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techtalk:ref:carb01p [2019/09/10 02:32] hippysmack [REF: Carburetor, Intake Manifold & Exhaust - Sub-01Q] |
techtalk:ref:carb01p [2024/01/10 21:21] (current) hippysmack |
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| ====== REF: Carburetor, Intake Manifold & Exhaust - Sub-01P ====== | ====== REF: Carburetor, Intake Manifold & Exhaust - Sub-01P ====== | ||
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| - | ====== S&S Intake Manifold Spacer ====== | + | ====== Testing an S&S Intake Manifold Spacer ====== |
| + | Article by biknut of the XLFORUM ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) \\ | ||
| + | The purpose of this was to evaluate what effect if any, a 1" manifold spacer has on performance in 2 areas; \\ | ||
| + | Horsepower and piston ping. \\ | ||
| + | The carburetor in this case is an S&S Super E. \\ | ||
| + | It's been said you can control or influence flat spots (caused by reversion) in your power band by changing your intake runner length. \\ | ||
| + | This theory was put that theory to the test. There were two expectations. \\ | ||
| + | - Stop the pinging. | ||
| + | - Improve the mid range performance. | ||
| + | |||
| + | In my recent tuning experience with the newest exhaust system I have; \\ | ||
| + | It has shown that I have a big honking zone of reversion starting about 3100 rpm lasting to about 3900. \\ | ||
| + | With extensive modification to the carburetor and jetting, arrived at by very thorough testing; \\ | ||
| + | I've succeeded in minimizing it to the point that the flat spot is now hardly noticeable. \\ | ||
| + | There is however still a slight problem with light pinging about 3700-3800 rpm accelerating in top gear on partial throttle (3/4). \\ | ||
| + | It doesn't show up under full throttle acceleration. | ||
| + | |||
| + | I've already tried different jetting and timing in an effort to get rid of it, but it always results in lost performance. \\ | ||
| + | My conclusion is that the jetting and timing is as good as it gets, and reversion is the cause of the pinging. \\ | ||
| + | I'm pretty sure if I baffle up the exhaust to stop the reversion it will also result in loss of power on the top end. \\ | ||
| + | So that brings us to the intake side of the equation.\\ | ||
| + | |||
| + | Most of the evidence, that changing the intake runner length will help with this problem, comes from the automotive world. \\ | ||
| + | I have found scant little information about the effects this will have on a motorcycles performance. \\ | ||
| + | So we're operating in basically unknown mostly territory here. \\ | ||
| + | |||
| + | Manifold Spacer Blocks: \\ | ||
| + | This is one reference from the ThunderJet tuning instructions provided by Zippers: \\ | ||
| + | //When tuning a long stroke engine, increasing runner (manifold) length may help control fuel stand-off and improve low- and mid-range carburetion. \\ | ||
| + | Different cams, exhausts, strokes and other changes will affect this area dramatically. \\ | ||
| + | If you are a serious tuner, we suggest you purchase spacers and insulator blocks and experiment with them in your applications.// http://www.zippersperformance.com/do...nst_101508.pdf | ||
| + | |||
| + | I've found a lot of places that sell intake spacers for Super E's, but when you ask them any questions about what they do you mostly get a big zero. \\ | ||
| + | The Spacer I have was purchased on eBay for $16. It came with a V-Twin Manufacturing label, and it's 1" wide. \\ | ||
| + | The seller advertised that it was to extend the carb farther out from the bike to clear over sized gas tanks. \\ | ||
| + | It does fit the Super E manifold. \\ | ||
| + | |||
| + | Results of testing; \\ | ||
| + | The effect on piston ping was noticeably positive. Compared to before the spacer was installed it's very difficult to make it ping now. \\ | ||
| + | Not quite impossible, but there was a very noticeable positive effect. Most stock bikes ping easier. \\ | ||
| + | |||
| + | [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426|You can read more about the testing here]]: \\ | ||
| + | More testing by biknut: \\ | ||
| + | [[http://xlforum.net/forums/showthread.php?t=648864|O2 Meter Carb Tuning]]. \\ | ||
| + | [[http://xlforum.net/forums/showthread.php?t=406951|S&S Jet Testing]]. \\ | ||
| + | [[http://xlforum.net/forums/showthread.php?t=644097|How to install a AFR meter]]. \\ | ||
| + | [[http://xlforum.net/forums/showthread.php?t=423092|How to install a KOSO Power meter]]. \\ | ||
| + | [[techtalk:ref:carb01q|Installing a ThunderJet® on a Super E]]. \\ | ||
| + | |||
| + | |||
| + | {{:techtalk:ref:carb:sands_intake_manifold_spacer_1_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) {{:techtalk:ref:carb:sands_intake_manifold_spacer_2_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) \\ | ||
| + | |||
| + | You have to space out the air cleaner back plate with longer bolts to install it. \\ | ||
| + | |||
| + | {{:techtalk:ref:carb:sands_intake_manifold_spacer_3_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) {{:techtalk:ref:carb:sands_intake_manifold_spacer_4_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) {{:techtalk:ref:carb:sands_intake_manifold_spacer_5_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) \\ | ||
| + | |||
| + | This is how far the carb sticks out with the spacer installed. \\ | ||
| + | |||
| + | {{:techtalk:ref:carb:sands_intake_manifold_spacer_6_by_biknut.jpg?direct&300|}} ((photo by biknut of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/88897-s-s-intake-manifold-spacer?t=710426)) \\ | ||
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