UNTIL NOW I HAD THE GOOD FORTUNE TO ONLY OWN ONE POWER PRODUCTS ENGINE. MY NEW DEAD DRIVE SEARS KART ARRIVED WITH A NEW 5 HP PP. WITH DIRECT DRIVE 41 CHAIN THE ENGINE WOULD START ON A BLOCK BUT NOT RUN ON THE GROUND. WHAT COULD POSSIBLY BE WRONG WITH A NEW ENGINE? OVER THE YEARS IT GOT TRIED BUT ALWAYS "FAILED TO FUNCTION" AS I TOLD MY MOM ON ITS FIRST "OUTING". THE KART WAS CONFINED IN THE BASEMENT FOR A LONG TIME. FINALLY, I GAVE IT TO A MECHANICALLY MINDED UNCLE WHO DISCOVERED THAT THE REEDS (WHAT WERE THOSE?) WERE BAD RIGHT FROM THE START. THAT PROBABLY EXPLAINED WHY FUEL WOULD COME OUT THE INTAKE OF THE CARB WHEN THE ENGINE RAN ON A BLOCK.
I JUST PICKED UP A 1965 SAE WITH A PP H81. I KNOW NOTHING ABOUT THIS ENGINE. ANY INFORMATION OR INSIGHT WOULD BE WELCOME. THERE IS A GUY ON EBAY WHO WANTS A RATHER LARGE FORTUNE FOR AN H81 MOTOR MOUNT. I REALLY DOUBT THAT WILL HAPPEN. IF IT DOES MY MOTOR WITH A MOUNT, CLUTCH, AND EXHAUST HEADER MUST BE LIKE g0ld.
A CANADIAN CHAINSAW COLLECTORS WEB SITE LISTS THE PP H81 AND AH81 AS 7.98 CU. IN. WITH 1.625 STROKE (SOUNDS FAMILIAR) WITH A 2.5 INCH BORE. OIL MIX A RICH 3/4 PINT PER GALLON. THESE WERE APPARENTLY POPULAR CHAIN SAW MOTORS AT ONE TIME.
05-15-2021, 09:57 PM (This post was last modified: 05-15-2021, 09:59 PM by Terry Bentley.)
They are great chainsaw motors. I have good dozen of them. Sears sold David Bradley model chainsaws. The PP81 is a heavy monster of a saw.
Montgomery Wards sold a line of saws using the Power products engines. They were seriously detuned by using that small Tecumseh diaphragm carburetor found on 2.5 and 3 hp lawnmower and mini-bike engines. If you get a decent aftermarket intake using a pyramid reed and a newer model Tillotson carburetor, that motor will surprise you.
I made billet heads for a few of my project engines. Hard to find originals. You can also rotate the cylinder 90 degrees, so exhaust shoots down instead out the side. The intake ports are fed thru holes in the piston skirts on some models. You can case feed the intakes with some grinding and spare time.
The early models, including the Ah-81 are horribly out of ba1ance. You can add counterweights to crankshaft or grind off a lot of dead weight around the rod end of crank.
For pistons, bore out the cylinder +0.020 and use the Westbend 820. The Westbend rod is another good swap. It is stronger than the PP rod.
A pair of these engines develops a ton of torque. With some simple mods, they can be made fairly fast. Just keep the rpms low and you wont be blowing them up every time they get run.
The flywheels are huge and need to be cut way down. Most of the fins can be removed completely. You can shorten the square style shrouds a lot to better fit the cut down flywheels. The flywheels were known to explode, so a reinforcing plate welded inside keeps them from breaking.
Otherwise a fairly fun motor to play with. When using one of the chainsaws, my arms would stay vibrating for about an hour after I am done cutting wood. I can even feel it in my teeth.
I hope all is well. Regarding your Power Products motor, look for the tin ID tag usually found on the underside of the motor. If it’s there and legible, you can message me or call me with the number and I can see if it’s in my Power Products manual. If it is, I’ll copy what is available and mail it to you.
