What to Look for When Buying Used Engine Parts

Used engine parts can be a great deal, if you know what you are looking for. They can also kill your engine. Here’s what to look for in used engine parts. Most of the places that you’d go engine parts hunting are swap meets. Bring a cheat sheet of engine codes and casting numbers with you, or you might end up with a completely different part than you need.

• Intake Manifolds: Most factory performance air intakes are fairly easy to identify because there is a casting number and date code on them. Cast iron intakes are virtually indestructible, but are fairly heavy. Aluminum intakes offer better performance, but are more susceptible to problems. Look at the thermostat’s counterbore, as it is common for that area to get rusted and corroded on aluminum intakes only. If it’s not too badly eaten away, any good machinist can repair it. If it’s badly eaten away, look for another one. If you really want it, however, the bad area can be cut out, and a new piece can be welded on and machined to the original shape. It’s common to see other problems, and if it looks like it’s been modified, make sure that it was done well!
• Pistons: Careful with these. Most new pistons are relatively inexpensive, but you can score a good deal on them at a swap meet if you know what you’re looking for. If there’s a full set of them and they’re still in the box, you’ve got a great deal. Get them if they fit your car. If they are used, be sure to clean off all of the carbon deposits from the tops and inspect them thoroughly. Also, check for ring lands and grooves on them – this means that something was wrong with the engine that they came out of, and that they are damaged. DON’T buy those! If they don’t fit your engine, they make great pencil or screw holders.
• Connecting Rods: Used connecting rods are very difficult to evaluate without the proper equipment. Yes, it’s easy to bead-blast and hone an old pair, but you need to take them to a good machinist to make sure that they are good to put into your engine.
• Camshafts: If it’s unused, in it’s original box, and has full documentation from day one, you can definitely consider it. When buying used camshafts, it’s very difficult to tell whether it’s a stock, weak camshaft or a high-performance camshaft. Plus, modern camshaft technology has advanced so much in the past 50 years that it’s worth it to just buy a brand-new camshaft. It’ll be easier to get one that’s essentially tailored for your driving style.
• Exhaust Manifolds and Headers: Exhaust manifolds are sturdy parts, but can be abused and broken. It’s not uncommon to find a broken stud in an exhaust manifold. Luckily, they are fairly easy to remove. Used headers can be a great deal or a massive head ache. Ask the seller what they fit, rather than, “will they fit on my Challenger?” Check the welds and flanges on the headers – if the flanges are warped, they will not seal against the head, resulting in exhaust leaks. You don’t want to be like Freiburger and Finnegan from Roadkill. Also inspect headers for dents and scratches that could have come from bottoming out or from hammering them into place.
• Carburetors: Have a carburetor cheat sheet on hand when you go looking for carbs. You can determine it’s original application and CFM rating. The overall appearance of a carburetor is a good indicator of it’s health. Rebuild kits are available for nearly every carburetor under the sun, so it makes it a good deal less risky to buy a used carburetor.