Daily Slideshow: Engine Building 101: Selecting a Block
New to engine building? Looking to start a project car that is LS based? Read these tips on selecting a base block for your next project.
Eyes Don’t Lie
Unless you’re buying a brand new block, you’re going to need to inspect whatever it is you’re about to buy. Visual cues will save you tons of cash when it comes to getting the right candidate. Here are some basic things to look for.
If you see sludge or gunk in the valley of an engine it’s a good indicator that oil wasn’t attended to regularly and this might be an engine you should pass on. Knowing what you’re getting into will save you a lot of hassle down the line. The last thing you want to do is think you’re getting a bargain when, in fact, you’re getting a total waste of time and money.
Cracks in a block are grounds to immediately disqualify a block. While some can be seen by your eyes alone, it should be noted there can be microscopic cracks in the block that cause huge problems later when you start adding boost or stressing the block. Iron blocks can be magnafluxed where aluminum blocks can use a dye penetrant to find the same gremlins.
Cylinder heads and blocks can warp from excessive heat. To check for this, you can use a good straight edge and feeler gauge. Place the ruler over the engine in several different planes and then slide the feeler gauge underneath to see how much clearance you have. Measure diagonally in an “X” and straight across the center of the block in a line. Be sure to check factory acceptable tolerances beforehand.
Any oil that is a kind of milky white color indicates that water mixed in with the oil. These are all signs an engine could have been misused that should steer your dollars elsewhere. Avoid this one and save yourself some trouble.
Measure Cylinder Bores
Measuring the cylinder bores is going to tell you how often a motor has been rebuilt. Each time an engine is bored, the manufacturer will indicate the next size piston to be used. How many times this has happened will affect the strength of the cylinder bores. If this is out of spec, run like hell and do not purchase this engine. You will run into major issues if you start to build up something that has thin cylinder walls! Beware!
Final Thoughts and Summary
A visual inspection with basic disassembly can tell you a lot about the condition of a motor, how it was treated, and if you should spend your dollars on it. Getting the right engine for a project is all about arming yourself with the knowledge necessary to not get caught out or duped when you visit a parts yard or craigslist seller. Be aware, be knowledgeable, and be smart with your money. You can build a badass ride and save a ton if you do it right! Hope you enjoyed. Next time we go over cleaning the block you have selected. Hope you enjoyed reading.