How to Build the Cheapest Motor Possible

Yes, that is a seatbelt on... 

   

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Yes, that is a seatbelt on the hook. Don't do this.

'The idea behind this story came to our inbox by way of one of our readers. Glad said, "It's a picture of a guy washing off his mains with a garden hose." The guy in question races Camaros on lots of boost and nitrous. He wrote in to tell us that when he blows up one engine, he goes to the junkyard and gets another one, hoses it down, drops it in, and goes racing again. We all thought this was completely crazy, but kinda cool too, and it got us wondering how little money we would need to rebuild an engine.

A third quick, prepurchase... 

   

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A third quick, prepurchase check is to drop the oil pan. Check this out-that's the oil-pump driveshaft hanging out in the pan. Also alarming was the milkshake-brown oil indicating the lethal mix of oil and coolant, probably due to a leaking intake manifold gasket. The combination of contaminated oil and a dropped oil-pump drive indicated why this car ended up in the junkyard in the first place. We knew to examine the crankshaft and pistons very carefully to see if the engine had seized up. "That engine probably knocked like a *@!#," exclaimed JMS' Mike Johnson.

Of course there are a lot of variables with this situation. Yes, it is possible to buy a junkyard engine, hose it off, and put it in your car. You may get lucky and the engine will run fine for a while, or you could end up with a turd like the Gremlin 304 we stuck in the CC/Rambler last year. That engine labored to an 18-second eighth-mile elapsed time and oiled down the mufflers from Los Angeles to San Diego and back on the '06 Anti-Tour. Here's what you need to consider: Is it financially responsible to buy a string of junkyard motors? Do you want to swap an engine every year?

The good news was that our... 

   

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The good news was that our combustion chambers were in good shape. Here Hernandez points out a place to look for cracks, particularly on Ford cylinder heads.

We're calling this story the cheapest rebuild ever, but we're approaching it from an angle that will help you make educated decisions when buying and rebuilding a junkyard engine. We want to show what to look for in an engine, what parts can be reused, how to tell if something is too worn out to be reused, and how to reassemble the engine, all while spending as little money as possible. To that end, Glad yanked a supercrusty 302 from the yard, and we took it over to the folks at JMS Racing Engines in El Monte, California, for their assistance in our budget rebuild. Here goes nothin'.

Our first piece of advice...        read full caption Our first piece of advice is to inspect as much of the engine as possible BEFORE you pull it from the yard. At the very least, yank the valve covers. There was a lot of sludge buildup in our little 302, which was a good indicator of bad parts lurking inside. The previous owner never changed the oil.

We checked with JMS' cylinder-head...        read full caption We checked with JMS' cylinder-head guru Pete Hillemeyer, who said the valves should look like they are sitting ON their seats rather than being flush with the combustion chamber as seen here on our Ford heads. That meant our seats were worn out and would need to be reground. Also, Hillemeyer showed us how to check the condition of the valve guides by wiggling the valve: The valve should slide in and out easily but not wobble back and forth during its travel. Our engine had previously undergone a cheapo rebuild that resulted in a few mismatched exhaust valves and bronze guides, which Hillemeyer doesn't like very much. He drilled out the bronze liners and replaced them with cast-iron ones.

It's a wise idea to establish...        read full caption It's a wise idea to establish a good relationship with a machine shop. That way you'll have access to experts for advice and guidance once you start tearing down the engine and inspecting the internals. JMS' Freddy Hernandez showed us a cool tip: Check the height of the valve stems with a straight edge. "The valves should all be at the same height. You can tell if the valves and seats are hammered if any are sticking up higher than the others."