Building A looper Beast

[R Austin]

This thread will be documenting a QUINCY LOOPER “BEAST” reproduction project. It will actually be a hybrid because of changes to the induction side of the engine and ignition system. After looking at a billet of aluminum that had been purchased to make a new 60/66 inch looper block, I realized that it was big enough to build the a SUPER BEAST HYBRID.

The 15’ Jones really could stand a larger motor and heck, the motor is to short, and does not come to the top of the fairing. So, with that being justified, over the past year and a half I spent hours doing general layout work to confirm that it was something that could really be accomplished. The project has now been committed to and more will follow.

[R Austin]

This build of a 100 Cubic Inch Looper will be the 4th engine I have spent time designing and the 3rd one that I have built. Each time I have gone thru this exercise, I run into the same problem.
The first engine was built in the spring of 1970 as an attempt to improve reliability and performance. I sat down with a 4 carb Konig C motor and copied its design, incorporating it into a 6 cylinder, again around a Merc crank,this one from the 850 6 cylinder. This crank was still a 2.125 inch stroke. This gave me more room between cylinders for transfers and remain a 60 cubic in engine. Rotary valves were also built into the crank and the reed blocks were replaced with steel bodies with hardened centers for roller bearings. That's when I learned why some hardened steel parts, like connecting rods, are copper plated. Carbon will not go thru the copper.
The crank was suspended from the top double row thrust bearing that was locked into the top cap and snap ring grove cut into crank, keeping the clearance controlled between the discs and bodies. The engine was assembled with .010 feelers thru the carb inlet holes on each side of the valve body, then the case was tightened down. Rotary timing also came from the Konig.
All patterns for casing and the machine work was done by my father and myself. I spent quite a few evenings after work at a small aluminum foundry as free help learning the hows and whys of the casing processes.
The engine was completed the spring of 1970 and first ran on Mothers Day at Lake Lansing. Its a strange feeling when you add the electricity and the fuel to make it come alive for the first time. Could just be a lot of wasted work and a dud. However it ran. Not the strongest on the first run, but acceptable and we had something left to fine tune.

It was run a number of times that summer with significant improvements in performance. The last run, resulted in a piston failure and destroyed the engine. Pulling the wrist pin from the bottom of the pin tower. The spinning rod cut the block in two and caught a section of the block strong enough to bend the rod 90 degrees, split the rod crank roller bearings length ways and thankfully sheared the pinion gear at the drive shaft allowing the boat to coast to a stop. I had used the Levendusky pistons, however the wrist pin in the 850 was larger in diameter and thinned the tower to much.

[R Austin]

That last run felt every bit as strong as the 6 looper that I had previously ran in 1967.

Now, 42 years wiser, I will foolishly attempt another, why, because I can.

[Mark75H]

From Mr Austin:

Because I Am falling behind on keeping this thread active I will skip the progression of the other generations of motors that got me to this point.

I will say that, each time I have made an attempt, the piston is always the road block. A set of pistons for a 6 cylinder is almost as labor intensive as the block itself. And the reality is that the piston is the most critical part. Each time I am unable to find a piston of sound manufacture that will work or be modified for the design. I will insert a model of a 50ci 6 Cylinder Internal Rotary valve concept that I could not find a piston for.

For this engine, using the “Direct Charge” piston, which I think was a marketing driven joke to compete with OMC’s Looper, provides enough material, to just remove the heat soaking dam and have a sound flat top piston for a looper. With that problem 90% resolved I have proceeded with the design. The balance of 10% will be to obtain a set of pistons without the boost port hole and top notch. Contacted Wiseco and they said they could provide that piston. When asked about without ring grooves, communications ended. I need to make a trip to Ohio.

I will attach pics of the piston and resulting layout drawing. Models that confirm the build will follow. I will then move to the drawings of the patterns required for casting of new parts. The molds have been made and the castings produced. All that is need now is machining time.

[Mark75H]

Update:

The following will be the line drawings and the models of the final version of the cylinder block. The is being machined out of 2024T4 aluminum billet. The down side to the billet is that is not friendly for welding should a mistake be made machining and it is just tougher to machine. I wish that I just made a pattern and cast. One single core box for the cylinder with roughed in ports would have made machining much easier. Will make molds for that next winter. For now, machine the billet.

700

[Mark75H]

More

I did not realized that the file name of the attachments would not show up on the site, so I will explain each pic in the text as I move forward.
The last post is as follows:
Pics 1&2: Mid case and block porting passages as cores. Cores being the removed material.
Pic 3: Same coring including water pockets and passages.
Remaining pics are 3D line drawings and photo rendered pics of the block.

So what is the real status of the block? The block has been roughed in, which was just a weekends work. I quickly realized that this is foolish without the rest of the required parts. The mid case, the front case and the cylinder heads. So I stopped work on the block to proceed to build patterns for the balance of the required parts.

