A long block is an engine sub-assembly that's largely used when doing an engine overhaul. Nearly all parts of the engine are included and pre-assembled in a long block, including the attachments and wirings. These parts include the manifolds, cylinder heads, timing gears and bearings, valves, guides and springs, and camshaft.
Why is it better to invest in a long block than in a short block?Both sub-assemblies are composed of the different parts required to run a vehicle. The main difference is the cylinder heads. In most cases, the long block is considered as the complete version of the short block and is more cost-efficient. Short blocks require additional parts and longer installation time, so they're basically more expensive than long blocks. Your engine will also achieve better performance with a long block, as it is already in a complete state and all parts are brand new. Aside from that, the components included in the sub-assembly will also wear out evenly, minimizing replacement costs.
What are the things to consider when choosing a long block?
The first is, of course, the cost. Additional external long block parts are cheaper compared to internal short block components. Labor charges also cost less, as this sub-assembly requires shorter installation time. Engine long blocks are priced at around $1,500 to $5,000. Add to that amount the labor cost if a mechanic will do the installation for you.
Like any other auto part, not all long blocks will work well with your vehicle's make and model. Although it is already a complete assembly, you have to make sure the transmission system and electronic control unit of your vehicle are compatible with the long block you wish to install. Check the compatibility of the shift linkages, sensors, axles, wiring harnesses, and mounts first before purchasing a new long block.