Planning Your Ford Small-Block Rebuild Project

Engine planning begins with knowing the path you intend to take. We’ve already discussed crate engines and kits. Now, we want to address planning and building an engine from scratch. This road is usually for the more experienced engine builder, but you didn’t buy this book to take the easy way out.

There are two basic approaches to a from-scratch engine build. The purist method involves using all of the correct date-coded parts, with model-year specific casting numbers. The other is the devil-may-care method, where you use any combination of parts and castings as long as they all work well together.

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This Tech Tip is From the Full Book, HOW TO REBUILD THE SMALL-BLOCK FORD. For a comprehensive guide on this entire subject you can visit this link:

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Whenever you shop for a core engine to build, you want to determine if it has ever been apart. Engines that have been apart typically look like it – gasket sealer weeping out from around the gaskets, chipped paint on bolt heads, and the like. An engine like that can often be a crapshoot depending on how it was rebuilt.

 

Ideally, you’ll find a small-block Ford that has never been apart. An engine that has never been apart will have standard 4.000-inch bores and will be ready to grow a little. If you get lucky and find a standard-bore block with less than .011- inch of bore taper, you won’t have to over-bore it; just hone the block and install standard pistons. This means greater block life, because you can always over-bore it down the road.

So how do you tell if an engine has ever been apart? As a rule, it boils down to the paint and condition of the gaskets and hardware you can see. Ford usually did a nice, clean job of gasket installation, with a minimum of sealer and goop around the edges. Engines that have never been disturbed have virgin paint on their bolt heads. Undisturbed engines have a clean, uncluttered look, even though they may be dirty and greasy. One exception to this rule is engines that have had repair work performed, such as timing set replacements, new oil pumps, rear main seal replacement, gasket replacement, valve jobs, and the like.

The best way to determine an engine’s virginity is to pull a cylinder head and measure the bores. A 4.000-inch bore indicates an undisturbed engine. Our project engine for this book, a 1965 289-ci engine, was torn down and rebuilt with high-performance parts back in the 1960s when it was new. Because the bores were nice and true at the time, the builder opted for finish honing and a fresh set of TRW forged aluminum pistons. The original Ford cast pistons were gone.

 

Jim Grubbs Motorsports came to the conclusion that our 289 had already been apart, based on gasket condition, chipped paint, the fact that it was Ford Blue (a ’65 engine should be black), brass freeze plugs, the wrong timing cover, and more.

 

Our 289-ci block find was a huge exception to the rule. Most small-block Fords, especially older 221s, 260s, 289s, and 302s, have been rebuilt at some time, leaving most of them with .020- and .030-inch oversize bores, making it hard to find rebuildable cores today. Perseverance is the key to finding a rebuildable block. If you are unable to find a rebuildable used block, you may order a new 5.0L or 5.8L bare block from Mustangs Plus. These are all-new Ford castings from Ford Racing Performance Parts. If you go with a new block, you’ll need a compatible crankshaft designed for the one-piece rear main seal. This pretty much rules out the older 289/302/351W cranks with the seal lip. Any competent machinist can remove the lip, but we suggest finding a compatible crank to begin with – less time and money involved that way.

 

This is our 289-ci V-8 engine project for this book. At first glance, it looks like it has seen better times. It has a loud knock, steam in the exhaust, and is down on power.

 

 

Cylinder heads, unless they’re cracked or have been milled excessively, are nearly always salvageable. Valveguides and seats can always be replaced. Ford cylinder heads weren’t fitted with hardened exhaust valve seats until the early 1970s, which means virtually every Ford cylinder head you’re going to find prior to that period will have iron seats.

Usable crankshafts, especially the older 1M cranks with a 2.87-inch stroke for the 221-, 260-, and 289-ci V-8s, are becoming harder to find. This crank was produced from 1962 to ’68. The same can be said for the C3AE connecting rod forgings also used in these early Ford small blocks. If you’re not fussy about what’s inside your small-block Ford, we suggest searching for what’s plentiful and invisible once inside the block. The 302’s C8OE rods, 2M crankshaft (3.00-inch stroke), and block are all plentiful and cheap, making a 302-inch smallblock even more affordable to build.

 

Close inspection shows why we think this engine has been apart. It’s a ’65 Ford casting painted Ford Blue, which is a 1966-up characteristic. It has brass freeze plugs. Factory freeze plugs were steel. Note the gasket sealer seeping from between the castings. We also observed one cylinder-head gasket that was installed backwards, which really made this engine prone to overheating.

 

Finding a good, rebuildable core takes time scouting the salvage yards, checking the classifieds, visiting eBay, wandering the Internet, and putting the word out for what you need. We have so many means today at our disposal for finding good, rebuildable engines, but it gets challenging when we become very specific about what we want. For example, if you are restoring a ’66 Mustang convertible and want to show it as a concours restoration, you are greatly limited to date-code specific castings for the engine build. Date codes and casting numbers are critical to concours restorations and the scrutiny of show judges. They are also crucial to resale value, especially if you are restoring a 289 High Performance GT or Boss 302.

Written by George Reid and Republished with Permission of CarTech Inc