Technical midget persuing a giant of a project

June 25, 2007 11:56 AM

I want to build an engine as a hobby. How misguided is this, and how would I go about it?

I sometimes watch garage shows (you know, the ones where the mulletted gentleman restores some classic car or another), and I always see a fully functional engine sitting on supports somewhere in the background. I always think about how cool it would be to build one of those suckers, but never know where to start.

See, I'm not the most technically proficient fella around, but I would like to learn. How better to go about it than just getting my hands dirty? In my ignorant imagination it seems that I could just start ordering parts piecemeal starting with the block and building outwards.

So I guess my question is one of feasibility and details. Is this even possible or practical for someone like me? If it is, what would I need to purchase in order to get started, and what would be a good source? What would I need to read as a guide through the process?

Help me, gearhead MeFites!

posted by Willie0248 to travel & transportation (24 answers total)

Speaking as a not-very-good shade tree mechanic, have you considered starting by rebuilding engines, starting with, say, a lawn mower? That would give you a solid grounding in what the various parts are and how they work and how good you are at handling them.

Once you've done that a couple of times you might be ready to, say, modify a riding lawn mower into a go-kart.

The mullet guys on TV have literally been doing this their whole lives, so it looks easy. Sure, to them.

But if you don't have the slightest comprehension of (say) torque or compression, you're just going to waste a lot of time and money. IMO.
posted by dhartung at 12:06 PM on June 25, 2007

How about a steam engine?
posted by zeoslap at 12:08 PM on June 25, 2007

So I think, from reading your question, that you want to build a *car* engine. The reason I make the distinction is that I often see a kind of hobbyist, at fairs and such, who brings in his 1880s vintage gasoline engine and starts it running, with much turning of gears and belching of oily smoke. These engines are about the size and shape of a sewing machine and can go right in the trunk of the car at the end of the fair. It seems like a viable hobby.

Car engines are different. You can buy one mostly pre-assembled, in a crate; these are called 'crate engines.' These can be cheap, if they're just a replacement for an economy 4-cylinder; or they can run into the tens of thousands of dollars, for big-block V-8s suitable for racing. Most folks start with a crate engine and modify it to suit their needs.

The set of tools required to do what you want to do is quite expensive. About 20 years ago, I was interested in this as a hobby. I calculated that it would cost me about $20000 to buy the tools that would be necessary to get the job done. An engine hoist, an air compressor, set of pneumatic torque wrenches, various pliers and mallets, screws, screwdrivers, nuts, bolts, clamps are the obvious ones. But if you're really planning to build it from the ground up, you need a soldering gun, a timing light, a set of fiddly little picks and gauges for gapping spark plugs, some kind of grinder for deburring edges, a micrometer, one of those thingies that puts piston rings on, and probably dozens of other specialized tools that I've either forgotten or never encountered.

So that's not what I consider a hobby; it's more of a lifestyle. It probably makes sense to go that route only if you are considering changing careers to become an auto mechanic.
posted by ikkyu2 at 12:16 PM on June 25, 2007 [1 favorite]

When I was a kid, I remember seeing a small scale rotary engine model that you could build, just like an airplane or a car. A search on amazon brings up a couple, though they all seem to be 1/5th scale.
posted by Dave Faris at 12:17 PM on June 25, 2007

Oof, twenty grand would be quite an investment (and yes, I'm talking about a car engine).

I suspected it might be too costly and difficult a task to undertake, but I'm not giving up. There has to be a way to get the practical technical knowledge I wanted while appealing to my goal-oriented hobby tastes.
posted by Willie0248 at 12:27 PM on June 25, 2007

go ahead - it will be a great learing experience - if you have the space and enough tools (you can get away with hand tools). My suggestion is to pick an engine that is easy to work on (...I'm being realtive here), doenst require to many special tools and is cheap. My choice for you is the air-cooled VW 1600. Lots of parts/donors available, easy to work on (i worked on one on the floor of my apartment).

Bonus is that being air-cooled, you have less plumbing to worry about, can start it up if needed and, as I have done, carried it whereever you needed it to go. Its a simple engine, relatively compact and easy to find.

just my 2 cents

CDM
posted by Country Dick Montana at 12:30 PM on June 25, 2007

Check out Lindsay's Technical Books

From the web site: Exceptional technical books for experimenters, inventors, tinkerers,
mad scientists, and "Thomas-Edison-types."

