OK...Just a little fun my Son and I had hanging parts we found around the shop on the Doodlebug....guess we needed a laugh. But the scary thing is the engine actualy would fit in the frame. Which had us thinkin. hehe But then the reality of all the things needed to complete the project sank in....mainly bigger balls.
That thing is GNAR'ls-barkley!! I dont think that I would even ride it haha. is that seriously like a 75-100 hp engine sitting in your doodlebug?? Is that thing really turboed like it looks??!?
But seriously man, you gotta build that bike safely.. Think about extending the wheelbase too man. Brakes... This takes that whole "whats the biggest engine I can fit in a DB" question to a whole nother level..
But seriously man, you gotta build that bike safely.. Think about extending the wheelbase too man. Brakes... This takes that whole "whats the biggest engine I can fit in a DB" question to a whole nother level..
Yea, The built 270 Sprint motors can make around 70hp. The crank driven turbo compressor housing was my Sons giggling brain fart and just a mock up for laughs.
But actualy not impossible. He got the idea from another project I am working on. Anyone interested in supercharging small engines should checkout Dick Datson's book on making your own belt driven supercharger. I am working on a blown alky gx200 project, or I should say Bomb if I get greedy with the boost level. I will share pics if it works out.
Anyway... in regards to your big engine for a doodlebug question... If you want to play around with making a crazy fast Doodle, The gx200 clone is the most fun. Tons of performance available. My favorite build has a ported/milled 14cc head, 25mm ex valve, 28.5mm intake valve. .276 cam with 1.2 rockers giving it .331 lift. ARC flywheel and rod.
Mikuni carb on alky and the timing advanced a bit. It makes great power from right off idle to over 9000rpm. And no matter how hard I have tried, I can't blow it up in the Kart it's in. I thought I was running it to death on my Dyno when I was tuning it. But after several tear downs to inspect the valve train and checking for metal in the oil I discovered that it loves being flogged. I must say I didn't think the clone castings and crank could take it. I'm impressed.
I use my doodlebug for a pitbike and like to be able to start it on the first pull and not have it jump out from between my legs when it does start. So I like the stock motor with the Jackshaft kit the best. It's still pretty zippy and fun. If I were to want to build a mini drag bike It would make more sense to build a chrome molly frame and have a good brake system. But this is just my opinion on what I think is cool and practical.
But actualy not impossible. He got the idea from another project I am working on. Anyone interested in supercharging small engines should checkout Dick Datson's book on making your own belt driven supercharger. I am working on a blown alky gx200 project, or I should say Bomb if I get greedy with the boost level. I will share pics if it works out.
Anyway... in regards to your big engine for a doodlebug question... If you want to play around with making a crazy fast Doodle, The gx200 clone is the most fun. Tons of performance available. My favorite build has a ported/milled 14cc head, 25mm ex valve, 28.5mm intake valve. .276 cam with 1.2 rockers giving it .331 lift. ARC flywheel and rod.
Mikuni carb on alky and the timing advanced a bit. It makes great power from right off idle to over 9000rpm. And no matter how hard I have tried, I can't blow it up in the Kart it's in. I thought I was running it to death on my Dyno when I was tuning it. But after several tear downs to inspect the valve train and checking for metal in the oil I discovered that it loves being flogged. I must say I didn't think the clone castings and crank could take it. I'm impressed.
I use my doodlebug for a pitbike and like to be able to start it on the first pull and not have it jump out from between my legs when it does start. So I like the stock motor with the Jackshaft kit the best. It's still pretty zippy and fun. If I were to want to build a mini drag bike It would make more sense to build a chrome molly frame and have a good brake system. But this is just my opinion on what I think is cool and practical.
For the record, that was a turbo system mock up (crank driven, instead of exhaust) right? I ask because if not, that looks like a $3000 blower (and everyone keeps saying supercharger)..
Also, you say that a crank driven turbo would work. To do so, would you take off the turbine housing and connect only the compressor housing to the crank? In theory, that would make it supercharged right? I read up a lot on turbo systems for cars, I love talking to knowledgable people about forced induction.
Im tryin to build up my stock DB30 over the winter, so its a beast when spring comes :thumbsup:. MY plans are: hydro brake set-up OR stock front brake set-up (I think I want fronts..), new chain, 6.5 swap with 18lb springs, intake, exhaust header, carb upgrade and removed gov, rod. Questions, when I do the rod upgrade would I need a piston upgrade too? Also, would the stock gx390 carb be overkill for this set-up? One thing that i've learned from high performance engines is that most time, OEM is your homie. Haha.
Also, you say that a crank driven turbo would work. To do so, would you take off the turbine housing and connect only the compressor housing to the crank? In theory, that would make it supercharged right? I read up a lot on turbo systems for cars, I love talking to knowledgable people about forced induction.
Im tryin to build up my stock DB30 over the winter, so its a beast when spring comes :thumbsup:. MY plans are: hydro brake set-up OR stock front brake set-up (I think I want fronts..), new chain, 6.5 swap with 18lb springs, intake, exhaust header, carb upgrade and removed gov, rod. Questions, when I do the rod upgrade would I need a piston upgrade too? Also, would the stock gx390 carb be overkill for this set-up? One thing that i've learned from high performance engines is that most time, OEM is your homie. Haha.
you don't need to do a piston but might as well since everything is taken apart. you will need to remove the low oil sensor from in the case because there are clearance issues with the rod. be sure to remove all the internal governor pieces when you remove it too.
i'd go with a cheap 22mm Mikuni (under $40 on Ebay) and AGK intake. just having the easy throttle setup makes it worth getting one IMO.
i'd go with a cheap 22mm Mikuni (under $40 on Ebay) and AGK intake. just having the easy throttle setup makes it worth getting one IMO.