How to Build a 355 Chevy Motorby Bobby R. Goldsmith
Though the name makes it sound like some special, unheard of Chevy engine, the 355 CID small block is actually the most common engine in the world -- the 350. For all of this time, the 350 small block -- all stock 350s, in fact -- has actually displaced 355 cubic inches of air and fuel, rather than 350. Chevy chose to market the engine as the "350," though, because it simply rolled off of the tongue better than "355." To rebuild a 355 small block, you need a few parts, some special tools and time.
Install new freeze plugs into the small block. Fit new main bearings that are included in the rebuild kit. Slide the crankshaft into place, then attach the main bearing caps. Tighten the bolts on the main bearing caps to 90 foot pounds with your torque wrench.
Assemble the pistons and connecting rods. For a standard 355 small block, you will need piston heads for the 350, and these should be included in your rebuild kit. Slide each piston through the open breach of the cylinder -- connecting rod first -- and attach each to the crankshaft. Once all pistons are in place, rotate the crankshaft to ensure that all eight pistons have full range of travel. Also, look for any binding along the cylinder walls. Binding could lead to scoring and scratching the cylinder walls, which will prematurely destroy your engine.
Fit the oil pump to the port at the rear of the small block. Insert the camshaft, rotating it clockwise as you go. Once the crankshaft is installed, rotate the crankshaft again for a few revolutions to see that none of the pistons lash against the cam. Once all is clear, stop rotating at the point where the front-left cylinder is at top dead center (the height of its travel). Attach the oil pan, and both front and rear seals. Attach bottom and top timing gears, then the timing chain. Fit the timing chain cover into place, and bolt it on.
Thread the head bolts into the 355 block, then slide fresh head gaskets into place. Slide the cylinder heads onto the block, then torque them down with the torque wrench. Though the specifications vary by make and type of cylinder head, generally you will want to torque them to about 75 foot pounds.
Install the valve lifters and pushrods into place, through the heads. Affix the rocker arms, and tighten them down as far as you can. Though the valve lash will still need to be adjusted later, tightening the rocker arms fully now will put you ahead of the game. Place valve covers on the cylinder heads.
Affix new intake manifold gaskets to the intake manifold, and place the manifold on top of the engine. Tighten it down, then install the carburetor. Slide the distributor into place at the rear of the engine, ensuring that the rotor points to the left-front cylinder. Place the distributor bracket into place, but do not tighten it. Attach the water pump to the front of the engine.
Things You'll Need
- Bare block that has been cleaned and magnafluxed
- Torque wrench
- Standard socket set w/ratchets and extensions
- Freeze plugs
- Rebuild kit w/ gaskets
Bobby R. Goldsmith is a writer and editor with over 12 years of experience in journalism, marketing and academics. His work has been published by the Santa Fe Writers Project, "DASH Literary Journal," the "Inland Valley Daily Bulletin" and WiseGEEK.