T: (800) 992-7007

P: (530) 777-7759

All orders ship from the U.S.A.

Keeping classic Minis on the road since 1974

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

Rebuilt Engines

Celebrating the shipment of over 500 classic Mini power units since 2002!

Seven Enterprises is the leader in furnishing remanufactured classic Mini power units, whether it is a standard specification or one of our high-performance (HP) assemblies. Seven is the ONLY classic Mini parts and service company in the business that has a complete in-house machine shop and a staff with over 60 combined years of experience building every level of power unit (including five SCCA National Championships in the GT class!).

Please take the time to compare our specifications and ask questions to see if you are getting the most value for your money. It will be very clear there is only one company that can deliver fantastic reliability and performance: Seven Enterprises! Please click on of the links below for more information about our Rebuilt Engine Packages, or see below for further details on our engine rebuild procedures, and compare when choosing your motor supplier!

The procedures detailed below are performed by Seven on EVERY motor (not just "when applicable")!

  • Core motors are 1275 A+ Mini and Metro units from Great Britain
  • Block Preparation STD and HP
    • Stripped of all core plugs, oil galley plugs, cam bearings removed and then chemically spray washed before glass beading the block. This final step ensures the block is as clean as it was when new.
    • Blocks are then surfaced and bored to the required size for the piston chosen, HP blocks have the extra two head stud holes drilled and tapped then back to the spray washer for final cleaning before going to be painted.
    • New cam bearings, core plugs and oil galley plugs are fitted, HP motors get the Fortech steel main cap strap fitted and main caps modified for full groove Vandervell VP2 bearings.
    • The block is now ready for Seven's clean area and assembly.
  • Connecting Rods and Crankshaft
    • Every connecting rod is closely inspected after cleaning and glass beading, then resized to specifications.
    • HP motors have ARP rod bolts installed before resizing.
    • Piston and rod assemblies are balanced on every Seven motor.
    • Rods and pistons are then mounted and aligned.
    • Crankshafts are not always machined undersize; a standard journal crank is stronger than a machined one, so if a core crankshaft is in great condition, after magnafluxing and polishing it would be installed that way.
    • Every crankshaft assembly, damper, clutch assembly is balanced as a rotating mass. Seven uses nothing but the finest AE and Vandervell VP2 bearings in our rebuilt motors!
  • Pistons
    Standard rebuilds get the 21251 AE piston, and the HPs get the 21253 AE Cooper S style piston. We also feature 1380 Power Max and JE Pistons for the serious motor enthusiasts. Every piston is balanced before mounting to the rod!
  • Cylinder Head
    Great care is taken with our remanufactured cylinder heads:
    • After cleaning and glass beading the casting, new AE valve guides are installed.
    • The exhaust valve seats are then replaced with unleaded, heat treated ones.
    • Every head then gets new exhaust valves and a three angle valve job plus is surfaced.
    • Our HP motor cylinder heads are provided by English tuner Keith Calver. They feature the extra holes drilled for 11 head studs, ported intake and exhaust ports, new stainless steel valves, new valve guides, dual valve springs, the head is surfaced and three angle valve job done.
  • Camshafts and Timing Chains/Gears
    • Our camshafts are ground by Dema Elgin to our specifications - even our standard motor has a cam, ELG001, more efficient than a stock Cooper S, with a great idle and good torque.
    • Our HP cams, ELG103 and ELG005 have been developed over the years and have proven to be the best performing street cams available
    • All motors come with new AE cam followers.
    • Our standard motor comes with a new OE timing chain and tensioner.
    • Our HP motor comes with new duplex gears and no master link timing chain.
  • Oil Pump
    Every motor comes with a brand new oil pump, same on both STD and HP motors
  • Flywheel and Clutch
    • Every flywheel receives a new ring gear when needed, and both the flywheel and back plate are surfaced on every motor assembled.
    • A new blue spot clutch diaphragm and AP clutch disc is used on all 1275 cc motors.
    • Flywheel and clutch are balanced as part of the crank assembly.
  • Other parts included in a Seven Enterprises Motor:
    • Thermostat
    • Thermostat Housing
    • Throw out bearing
    • ARP Head Studs (HP only)
    • New Water Pump
    • ALL Gaskets and Seals
    • Rocker Shaft
    • Spin on filter head and filter
    • Break in oil 20W50
  • Did you know... ... that Seven is the leader in transmission rebuilding? It's true! We get transmissions sent to our shop every month for rebuilding, and our extensive stock of OE parts makes our gear boxes the best in the industry.
    • Every core is completely stripped to the bare case; all parts are cleaned and inspected.
    • We glass bead every transmission case and install a threadsert for the drain plug, stronger than new threads in just the case.
    • We replace all the bearings, all the synchros, all the lock tabs, all the seals and gaskets.
    • The differential is also rebuilt to factory specifications.
    • The end housing is restored with all new bearings and races and idler gear clearance is checked and adjusted to spec.
  • Motor Break In
    • All power units are run on our engine stand for 20 minutes as a first stage
    • The motor is run at 3,000 RPM to break in the camshaft.
    • The next day, the head is re-torqued and valve adjusted, then the motor is run again to make sure all seals and gaskets are working properly.
  • Shipment
    Finally, we ship our power units in special containers to their new owners.

For more information about our engine and transmission rebuilds, or additional Machine Shop services, please contact us at (800) 992-7007 (U.S.) or (530) 886-0771!