Although we maintain our support of used hardware for the budget-minded, it’s tough to deny that locating sound 350 Chevy engines in certain parts of the country may be more of a trick than it is here in the oasis of aged automobiles. Your humble editors know all too well the trials faced by Rust Belt rodders; we were once among you. For some, simply scoring a sound core is a challenge that involves outsmarting (or at least outbidding) fervent cabbies, work truck jockeys, and other professional consumers that voraciously chew up and spit out small-blocks for a living. Fitting one of these clapped-out lumps with new heads and cam would likely prove futile.
So whether you’re one of these unfortunates or simply have no faith in pre-owned merchandise, we’ve returned to address the opposing school of thought and investigate the economic value of an engine that is inexpensive, yet all-new.
As with the rehabbed junkyard motors, we’ll start with a small-block Chevy. The Mouse can be freshened so cheaply that even tight budgets can often withstand a complete overhaul. Upon this very notion, we considered the rebuilding process as an opportunity for increased cubic inches. So rather than renewing a 350 and grabbing the handful of horsepower that an overbore and fresh rings would deliver, we opted to stuff it with a stroker kit. In the universe of the small-block Chev, a crank kit is often slightly more expensive than reconditioning the stock pieces, particularly if the core has no crank, or one that’s damaged. By punching our motor out to 383 inches, we stood to make considerably more power (mainly torque) by spending a marginal amount.
Back to the Boneyard
Despite the alternative approach, we returned to our favorite self-serve salvage yard to find a foundation for our project. Other sources for rebuildable cores are scrap yards, repair garages, the classifieds, and so on. In some areas you can even source core dealers: businesses dedicated to gathering blocks and heads for rebuilders.
Obviously, you’ll want to pay as little as possible, but you must consider the condition of the block. A good rule of thumb is, the more you have to pay, the more assurance you should get that the block in question is actually rebuildable. In other words, if that freebie you grabbed from the alley behind the cab company turns out to be scrap, you’re not out much. However, if you laid out a C-note for a “standard-bore virgin” that turns out to be 0.060-over and has a couple of sleeves, consider yourself officially screwed. Arm yourself with some knowledge and a caliper capable of measuring the bores and possibly the mains. Keep in mind that even a good eyeball inspection may not reveal critical flaws; the machine shop will have the final say.
This time we searched for an unmolested engine, the theory being that an engine that hadn’t been messed with would be the most likely to be useable. Of course, there is that bit about judging a book by its cover, but it’s all a game of odds in the ’yard. We picked over some passenger car 350 assemblies, thinking that truck stuff would be thoroughly hammered, but it was actually a ’79 GMC dualie that harbored the most original-looking engine.
Once we had the heads off, the dial-caliper showed us an even 4-inch bore. Pulling the pan brought more good news: clean bearings that carried factory date codes and a bonus—four-bolt mains. The important thing here is to retain the main caps. The expense of obtaining caps and having them align-bored to match a block not originally machined with them may turn your score into a money pit, especially if the block can’t be cut enough to form a match (0.005-inch is the generally accepted max for resized mains).
We gathered up the goods and hit the checkout counter.
Plan of Attack
Although our core seemed kosher, we had the block inspected by the machine shop prior to ordering any hard parts. You’ll need to know the final bore size and the size of the mains for the block; crank journal sizes are also relevant if you’re having one reconditioned. After our block had been checked out, we knew we’d be dealing with a 0.030-inch overbore and standard mains.
As mentioned, the strategy called for a stroker kit to replace the stock rotating assembly, but we wanted to monitor expenses to maintain the premise that our new stroker was a viable alternative to a recycled runner. Powerhouse (Bakersfield, California) offers an array of engine kits and parts, including some of the most inexpensive stroker kits around. Despite the bargain price, the components are name-brand quality, so we decided to give them a go.
We selected the basic small-block Chevy 383 assembly, which includes a brand-new cast-steel crankshaft, manufactured with 2.45-inch mains so it’s ready to drop into a 350, instead of reconditioned factory 400 cranks that have cut-down mains. Also, it has cast flat-top pistons, reconditioned GM 5.7-inch connecting rods with new bolts, Hastings rings, King rod and main bearings, and Fel-Pro gaskets.
