Johnson's Quality Machine Custom Engines

At Johnson's Quality Machine we can build a custom engine to your specifications, or we can make recommendations to give you an engine that will meet your needs. All custom engines get the same basic preparations as every motor to start. Then the block gets align honed to make sure all main journals are in perfect alignment, round, and to size. Then the block gets parallel decked, to get the decks squared to the crankshaft centerline, as well as setting the piston to deck height at desired specs. The block also gets bored off of the crankshaft centerline to get the bores 90° to the crank. The block then gets power honed to exacting standards, giving each piston the same clearance, and bores that are within .0001 inch of perfectly straight.

The crankshafts are precision ground, indexed, and stroke equalized, as needed. The connecting rods get ARP rod bolts, and precision remanufactured, if not new rods. Then the entire rotating assembly gets precision balancing.

Before final assembly, the motor is mocked up to check deck height and valve to piston clearance. Bearing clearances are checked by miking the crankshaft, and setting a dial bore gauge to crank diameter and checking each bearing for proper clearance. The cam is degreed in using the intake centerline method.

Cylinder heads get either hardened iron guides, or bronze guides. All guides are honed to fit the valves on an individual basis, keeping each valve-to-guide clearance the same. Most custom engines get stainless valves with either stock or oversize head diameters. Seats are a minimum of three angles, with multi-angle seat cutters and radius cutters available. All guide-to-retainer clearances are checked to make sure retainers will clear stem seals. Springs with appropriate seat pressure and open pressure are selected to go with the camshaft used, setting all installed heights and checking for coil bind clearances. Custom head porting or gasket matching is also available.

All of the popular aftermarket blocks, cranks, rods, pistons, cams, heads, etc. are available through Johnson's Quality Machine for your custom build.