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| Engine Rebuild |
On several pages, I will take you through the steps for rebuilding your engine. We will be using a 3 main 1800cc MGB engine for demonstration purposes, but the principles should apply to all engines.
(Photos referred to in text can be seen by clicking on the photo at bottom of page.)
Part I
Know & trust your machine shop. Unfamiliar machine shops will always give you a problem! You need to know exactly what steps your machine shop will take so nothing is missed.
Deliver your unassembled engine to your machine shop. Take your block with main caps & bearings, crankshaft, pistons with attached rods and bearings, head with valves intact but with rocker assembly removed, and flywheel. Your shop should boil out the block & head. Check the block, head, & crankshaft for cracks. Then the bore will be determined for the block and the amount the crankshaft will need to be turned. If you are supplying parts the shop should notify you about needed sizes. Send to the shop pistons, cam bearings, pressure plate, ring gear, valves, guides, springs, oil seals and any other requested parts. You can order the additional parts you will require (bearings, oil pump, water pump, camshaft, etc) and have them shipped to you. Have the flywheel lightened and the ring gear replaced if needed. Have all moving parts balanced for a smooth running engine. After completing their work the shop will have you pick up the various parts.
When you get the engine home you should tape off the block & head and paint with the engine paint of your choice (See Photo 1). The first assembly step is to be sure the block is completely clean. Use compressed air, engine block brushes, and cleaners to be sure the inner engine is clean. If your machine shop didn’t assemble the rods to the pistons, do this first. Next you need to check every piston ring in the bores to be sure they aren’t oversized or undersized (Photo 2). Use a piston to push the ring several inches into the bore, check the gap of the ring to be sure it is within spec (Photo 3). If the ring gap is too small, a ring gap grinder (Photo 4) is available to increase this gap. If the gap is too large you will have to get new rings. Fit the oil rings to the piston first then fit the compression rings using a piston ring expander (Photo 5). Be sure to space the ring gap around the piston diameter so the gaps aren’t in line. Lubricate each bore & piston with motor oil. Use a piston ring compressor to compress the rings so the piston can be tapped in place using a wooden handle of a hammer.
With the four pistons in place we will turn the engine over and on next page we will start with the crankshaft.
Any questions or comments can be directed to Ron Redding at 281-346-2417 or e-mail ron@5RRestorations.com