The Powerhouse basic 383 kit is $469, which may sound like a big hit for a budget build, but it has all we’d need to complete a short-block, plus the core and some machine work. We opted for the balanced assembly (an additional $199) as well. This way, the kit is virtually ready to drop into the machined block.
Even our machine service, JMS Racing Engines, felt that this was a wise choice. Shop manager Mike Johnson says he’s witnessed some aftermarket cranks that required so much balancing that the savings of using an “economical” kit were devoured by the cost of labor and heavy metal needed to true them.
As it has in the past, JMS handled all of our machine work on this project. It takes a worthless chunk of iron and turns it into a tuned, turn-key dynamo without leaving the building, thanks to full machine shop facilities and a DTS engine dynamometer. Despite the fact that it’s been building winning race engines for strip, circle track, land-speed, and marine competition since the ’70s, the pricing is quite reasonable. We might have been able to shave some dollars at a cheaper shop, but if you splurge on nothing else, do it on quality machine work.
This engine construction was covered in excruciating detail in the “Build Your First Engine” section included with the September 2000 issue. In a nutshell, JMS hot-tanked our block, magnaflux-tested it for cracks, bored and honed it 0.030-inch oversize, and resurfaced the cylinder decks. They also installed new cam bearings and checked the main bores, which did not need honing. The itemized cost breakdown can be found on page 26, but our total bill for block prep was $225. For peace of mind, JMS checked the balance work on the crank and rods, and found it to be right on the money. For additional cost, JMS could have assembled the short-block, but with freshly machined components, most experienced rodders can handle the task themselves.
Choose Your Weapons
With the short-block completed, we had to pick the respiratory organs that would help us achieve the best bang for the buck. We looked for the least expensive combination first. The cylinder heads are key to power production and to economic success; finding a set that can pass air as readily as they fit the budget is the trick. Of course, we didn’t want to hinder the engine’s potential by being too cheap, so we came up with three sets, all of which could be considered affordable, depending on the budget. All of the heads we used will create a static compression ratio of around 10.5:1 with the Powerhouse pistons. That’s a little steep for pump gas, but we opted to forgo custom machine work and forge ahead. The 92-octane test fuel posed no problems.
We’d set the engine up in its mildest configuration, then mount it to the JMS engine dyno and chart the results. From there, we would upgrade the heads and cam in steps, noting the additional cost and as well as the improvement in performance.
Phase I
We landed a set of complete “camel-hump” Chevy heads (1964 castings) at the swaps with 1.94/1.50 valves and 64cc chambers. At $100 for the pair, we accepted the risks associated with desirable 35-year-old castings. Fortunately, they received a clean bill of health from JMS cylinder head guy Pete Hillemeyer and required only a basic valve job, which JMS provided for $150. Some may balk that these castings have become quite scarce; they were once highly sought after (though not as much as their 2.02 “fuelie” brethren), but they’re a bit inferior by today’s standards. On our first Chevy Jewel, we used iron 1.94/1.50/64cc heads originally found on 5.7L Tuned Port Injected Camaros and Firebirds; they are more plentiful and superior in design. Plus, they offer the advantage of unleaded-friendly valve seats, accessory mounting holes, and best of all, a dirt-cheap price.
As for cam phasing, we sought some variety: one grind on the mild side and another with some attitude. Crane Cams responded with a tame street profile measuring 222/234 degrees of duration at 0.050-inch lift and 0.467/0.494-inch lift, and a bigger stick carrying 244/252 duration and 0.516/0.525-inch lift. We set the engine up with the camel-hump heads and the smaller cam, and topped it off with a used Holley Street Dominator intake—a high-rise, dual-plane design. Feeding the whole mess is another swap meet score, a Holley 800-cfm double-pumper. The 800-cfm rating may seem excessive for a small-block, but we were confident that jetting changes would dial it in. A stock GM HEI distributor provided the fire.
Todd Butts runs the dyno cell at JMS, and once he had the 383 mounted to the DTS stand and water brake, he fired it and began the cam break-in while keeping close watch on the vital stats. Moments later, we were horrified—only 322hp? We feared tuning changes might only bring another five ponies, but evidently, the engine wanted a lot more timing. We went from 32 to 38 degrees total, and jetted the Holley 70/83 front/rear, which brought total output to 354hp at 5,000 rpm.