They have books on a lot of fun and crazy stuff you can build. I haven't seen a catalog for awhile (it has a lot more stuff than their web site it appears), but if I recall correctly if you want to go extremely all the way of building it yourself they have books that instruct you on how to refine you're own iron ore, building your own machine shop from scratch, and building engines.
posted by ShooBoo at 12:37 PM on June 25, 2007

I am glad you asked this question, as I have been thinking about it a lot myself.

For instance, the story is that the Wright brothers designed and built their own engine, and they used a tin can for the carburetor. Were they geniuses, or did they just have a lot of time on their hands to try out different designs?
posted by ArgentCorvid at 12:42 PM on June 25, 2007

If you really want to build an engine, if you pick up one of the better modelmaking magazines, you'll sometimes see ads for people selling plans or occasionally kits for working ICEs or steam engines.

Usually they require some metalworking tools and experience, though. There are some plans that purport to be doable without a mill and just use a small lathe, like a Sherline. Still, I've read some books that recommend specifically against jumping into an engine project as your first metalworking attempt, because it can be discouraging.

I think the recommendations to rebuild an engine first, before you decide to actually built one, are right on target.
posted by Kadin2048 at 12:47 PM on June 25, 2007

Oh, you can SOO do this. I've been playing with cars since I was 14, but a buddy of mine with no experience just finished building a Chevy 350. He had a little help from me and others with experience but he mostly did it on his own.
Buy a book or two and study study study. You can buy the tools you need as you go and rent or borrow the specialized tools you need for particular tasks. The 350 is a big hunk of cast iron, so you'll need an engine hoist and a stand. I got mine as a set at auction for $75. You'll need a truck to move it around.
The Chevy 350 is a common engine with a lot of support online and locally (if you're in the US) so you'll never get totally stuck. You are at least as smart as the guys who assembled and tested it at the factory, and probably as smart as the guys who designed it so don't be intimidated. Every task you have to do is a series of smaller tasks that can easily be done by someone with enough patience and the ability to to research. When you're done you'll have an engine that is built for what you want it to do. There's nothing like the feeling that comes from hearing that baby fire up for the first time and knowing "yeah, I built that."
If you don't have a need for brute horsepower, or if your tastes run toward something smaller, a Honda 4 cylinder might be a good choice. At any rate, you can do it, the tools can be bought piece-meal or borrowed, and it's a nice respite from sitting in a cube doing "knowledge work" My email's in my profile if you have any questions.
(On preview) To clear up any misconceptions: when an auto mechanic "builds" an engine it means starting with a block and adding the components needed for the performance desired. It doesn't mean casting and milling a block from scratch and building up from there, although that would be fun, too. And Country Dick Montana has an excellent suggestion, the air cooled VW engines are a great start.
posted by Floydd at 1:02 PM on June 25, 2007

I calculated that it would cost me about $20000 to buy the tools that would be necessary to get the job done.

come on, now. this is kind of ridiculous. you don't need a pneumatic torque wrench unless you're torquing things to spec all day every day. a regular old 60-buck manual torque wrench works just fine. in fact you don't need a pneumatic anything unless you're working on seized bolts on a 20 year old rustbucket, and even then you're gonna replace half that shit anyway, and a hacksaw/breaker bar/wd40/swearing works just fine for those.

yeah, sometimes you need a shop press for pulleys and whatever. guess what, you can take whatever it is to a parts store and ask them to press it in/out for you and you dont have to buy the damn press.

a spark plug gapper costs like a buck fifty. i got a set of 4 snap ring expanders at kragen for 8 bucks. you don't need the silicon carbide soket if you're doing this stuff as a hobby.

there are some specialized tools you'll need to completely rebuild an engine, like that brush thingy that you use to hone the inside of the cylinder and so on. yeah, you'll probably need a hoist. but you dont necessarily need all of these things for a particular rebuild, depending on the shape of the motor you start with, and they can often be borrowed or rented or bought as need be. but 20k on necessary tools is like.. kind of ridiculous any way you dangle it.

willie, it isnt clear what your level of ability / interest is. have you ever worked on a car before? if you haven't and if you're interested in doing this and you're really starting from zero you should pick up a set of 4-ton jackstands and a floor jack, a tool kit when they're on sale (hint, you dont need the googleplex-piece one) and learn by doing basic maintenance on your car. see if you actually like it. you may not.

