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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Evolution of a Hot Rod - Part 1: The Stocker /cgi-bin/YaBB.pl?num=1620523526 Message started by DragBikeMike on 05/08/21 at 18:25:26 |
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Title: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:25:26 I purchased my LS650 about 3 years ago. I wanted to use it as a test mule to try some ideas and learn a thing or two. The first thing I did was throw it on a dyno to get a baseline on the horsepower and torque. My plan was to start with the box-stock Savage, and then dyno periodically as I tried various modifications. It didn’t take long to figure out that all that dyno time would be expensive and cumbersome. As I plodded along making more horsepower, it was evident that I would never be able to keep up with the dyno runs. I switched to timed acceleration runs. I had more control over the test program, and I could test at my leisure. But even the timed acceleration runs had a learning curve. Initially, I only did second gear pulls. It was safer. That morphed into second & third gear pulls, and eventually included fifth gear pulls to get the complete performance picture. I found myself with a pile of data, but no way to compare the early modifications to my current setup. I had made a lot of changes. I wanted to be able to compare one setup to another using the same standards. The only solution was to turn the little Savage back into the pathetic box-stock cruiser that I started with. Test it by doing timed pulls in second, third and fifth to establish the box-stock baseline. Then do modifications in small increments and test to the same standards. That looked like an interesting project. I suspect I will learn a whole bunch of new tidbits along the way. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:27:28 The Plan 1. Put it completely back to stock. Stock head, stock carburetor, stock airbox, stock cam, stock piston, stock exhaust, stock muffler, stock flywheel, stock gearing, stock (or equivalent to stock) everything. I have been careful to save all the stock parts over the last 36 months, or at least modify the components in a manner that would allow restoration to stock equivalent. 2. The only exception will be the carburetion. As a minimum, it must be rideable. IMO, the stock carburetion is not suitable for normal operation. The slide needle will be raised slightly. Main jet and pilot jet must remain as-delivered so WOT acceleration will be unaffected. 3. Test the stock setup. Observe temperatures. Measure audible noise. Evaluate vibration levels. Observe the fuel mixture using the air/fuel ratio gage. Measure acceleration in second, third and fifth gears. Measure fuel economy. Evaluate overall drivability and performance. 4. Do all the simple and inexpensive mods. The stuff I refer to as “the low hanging fruit”. Airbox mods to let the poor thing breath. Jetting to give it sustenance. Exhaust mods, like a dyna muffler, to un-constipate the little pooper. Keep the mods simple and rock-bottom cheap. No special tools or skills will be required to do these mods. Confine the initial mods to things that do not require going into the internal portions of the engine. Test after each mod and report the results. 5. Do mods that are a bit more involved. Stuff that might require removal of the clutch cover, head cover, or alternator cover. These mods might require a little cash infusion, or some special tools or skills, but still no deep-dive into the guts of the engine. Maybe a carburetor, camshaft, or a lighter flywheel. Possibly an exhaust system rather than just a muffler, a special exhaust fitting, or a free-flow muffler. Test after each mod and report the results. 6. Take the plunge. Start doing elective surgery on the power plant. These mods might include a high-compression piston and minor head-work. They would include bolt-in cams, or might alter cam timing. “Bolt-in” meaning cams that don’t require modifications to guides or pistons, special valve springs, retainers, etc. Theses mods will build on the mods previously accomplished. They will require more special tools and more cash. 7. At this point, I have good test data on extensive modifications that I performed after incorporating my latest testing regimen. I will add that test data to whatever I collect on this project. