It's hard to believe that we built our "Shoestring Stroker" 383 cubic-inch engine that's in Project Homewrecker almost six years ago (2007!). But in the performance engine world, having a drama-free engine for that long is always a good thing. Back when the Shoestring Stroker went together, we built it to show what a real enthusiast could put together on a really tight budget. From oil pan to carb, our 383 was built for less than $3,500 and made roughly 285-rwhp to the tires in our '72 Corvette Stingray project car (426 on the engine dyno). That included a set of budget aftermarket 190cc aluminum cylinder heads and a decent camshaft, and we were happy with the numbers—in both dollars and output—not the mention reliability. Of course, here in the year 2013, 285-rwhp just isn't what it used to be.
So, the question was, given more money and several more years for research and development, what could the Shoestring 383 make with just a cylinder head and camshaft upgrade? As we started searching, we began to have high hopes, but knew that outperforming already good stuff would be hard to do. So, we teamed up with the crews at Crane Cams and Air Flow Research, to see what they could bring to the table.
Super Chevy contributor Dan "Nova Man" Foley picked a new hydraulic roller stick out of the Crane catalog that would behave really well on the street (with plenty of vacuum), while picking up horsepower and torque, especially under the curve. What he came up with was part number 119581, with 238/242 degrees of duration at .050-inches, .558/.558-inches of lift, and 110-degree lobe separation angle.
Of course, we also decided it was time to upgrade to a set of Crane's hydraulic roller lifters, which would ride on the new camshaft and free up a couple extra horsepower while being gentle on our valvetrain. Along with the stick and the lifters, we also had Crane send us a set of its Gold Race 1.5:1 ratio rockers, and a set of 7.046-inch hardened .080 wall one-pice pushrods.
Air Flow Research was tasked with supplying our cylinder heads and they had their work cut out for them, going up against a set of as-cast 190cc aftermarket units. Of course, AFR is never one to shy away from a head-to-head challenge, and it sent us a set of 195cc SBC Eliminator Street cylinder heads (P/N 1040; $1,564.00), which feature 3/32-inch raised exhaust ports, 23-degree valve angles, and 65cc combustion chambers. Fully CNC-ported on all of the intake and exhaust ports, along with the combustion chambers, the AFR 195cc street heads flow 280cfm at .550-inches of lift, and have an ideal operating range of 2,000-6,500rpm, which is perfect for our camshaft, intake manifold, and engine setup. Of course, they bolt right up to almost any SBC, and ship complete with everything you need for an easy swap.
With everything in our greasy little hands, the only thing left to do was bring in the big gun from Seffner, Florida's AntiVenom Performance, owner Greg Lovell, to get everything installed. We'll tell you now, this is a lengthy installation for a novice, but with a professional like Greg, it went smooth as silk. And the results, well, let's just say they were definitely worthwhile.
1 Our "Shoestring Stroker" 383 has been up and running for the better part of six years, and has been a great low-buck mill. But, what's good can always be better, and we were hoping that a new set of Air Flow Research cylinder heads and a hydraulic roller camshaft from Crane would improve performance and give the ol' 383 a new lease on life.
2 Baseline testing revealed that our budget 383 was putting down 285.41-rwhp and 335.08 lb-ft of torque using a pair of $800 as-cast 190cc cylinder heads and a flat-tappet hydraulic camshaft, which featured 234/244 degrees of duration, .488/.510 inches of lift, and a 110-degree LSA. Not bad, but not enough for our heavy right foot!
3 We chose to first install the new hydraulic roller camshaft kit from Crane, which included a set of 16 roller lifters, new pushrods, and a set of 1.5:1 ratio rocker arms (same ratio as before). This way we could see what the gains were from just the cam and just the heads. It was a lot of extra work, but how else could we show the real gains? Greg Lovell, the owner of AntiVenom Performance, dug into Homewrecker right away, pulling the front accessory drive off after draining the coolant and oil.
4 On many of Chevy's finest, you'll find that the radiator must be removed in order to make room to slide the camshaft out of the way. Greg had no issue pulling our Flex-a-lite aluminum radiator out of the way to give himself more than enough forward space.
5 Up top, Greg unbolted the valve covers, along with the Holley carburetor, and finally the factory distributor and Weiand Stealth intake manifold. With access to the valley, it was time to pull the rocker arms and pushrods, before pulling our flat-tappet hydraulic lifters out of the block.
6 Back up at the front of the motor, Greg removed the water pump and balancer, which gave him access to the front timing cover. On our small block Corvette, it was easy to drop the oil pan (just a little) to free up room to work. With everything out of the way, Greg pulled the front timing cover and began removing the old timing set.