(also, generally, you don't just build a motor like you'd build something from legos. each little part is engineered specifically for that motor and you cant just pick a set of pistons, pick a gasket, pick a cam gear and so on until you have all the parts you need. its designed as a unit, so generally you buy it as a unit, either as a crate engine like ikkyu2 mentioned, or as an engine in a car. you could conceivably design and machine your own engine parts from metal stock but really, i dont think thats what you're getting at.)

if you do like it, then drop a grand on some junker of a 92 civic or something that you wont feel bad about tearing apart and not being able to put back together, and a shop manual. tear it apart. put it back together. cry because you cant figure out how its supposed to fit together. use a digital camera and take pictures of each step from multiple angles, so you dont have to cry.

use little labeled plastic bags to keep all the nuts and washers associated with each part you take off all together. always, always put labels on wires and hoses you disconnect so that you can match them up with what they're supposed to connect back to. 3 weeks later you won't remember.

i'm saying all this because i suspect you've never done any of it before and really it's better than learning the hard way. anyway, hope you give it a shot. its a great and empowering hobby and honestly, just jumping in and getting your hands dirty really is the best way to go. (oh yeah, pick up some goop too.)
posted by sergeant sandwich at 1:03 PM on June 25, 2007 [1 favorite]

Here's a good walk-through building a Chevy.
posted by Floydd at 1:19 PM on June 25, 2007 [1 favorite]

oh yeah, the VW suggestion is a great one. this is the classic VW book, and this looks like the sort of guide you'd need. (and god, how i would love to take six months off from my life and do this to a ghia!)
posted by sergeant sandwich at 1:23 PM on June 25, 2007

Go for the VW. I've rebuilt motorcycles and the better the initial design, the more common the machine generally, the easier everything else. Specialty parts are a pain in the wazoo: sure, you _can_ always find them on the internet, but then you have to wait for shipping and etc. If you can just pop down to NAPA (or equivalent Auto Parts Store) and just get what you need it just makes everything more pleasureable.

The VW? I believe covers all those bases. Oh, and Significant Others sometimes have strong opinions about these motor obsessions, tread carefully lest thy S.O. should feel neglected.
posted by From Bklyn at 1:26 PM on June 25, 2007

I was all set to recommend the VW... because...(yt)
posted by acro at 1:43 PM on June 25, 2007

In the same vein as the VW engine, another option is a BMW Boxer motorcycle ("airhead"). They're air-cooled, about the size of the VW engine, dirt simple, and if you ever want to use it a motorcycle is a lot cheaper and takes up less space than a car. This article talks about buying one new, but they're all over the place.
posted by Skorgu at 2:00 PM on June 25, 2007

That is a very good suggestion Skorgu but, respectfully, that is an "oil-head", not an "air-head" for the literal reason that it is oil-cooled and not air-cooled.
It's a very good bike (I had it's bigger iteration), but not friendly to work on if you are not a mechanic. Intentionally. There was a big shake-up among small BMW motorcycle dealers about six or seven years ago and a lot of them closed down. (here in the N.E. USA)

If you look at e-bay you can often find nice air-heads with the 'toaster' tank, which is a very good looking bike.
posted by From Bklyn at 2:25 PM on June 25, 2007

I'm with the crowd that says "go for it!" Look around for second hand tools at junk yards, garage sales and estate sales. Buy what you need, when you need it, but buy the best hand tools you can afford, when you do.

As for starting with small engines, vs. the VW engine, vs. a project car debate, I think there is no "right" way for everyone, but I will say that your learning won't be the same unless you have plenty of use for the engines you build, and get a chance to see how they run and hold up. Part of the fun of working on engines is diagnosing performance problems, making repairs or modifications, and letting the engine's performance instruct you on whether you've corrected it or not.

I will say that older carbureted or mechanically fuel injected engines are a bit more amenable to tinkering than new engines which depend on Electronic Engine Management systems for their operation. It's just easier to "see" and "feel" what is happening with a purely mechanical system, but such engines are getting harder to find as re-build candidates. The air-cooled VW engine installed in a dune buggy is a fine learning option, if you can afford such, and have an off road area to run it in. But for the lowest cost and financial risk, I endorse getting an older model of a popular car that needs work, and starting with some basic repairs to fix what is wrong, with an eventual goal of doing an engine overhaul.

Repairing small engines, as in single cylinder air-cooled lawn mowers, is something of an art in itself, as they use pretty small parts and simple magneto ignition to operate. The principals of operation are the same as those that drive multi-cylinder car engines, but these little workhorses are engineered for weight and build cost reduction, and aren't very robust when it comes to tinkering.