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:28:32 I am hoping some of you have ideas that hold the promise of improved performance for the average Savage. I solicit your input. If you have a particular component or idea that you want tested, throw your hat in the ring. We can collaborate. I can’t guarantee that I can pull it off, but I will do my best. There are a few things that need to come off the table right up front. For instance, filling in the dipsy-doodle in the exhaust port. That ain’t gonna happen. A supercharger or turbocharger would be a bit over the top. I think a wet nitrous system is also not a good candidate. But a particular air filter, airbox mod, carburetor, muffler, header, or camshaft. Those might be good candidates. Possibly even a porting scheme. Throw your idea out there and we can have a discussion, figure out what you think it will do, determine what it will take to get it installed, and fit it into the project. Let’s get started. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:29:42 Here you see the stock Savage engine ready for test. ALL Stock, top to bottom. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:30:34 I threw on a stock cylinder and piston. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:31:18 The bore was in top shape. Great finish after a few quick trips with a hone. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:31:58 Check out that deck height. It’s the classic Suzuki Savage LowPo piston. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:32:49 I got this cylinder head off eBay from an outfit called Stars&Stripes. Good folks. It’s a primo head, vintage 1996. There was a small shipping glitch, but Stars&Stripes ironed things out ASAP. Overall good experience. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:33:33 Only problem with the head was the 8mm stud under the exhaust port. It was slightly bent. The stud was frozen, so I suspect it got bent when someone tried to remove it. I just lobbed it off, drilled & tapped for an 8mm stud identical to the intake stud. That worked well. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:34:25 The stock intake ports are the best I have seen. The valve seats are aligned well with the aluminum port, very little overhang. No undercuts either. Flow tests showed the intake flowed about 4% better than the other stock heads I have tested. The exhaust ports flowed about 8% less than the other stock heads. I really couldn’t find any reason for the reduced exhaust flow. I checked it dimensionally and it agreed with my old sketches. Tried a different set of valves. De-carboned the port surfaces. Must be a nuclear phenomenon. Look at this intake port. Pretty nice right outa da box. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:35:11 The improved intake flow might be due to the valves. This head came with valves that have reduced diameter stems. Never encountered a stock Savage head with reduced diameter valve stems. It didn’t have any tell-tale signs of prior valve work. Really looked like it came off the assembly line with these valves. The 1996 part numbers are the same as the 2016 part numbers. Any of you old-timers seen a stock Savage with reduced diameter valve stems? Normal valve shown on left, reduced stem on right. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:35:58 The head came with a head cover, rocker arms, rocker shafts, and a cam. There were a few pits in the exhaust lobe and rocker pad, but nothing that would affect performance. I used all the stuff that came with the head. It was all in good shape. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:36:39 A while back, I purchased a gasket kit on eBay. It cost about $50 bucks. I figured this would be a good time to try out the aftermarket head gasket. The kit is made by an outfit called “NE Brand Super Gasket”. Their part number is VG-3049M. The head gasket fit well. It’s a multi-layer steel (MLS) gasket but the coating does not look like Nitrile or Buna-N. The coating looks more like flat-finish paint. It was time to see if it could hack the mission. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:37:23 The guide seals that came with the NE kit failed on installation. I ended up using OEM guide seals. The NE seals were just too soft. They tore as soon as I tried to install the valve. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:38:21 The head cover needed a small epoxy repair to the sealing surface. JB Weld worked fine. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:39:06 I checked all the valve springs to make sure they were in good shape. They were all about 55 pounds @ 1.3”. Same as a brand-new spring. This little spring tester is killer. I love it. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:40:15 I restored the carburetor to the stock configuration. That meant any mods I had done previously had to be undone. I used a new retainer plate to cover up the extra hole I drilled in the slide. The special retainer plate is shown on the left. Leaving out the third notch results in the extra hole being covered up by the plate. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:41:05 The special slide needle with the compound taper had to go. A stock 5C39 needle went in. I knew mid-range would be grossly lean, so I installed a .063” thick washer in lieu of the stock .110” washer. That raised the needle .047” (slightly over 1mm) so that at least I could ride the bike without it lurching and bucking. It wouldn’t be any faster at WOT, it would just have better manners when trying to cruise. The black washer is the one I installed. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:41:48 My OEM carb already had the mixture screw plug removed and I wasn’t about to put that back in. I set it at two-turns, which is where I found it when I first removed the plug 3 years ago. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:42:31 All jets were restored to stock. Main jet #145, pilot jet #52.5, small air bleed #45, large air bleed #230. Float level was checked. It was 28mm. Perfect. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:43:15 It wouldn’t be a proper stocker without a grossly restrictive induction system. A stock airbox was in order. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:43:58 It had to have a snorkel. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:44:31 And the crankcase breather system had to be connected to the airbox. Nothing like a healthy dose of crankcase vapors to wake that puppy up. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:45:34 I figured one good turn deserves another. If I was gonna choke that sucker, I might as well plug up the other end too. The modified stock muffler had to be returned to the OEM configuration. That meant my special ¾” transit tube had to be removed and capped off. This would be the tube in question. The stock internal tube is just about ½” ID. With this ¾” ID external tube added, the flow path is a lot less restrictive. Can’t have that. Rip it off. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:46:22 And plug it up. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:46:58 That big 26.5mm exit tube had to go too. It got replaced with the stock 20mm tube. Factory fresh. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:47:35 Just imagine 40 cubic inches of throbbing red-hot gas squeezing out of this little anus 3000 times per minute. Oh my! |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:48:14 The exhaust system just wouldn’t be complete without that special 1.3” diameter header pipe. Looks mighty BIG on the outside, but it’s teeny-weeny on the inside. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:48:40 A quick test on the trusty flow bench showed that the stock muffler wins the restriction contest hands down. It pulled a whopping 46.5” H2O. In contrast, the modified muffler pulled 42.5” and the Dyna pulled 41”. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:49:29 The planned slowdown wouldn’t be complete without some additional rotating mass. So, the special 3” flywheel had to go. The 15-ounce flywheel was replaced. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:50:43 With the 6-pound stocker. What was Newton’s first law? A body at rest will remain at rest; a body in motion will remain in motion; unless acted upon………. The flywheel law. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:51:19 It got a new set of rings. The valves, seats & guides all looked primo. A quick compression check pumped 160 psi, right where it’s supposed to be. Ready for action. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:52:50 Break-in consisted of two-hundred miles to seat the rings. I observed a few things during the break-in. It ran a lot hotter than the Wiseco Flat-top engine. It was especially evident at steady-state operation, like on the freeway. Nothing to be alarmed about, but it runs hotter. Cylinder head temps were in the 310°F to 340°F range, and oil temp was in the 190°F to 220°F range. Fuel economy was significantly lower than the Wiseco Flat-top engine. The stocker was getting about 57 mpg. Vibration levels were low. The mirrors were crystal clear between 3500 and 4500 rpm. Noise levels were exceptionally low. I used my iPad with the NIOSH app to check the decibels at 1300/3000/4000 rpm under the exact conditions used for my muffler shootout. The box-stock Savage whispered 57/72/76 dB. (typo DBM) Mechanical noise was also much lower. Clicking, tapping and slapping seemed significantly reduced from the levels I was hearing with the forged Wiseco pistons and bigger cams. It ran a bit erratic. Lot’s of afterfire, popping, KaBooms, etc. Deceleration was horrible. It was embarrassing. Steady-state was OK and it had decent throttle response. As expected, warmup was not pleasant. At least it wasn’t surging. It was anemic, consistent with a box-stock Savage. Three years ago, I dynoed this thing when it was totally stock. It pumped out a blistering 30.5 horsepower at 5300 rpm (dead nuts on the factory rating). So now, when I do the performance tests on the stocker, the timed runs should be a good representation of what a 30.5 HP Savage can do. