How To Rebuild A 289 Hi-Po Engine

Always use a block deck torque plate for cylinder honing. The torque plate, when torqued properly, simulates cylinder head installation. A torque plate is not necessary for boring. JGM has bored the block to 4.025 inches.

Honing takes these bores from 0.005 inch to 4.030 inches. Bores should be match-honed to each piston's outside diameter to achieve ideal piston-to-cylinder wall clearances.

Although this is not our Hi-Po block, it is a small-block Ford getting a thread chasing. Chase and clean up all threads to ensure smooth application of fastener torque.

JGM Motorsports hones all lifter bores for the same reason it hones cylinders-to get a true surface. Honing lifter bores improves oil control.

Connecting rods get reconditioned where all caps and rods are milled...

...then honed back to the proper size. Honing the rod journal improves bearing security.

C3AE connecting rods originally had oil holes to splash oil on cylinder walls. Ford engineers ultimately learned this splash hole (right rod) wasn't necessary for good oil splash. With good oil flow across the rod journal, splash comes naturally.

Rolo's Hi-Po heads get a good three-angle valve job and new guides. Some rebuilders go with bronze guides. But if you really want to do it right for longevity, go with new steel guides and stainless steel valves. Hardened exhaust valve seats are installed for use with today's unleaded fuels.

The cylinder heads and the block deck were cut for perfect mating surfaces. Decks and heads should never be milled more than 0.005 inch.

These are new stainless steel valves, which must receive the same treatment as used valves. Stems are dressed perfectly smooth and measured.

Valve contact faces are ground in order to provide a good seal.

Screw-in oil gallery plugs should always be installed in place of press-in plugs. This eliminates the risk of oil gallery plug failure. By the way, all oil galleries have been checked for debris, wire brushed, and flushed, which should always happen when machine work is finished.

Once machine work and clean up is finished, cam bearings are installed, making sure oil galleries line up perfectly.