that was my thought, but I filled to what the manual recommended - .9 quarts. If it was overfilled, I'm not going to blow out any seals or anything am I?

The OHV is not the main reason,it's only 1/3 of the difference;The compression is the reason,as well as the valve timing;more so,than the overhead valves.And it takes someone that knows what they are talking about,to know it has higher compression,without even seeing the engine...(pretty good huh?)................also I said ABOUT 1 extra HP., and "if that" ....................To get 2 extra HP,you need more than just valve design,......you need to use hotter valve timing,and raise the comp. ratio..(everything else being the same,such as bore;stroke).........Look at your thread,read it carefully...........According to you,if an engine has OHV,it automatically has more power,irregardless of valve timing,comp. ratio,etc. That's like me saying My car goes faster than a bus,because it runs on gasoline,and the bus runs on diesel fuel; a little extreme,but I think you get the point...........................

This is all great and dandy but how can we apply this info? How can you compare older mowers (before 2008) to the newer ones (2008 onward) to make a decision on what to buy? I have decided to summarize the pertinent information in a very concise way so any consumer can have a starting point for comparison in a SIMPLE way. First, if you have an "older mower" you need to know its effective HP based on its operating RPM. Example: Want to know the actual HP of your older mower? Older mower is 6 HP. Multiply by 0.85 = 5.1 HP ("Real" HP) 0.85 = 3060/3600 (to convert from tested RPM to actual RPM) Too hard to calculate in your head on the spot? Try multiplying by 0.8, then add 0.3 to your answer. This is a close approximation. Want to know the torque of your older mower? First, make sure you know the "real" HP of your motor (as above). Then use the "real" HP as follows: Older mower is 5.1 HP. Divide by 0.6 (or multiply by 10 and divide by 6) = 8.5 ft-lb. Want to know the HP of a newer mower? Newer mower is 7 ft-lb torque. Multiply by 0.6 = 4.2 HP Remember, this is only to give you simple way to do a comparison but it is based on a few assumptions. (They are not important, just to keep it simple.) Don't bother trying to compare size or displacement of a motor shown in cc's for the simple reason that even B & S has the same 190 cc motor that is sold as a 6.75 ft-lb torque model all the way to an 8.5 ft-lb torque model. I hope this helps someone. It sure did for me when I had to buy a new one yesterday. (I registered on this forum just so I could share this.)

This is a very old thread, things have changed at Ariens. The units sold at Home Depot are rebadged Husqvarna/Poulan/Craftsman and certainly not up to their usual standards. The average consumer simply will not pay for the traditional quality although long time Ariens fans such as myself will step up to the plate and go for the dealer only models. Having said that, it appears all models are getting an Ariens branded engines which likely means Chinese. With my experience with MTD's Powermore crapola, I will stick with an older model and repower with Briggs if necessary if and when I need a snowthrower, certainly not at the moment in southwestern British Columbia lol.