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:53:28 Look at that power curve. Pretty impressive. It goes flat right at 5000 rpm. The real-world performance was consistent with the dyno data. It was done at 5500. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:54:26 All that was left were the performance tests to see what this econo-cruiser could do. The test plan was to do timed pulls in second, third and fifth gear. Each pull would be performed in the same location (Secret DBM Closed-Course Test Track). The second gear pulls are intended to get a feel for how the thing is running. I start the pull about 3000 rpm and stop about 7500 rpm. Then I review the video and use a stopwatch to time acceleration from 4000 rpm to 7000 rpm. If the second gear pull isn’t clean, or if there’s a significant disparity (like grossly lean fuel mixture), no sense forging ahead with the taller gears. The third gear pulls are a measure of all-out acceleration. These pulls are much easier to time, and the stop-watch readings are consistent. If there’s a change in performance, it’s obvious. Start, stop and timing points are the same as the second gear pull. Since it’s an all-out test, I crouch down out of the wind (get under the paint) to maximize the performance. The fifth gear pulls are a measure of real-world performance. I start the pull about 3000 rpm and stop about 6000 rpm. Timing points are 3500 rpm to 5500 rpm (55 mph to 85 mph). Like the third gear pulls, they are easy to time, and the stop-watch readings are consistent. I sit straight up on the bike and barge through the wind, just like you would do if you were trying to pass an 18-wheeler. I view this test as the most instructive. I think it measures exactly what most of us are looking for. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:56:56 The second gear test went well. The stocker pulled 4K to 7K in 4.60 seconds. No glitches, air/fuel ratio was in the mid twelves. It was safe to forge ahead. The third gear test didn’t go as well. It couldn’t pull 7K in third. It signed off at 6700 rpm. I will have to lower the timing point for the baseline and initial tests until I reach a level of modification where “the little engine that could” can pull past 7000 rpm. For now, looks like we will have to settle for 6500 rpm. So, the stocker pulled 4K to 6.5K in 10.48 seconds. The fifth gear test went a bit better. The stocker pulled 3.5K to 5.5K in 22.43 seconds. Hey, at least it made it to 5.5K. I must admit, the video was painful to watch. The showroom sled signed off completely at 5500 rpm. It simply wasn’t going any faster. In the interest of fairness, I figured I should reduce the fifth gear timing threshold too. It does a lot better if you stop the timing at 5000 rpm (about 75 mph). So, similar to third gear, I will be using a lower threshold for the initial fifth gear tests. The timing points will be 3.5K to 5K until I reach a level of modification where the thing can pull past 5.5K. The stocker does 3.5K to 5K in 9.47 seconds. There you have it. The box-stock Savage baseline is: Second gear 4K to 7K = 4.60 seconds Third gear 4K to 6.5K = 10.48 seconds Fifth gear 3.5K to 5K = 9.47 seconds Fifth gear 3.5K to 5.5K = 22.43 seconds |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/08/21 at 18:59:40 Next stop (Part 2) is the airbox. We’re going to free up a little airflow and add a bit of fuel to see how much performance lurks in the bowels of that black plastic mouse trap. I think some of you will be surprised. Once the airbox is optimized, we will focus on the exhaust system. After the exhaust system, maybe the carburetor or possibly the flywheel. Give me some feedback to help decide which one to test first. One costs money, the other needs special tools. I hope some of you find this project informative and can use the data I collect to help make decisions on your own project. If you have suggestions or comments on my test methods, post a reply so we can discuss. As mentioned earlier, if you have a particular component or modification that you would like to see included, let me know and we can collaborate. Best regards, Mike |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Fast 650 on 05/08/21 at 20:03:34 Swapping in a lighter flywheel requires special tools that most people don't have on hand. I say go for the mods that are the most likely things that the average guy can do in his garage. Do the carb swap then the cam before going to the lighter flywheel. