Greg Jones, Author at UnderhoodService
Diesel Exhaust Fluid (DEF) Changes

Modern diesel exhaust systems are complex and they include multiple sub systems to keep exhaust clean.

Building 6.6L Duramax Diesel Engines

The Duramax diesel can be built to do anything you want. The only obstacle is your wallet.

Small-Scale Cosworth Engine More Than Just A Model

Why would you want to build a fully working 1:3 scale Cosworth DFV engine? Marcel Bouland asks, ‘why not?’

Piston Rings, Oil & Cylinder Bore Surface Finish

The relationship between piston rings and the cylinder bore finish is critical to engine efficiency.

VIDEO: Diesel Oil Viscosity Options And Weights

Depending on how they’re used, diesel engines can require different viscosity oil. This video is sponsored by AMSOIL.

Simple Engine Fasteners Actually Complex Engineering Systems

Fasteners act much the same as a spring due to the physics of stretch and rebound.

Cylinder Head Porting; Turning Air Into Power

Cylinder head porting can be a very effective way to improve the efficiency and airflow capabilities of any cylinder head.

Engine Build: Toyota Supra B58 Inline 6-Cylinder Engine

Boasting 335 hp from the factory, find out how Stephan Papadakis tripled the power output!

Engine Build: Roots Blown 540 cid Big Block Chevy Engine

Check out this Roots blown 540 cid big block Chevy Hilltoppers Speed Shop recently built for a street rod.

Engine Build: 452 cid SB2 Small Block Chevy Engine

This 452 cid small block Chevy engine is one of Gibbons Motorsports more intense custom engine builds.

Engine Build: Stage 2 6.7L Twin Turbo Cummins Engine

This truck started as a $225 1949 Ford F1 and is now a more than $400,000 full-blown race truck.

Engine Build: Procharged 6.4L Powerstroke Engine

Choate Engineering Performance created a hybrid 6.0L/6.4L with a Procharger and nitrous. Find out what went into the build!