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I have several older saws with the Power Products AH-81 powerhead. It has been difficult for me to destroy good running saws for other more enjoyable venues. Today one showed up like another I already have. Its a gear driven saw, which I dont ususally like to donate these to another cause, but........decided to strip it down for a new project. I was plesantly suprised to find there was almost no gap in rings. Most of these old battle cruisers have 1/4" or more end gap. Its amazing they even have any compression to start. As I stripped off the non essentials to expose motor, another pleasant suprise. It is a late model with the much beefier aluminum cranakcase, lightened crank and newer style connectiong rod. The rod has a heavier beam, more material around the bosses and oiling holes drilled in cap. As unpopular as these motors became with bad balance issues and completely underported, it really doesnt take that much work to turn it into a very powerful workhorse. Cutting top of cylinder off and adding a large finned billet head, lightened thin ring domed piston, adding two booster ports, taking more weight off crank around rod journal, removing substantial dead weight off flywheel, mostly from fins, narrow down the shroud add dual carb manifold, and a final balance of all rotating parts, it has some serious potential to be competitive against a stock WB 820. So now the work begins to develop a non self-destructing motor. I think adding a girdle would be also in order just for a little added insurance. If I get really possessed the bore can be punched out to install a WB 820 piston to bring up to 8.17 cubic inches. Then stroke with an AH-82 crank thats been lightened and counterweighted to bring the cubes up to 8.4. Decisions decisions decisions...



I know, thats a 58 piston on the heavier rod. The 81 was still assembled, so it was difficult to snap a shot inside of crankcase. And the crankcase is not from a chainsaw, but just a reference pic thats still the same casting.

When I was a Junior driver I use to pass dual PP-82s during practice with my stock Mc-7. I was warned not to stay directly behind PP-82s because they had a tendency to shoot the spark plugs straight back out of the head!

Hank Rotroff of Hillsboro, Ohio, has been doing the head removal, porting +9 porting drill on '81's and '82's for years. If I'm not mistaken, he has used the 820 piston as well. His twin '82's on his Fox run pretty doggone good against the other duals. We get to see them at Fremont every year. He builds his own dual intakes and cylinder girdle setups also. One of the all around best guys you could ever meet. Pic attached.

Now thats what I am talkin about...Some people have all the fun. My dad commented about some of the dual guys. He said there were a few older stocky gents that needed the larger motors just to get them around the track. Even with both motors, they guys were not normally fast and usually didnt have much driving skills, making them a little dangerous to be around in practice. He said you sometimes had to stuff it in front of them entering the next turn. If you could maintain a good exit speed that would be the last time you saw them. Well that is if they didnt panic and slam on their brakes spinnig off the track. Then you got to meet them personally in the pits.

I came up with a machined crankcase/backplate that used all the 820 innards and the PP82 shrouds and cylinder with Hank's head. It's set up to take the big Mac reed cage with an HR in the stock location, plus a West Bend reed and HL in either or none of the other locations, as you machine it. As you can see from the attached JPEGs, it has built-in girdle attachment points. Too darn much money to machine it! Might have been fun with one of Hank's cylinders, though. A fun excercise for me on Pro/Engineer about five years ago.

I have had the pleasure of driving Hanks dual 82 and they are a hand full .

ted johnson wrote:I came up with a machined crankcase/backplate that used all the 820 innards and the PP82 shrouds and cylinder with Hank's head. It's set up to take the big Mac reed cage with an HR in the stock location, plus a West Bend reed and HL in either or none of the other locations, as you machine it. As you can see from the attached JPEGs, it has built-in girdle attachment points. Too darn much money to machine it! Might have been fun with one of Hank's cylinders, though. A fun excercise for me on Pro/Engineer about five years ago.

Heck you might as well cast up an aluminum jug with large fin area, machine a drop in liner, and add motoplat ignition while you are at it. Oh wait then there would not be anything left resembling a Power Products.

When I was barely 14, one of my most prized toys included a Power Products AH-61. It had Palamini head with cradle, dual carbs, and full circle crank. It was an antique in 1975, but I still enjoyed working on it and running it up and down the street. I remember reading an article in an old magazine(even at that time), Tom Spauldings dual cylinder PP motor with fully machined crankcase and four cresent carbs mounted on front. So I decided to make improvements on my own motor. I had finished a basic drafting course in jr high and was taking machine shop for the current semester. So i started drawing up a radically new crankcase for my favorite motor. It was basically shaped just like a scaled down Komet K88 with plenty of fins. Motor would sit flat with cylinder upright. On front of case it was setup tp accept two pyrimid reeds like the Homelite KL-100. Even years later I had acquired the aluminum to machine those cases and finish my project. Unfortunately I always have a hunderd projects going on at any one time and those cases are consistantly on the back forty. But one day...

Better late than never........

Terry, believe it or not someone built something very similar back in the day utilizing the PP head, innards and a machined case. I can't remember the name off hand, but Brian T. owns what is the only known example. (Maybe he'll post the pics) Personally, I think its kinda of cool and Spaulding'ish about the case.

I can't imagine how much time and expense it would be to pull it off. I bet it would be a big chunk of aluminum, a lot of shavings and a butt load of time.