02-13-2017, 10:48 AM | #406 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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High compression
Although I started this about high-end horsepower, upping the compression ratio adds power all the way up the scale. There is more than one way to up compression ratios, two rather obvious ways, and one not so obvious. The most obvious way might be to lower the head as compared to the piston at TDC. Either by milling the head or by turning a few thousandths off of the bottom of the cylinder. I would do the latter, because 1] No chance of weakening the head/cylinder joint, 2] Easy to adjust compression ratios by various shims between the bottom of the barrel and the engine cases. Then the not-so-obvious way mentioned above, which is for you that have TIG welders lurking in the garage, which is to add metal inside the combustion chamber to reduce the cc's of the combustion chamber, as compared to the swept volume of the piston. Even better when adding metal, is to add squish bands to the equation. Squish bands cause more turbulance in the mixture. This causes the mixture to burn faster, leaving more time for the expansion of the gases of combustion, and thus add more pressure on the piston. I don't know whether the younger set can think in steam engine terms, like some people of my age can, But if you can, it really simplifies the grasping of the concept. Imagine a steam locomotive of the turn of the last century, running about 250 lbs of steam pressure, and a temperature of 275 degrees f. Now look at the 1950's engine, running steam at 600 degrees, and 300 lbs pressure. The 600 degree steam is what is causing the great increase in power over the engine of 50 years earlier. Because 600 degree steam expands much more than 275 degree steam. So, too the air in the cylinder expands more than an engine of lower compression. And because of the added turbulance, all of the fuel is consumed earlier, leaving more time for expansion of the exhaust gases. So it is really quite similar to a steam engine, in that the goal is to get as much push out of these expanding gases as is possible. One engine is classed as internal combustion, and the other is external combustion, but expanding hot gases do the work in both cases.
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02-13-2017, 01:10 PM | #407 |
Join Date: Dec 2016
Posts: 269
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ARH I enjoy reading all of your posts, you have such an amazing amount of information and I have the utmost respect for you. Can you give us a rundown of your career so we can better understand how you came to be so knowledgeable about motorcycles and engines?
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Hawk 250 Mikuni carb 115 main. De-catted pipe. Air box mod. 15/42 sprockets. Digital instrument cluster, FMF end cap on muffler, handlebar toolbag, Custom foot pegs |
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02-13-2017, 07:41 PM | #408 | |
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Location: akwesasne, NY-13655
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Quote:
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02-13-2017, 09:01 PM | #409 |
Join Date: Dec 2016
Posts: 269
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"Well that's enough for today"
Please continue soon... we're all ears ready to hear more
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Hawk 250 Mikuni carb 115 main. De-catted pipe. Air box mod. 15/42 sprockets. Digital instrument cluster, FMF end cap on muffler, handlebar toolbag, Custom foot pegs |
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02-14-2017, 10:56 AM | #410 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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Really? I don't really like tooting my own horn. Can't imagine why any one would be interested in this stuff......ARH
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02-14-2017, 12:09 PM | #411 |
Join Date: Dec 2016
Posts: 269
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ARH you're not tooting your own horn at all. It's very interesting, to me at least and I would imagine several others.
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Hawk 250 Mikuni carb 115 main. De-catted pipe. Air box mod. 15/42 sprockets. Digital instrument cluster, FMF end cap on muffler, handlebar toolbag, Custom foot pegs |
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02-14-2017, 01:09 PM | #412 |
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Great story ARH. We are lucky to have someone here like you with your knowledge.
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2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel |
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02-14-2017, 01:21 PM | #413 |
Join Date: Feb 2016
Location: George West, Texas
Posts: 4,097
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He he he, and cheap price of admission.
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***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
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02-14-2017, 08:48 PM | #414 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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And some more of the story
By now it's time to do my duty for God and Country, so I enlisted in the Navy. 2 years active-4 years in the reserves. When I got home, the Ariel Red Hunter had "dis-appeared". But now we had a new bike shop in Woodland Hills. Kolbe-Ekins BSA & Honda. So, naturally, I hung around that shop. Originally, Dave Ekins did the wrench work, and Andy Kolbe got the business going, doing up all the paperwork, making sure warranty claims were handled the way they should be, and all of that stuff. Kolbe was carrying the shop out of his wages at Rocketdyne, until it started breaking even, and then started making money. It is a sad fact that if you make no money, you will fail at business. And then you won't have a local Motorcycle Shop. At the time, they weren't selling very many BSA's, as people wanted those step-through Honda Fifties. But, as time went on, and Honda offered the 250 and 305 Sports models they started getting customers in interested in go-fast machinery. In addition to the step-thru customers. Unlike most bike shops, Andy kept everybody happy. Then I got a week-end job at Alan Fortney's Honda of Santa Monica. They were happy with me because they had a lot of older bikes they had taken in on trade, and I sold pretty near all of them in a couple of months. I kinda had my own clientele after I had been there a month or so. People wanting something cheap to run for going to work. There was a 250cc Pannanonia 2-strocker there that was in like new shape that they had traded for 8 months earlier, and the new sales manager told me they were going to have to junk it because no one wanted it. Really, I said, how deep are you in it? Don't worry about that, he said anything over scrap metal money will be considered manna from heaven. Wouldn't you know it but here comes a guy the very next Sunday looking for something to ride to work. I had been riding the Pannanonia around for a few days to limber it up, and make sure there was nothing wrong with it, then a good wash and wax and parked it right in front of the door, kinda' like bait. This guy shows up with his wife and 3-4 kids, and says he's looking for something to ride to work so his wife can have the car for emergencies and stuff. Anyway, he bought that cherry Pannanonia for $250.00 plus registration and title. Did I just turn him loose? No I made sure he knew how much oil to add to the gas, where to check for loose nuts, all that kinda stuff. Basically I sold most of their trade ins that way. Next installment- Gold Stars, and flat tracking.
