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Awesomeness. The A series, ZZ series, and ZR series all share a bore pitch of 87.5mm. I'm sure there are other engines from other manufacturers that share a similar bore pitch.

Let's start with a shortblock.

Yes, I'd like to use crankshafts, connecting rods, and pistons suitable for the 4A-GE to begin with. Those critical dimensions are up on +EM. I'm starting a new spreadsheet in google docs that will include development milestones and the such.

I'm still not sure what we should be modeling this in. My gut tells me that Google Sketchup would be the most widely available method for doing so, but it's also the most restrictive. It's also the only thing I have access to at the moment.

Would anyone like to be our Faceman and petition to anyone and everyone for resources?

Also: What do we call this? Open Engine Design Project was a simple way for me to be descriptive about it.

SPREADSHEET AHHHH!
http://spreadsheets.google.com/ccc?key= ... kMmc&hl=en

umm umm ok wild ideas are running amok in the cavernous wilderness of my brain pan.
i like the idea of a oversquare motor and a long rod ratio.
i like the idea of a "construct" crankshaft, it works well in soooo many motorcycle applications and is relatively easy to put together without huge numbers of specialized tools.
ummmm, help me out here because i disremember but isn't a harley a single forked connecting rod with a 70 or 75 degree included angle and a construct type crankshaft? a forked connecting rod means you don't need an offset between banks or a "wide" and a "narrow" head. a v4 harley, talk about a potAto shooter. ....
the bangbangcoastbangbang power delivery pattern would copy the current gp bikes as well.

I haven't really much experience with construct-type crankshafts, other than they aren't used in endurance racing.

I'm really hoping to have an engine that COULD BE competitive in ALMS and the like. I don't have any intentions on doing so, but it's a bar, and that's where it's set.

Not that someone couldn't take the components drawings and make a construct-type crankshaft. See the advantage of an open-source engine?

Take the 4A-GE crank dimensions and model a construct-type crankshaft. Then increase the stroke, or model it to have crankpins to allow a V-type engine. Then share. Then someone else takes that and models a V4. They share. See how this works? I can have my goal for it, you can have yours, we can have ours.

if you use the connecting rods and pistons of an existing engine, then you can readily upgrade to aftermarket internals (assuming you base it on something with good aftermarket support). IOW, someone could build a basic version with oem rods/pistons, then upgrade to forged internals. I understand that may be borrowing a bit heavily from the original engine for some, but it kinda appeals to me.

the other thing to consider is whether an existing small v8 crank could be used with custom connecting rods and pistons from an I4, so you don't have to have a custom crank made. (rods would be cheaper)

what i was thinking, with a forked rod, was using a 4 cylinder crank and a custom case/ barrels(?) to greate a v8 or using something like a cb200t crank to make a v4 (i'm just picking on the cb200t, i had one for my second motorbike. smooth and quiet but a bit underpowered) i happen to agree with using other peoples parts. ..
wheeeeeeee open source!!!!

Intersting proposal, but I'm not feeling it. No offence meant but to me it seems pretty arrogant and naive to think you as an engineering student can build a better engine than a massive company like Toyota which is staffed with legions of experienced, credentialed engineers with access to the best equipment and materials money can buy. I know that sounds harsh, but as stated, I'm not trying to offend, just trying to "keep it real" as the kids like to say. And even if you are capable of such an unlikely feat, getting other people to invest their time in such an unlikely endeavor might be a tough sell when you start from the outset with the goal of bettering an already successful if not legendary engine.
On the other hand if you were trying to do something truly unique by building or designing something like others here have suggested you will undoubtedly have less trouble recruiting help. Sure it might make the job harder and it might not match your original vision, but it looks a lot less like a well intentioned student laboring to reinvent the wheel.

Anyway, that's my $.02 worthless opinion. No matter what you choose to do, my hat is off to you for using your grey matter constructively. Seeing young people "think" these days is rare and inspiring. Best of luck to you.

Make it something unique, small, a screamer with an amazing power/cc ratio and I would be interested in donating some CNC mill time. I would make the cyliner banks separate from the main block (like a motorcycle). This would make it possible to machine the entire block instead of casting it. At least for a prototype. Solidworks or nothing!!! There is a free solidworks viewer so anyone could view progress.

