Words And Photos: Richard Holdener

What can we say, we are junkyard dogs at heart. In our opinion, there is no better way to spend an afternoon than by rummaging through the junkyard to find hidden treasure. If you don’t look under the hood of every vehicle there and think, hey, we could make that into something seriously cool, then you are NOT a real car guy (or gal). Every engine bay is home to a stock motor, which is already cool, but there is so much more. Lurking under all that grease and grime was (in our case) a small block just begging for new lease on life. Having served faithfully for more than 100,000 miles towing that fishing boat, lugging that 5th wheel or just lumbering around town with a box bed full of supplies, it was time to resurrect the Phoenix that awaited within. Chose wisely as we did, and it’s a simple matter of upgrading the existing components to get that Chevy to haul ass instead of bass. If it seems like we are excited about boneyard builds, you don’t know the half of it.

The idea behind this Boneyard build up was to remove a (hopefully) running small block and upgrade it from stock to let’s rock status. Given its use over the years, the wrecking yards are full of small blocks, but the abundance also means choosing the right one can be difficult. Some reached the yard because they no longer possessed the simple ability to provide forward motion, while others were imprisoned for nothing more than damaged sheet metal. Vehicle damage (though unfortunate for the previous owner) is the ideal candidate for engine removal, as it is likely the vehicle was running when the vehicles had a coming together. We started our selection process with a visual inspection, looking for major issues like holes in the block, excessive rust or that nasty, burnt bearing smell of death. Removing a valve cover is always a good idea, as it gives you an indication of the service provided. Is there oil sludge or build up, or does it look like the motor had regular oil changes? We finished up the inspection with plug removal and checking to ensure the motor spun over freely. Usually, if it spins-we wins!

For this adventure, we chose a late-model small block that featured a 1-piece rear main seal and hydraulic roller camshaft. The 4-bolt block came from a 1-ton truck, but there were literally dozens and dozens of small blocks available from a variety of different applications. The carbureted motor was purchased complete from carb to oil pan with accessories for less than $300. For any small block, even just a 4-bolt block core, that is a decent deal. If it runs, that was just icing on the cake. The motor was removed from the truck and immediately brought to the dyno for testing.

We replaced the accessories with an electric water pump from Meziere then popped off the stock cast-iron intake and Q-Jet carb. Though the stock induction might well have worked, we installed a dual-plane Speedmaster Eliminator intake and Holley 750 HP carb in its place. Run with 1 ¾-inch long-tube headers and an MSD distributor (replacing the HEI), the wrecking yard motor surprised us by producing 312 hp at 5,500 rpm and 354 lb-ft of torque at 3,800 rpm. Having run truck motors like this before from the wrecking yard, we suspect the elevated power numbers were the result of a mild RV camshaft of some sort, as most (low-compression) stock 350s of this manner produce closer to 275-280 horsepower.

Needless to say, we were happy with our purchase of the high-mileage small block as it offered good oil pressure and seemed eager to please. Pumping out over 300 horsepower was fine for the truck motor, but we wanted something a little stronger. To pump up our Boneyard Build, we decided to replace the factory heads and unknown camshaft with something a little more performance oriented. First on the list was a COMP XR276HR cam. There were certainly more powerful camshafts available, but this build was all about daily driven performance. We wanted performance but knew that the best 350 is one that serves double duty.

Camshaft timing is critical for street manners, and the XR276HR was just what the doctor ordered. Sporting a .502/.510 lift split, a 224/230-degree duration split and 110 lsa, the COMP grind seemed like the ideal compromise. Next on the list was a set of as-cast, 200cc, RHS Pro-Action aluminum heads. The RHS heads represented a three-tiered improvement in performance over the factory heads that included reduced weight, improved flow and increased compression ratio. The aluminum heads obviously weighed considerably less than their heavy cast-iron counterparts and the RHS 200cc ports outflowed the stock heads by nearly 70 cfm. The finishing touch was a drop in combustion chamber volume from 76cc to 64cc, increasing the static compression by over 1 full point.

On paper the head and camshaft upgraded sounded good, but there was only one way to find out for sure. Off came the stock heads and out came the mystery camshaft and in went the XR276HR cam and on went the RHS Pro Action heads. The heads were installed using Fel-Pro head gaskets and ARP head studs and the camshaft was installed using the factory hydraulic roller lifters (still in good shape). No small block should be running iron heads in this day and age if for no other reason than they are just too dang heavy. The aluminum heads are so much easier to work with, to say nothing of flowing better, making more power and greatly reducing the chance of harmful detonation (important with increased compression). Equipped with the head and camshaft upgrade, our Boneyard Build now pumped out some impressive numbers, with peaks of 420 hp at 6,000 rpm and 415 lb-ft of torque at 4,200 rpm. The power gains were massive and consistent, starting with an additional 35 lb-ft of torque as low as 3,000 rpm then finishing with over 100 horsepower at 6,000 rpm-Boneyard Builds FTW!

The results speak for themselves as the RHS head and COMP Cam upgrade on the 350 small block increased the power output by over 100 horsepower. This was made all the more impressive by the fact that the junkyard motor was sporting the dual-plane RPM intake, Holley carb and we suspect something other than a factory camshaft profile in baseline trim. Equipped with the stock heads and unknown camshaft, the 350 produced 312 hp at 5,500 rpm and 354 lb-ft of torque at 3,800 rpm. This power output is about 30 hp higher than we have seen from similar junkyard small blocks, so we suspect the camshaft was something other than stock. After adding the COMP XR276HR and RHS 200cc Pro Action heads, the power numbers jumped to 420 hp at 6,000 rpm and 415 lb-ft of torque at 4,200 rpm. The mild camshaft and free-flowing heads offered an impressive and usable power band.

Sources

COMP Cams
compcams.com

Holley/Hooker
holley.com

Lucas Oil
lucasoil.com

RHS Cylinder Heads
racingheadservice.com

Speedmaster
speedmaster79.com