Popular Post BR46 Posted January 22, 2021 Popular Post Share #1 Posted January 22, 2021 Went to hang out at Dave's shop today. Dave was giving me some of his cylinder head secrets and what he is doing to my cylinder heads. Dave is also the engine master mind behind 4 land speed records. 1 4 Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 22, 2021 Share #2 Posted January 22, 2021 Bigger valves? Multi angle seats? 1 Link to comment Share on other sites More sharing options...
Thaddeus Kosciuszko Posted January 22, 2021 Share #3 Posted January 22, 2021 8 minutes ago, BR46 said: Dave is also the engine master mind behind 4 land speed records. Spending time with someone so accomplished has to be incredible! I'd think to reach that level of achievement an engine not only has to be technically perfect but a work of art as well. 2 Link to comment Share on other sites More sharing options...
Further Posted January 22, 2021 Share #4 Posted January 22, 2021 13 minutes ago, BR46 said: Went to hang out at Dave's shop today. Dave was giving me some of his cylinder head secrets and what he is doing to my cylinder heads. Dave is also the engine master mind behind 4 land speed records. Those are some honkin big valves !! 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #5 Posted January 22, 2021 3 minutes ago, Further said: Those are some honkin big valves !! The valves in the plastic container are the valves out of the sidecar motor. Dave has some valves sitting on his desk the are f'n huge now that's a big ass valve Link to comment Share on other sites More sharing options...
Further Posted January 22, 2021 Share #6 Posted January 22, 2021 Oly chit !!! That is the size of the piston in my tractor ! Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #7 Posted January 22, 2021 16 minutes ago, maddmaxx said: Bigger valves? Multi angle seats? The rulebook says that we have to run the stock value size. Dave wants me to find valves 1mm larger and he machines them down to the stock size with some multi angle cut. Dave said that when he is done the valve is stock give or take a few thousands but with the 5 angle grind they will flow better. 1 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #8 Posted January 22, 2021 5 minutes ago, Further said: Oly chit !!! That is the size of the piston in my tractor ! The valve is almost the size of one of the sidecar pistons. When I asked Dave what the monster value was out of he only responded with.....a big motor. 2 Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 22, 2021 Share #9 Posted January 22, 2021 Unless you super or turbo charge, the path to more horsepower is to boost the air flow. Either make the holes bigger or move the air faster. You can always adjust the fuel ratio..............except in nitro motors where the fuel makes its own oxygen and it's possible to feed so much that the engine hydrolocks during compression goes boom. Well there's just a bit more than that. You can also direct the air to the optimum place in the combustion chamber for a good burn. 1. work the air passages in the manifold and head to smooth them and direct the air better. 2. work the valve size and seat angles to remove sharp corners and promote smooth faster flow of air. 3. shape the combustion chamber to provide the best possible flame front from the point of ignition of the mixture. Sometimes this is also done to promote some swirl of air within the chamber to keep the air/fuel mixture proper throughout the chamber, again for good flame front travel. 4. Ditto on the exhaust side. Get the exhaust out. Outside the engine you tune exhaust and intake to add to the air flow. 1 Link to comment Share on other sites More sharing options...
Longjohn ★ Posted January 22, 2021 Share #10 Posted January 22, 2021 14 minutes ago, BR46 said: The valve is almost the size of one of the sidecar pistons. When I asked Dave what the monster value was out of he only responded with.....a big motor. At the forge we made pistons the size of crock pots. I think they were for locomotive engines. 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #11 Posted January 22, 2021 16 minutes ago, maddmaxx said: Unless you super or turbo charge, the path to more horsepower is to boost the air flow. Either make the holes bigger or move the air faster. You can always adjust the fuel ratio..............except in nitro motors where the fuel makes its own oxygen and it's possible to feed so much that the engine hydrolocks during compression goes boom. Well there's just a bit more than that. You can also direct the air to the optimum place in the combustion chamber for a good burn. 1. work the air passages in the manifold and head to smooth them and direct the air better. 2. work the valve size and seat angles to remove sharp corners and promote smooth faster flow of air. 3. shape the combustion chamber to provide the best possible flame front from the point of ignition of the mixture. Sometimes this is also done to promote some swirl of air within the chamber to keep the air/fuel mixture proper throughout the chamber, again for good flame front travel. 4. Ditto on the exhaust side. Get the exhaust out. Outside the engine you tune exhaust and intake to add to the air flow. The cool thing about racing the vintage motor that I have is all the information on what Yamaha did to Kenny Roberts factory flat track xs650 is online. I copied as much as I could with still staying inside the rules. The motor that I built for last year made good horse power but there was room for just a little bit more. 2 Link to comment Share on other sites More sharing options...
maddmaxx ★ Posted January 22, 2021 Share #12 Posted January 22, 2021 2 minutes ago, BR46 said: The cool thing about racing the vintage motor that I have is all the information on what Yamaha did to Kenny Roberts factory flat track xs650 is online. I copied as much as I could with still staying inside the rules. The motor that I built for last year made good horse power but there was room for just a little bit more. That's the amazing thing about race motors over the years. There's always someone who finds a way to make just a little bit more. TK is right. Some is science and some is art. 1 Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #13 Posted January 22, 2021 The one problem I have with the sidecar that I'm struggling to figure out is in right hand turns we get front end push. ...it's only in right turns. So the next guy that I'm going to pick his brain is just getting into sidecar racing. He already races motorcycles but him and his wife want to race sidecars. He told me that when I get my motor done I should bring it to his shop for some dyno time. While I'm there I'm going to see if he can inprove the right turn issue. I know that with the right suspension setup we can get the weight transfer needed. Warren is the suspension tuner for AJ Foyt enterprise. 1 1 Link to comment Share on other sites More sharing options...
Bikeguy Posted January 22, 2021 Share #14 Posted January 22, 2021 24 minutes ago, BR46 said: with still staying inside the rules. Are there rules for position and size of the intake runners/manifold (not sure about a motor cycle engine)? Seems like if you are going 100+ mph... (etc..) you could possibly use the wind to 'boost' your intake manifold pressure.... for a few more hp. Link to comment Share on other sites More sharing options...
BR46 Posted January 22, 2021 Author Share #15 Posted January 22, 2021 20 minutes ago, Bikeguy said: you could possibly use the wind to 'boost' your intake manifold pressure.... for a few more hp. Nothing in the rules agent it but it would be hard to do on the vintage rigs but on the modern sidecars their intake and air box is set up for that Link to comment Share on other sites More sharing options...
Kzoo Posted January 22, 2021 Share #16 Posted January 22, 2021 1 hour ago, Longjohn said: At the forge we made pistons the size of crock pots. I think they were for locomotive engines. I worked at GE locomotive in Erie. We made cylinder sleeves you could stand inside of. 2 1 Link to comment Share on other sites More sharing options...
jsharr ★ Posted January 22, 2021 Share #17 Posted January 22, 2021 1 hour ago, BR46 said: The one problem I have with the sidecar that I'm struggling to figure out is in right hand turns we get front end push. ...it's only in right turns. So the next guy that I'm going to pick his brain is just getting into sidecar racing. He already races motorcycles but him and his wife want to race sidecars. He told me that when I get my motor done I should bring it to his shop for some dyno time. While I'm there I'm going to see if he can inprove the right turn issue. I know that with the right suspension setup we can get the weight transfer needed. Warren is the suspension tuner for AJ Foyt enterprise. Ask him if he knows a guy from Plano Texas named Greg. 1 Link to comment Share on other sites More sharing options...
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