The Harrison Racing Outboards - Legendary Birmingham Metal Products Alky Outboards

[John (Taylor) Gabrowski]

In examining Harrison cylinder wall ports on a B Block, the squarish piston port piston skirt windows are rectangular but the cylinder liner ports at the piston skirt windows are not the same shape. These pistons were run in the Harrison block for some time without any adverse affects. But, how could this which looks like missmatch be optimum transfer flow when one would think that the cylinder wall port and the piston port window would have the same shapes? In Anzani engines the match is there to within thousandths.

Can anyone shed some more light on piston skirt port window shapes optimized for Harrisons?

[John (Taylor) Gabrowski]

Acting on advice given here on BRF the cylinder liner for this class A - Alky Harrison block was re-installed successfuly.

The empty alluminum cylinder was prepped by giving its surface a good check. Any metal burring from taking the liner out was removed. The alluminum surface area was lightly honed to find high spots if any. The port window areas adjacent the cylinder liner to be put in were minimally radiused to stop any possible catching of the chilled liner being pushed in.

The aluminum block was heated in the oven in an alluminum pan at 400 degrees F for 1/2 an hour and the liner was frozen for the same period. Taking the aluminum block out of the oven, the cast machined liner was removed from the freezer and while I dropped the liner into the block with BBQ mits and twisted it to get proper ports alignments while my son shot electrical component cooler aerosol into the cylinder extending the time the liner could be worked and aligned which in reality was only a few extra seconds before the alluminum block cooled and shrank and cold liner expanded with the transferred warmth of the block locking both together. Minor leveling out of the liner in the block to make both sides flush was done with a 20 Ton hand pumped hydralic press with the block between 2 flat machined plates, plunger centered accurately over the liner surfaces making everthing flush. The installation and leveling went without any hitches...........

Thanks for the great advice given here on BRF on doing all this......

[John (Taylor) Gabrowski]

I took apart the only loose Harrison crankshaft I have which is I imagine the same or similar type Harrison crankshaft in Roger Wendt`s (Northwest USA) 350cc historical engine. This crankshaft as his does uses Konig rods and in his engine when the restoration was going on here, looked indestructable and could go on for ever. What happened to this current crankshaft I am re-working is pretty awsome. Both Konig class D rods, though polished to resist fracturing have serious nitro droop bending and the small end bearing holding support of the small end connecting rod structure is disintegrating by fracturing at the small end center oiling slit gallery. Evidently this can be too much nitro in the methanol fuel mix but then Roger Wendt`s was known to run 30% to 40% nitro and it showed no signs of any of these rod problems so this might more than likely also be too much ignition timing too before top dead center. The Konig class D (40 cube 4 cylinder Konig engines) rod is a very well made high strength one piece connecting rod product but a combination of too much nitro and excessive timing looks like its putting the rod past its limits.

Some pictures will follow in another post in the next few days for viewing these rods impending failures if they were not to be changed out and used again.

[John (Taylor) Gabrowski]

The following pictures are an opening mockup of a increasingly Harrison and decreasing in content the Anzani percentage of engine in this class A Alky block and crankcase asssembly.

The developer of this version added a second Tillotson HL Alky carb to the (from the rear) right side of the front crankcase half offset from the Lucas or Bosch gear driven magneto. This second carb was designed in to feed the crank rotary valve straight line direct instead of feeding the rotary valve from the air/fuel flow of the primary carb's air/fuel flow stream with its tortuous "S" shape making the rotary valve a direct feed affair. To do that the center main bearing with its crank opening window was turned the same direction toward the right front and re-pinned to retain its floating mode of operation. An internal flow director wedge was installed to reduce the crank rotary valve tunnel keeping the carb throat to base to rotary valve through the crankshaft one constant diameter.

On the major carb side the original rotary valve tunnel was blocked and filled. From the original carb mounts both a Tillotson HR self pumping carb or a Konig type rotary barrel carb of suitable size fit the same adapter mounting holes/studs. The engine is sporting strictly Tillotson carbs for mockup. The entire component set fit together with such a hand in glove fit, adding the crank, rods and pistons was no different as if the engine was either a Harrison or Anzani was easy. Here was a melding of both brands of engines very nicely which eventually led to an all Harrison HRP engine.

The exhaust pipes are Harrison HRP alluminum megaphone tubes set into fabricated steel flanges (Harrison did make and sell cast alluminum exhaust flange and pipe elbo(s) cast as one for weight saving over a steel product) and pipe sockets in its typical crescent shape not unlike that of Anzani which also had the exhausts ports exiting the top and the bottom of the block per cylinder. The Harrison HRP megaphone exhausts were held in place with stiff exhaust retainer springs. There were no struts as Anzanis used to retain and support the megaphones with just the retaining spring loading keeping the pipes plugged into the center of their holders and maintained there.

Enjoy the pictures.

[John (Taylor) Gabrowski]

Some engine mockup pictures with the Harrison Racing Products alluminum megaphone pipes.

Enjoy the extra pictures.

[John (Taylor) Gabrowski]

The open hole on the other side of the block opposite the carb opening I understand was initially machined through to give correct alignment from the carb barrel base right through to the piston port's long rectangular windows between the cylinders. On the close off plate for the opposite side port is a type of wedge deflector that separates the air / fuel streams to each piston port side (up and down) leading to each block and crankcase half. How that wedge is setup into the transfer tunnel along with its own displacement and placement can be used to increase or decrease air / fuel flow velocities.

[John (Taylor) Gabrowski]

While examining the 2 Harrison blocks that bolt up to Anzani crankcases both main crankcase bolts through to threaded Harrison block are both different. One is 3/8ths National Fine and the other is Metric. Both in block threads sets are originals in each case. Did Harrison give the user the option of what threads standards were used for engine manufacture and assembly or was the stuff blank and ready for what ever the end user wanted to do themselves?

[John (Taylor) Gabrowski]

The following fuel pump pictured was used on a Harrison with a rotary barrel carb not unlike that used on Konigs. The unit has no marking identifying who's product it is. The pump is actually a large pump cast together with a smaller pump in line but both separate with separate crankcase pulse lines to actuate the separate diaphrams as well as each pump having both input and discharge fuel lines to the carb(s). This twin diaphramed pump could be used in parrallel or in series within itself. Has anyone ever seen these pumps before and be able identify the product manufacturer?

Enjoy the pictures.

[John (Taylor) Gabrowski]

Earlier this summer it was quite interesting to see how and picture how Harrison parts and assemblies could interchange or mate very easily with Anzani engine components and assemblies. It was very easy to hang an Anzani saddle and torque tube clamp, torque tube engine and gearcase pipe mount from Harrison (HRP) clamps. To put a Harrison crankshaft assembly with flywheel ignition, stator and assembly required the top and bottom of the crankcase to be machined larger to accept the bigger caged roller bearing systems and their end caps used though the overall diameter and length of the beafier Harrison crankshaft was the same as Anzani.

The following are some pictures of the mockups looked at for future assembly.

Enjoy the pictures.

[Mark75H]

Maybe Kay can answer directly or indirectly, but I thought he told me some years ago that he did not make the crankshafts ... when he ran out of the last type crank he could not make any more motors.