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by zipidachimp on 05/09/21 at 14:14:35 I'd like to see if a larger K&N than the RC1250 would have any effect. It might mean cutting the bar mating the 2 tank bolts. Yes, I'm cheap, otherwise I would have done it already. DBM, you appear to have more patience than I could ever muster. Love to read about all your experiments. From the immortal Burt Munro: 'sacrifices to the god of speed!' |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Armen on 05/09/21 at 14:37:44 Love it! Thanks for posting! |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Hiko on 05/10/21 at 00:05:05 Looking forward to seeing the airbox data I have done the carb jetting and the dyna muffler i also have done the exhaust header / head sleeve mod from Drag bike Mike and his rear pulley wobble fix I am something of a fan ! All these mods have been improvements and made the bike run better |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Fast 650 on 05/10/21 at 10:34:45 The LS650 suffers from chronic asthma. Get it to breathe right and the power is there. Just the airbox, jetting, and muffler changes alone will reap big gains for practically no money spent. Those are so easy that anyone should be able to those mods at home with simple hand tools. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Armen on 05/10/21 at 10:41:53 Fast, that's like saying "Just win a land war against Russia." A 4 valve OHC 650 should be making 50 HP in even a mediocre state of tune. My guess is that Jesus Christ on a bet couldn't get 50 HP out of one. If you read all the work DBM did to squeeze some HP out of these, it's anything but quick and easy. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Fast 650 on 05/10/21 at 12:23:49 I meant that those first few hp were easy. A 10% gain is simple. The next 10% will take more work, and the difficulty increases with each additional percent. It is like climbing a ladder with each higher rung being harder and more expensive. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by DragBikeMike on 05/10/21 at 13:59:14 Zipidachimp, I normally run a K&N RD0710 cylindrical filter. It's 3.5" x 5". It should have quite a bit more surface area than the RD1250 conical filter. I will be including that mod in this project, but not until I get into a larger carburetor. My airbox tests indicate that a larger filter probably won't do much for any setup using the stock carb. We'll see. Thanks for suggesting a larger element. It will certainly be on the list. Hiko, I just finished up on the airbox tests. Working on the report now. The results were fantastic. Armen, you make a good point regarding the limits of our LS650 engine. I suspect the cylinder head is the culprit. That's a very difficult component to alter. A good friend of mine recently sent me some pics of a wind chime he made from an old piston & valves from a Honda CRF450. I was impressed with the valves so I googled to find out the size. That engine uses 38mm intake valves. Our LS uses 33mm intakes. The Honda has 200 cc less displacement but 5mm larger valves. Geeeeez! You're right. BIG horsepower is anything but quick & easy. But you can realize HUGE improvements in HP and drivability on the LS with modest investments of time & money. That Honda redlines at 13,500. Just imagine how hard it would be to squeeze a few more ponies out of that thing. Fastman, thanks for the suggestion regarding the cam vs flywheel. That's an interesting problem. The flywheel requires a puller, special deep socket, and offest wrench. I suspect a prudent shopper could probably find those tools on Amazon or eBay for about the price of a DR650 cam. You do the flywheel and you get to keep the tools for future projects. You do the cam and you get the benefit of the extended powerband, but you have to go a bit deeper into the engine. It would be interesting to hear from some of the novices regarding which to tackle first. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Armen on 05/10/21 at 14:24:05 It might be pointed out that Dave had a tool rental program with the light flywheels he was selling. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by ohiomoto on 05/11/21 at 05:33:34 What I really want to know is who the hell is this DragBikeMike guy and what does he do in his spare time?!* #laboroflove #dedication #informationquest #profileplease :) *Spare time being time NOT spent working on the LS650. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by verslagen1 on 05/11/21 at 09:09:19 51575824262125150 wrote:
For me it's cam before flywheel because while the lighter flywheel will let you spin faster, it's not what gets you there. Most of us are not looking to beat the next guy to the next corner anyway. |
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Title: Re: Evolution of a Hot Rod - Part 1: The Stocker Post by Fast 650 on 05/11/21 at 10:51:20 Quote:
Look back at the number of posts from people asking for lighter flywheels vs people asking for Stage 3 or DR cams too. Based on that, cam swaps are the path most people take first. |
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