In a car, for example, you needn't do an entire overhaul at once, if you don't mind doing some jobs repeatedly. As an example, you might find an older engine with a 150,000 miles on it, and low compression, that really needs a valve job, and will obviously have some ring wear at that mileage, too. You could either just do the valve job and top end, and get some improvement, or do a complete overhaul, and bring it back to overhaul specs throughout. In that case, I'd argue that the better learning situation might be to do the valve job first, and put it back together, since if just doing that didn't restore driveability, all the machine work to the heads would still be salvageable on a full rebuild or short block exchange- all you'd really be out of pocket is a gasket set. And you'd get a look at the engine internals (with a chance to measure cylinder walls), and replace camshaft drive belts or chains, oil pumps, water pumps, and ignition parts, all for 1/2 the cost of a complete overhaul. So, the incremental approach can teach you a lot, and lower your costs and financial risks in fixing an older car. Ideally, you should be able to fix and drive an older car for a couple of years, nearly for free, throwing in your own "hobby" time, considering the costs of parts as maintenance, if you don't overspend on buying it in the first place. In the last 20 years, I've bought a lot of 100,000 mile cars that were running badly, spent a few hundred on parts, driven them for 2 to 5 years, and sold them, running better, for what I paid for them. And spent substantially less on insurance, depreciation and interest payments while doing it.
posted by paulsc at 3:07 PM on June 25, 2007

You might want to also look into whether any local college offers part-time evening courses in engine rebuilding or small engine repair to get your feet wet.
posted by hungrysquirrels at 3:27 PM on June 25, 2007

You don't need a soldering iron or $20,000 to rebuild an engine. Is there even such a thing as a pneumatic torque wrench?

Taking a quick glance at Sears' web site (Craftsman is not the bestest mechanic's tools out there but they're far from the worst) you could probably pick up most of what you need for $300-700. This may seem like a lot but you don't have to do much to make them pay for themselves. Figure that much again for a jack and stands, torgue wrench (a 3/8th w/o pneumatics, computer control and laser guidance would be sufficient), a timing light and some other specialty bits you'll need here or there.

As for where to start, you don't want to build up out of parts. You'd end up spending more than if you just bough a new car, took it apart and but it back together 10 ft. to the left. I'd echo the start with something like a lawn mower engine and work your way up. You can probably get one for free if you ask on freecycle.

The big question is, do you have a place where you can do all this? If you have to build a garage first, then go back to that $20K mark.
posted by Kid Charlemagne at 4:25 PM on June 25, 2007

From Bklyn ahh, I had foolishly assumed that a BMW boxer was a BMW boxer and that was the neatest article I could find. I was under the impression that the actual airhead BMWs were rather trivial to work on, apologies all around if this is not the case.
posted by Skorgu at 4:28 PM on June 25, 2007

Paulsc makes some good points (as always) but remember a project car is a project car. It's not just the engine. You will want to hitch your lovely beast to a chariot at some point, and then you're off the map. There be dragons. Electrical dragons, transmission dragons, suspension dragons, all kinds of dragons.
Beautiful, challenging dragons, but dragons nonetheless.
posted by Floydd at 5:04 PM on June 25, 2007

The $20K estimate included a Pontiac 421 Super Duty crate motor; and everything I thought I might need and wasn't in my dad's tool chest to get it safely into my '65 GTO and get it tuned and running. Most of the expense was tools and equipment, though. I didn't actually end up doing it, but I probably dropped a couple grand into tools anyway over the two years I wrenched on that car. That thingy to get the oil filter off? $8, I remember well - but the shitty $8 one ripped the oil filter in half, spilling oil all over the garage floor, and then it was $34.95 to get a decent oil filter remover, and $20 in cleaning supplies for the floor.

Stuff adds up. A $60 non-pneumatic torque wrench here, a $100 timing light there, and then you find out your long-handled torque wrench doesn't fit where you need it to so another $60 on another one. The pneumatic wrench is very helpful when fasteners have corroded in place, by the way; I'm not a super strong dude.
posted by ikkyu2 at 6:19 PM on June 25, 2007

If you want to do it, you should totally do it, assuming you have someplace to work and a bit of money to spend.

I really want to reiterate "find somebody who does this and can mentor you" or "take a night class first" advice. I've never done an engine rebuild, but I taught myself a lot of basic machine shop/electronics skills in college with the help of a couple of professors (in the theater department, strangely enough) I knew who happened to need some simple builds done and were willing to spend some time and effort coaching a newbie.
posted by Alterscape at 6:33 PM on June 25, 2007