Would any of you guys know where I could find somewhat detailed drawings of motorcycle engines, for free? Things like overall dimensions, mounting locations, weight, etc.
I've got a personal design project I'm working on, and I would like to build it someday, but I need an engine. I don't have the room or money at the moment to actually get one and study it first hand. I've considered using the 919 engine, but it's halfway across the country at the moment and I think I'd like something with a little (a lot) more power to design around.
I've never seen such info.
BUT
I'd think the pure engine builders of the HD conceptual type engines that get fitted into custom frames by others, would have to have info packages with mounting locations and spacial requirements.
The problem is getting that for free.
Maybe a local bike builder that has done such work would be open to letting you use such info as they surely must have got from the engine supplier.
Dress the need up as a self education project, perhaps offer to do some renditions work for the shop as barter?
Also try the engine building company, who knows what they might have available on their website.
True, all this is for vertical twins, but so what!
I considered looking into engine manufacturers, but the only one I could think of that comes close to what I'm thinking is Rotax and they didn't have anything on their website that fit the bill. They had a couple of two-strokes designed for snowmobiles that looked pretty sweet, but designing a gearbox to go with it was a little more than I wanted to try tackling.
As a starting point I always go to ebay, search for whatever engine I'm looking for and amongst the pictures is usually one or both side on views which is handy for mount centers, clearance issues, countershaft location, and whatever else you may need. The problem is scale. If there is a sprocket in the picture you're golden: count the number of teeth and multiply by the pitch of a (usually) 530 chain, which is .625". This gives the pitch circle of the sprocket. Divide by Pi (3.14159265358) and you have a scale for anything in that picture. Otherwise find something in the picture that has identifiable dimensions and go from there.
Alternatively, if there is a motorcycle salvage within a reasonable distance go there and tell the counterperson what you need. Usually they will be happy to show you what they have and allow pictures (with a clearly marked ruler in each) and measure to your heart's content. When taking pictures use as long a lens ... oh, wait ... that's in the SLR era ... as much optical zoom as you can. It will help to reduce the parallax error without sacrificing picture quality.
Are you using CAD? If so it is usually equipped to import .BMP images, giving you a ready reference when drafting around the engine.
There are websites dedicated to CAD renderings of pretty much anything and the one I occasionally visit, GrabCAD.com, has at least one rendering of a CBR600 F4i motor which I was able to import as a STEP file. The second is my take on bracing the 919 frame. CAD is very useful!
That's a great tip on the picture scaling and GrabCAD. Right now I'm working on dimensions, sizing, and some basic geometry on paper. I have AutoCAD, but I haven't used it at all (had a couple of classes for Inventor, though) so once I get a few things sorted out on paper I'm going to start poking around with it.
What I have in mind might be a little ambitious...
I'm working on a 3 passenger car with the driver in the middle and the passengers on the side and to the rear. I'd like for it to reach 60 MPH in less than 4 seconds and handle like it's on rails. A lot of my inspiration is coming from Formula SAE cars, but without the competition restrictions and mandates. I'll be in my last year of my mech. engineering degree this fall, and my school is too small to have a FSAE team, or very many automotive focused courses. So, I'm kind of doing my own thing.
The closest thing I can think of is an actual Service Manual for the Parent Motorcycle but I just don't think that it will include ANY actual system level design information.
As a starting point I always go to ebay, search for whatever engine I'm looking for and amongst the pictures is usually one or both side on views which is handy for mount centers, clearance issues, countershaft location, and whatever else you may need. The problem is scale. If there is a sprocket in the picture you're golden: count the number of teeth and multiply by the pitch of a (usually) 530 chain, which is .625". This gives the pitch circle of the sprocket. Divide by Pi (3.14159265358) and you have a scale for anything in that picture. Otherwise find something in the picture that has identifiable dimensions and go from there.
Alternatively, if there is a motorcycle salvage within a reasonable distance go there and tell the counterperson what you need. Usually they will be happy to show you what they have and allow pictures (with a clearly marked ruler in each) and measure to your heart's content. When taking pictures use as long a lens ... oh, wait ... that's in the SLR era ... as much optical zoom as you can. It will help to reduce the parallax error without sacrificing picture quality.
Are you using CAD? If so it is usually equipped to import .BMP images, giving you a ready reference when drafting around the engine.
There are websites dedicated to CAD renderings of pretty much anything and the one I occasionally visit, GrabCAD.com, has at least one rendering of a CBR600 F4i motor which I was able to import as a STEP file. The second is my take on bracing the 919 frame. CAD is very useful!
It's more of a design exercise than a firm desire to modify anything, but I have found that much past 7/10ths the deficiencies of the chassis become obvious, manifesting as a sort of "hinge in the middle" feeling, though not nearly as bad as roadracing a '74 Kawasaki Z1 with a full drag race motor when on the track the chassis and swingarm flexed so badly that the countershaft sprocket had to have almost 13mm of lateral movement to keep from throwing the chain exiting corners!
