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On 26 Aug 2003 at 19:57, Aaron Clow wrote: > --- Jim Adney <jadney@vwtype3.org> wrote: > > > I doubt if it's wrong, I'm just guessing that they > > were forced to use a > > different standard for Horsepower and it just came > > out to be a different number. > > These are all US Spec models, figures from the owners > manuals: > > 1963 (1493cc) - 53bhp at 4000rpm (SAE) > 1965 (1493cc) - 66bhp at 4800rpm (SAE) > 1966 (1584cc) - 65bhp at 4600rpm (SAE) > 1967 (1584cc) - 65bhp at 4600rpm (SAE) > 1968 (1584cc) - 65bhp at 4600rpm (SAE) > 1969 (1584cc) - 65bhp at 4600rpm (SAE) > 1970 (1584cc) - 65bhp at 4600rpm (SAE) > 1971 (1584cc) - 65bhp at 4600rpm (SAE) > 1973 (1584cc) - 52hp at 4000rpm (SAE), torque is 77.0 > ft/lb at 2200rpm > > 1972 -- not listed? Torque rating is same as > 71(86.8ft/lb at 2800 SAE), so I imagine hp is probably > the same as well . Okay, there were NO US spec cars until 66, so we can toss the earlier ones out. I checked a 72 manual here, too, and also found no HP spec. I don't dispute your numbers. I'm just suggesting that the early numbers could all be early SAE HP and the '73 might be revised SAE HP, and it just might be that 65 (early) SAE HP = 52 (revised) SAE HP. It's possible that '72 was the transition year and VW didn't know WHAT to do when it came time to get the manuals printed. When I look at the microfilm, I see that ALL these engines were rated by VW as 40kW or 54 (unspecified, perhaps DIN) HP for ALL the FI engines, even the Cal X... engines. Of course, the microfilm could also be wrong. It's always seemed strange to me that the 1600 dual carb and the FI engines all came out to be the same power in all years, and that the single carb 1600 came out to somewhat less (36kW/50HP.) SAE HP underwent a revision after the muscle car years of the late 60s when HP ratings got out of hand and were completely rediculous. The SAE rating system was poor to start with and I have the impression that the automakers further abused it. It allowed for the measurement (in true HP) of the engine output without ANY of the normal loads that an engine normally has to carry to run itself. So the test stands would provide engine cooling, electrical power, maybe even oil pump power, so that the measured output was gross output. The auto makers could abuse these measurements by providing engines that were not typical in any way. The measurement scheme was later changed to require that the engines provide their own drive for all required loads so that the output power was that which would have actually been delivered to the transmission. I'm not sure, but it's possible that this has since been further revised to be the power actually delivered to the wheels. It's also possible that the measurements had to come from typical engines, or be averages from a number of randomly selected production line engines. If I'm right about any of this, then the 65 HP that VW advertised for our engines was what they could deliver on the test stand with externally provided air cooling, oil flow, and electrical power; ie this was the gross power BEFORE the engine was asked to drive a fan, oil pump, and generator. Maybe even the distributor could be removed. Yes, this was cheating, but this was what Detroit wanted in order to drive up the HP wars of the late 60s, and this was the arena that VW had to compete in. I don't know what forced the change to NET HP later on, but there was certainly a period in the early 70s when HP ratings suddenly dropped with little apparent change in performance. All this was clouded, however, because emission controls in the early 70s also forced a lot of changes which led to nearly a decade of scrambling for acceptable engine performance while still meeting the EPA regs. There were a LOT of pretty undesirable cars from the 70s that were poorly engineered while Detroit, and everyone else, worked hard to try to figure out how to get reasonable gas mileage and good emissions at the same time. Most of this seemed to get settled down by the mid 80s, and by the mid 90s HP ratings were climbing again and the HP battle has been rekindled. Now we seem to be back in the mode of "why should I care about fuel efficiency" and HP ratings continue to climb as average fuel efficiency drops. Most of the drop in average fuel efficiency in recent years has been the result of increases in pickup truck sales and, more recently, SUVs, both of which are exempted from the Corporate Average Fuel Economy (CAFE) regs. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org