What's the point? And no you can't do that, it's ridiculous on the face of it. Choose to do something different. Most of the motors people are using are too big and too heavy. Decide on a power you want and choose to build something lighter and physically smaller. If you want it to go the same direction as people that spend 10's of millions of dollars on development, you'll do a crummy job. Or you'll have the same thing they do when your done.

Look at the problem your trying to solve and try to understand what's different about what you want and why readily available motors aren't better and do something different. Make a 200 HP engine that's less then 200 lbs. and 18" tall, maybe a pushrod V8 maybe not. Focus on light and small with big displacement would be different, maybe you can come up with something else. I think the I4 DOHC is pretty much a covered subject...

What is it about power/cc ratio anyway, what does a cc cost you? It's obvious what a pound costs you, focus on direct costs.

Sorry for the grumpiness...

I'd like to see a super-light four cylinder.

Bespoke racing engines happen every day. A small group of engineers with a nearly unlimited budget. What, then, is different with a large number of engineers with unlimited man-hours?

I'm having trouble arguing against an all-aluminum rotary.

While you are entirely correct - Toyota (or any mainstream auto company) will be able to out-spend any garage mechanic for R&D, materials, process development, etc. However, they will also be very firmly handcuffed to making an engine that fits the corporate vision for the product (no 10k rpm screamer in your base Camry), can be made as inexpensively as possible, and be made in huge volumes, not to mention reliability, cost-justifying every decision not to use something out of the corporate parts bin, emissions, fuel type (a Yaris that requires premium = zero sales) and so on. A bespoke engine simply isn't even comparable - you're talking about apples from a corporate agribusiness versus oranges from your backyard tree.

At the same time, I'll admit I'd be much more likely to put more time into a really unique engine (can't get that 1.2L 12,000 rpm V8 idea out of my head), but am willing to put some time into a bespoke 4-cylinder. However, unless it becomes fairly obvious the benefits of this 4-cylinder over any other existing one, I fear interest in the project will wane pretty quickly.

Started a forum for this:
http://www.orionengineeredmotorwerks.com/phpBB3/

how about a direct injection, clean-burning two-stroke?

Replace "engineering student" with any of our names, and "engine" with "car", and hopefully you'll see the irony in that statement.

Like someone else said, large companies are not making performance a priority, they are taking into consideration tooling costs, production costs, the average person's maintenance habits, etc.


OP, why not make a rotary then? I'm no expert on how they work, would it be possible to use the eccentric shaft from an RX-7 with your own housing and rotor, say with a displacement of 1 litre+ per rotor instead of 700cc? The eccentric shaft and apex seals are the critical parts of the rotary, and the apex seals could be transferred over as long as we kept the rotor width the same (which would be neccessary anyway to use the eccentric shaft, if possible).

A 3 litre triple rotor aluminum engine sounds good to me. It would help tremendously with low end torque, and with a rotary that size N/A would be fine, which is good for reliability.

you can buy aluminum rotor housings for a 13b from the aircraft market. .. amazingly lightweight, 110 lb longblock i think?
how about and what if......
a construct type crankshaft for an existing well loved motor? ball bearings (needle bearings?) on the rods alone would give faster rev'ing and higher rpm limit. 15k rpm on a 4 valve inline 4? yeouch!!! but how do you provide oiling if you do rods and mains as ball bearings? that i don't know, anyone have any ideas? what about the valvetrain, maybe a lot of intake time before tdc and reed valves on the intake runners to deal with charge reversion at low rpm? i say 20k rpm is the goal

i wonder..... could a bolt together connecting rod be machined so that the bearing could be "filled" with needle rollers prior to the cap being tightened? would there be an issue with rollers getting stuck on the joints (seams) between the rod and the cap? would it cause too great of an oil pressure drop? would side thrust clearance be an issue? how do you calculate and measure clearances? what if i machined a groove in the rod and another one in the crank? aaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(hackcougcoughachoooosniffsniff)

hmmmmm...............

Or go the opposite way, make a 4-500cc rotor, lash 3 of them together with the crank from a Cosmo 20B, and aim for 12k rpm. Yeeee-haww!!



It's possible - it's been done...