As chance would have it, I came across an add on E-Bay for some T2X parts. I acquired a block with a front cover and the 7 main bearing crank. That cut a good year off the making of patterns and modifying a standard crank and bearing bodies to achieve a 7 main crank.

That left the mid case and the cylinder head patterns to make. A project that could be managed in a couple of months.

I will include in this segment pics of the roughed block and all the dimensioned drawings for finish machining the block.

Pics: 1 Exhaust Positions, 2 Head bolt locations, 3 Lower Transfer port position,
4 Top Transfer port position, 5 Transfer runner positions, 6 Porting angles, 7 Water jacket positions, 8,9,10 Block rough machining.

I will try to honor Ron's request for more pics. The drawings and pics for producing patterns is many. The mid case is a very involved pattern requiring a cope, drag and 2 cheeks. Easier understood by saying the mold has to pull apart in 4 directions.

[R Austin]

The head is probably the easiest part to make patterns for and to machine, of the parts that I need to make. After much contemplation on the water jacket design, I took an old Quincy head that looked like it had been used for shot gun testing and split it. For those that do not understand, I will take a pic of the combustion chamber side. I am aware that alcohol runs cooler than gas, but how little water was required was a guess. The Quincy head was quite revealing. Not only was there not much volume but the core pattern was a single sided mold with sand pored over it and screed-ed off. Trying to determine the combustion chamber shape and position was another challenge.

Having run across a Quote letter by O.F. to a customer, I gleaned good information. His statement was that a "B" motor was running a 13cc chamber at 135 thousands timing. That was a good enough number for me to run with. My timing will very due to the larger chamber volume, design and flame front time which may be compensated with dual plug ignition. With 13cc for 10ci and knowing port positions of the "B" engine, let me compare total cylinder volume ratio and actual port closing ratios to determine a chamber size of 21cc's. That chamber calculates to a 13.9:1 compression ratio for the total cylinder volume and a 8.8:1 ratio using port closing time. Those 2 numbers match that of the "B" motor calculations.

[R Austin]

With all that funny information I design a 3 piece head, as was the looper beast. Which is the most practical for molding and coring purposes. I will not use a head gasket, but a flanged sleeve with silicon o-rings. I do find it interesting that the Konig did not use anything but interference and per-matex for sealing. Which is what I did on the 6 rotary valve motor at the beginning of this piece. Worked fine. Mainly because it was a open wet sleeve and the head was also open. This allowed the bolts which were place in notches a the sleeve base to actually clamp the cylinder sleeve and the block perimeter by deforming the head to comply.

Now a trailer ball of 1 8/7" size would make a good plug to create the chamber, except that they have a flat on the top. That's acceptable if I can find a ball with the right size flat. While walking thru the Wal Mart auto department a trailer ball in their rack caught my eye. It was a miss-machined ball that had been cut down to far on the blank making the base thin and you guessed it the flat on the top small. The size of a spark plug hole. I bought it.

[R Austin]

Thanks to modern age computer and printing systems the need to allow for aluminum shrinkage is some what easier. Aluminum shrinks at a rate of 1/64 of an inch per inch in all directions. Therefore all dimensions to create a pattern must be raised to include that rate. You will see wood pattern parts with paper glued to their faces. These paper patterns have been printed from the cad drawing full size to reflect a 1:1.0156 ratio at printing. All pattern prints were created in this manner to cover shrinkage.

Bondo is a great medium for fast pattern development as you see in many of the pattern making photos. Parts used a reverse pattern such as the trailer ball are painted with lite vegetable oil and plunged into the bondo to create the pocket. Removal as soon as the bondo takes a rubbery set, allows a few minutes window of time to trim excess material. It also allows easy sanding and shaping.

The trailer ball was bored and an alignment pin was added to center and square it in the head. Because of the added material for machining the head surface and changing chamber size, the ball went into the wood pattern beyond the spring point of the ball which would create a back draft condition. To cure that problem I turned a band that had a ID of the 1 7/8 ball and turned the OD to form a chamfer at the surface and zero at the ball mid point. The ring had a flange that seated on the wood and continued to displace the Bondo to finish the chamber. The final casting has enough material to allow chamber sizes for both alcohol and gas.

[R Austin]

My water core size was near double that of the Quincy. It is a split mold that is filled by air pressurizing the sand and blowing it into the mold. I Had 12 heads cast and made near 40 cores before getting my oven temp, mold air venting, time in mold and hand mold rotation correct to insure internal coverage right before I had enough cores for 12 pieces. That's correct, rotating a 450 degree mold by hand. The Quincy single side mold sure was easier to fill did not need rotation. Having 2 sides to the mold near doubled the water volume and still left adequate material around the chamber and the bolt bosses. I hope! That will really be a time prov-en test.