An Intro to Engine Builds: Finding the Right Machine Shop

Who doesn’t love scoring a sweet second-hand engine? Seriously, you go out to a junkyard, the local classifieds, FB marketplace, or Craigslist and grab yourself a piece of performance history. But as much as our hearts (and the sellers!) would like us to believe—chances are, that puppy is far from pristine. So, while maybe that $300 price tag didn’t buy you an engine that runs, it did buy you an opportunity to find the right machine shop and build yourself what is essentially a brand-new engine.

So, why do you want to go to the machine shop? Well, there are many good reasons, but perhaps the most important is reliability. Yes, a well-balanced and machined engine is going to free up horsepower, and alter performance output and range. But, ultimately, it can be the difference between successfully driving down the street or sending a rod into the oil pan. And yes, visiting a machine shop costs money. But you can bet your bottom dollar that a well-built powerplant will last a whole lot longer and save you the cost of replacing busted-up engines down the road.

Honestly, finding a good shop is one of the most important steps in the entire machining process. Because, while any reputable garage is going to have the proper tools to get the job done, finding the right machine shop with tribal knowledge to match your platform and build plan is crucial. This is something you might want to consider doing even before you buy an engine.

Where do you start?

First, form an idea of what you’re actually looking to achieve. Do you want to build a numbers-matching engine? Are you going to lightly enhance performance? Or are you looking for big power? Even if you don’t know every exact detail, it’s good to start with a general idea of what you would like your end-result to be—before you even walk out the door.

Then, ask around! Talk to other guys in the area who have experience in the field. And don’t be afraid to approach a machine shop and ask some questions. Oftentimes, you’ll find that if one place can’t help you, they’ll direct you to another shop that will—which brings us back to that bit about tribal knowledge.

Machine shops live off of their reputations, and happy customers can tell you a lot about their work. There’s nothing wrong with comparative shopping. Much like many things in life, you get what you pay for. The better machine shops will not be the cheapest in town. Be prepared to pay for good service. -Super Street Network

Each individual engine platform is going to have its own shortcomings. Sometimes, these shortcomings aren’t exactly common knowledge. And, more often than not, they aren’t simple fixes that require minor tweaks. So, if you have a vintage Hemi, a shop that can build the hell out of a small block Ford may not be the best option for you. They simply won’t know the ins and outs of your engine. This is especially true when it comes to performance builds.

I use the Hemi engine. Not because of my infatuation with Chrysler, but because it addresses another very important factor: budget. Some engines are just more expensive to build. So, if you don’t spend time finding the right machine shop, you can wave goodbye to your savings. Talk to fellow enthusiasts and find out where they go. And don’t be afraid to ask the hard questions—it’s your money, after all.

What do you ask?

So, you’ve found a machine shop and you feel pretty good about it. Now what?

Talk to the machinist. Let them know what you’re working with—budget, platform, and end goal. Because, unless you’re doing a numbers-matching build or something similar, you’re not really married to a particular engine. By talking to a shop that knows your platform options inside and out, that wild idea can start becoming a workable build plan. A good machine shop can tell you exactly what engines to look for. It might even have something in stock—saving you from sorting through classifieds and meeting up with Craigslist weirdos.

But, let’s say that you already have a complete build plan in mind or you already purchased an engine. Don’t be that guy who walks into a shop and tells someone how to do their job. Even if you have done your homework and you really know your stuff, you shouldn’t limit the builder’s abilities. (Besides, no one likes a jerk.)

Engine-building requires a supreme level of attention to detail and there are a lot of steps involved with the process. Even if you’re walking through the door with all brand-new parts, letting the machine shop go over everything and run through its own process may very well be a lifesaver for your build.

Cracks, warps, and scores are all likely to be missed by the naked eye. The last thing any shop wants is to send you off with an engine, only for you to come back later with a massive headache. Let them work their magic! This is why you’re paying them.

What can you expect?

I remember the first time I went to the machine shop to have an engine built. After explaining what I was working with and what I had in mind, the machinist told me to bring the engine in. I showed up with a bare block and a box of mix-matched parts from the engine—and I’ll never forget the look on his face. Luckily, he was a super cool guy and didn’t send me packing.

Yes, a machine shop will charge you for engine disassembly. And yes, you will likely be tempted to do this step yourself, in an effort to save some money. Word to the wise? Don’t. Not only does the shop see that you’re trying to save money, they see a headache walking through the door. If you’re determined to do it yourself, definitely make sure everything is properly marked and labeled so they know exactly which parts go where.

Overall though, the tear down is an important part of assessing the engine. It gives the machinist a good way to inspect condition and figure out what he or she is up against. Engine parts mate to their mounting surfaces uniquely, and other parts like rod caps and main caps are meant to mount specifically in their corresponding locations. When you take everything apart and don’t mark it, it’s on the shop to figure that puzzle out.

Sometimes if you’re after a certain engine with limited options, you may have to purchase it in parts. It’s unusual, but it happens. In that case, take my advice and let the shop know that you weren’t the one to tear it down so they don’t beat you over the head with a spare engine rod.

Stay Tuned

As I said, finding the right machine shop really is the most important part of the whole process. But what actually happens once the build plan gets underway? What does your engine’s tour of the machine shop look like?

Well, check back soon as I’ll be diving into just that. From the block itself, to the crankshaft, rods, pistons, and cylinder heads, to what kind of replacements and aftermarket upgrades you should consider—we’ve got a lot of ground to cover.

Machining is an art and it should be an enjoyable experience for both you and the shop. Knowing how your money is being used and what kind of time goes into the process will help. Remember, at the end of the day, a well-built engine will be worth it—and starting off on the right foot is everything.