T: (800) 992-7007

P: (530) 886-0771

All orders ship from the U.S.A.

Keeping classic Minis on the road since 1974

(800) 992-7007 | (530) 886-0771

Custom Engines

Details Make the Difference In Engine-Building Quality and Price!

What makes a Seven Enterprises engine superior to others you can buy?

Our engines are built up to a quality standard, not down to a price. Every engine sold by Seven is built personally by Mike Kearney and Steve Maxwell, each with over 30 years' experience in machining and building Mini street and race engines, including all Fortech Mini championship winners. Your engine receives our personal attention and unrivaled Mini-specific expertise. We don't take budget shortcuts that may compromise reliability and performance!


Contact Seven Enterprises today for a quote on a custom power unit or rebuild to your specs,or click here for our popular 1275 and 1380 engines. We ship worldwide!

We are proud to list the detailed steps that go into every Seven engine:

  • Block is completely stripped, including oil gallery plugs. The main journal alignment is checked with a dial bore gauge, and line bored if needed. The deck is surfaced, using in-house equipment. Block is bored in-house on Sunnen machine to desired oversize. Block is glass-beaded, and then pressure cleaned. New oil galley plugs and water jacket core plugs are installed. New cam bearings are installed.

  • Rods are glass beaded and resized on all engines. They are balanced from end-to-end and balanced piston assemblies are fitted. On HP engines, ARP rod bolts are added for higher safe RPM.

  • Crankshafts are pressure cleaned. They are sent out for regrinding to the first undersize, crack-tested, and polished. Proper balancing with flywheel/clutch assembly and front damper pulley in place is performed in-house.

  • Flywheel and backplate are cleaned and glass beaded. Both parts are surfaced to maintain critical dimensions. The assembly is balanced with all appropriate parts fitted for accuracy.

  • Cylinder head is pressure cleaned and glass beaded. New valve guides from original manufacturer AE are installed. Unleaded seats are installed. New valves are installed as needed, springs are checked for proper seat pressure, or replaced as required. New valve seal seals fitted. Head is surfaced and complete multi-angle valve job performed.

  • All exterior sheet metal covers, etc, are glass beaded and painted, all new hardware, bolts, washers, lock tabs installed. All aluminum housings pressure washed and glass beaded. Block and covers are painted to customer's choice of color. Transmissions are totally disassembled, all shift rods and forks are removed. Case and parts are pressure washed, case is glass beaded and drain plug thread insert is installed for easy drain plug removal. New transmission bearings, synchronizer rings, lock tabs, seals are fitted. Custom gears, final drive ratios, cross pin or limited-slip diff units, center oil pick ups can be ordered for installing at this time. Flywheel end housing is pressure washed and glass beaded. Roller bearing is always replaced. Bottom end is assembled with only lead-copper bearing shells on both rods and mains. No aluminum bearings are fitted.

  • New AE pistons from original supplier are fitted, with clearances and ring gaps checked.

  • Engines are assembled with all new gaskets, seals and lock tabs. Cam timing is checked on assembly. Critical drop gear inner and thrust clearances are measured and maintained during assembly.

  • Power units are first test run for 20 minutes to break in the camshaft, set timing, and inspect for possible leaks. The next day the head is retorqued, valves adjusted and run again for 10 minutes. Any leaks are corrected and adjustments made while on the test stand.

  • Custom shipping crates are available on request.

Our track record speaks for itself; visit the Fortech Racing page! More details and photos of our build process are available on our Machine Shop page.

Don't know where to start? Have a look at our Standard 1275, 1275 High Performance, or 1380 Big Bore power units. Then contact us for a quote on an engine built to your specifications!