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Old 04-30-2010, 01:12 PM
meowy84 meowy84 is offline
Motorized Bicycle Elite Member
Join Date: Jul 2009
Location: Canada
Posts: 238
Default Re: 60 MPH...achieveable? Who cares?!? Let blueprint an engine!

BarelyAWake, yup you're right. Even GPS is not 100%.

Someone else also made a comment not to ask if you can do this 'blueprinting' with a Dremel. I say NEVER say NEVER. If you're like McGyver you can go to the Moon with a couple CO2 canisters for propulsion, a coathanger, some bubble gum and an old tent. I swear on the workmanship of my HT I've seen it done!

The basic premise of blueprinting is to try to compensate for the often mass volume manufacturing techniques and to get every engine component to the dimension as it was originally indended by the designer in his 'blueprints'. Without a machine shop and lots of skill you can't do all that CreativeEngineering is doing. However, you CAN do quite a bit of basic blueprinting with very simple tools, including a Dremel. At least on multicylinder engines and if not for all-out performance than at least for longevity which also does transalate to free performance gains. I have some hours logged playing around with American V8's and VW air cooled flat fours. The VW is probably most similar to our engines in that it is also air cooled and the crankcase consists of 2 halves. Anyhow, you will find that when buying new rods and pistons their weight varies. You may find that the weight spread between the lightest piston and the heaviest one in a group of quality pistons might still be say 5 or 10 grams. Well even 5 grams spun at say 5000rpm is a huge deal and will over time pound out your bearings more. So we used to grind the pistons with the handy Dremel to make sure they're all the same weight. That's very basic blueprinting. Same goes for the rods. You just need to be very selective and mindful where to take material off. Then there's cc'ing the combustion chambers which can also be done with the Dremel to ensure same combustion volume in each cylinder which reduces engine vibration and makes for a smoother idle and throttle response. Then there's intake and exhaust matching so the mixture goes in smoother with less obstructions and exhaust comes out easier as well. The easier that mixture can enter the engine the more of it will enter per cycle increasing performance. Same with exhaust gasses. You want to get them out of there as fast as possible. You don't get this as much in the HT engines but in the VW jugs the fins are relatively close together and in new rebuild kits you will often find quite a lot of casting flash between the fins which you can remove with a hacksaw and a small file. This way cooling air has a better path around the fins providing better heat dissipation and so better performance. Now I've never tested the power gains with this simple blueprinting on a dyno but I'm sure that on an stock VW engine rated at 60bhp it probably does free up a horse or two but more importantly it does lead to smoother idle and throttle response, less vibration, cooler temperatures and ultimately longer engine life. Then of course you get into more advanced blueptinting where you need the machine shop and lots of expertise and then you can you align hone the cam and crank bearing saddles, match and dowel the case halves as Creative Eng is doing, and the list goes on and on.

With the 1 jug HT engines you obviously can't do much cc'ing or piston or rod matching but you can still match the intake and exhaust and if you know anything about port timing and such on 2 strokes do some port smoothing. There are also ways to statically balance you con rod without many tools which might also increase the longevity of these 'cheapie' engines. Since personally I have little experience with 2 strokes I'll just smooth the intake and exhaust ports and deburr here and there. And all with your Dremel and a couple of jewellers files. The bubble gum is optional.

Last edited by meowy84; 04-30-2010 at 01:15 PM.