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02-14-2017, 10:41 PM | #415 |
Join Date: Feb 2016
Location: George West, Texas
Posts: 4,097
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What were some of the nasty things said about those Japanese motorcycles in those early honda days?
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***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
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02-15-2017, 07:28 AM | #416 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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The same things, virtually word for word as is said now about China Bikes.....ARH
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02-15-2017, 08:23 AM | #417 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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And the story goes on. And on.
About this time, Dave Ekins (Bud Ekins younger brother) decided that working for himself was not making him happy. He preferred working for someone else. Nothing wrong with that. So he sold out his share to Andy Kolbe (Exactly how I don't know, besides it wasn't any of my business) and Andy built a new shop a few blocks away on Ventura Blvd in Woodland Hills. Much nicer than the old shop he had rented. Not overdone, just.....nice. It drew in more customers. Sold loads of those Super Hawks. BSA's started selling better as well. And then Andy hit on that famous idea that has worked a thousand times. Race on Sunday, Sell on Monday. So he bought from someone else a "Bent-frame BSA" with an engine, trans, and wheels. All the successful BSA flat trackers had "bent" frames. They were bent a little bit to reduce the head angle, and trail. Quickened up the steering. This wasn't done on Triumphs and Harleys, because they would break loose too quick coming out of the turns. Remember, a twin fires once per revolution of the engine, and a single fires once every other revolution. So a single had a better chance to catch full traction coming out of the corners then twins had. If you have ridden your Hawk much off road, you might have noticed this. This was on half-mile tracks. On the mile tracks, basically you could not make up in the corners what you lost to the K-Model Harleys on the straights. That was the theory, but reality is something else. BSA's won plenty of mile races. Why? Very simple. A single is easier to tune to get maximum horse power than is a twin, and, generally is more reliable. I heard one Harley rider telling his mechanic "Yeah it's really pulling good on one cylinder, but the other one is just going along for the ride". The hardest engine to tune, in those days was a Harley. 45 cubic inch flathead. 750cc to those of you who are confused as to which country you live in. It took a real artist at the flow bench to get that thing to not only breathe, but breathe the same on both cylinders. Overhead valve production engines ran 30.50 cubic inches, or 500cc. That was the "Class C Rule" in effect at the time. Until later......ARH
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02-15-2017, 05:46 PM | #418 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
Posts: 2,220
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Class C rules
Class C rules meant that you had to run the manufacturers product all the way. If you ran a BSA, you had to use a BSA frame, and forks and, on road racers, brakes out of the catalog of readily available BSA parts. Like wise for Triumph, Norton, and Harley-Davidson and Indian. Yes, there were a few 45 inch Indians running at that time. Norton could run the single overhead cam "International" but not the double overhead cam "Manx". This was because the International was a series produced motorcycle, that anyone could buy, and the "Manx" was not series produced for the road, and not anyone could buy one. So, what was the best single cylinder bike available, that fit class C rules, at that time? The BSA Goldstar! The Goldstar had the benefit of developement by two near geniuses. The man who initially designed it, Val Page. He also had designed the Ariel Red Hunters, another superb single. The second breath of fresh air for the Goldstar was the result of the work of Roland Pike, the famous tuner-rider of Rudge-Whitworth 250's well into the fifties, running a team of Pike-Rudge's until BSA hired him to work his magic on the Goldstar. Remember, the last Rudge was made before September, 1939, so it was quite an achievement to still be competitive 14 years after production ceased. That was Roland Pike. I posted a link to a youtube video of a historic race in England of a Rudge laying an ass whipping on a whole field of bikes as late as 2005. And that one was not even a Pike-Rudge. One of the Rudge's victoms was a 1960 something 250 Ducati, over head cam, telescopic forks and swing arm suspension at the rear and all. The Rudge had a rigid (Hardtail) frame, and girder front forks. You'll know a Pike-Rudge when you see one. It has girder front forks, and long travel shocks on the swing arm.
Last edited by Ariel Red Hunter; 02-15-2017 at 06:19 PM. |
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02-15-2017, 08:39 PM | #419 |
Join Date: Apr 2015
Location: Sudbury ,Ontario
Posts: 855
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Would that also be Kolbe Can Am from back in the day ?
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02-15-2017, 09:26 PM | #420 |
Join Date: Jun 2016
Location: akwesasne, NY-13655
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That was after I left the motorcycle racing scene the first time. Andy's rider on his Gold Star was Preston Petty.
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