05-17-2021, 08:41 AM (This post was last modified: 05-17-2021, 08:42 AM by ted johnson.)
Hank Rotroff, Jeff Campbell and Jack Canady all had wicked fast AH 81/82 PP engines. The flywheel side crank seal is a bear to replace, and the early thin cylinder castings were weak near the base, and the early three bolt mount crankcases were also weak. The later PP 82's weren't bad with proper porting, a boost port, head cut off and replaced with a billet head with ears for tie rods to hold things together. I've seen all three guys engines run very well against 820 Benders. You have to know how to gear them so they take advantage of their different power curve. Hank Rotroff was a master with the engines. I had one of the later ones when I lived in New Mexico, but I didn't have access to the machine tools I would have needed to make it run well Here's a pic of Hank's '61 Fox with dual PP 82's Ted
SOMETIMES A CLOSER INSPECTION TURNS UP DISCOURAGING NEWS. A CLOSER LOOK WITH A BRIGHT LIGHT REVEALED MY ENGINE IS AN AH81. AFTER TERRY'S FINE POST ON THE SUPERIORITY OF AN H81 (AND HOW TO MAKE THEM FASTER), I THOUGHT I STUMBLED INTO A GOOD ENGINE. i ACTUALLY HAVE AN AH81 SERIAL NUMBER 3567048. IF YOUR BOOK HAS ANYTHING INTERESTING ABOUT IT, I WOULD LIKE TO KNOW.
I AM GETTING READY FOR THE ANNUAL SUMMER IN ALASKA. OTHER THAN THE NORMAL WEAR AND TEAR AT 73 THERE'S NOTHING SPECIAL TO COMPLAIN ABOUT. NOT THAT COMPLAINING SEEMS TO DO ANY GOOD.
An H or AH 81 is NOT as good as the newer AH 82. The 82 is far stronger physically, has four mount bolts instead of three and is just the better engine. The little bit of extra displacement isn't a big deal, but the extra aluminum in the case and cylinder are both a big deal. Remember that PP was always revising their AH 58's and AH 82's, and the later versions of both models are the best versions. Ted
06-10-2021, 12:29 AM (This post was last modified: 06-10-2021, 01:53 AM by Vince Rosanelli.)
Blaine,
I hope all is well. What you provided is the serial number. I was hoping to see if there might be a smaller rectangular tin tag attached to the underside of the crankcase. It usually has four numbers stamped into it and sometimes is preceded with a letter. That is the engine type number and what my parts book goes by. Many of them disappear over the years and some are covered in grease and dirt making them unnoticeable. Wishing safe travel back to Alaska from Florida.
06-10-2021, 08:23 AM (This post was last modified: 06-10-2021, 04:52 PM by ted johnson.)
Smokey, Here's an old pic of the '61 Bug Scorpion my pal, Charlie, bought from my Pop in '62. He put the twin '82PP's on it and ran it for a while. He was a pretty big boy back then, and the torque served him well. If you look at my avatar at the heading of this post, you will see the same Scorpion as it was when Pop bought it new from Tom Pierson. Neither Pop nor I liked the kart, but it fit Charlie well, so Pop let him drive it until Charlie bought it. Charlie still has it with a 101D on it. It still looks and drives very well.
Whaddya know, I went back and got it to let me attach the pic of Charlie's Scorpion. Ted
06-10-2021, 02:47 PM (This post was last modified: 06-10-2021, 02:51 PM by Gary Wlodarsky.)
I remember a guy named Jake Moran...SAE kart twin PP82s done by Jerry...wicked fast ( nationally) as well as locally....
although I am not a fan of PP.....had one rebuilt by one of the the best PP guys in the country, gave it away at a local event, raffle drawing , the guy that won it...next time I saw him,,,,,,the crank busted off on the PTO side
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