rearenginekarts.com

I hope you all had a happy Thanksgiving!
Please correct any date that's wrong. The only dates known by me to be accurate are the ones for Konig and Kaaden.
1958- Konig outboards took the alky boat racing classes by storm. I dont know if the motors had boost ports yet.
1961- MZ chief engineer Walter Kaaden put boost ports in their 125 cc road racing engine. The mixture transfer was through holes in the pistons. The performance increase was outstanding.
???? Kart drivers cut channels in the cylinder from the third port holes up to, or just shy, of the height of the transfer ports on the early Macs.
???? Wiseco started making nine port pistons.
1964- Mac produced nine port motors
I am crazy about two stroke performance history, so please tell me more.
bill

Bill, my Pop owned a small engines repair and sales shop in the fifties thru the early eighties. He had a book from the mid-fifties that had schematics for quite a number of ways to port 2 stroke engines. Several of these showed ways of boost porting. There were also schemes that were said to be superior to conventional "loop scavenging", but were too expensive to produce. Wish I had that book, tattered as it was! I remember him building a "siamese-ported" Mc6 back in 1960. TJ

Hey Ted
Do you remember the name of the book ?
Brian

No, Brian. I've been thinking and thinking, but I'm gettin' older by the day! I remember the cover was missing, so the only way I'd have had of knowing the name would've been by the print at the bottom of the pages. If I can think of it, I'll post. I'd like to find a copy too! Some of the earlier Mac saws were there, but it was pre-karting. Dad mostly had it for the old lawn mower engines. TJ

Ted, that book would be at #1 on the best seller list for karters. The konigs were loopers from the start, the main reason they showed our Johnsons, Evinrudes and Mercs rooster tails. I know the Konigs were boosted by the early 1960's, same way as the MZ. Kaaden's #1 rider, Ernst Degner, fled E. Germany with a complete motor and turned it over to Yamaha. You know the rest!
Something better than a looper? I'd like to hear all about it! It's known that the loop scavenge system was started by Dr. Schnerule in the 1920's, but wasn't really in racing until the 1950's.Right?
Hank told me about a Mac that had a second charging piston. This motor was discontinued early on as Mac felt it to be too wild for any chain saw. It wasn,t anything like the Allstate 250.
By the way, how do the Macs keep their cylinder heads on with only six #10 screws holding them? Those captive nuts must help, no?
bill

Bill, me remembering that book's name after 50 years is a far fetched wish. I do remember that one of the scavenging systems was the Curtis system. If I remember, it had two separated exhaust ports outboard of the intake system. Pretty expensive. I believe they used it on some large 2 cycle diesels. Some of the infamous Quincy Looper racing outboards had exhausts out both sides of the cylinders. Their website is worth looking over:
http://www.quincylooperracing.us/
Really neat stuff. I had a karting friend in the very early sixties named Louie Daigh who was a multi-time small cube hydro champ. He had run many Konigs, and a couple of the Quincy Loopers. He even offered Pop one of his modified 15 C.I. powerheads, but Dad declined to buy it. Rats! Wish I knew the exact Looper porting layout! Ted

About four years ago, I sold a Konig B class hydro motor. It was date coded 1957. I did a little research on it and found out that in 1957 Dieter Konig brought 20 of his motors to the US to race and smoked the Quincy's so bad, that it was embarrassing. This started a technology and R+D war between the two companies that trickled down to the other race inspired motor manufacturers. McCulloch did build "Flying Scott" race outboards and I'm sure the Konig technology went into the McCulloch outboards and then to the kart motors. I thought my Konig might have been one of the original motors that Dieter brought to the US in 1957, but wasn't sure. After I sold it, I did more research and found out that he painted his lower units blue. Mine had a blue lower unit, so I am pretty sure it was one of the originals. One of the things in my life that I very much regret selling.

One thing that I thought was interesting was that hydro racers figured out that if you made the looper ports around the crankshaft a little wider and shallower, it produced more horses. Kinda strange to me that making the ports smaller would make more horsepower. I have two mod outboards that have had this mod done to them. You could send you motor to Quincy to have this done. They used "Marine Tech," which is pretty much JB weld, to raise the ports, or floor of the crankshaft. Another strange thing is that the carbs on mod outboards are fairly small in relation to the displacement. The biggest carbs I have seen on a 44 C.I. mod outboard is 33mm. They used two of them. An MC91 carb is 35mm and a 44 C.I. outboard is about 7.3 times more displacement.

One last thing.... The technology of raising the ports, in my opinion, is the reason that many companies made different style stuffers. The tighter the tolerance to the crank, the more horsepower you get. Just a guess, but makes sense.

The whole stuffer thing was funny. We used flat plates on the early Macs for super short tracks, and a tight stuffer for longer tracks and high revs. The "thing" in the VERY early days was to even fill the bottom of the piston with cork, and run a full circle crank on the 510/580/700 3-port West Bends. A well modified Bend with a small stuffer and a standard crank was much faster on a short track. I had a friend in the street racing days in Florida who ran full circle cranks in his 101's on the 1000'+ straights. They ran well there, but couldn't do a thing on a tight sprint track.