolant cannot absorb heat after it reaches it's vapor point. Furthermore, coolant absorbs heat at a progressively slower rate as it approaches this point. What that says is the faster the coolant flows, the more heat is removed (up to some practical limit, of course). Further, when the water flows too slowly, the hot spots in the cooling system cause the coolant to vaporize. Vapor is not a very good coolant. As a rule of thumb, a good flow rate for a new, clean engine is about 0.2 gpm/bhp at max rpm. As crud builds up in a cooling system, it acts as an insulator, so a higher flow rate is required, hence, Skip's pumps. Thermostats do reduce the flow, but they also allow the engine to heat up faster, which is a good thing. Why don't y'all just clean out your cooling systems and maintain them? It's kind of like the changing from 6 volts to 12 volts. Why not just fix the 6-volt system? Remember, our cars and trucks worked when they came from the factory.
Richard
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51f1 |
10-29-2010 @ 4:14 AM
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Senior
Posts: 573
Joined: Oct 2009
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Bearings are one of the most standardized products in the world. They have been for years. The numbers on a bearing made in the U.S. are the same numbers found on a bearing from almost anywhere. If you are concerned about quality, take your bearing to a local industrial bearing supplier. They can match most any bearing in many different brands. Richard
This message was edited by 51f1 on 10-29-10 @ 5:11 AM
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