We were disappointed; these figures seemed more apt for a 350 than our stroker. But looking back, our junkyard 350 had only made 320hp with the ’80s Tuned Port iron heads (similar 1.94/1.50, 64cc configuration) and a similar cam. What’s more significant is that the 383 made 422 lb-ft of torque—over 40 more than the 350. Perhaps even better is the fact that, at 3,000 rpm, the 383 was making 414 lb-ft while the 350 was generating only 196.
Phase II
Our next combination was a cam swap. Although the 383 really was making decent power in its base trim, we thought it would benefit from more cam. In truth, the second Crane stick with its long 244/252 duration at 0.050 was probably hairier than what we would run with an automatic street car, but we expected a decent power gain.
After a quick on-dyno cam swap, aided by our Comp Cams two-piece timing cover, we went through another break-in period, and then hit the load. The results didn’t surprise us: We made more horsepower and less torque. Specifically, the 383 churned out 367 hp at 5,300 rpm but fell to 415 lb-ft at 4,100. Carb jetting remained the same, though this combo seemed to work better with 36 degrees of timing. Depending on the application, many would consider this a respectable trade-off, particularly since the engine was still making more than 400 lb-ft at 3,000 rpm. This made us anxious to see how much better the combination would be with the Vortec heads.
Phase III
On our junkyard 350, the late-model Vortec iron heads had boosted output by nearly 55 hp over the TPI heads, which used the same valve and combustion chamber sizes as the Vortecs, as well as the ’64 heads we just ran. Our synapses were popping in anticipation.
We swapped the cylinder heads and installed a set of GM grooved-tip rocker arms, which are required with Vortecs. These stamped steel arms were used as far back as the mid-’80s, and take the place of the guide holes in the head castings to provide valvetrain alignment. The biggest obstacle with Vortec heads is the specific intake manifold, necessitated by the unusual intake bolt pattern. Currently, Edelbrock has four designs for Vortecs: Performer, Performer RPM, Performer RPM Air Gap (dual-planes), and the Victor (single-plane). We struck a balance between power potential and cost with the Performer RPM.
The Vortecs boosted power to 396 at 5,600 rpm, and they brought torque to a new high of 440 lb-ft at 4,200, seeming to eliminate the need for compromise. At 2,800 rpm, torque was over 400 lb-ft. As usual, the Vortec chambers required less timing, taking only 32 degrees to make max power, though a jet size increase to 72/85 was necessary. The JMS crew pointed out that the exhaust gas temperatures (EGTs) were quite even between cylinders, indicating that the RPM intake is an excellent dual-plane design.
Phase IV
This time, our ace in the hole was aluminum Trick Flow cylinder heads. At $850 a pair, they’re quite affordable and the design is simple: no altered valvetrain geometry, no moved ports, just a 23-degree small-block head cast in aluminum. Testing, however, has revealed exceptional performance. The 2.02/1.60-inch valves are set in modern fast-burn-style chambers, while the ports seem to offer an excellent balance of airflow and velocity.
These assemblies use guide-plates, which require the use of hardened pushrods, but stock-type rockers may be retained. We topped the aluminum heads off with the Holley intake from the first two phases as the Trick Flows were designed to accept conventional small-block manifolds. Another series of pulls produced the best numbers yet: 421 hp at 5,400 and 448 lb-ft at 4,300. The aluminum heads provided significantly more power and more torque, without the need for higher rpm. The aluminum construction and fast-burn chambers also make it the most likely candidate to handle pump gas and high compression.
Conclusion
Like its predecessors, this experiment could be deemed a success. We’d started with junk, refurbished it with proper machining and new components, boosted displacement, made a bunch of power, and still hadn’t cracked the $2,000 bank. For street use, we’d probably step back on the cam a couple notches, sacrificing a little horsepower to gain more torque and a smoother idle, but even in relaxed trim, this engine would likely provide enough motivation for 12-second e.t.’s in a typical Nova or Camaro. In fact, we’ll be trying that out real soon.