If I was to modify the stock chassis it would be with the engine and airbox in place to get the bracing in the correct location. That, and filling the backbone with 3 to 4 pound structural polyurethane foam to damp resonances, and replacing the swingarm with a CBR600RR unit to greatly improve the rigidity and wheel control due to the linkage's secant / cosecant characteristics. I have one coming from an Ebay seller. Should be fun to adapt it!
In making a car there are several considerations that must be addressed, particularly the need for a reverse gear (Or two slots cut in the floor pan and high traction shoes!), and a differential capable of changing the relative speeds of the rear wheels in a turn. That's at minimum. In light of that you're going to have to design at least a sub trans with reverse and final drive differential whether you want to or not.
A Mechanical Engineering degree without any experience in CAD? How things have changed from when I was in college: drafting tables and Freiden calculators were the order of the era. I strongly urge you to get as familiar as you can with it. While Solidworks is pretty much the industry's standard, there are many options that do not foster the kind of marketing that crows about ten thousand off a particular package. My preference is Punch! ViaCAD 2D / 3D. Been using it for years and it has generated income hundreds of times it's original cost. Pretty basic, but is exceptional at illustrating a concept and can import / export dozens of formats.
If you haven't already heard of the Ariel Atom, go here: https://www.arielna.com/arielatom
Incredibly cool! When in Malibu many's the time I'd see packs of ten or twelve of them on Mulholland and Piuma Road having a ball! What do you expect what with a curb weight of a paltry 1312 pounds, and even with the standard Honda 2.4 litre crate motor with 320 HP that's 4.1 lb / HP. Roughly the equivalent of the 919. And 0 to 60 in 2.8 seconds. Yikes!
I WANT!
Just for giggles I'm drafting up a simple reverse / final drive / differential unit. May come in handy some day. If you have any questions let me know.
Yeah, I'm not exactly confident in my CAD skills. I'd say they are probably on par with my design and analysis skills, though, if I'm being honest. There hasn't been a lot of work in either of those outside of fairly simple assignments from class. Most of the CAD assignments were making blocks with shapes cut out of them in Inventor. The final project for the class was a corkscrew that was to be assembled with appropriate degrees of freedom for motion. I don't think we touched 1/4 of the software's features. It's part of my motivation for this project. I've heard a lot about Solidworks, but I've never touched it. Luckily I have a free student license to most of the Autodesk software for the next year or so. I also found out while working on my machine design project (design only, unfortunately) that the Inventor library includes several bearings from SKF and a few other companies. Thanks for telling me about ViaCAD. $200 for the software, vs several thousand a year for others, is going to put it on my short list when my student licenses run out.
There's probably a lot that's changed since you were in college. It might just be the school I'm attending, but my fellow students and I feel like they are trying to cram more topics into the curriculum at the expense of a deeper understanding of the basics. There are a few required courses that we feel should have been electives, and several courses seem to have a heavier emphasis on programming than the course material.
I've seen the Ariel Atom before, but I didn't realize they were that fast! I was under the impression they were focused more on handling. I'm might have to talk to the girlfriend about reorganizing our vehicular priorities after graduation.
I considered using a FWD engine and transaxle, but I think a motorcycle engine/transmission would be simpler for a first try, even without a reverse gear. I really want to nail down the frame and suspension concepts before I go that route. It is somewhat relieving to hear Ariel is able to keep their weight down to 1300 lbs and still put it on the road. I'll have to look into how they fare in safety testing.
I may have a differential solution that would only require me to design and build a housing and attach the rear sprocket. Apparently the TorSen center diffs from the late 80's to early 90's Audi quattro equipped cars are somewhat common to see in the FSAE cars and they have been known to hold up just fine in 3500 lb cars with 400+ hp at the wheels. MIT used one on a FSAE entry. I just so happen to have such a car sitting around gathering dust that will hopefully be seeing some significant engine and transmission upgrades in the future and won't be needing that particular differential for much longer.
I've been noodling around a bike based open wheel racer in my head for a while. As for reverse, I've speculated about using a small electric motor (starter?) with a pulley on it looped around a pulley on the driveshaft. Thinking to run the belt loose such that the electric motor could be spun up and, through a lever in the cockpit, the motor pivoted to provide tension (and subsequently drive in reverse). All of this, of course would be controlled through a logic circuit (neutral light on, for example) such that, neutral... turn on motor through a button on the end of the lever... pull lever to reverse car, slipping the belt as necessary. I thought about using a clutch assembly (like an AC clutch) to lock the motor and then control the motor itself but that would require speed controls, etc.. I was thinking "slipping the belt" would be more controllable. It's reverse so you will only need it for a few feet at a time. It bothered me to build a gearbox for such limited usage.
The whole idea came from a memory of seeing pictures of a Trans-Am car where they mounted the alternator in the cockpit, passenger side, and ran it off of a belt on the driveshaft. Anything to move weight bias rearward on these cars. (They also mounted the starter in the cockpit and ran it through a shaft for the same reason.)
Just me and my mental masturbation.
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