7 Finally, it was time to pull the old camshaft, which had been commanding the valvetrain in Homewrecker for the last several years. The old bumpstick was decent, but our new hydraulic roller from Crane Cams was cut to be a little more aggressive, while giving us all of the modern advantages of a hydraulic roller cam.
8 Crane sent us everything we needed for the conversion, including a new small base circle camshaft, an adjustable double roller timing chain, a set of hydraulic roller lifters, hardened 7.046-inch .080-inch wall pushrods, 1.5:1 ratio roller rockers, and the correct distributor gear and fuel pump pushrod for our 383.
9 The new camshaft features 238/242 degrees of duration at .050-inches, and .558-inches of lift on both the intake and exhaust (P/N 119581; $490.00). Cut on a 110 LSA, the Crane Cams' unit features 4 more degrees of duration on the intake lobes, and +.070/+.048 inches of lift, which should help create more power up top, with much bigger gains through the mid section of the powerband.
10 Installing the new Crane timing set was a simple job for Greg, and only required a little effort to slide in place. We chose to install the lower timing gear (which is adjustable in 2-degree increments) at 0-degrees—or straight up—for our initial testing.
11a The double roller chain bolts onto the new camshaft, but make sure you install both the camshaft thrust plate and the new front roller button. These two pieces ensure that the camshaft is centered properly in the block and won't shift forwards (towards the timing cover) once everything is installed.
11b The double roller chain bolts onto the new camshaft, but make sure you install both the camshaft thrust plate and the new front roller button. These two pieces ensure that the camshaft is centered properly in the block and won't shift forwards (towards the timing cover) once everything is installed.
12 The Crane hydraulic roller vertical alignment bar lifters slide in next (lubricate them prior to dropping them in place), followed by the 7.046-inch pushrods. Crane Cams has certainly done its homework with this combination, as everything fit perfectly every step of the way.
13 Installing the new Gold Race billet aluminum CNC-machined roller rockers is a simple job, as they just slide over the rocker arm studs in the cylinder heads and bolt down in place. Of course, you will need to properly set lash/preload, as Greg did, but that's also easy with the provided adjustable locking nuts.
14 And then you put everything else back in place. Sounds easy, and it was. Distributor (with the new gear), intake, carb, valve covers, timing cover, oil pan, front drive, radiator, water, coolant, fuel lines, and belts … and then it was dyno time.
15 With no additional changes (just the new camshaft) we recorded a new peak horsepower of 295.70 with peak torque ringing in at 343.74 lb-ft. That's a nice gain of 11.07-rwhp and 8.8 lb-ft of torque. Of course, the real gains were
16 There is only so much you can do with a pair of super-low-buck cylinder heads, and all of the camshaft and cubic-inches in the world won't make a difference if you can't get air in and out efficiently. Air Flow Research said it could solve that problem, and Greg barely let our 383 cool before he started pulling the long-tube headers out of the engine bay.
17 Pulling the cylinder heads requires almost the same labor as pulling the camshaft, although the radiator and front timing cover can stay in place. Fast forwarding a little, here you can see Greg removing the head bolts from the block, after he already pulled the valve covers, intake manifold, rockers, pushrods, and other miscellaneous items out of the way.
18 And just like that, the old heads were coming off. Officially listed as 190cc cylinder heads, these budget pieces reportedly flowed 260cfm on the intake side and came equipped with 2.050-inch intake and 1.600-inch exhaust valves (same valve size as our AFR's) and 64cc chambers. They served us well, but we knew a serious cylinder head with heavy development work could outshine them.
19 If we were going to go through all of this trouble, we wanted to make sure we did it right. Enter the 23-degree 195cc SBC Eliminator Street cylinder heads from Air Flow Research. With 65cc combustion chambers, 2.050/1.600-inch valves, and 100-percent CNC-ported combustion chambers, intake, and exhaust ports, along with a competition five-angle valve job, these beauties flow 280cfm at .550 lift.
20 Lightweight 8mm 2.050-inch intake valves, paired with 1.600-inch exhaust valves fill the CNC-ported combustion chambers, which also feature a 5-angle competition valve job. With a thick .750-inch deck and 65cc chambers, these heads would do great with a little boost or a shot of nitrous, but we're running good old atmospheric air through our 383.
21a Both the intake and exhaust ports have been heavily worked by the engineers and machinists at AFR, and the results speak for themselves. 280cfm of flow on the intake side at .550-inches of lift and 218-cfm on the exhaust port (with a 1.75-inch pipe) is great for a 195cc street head.
21b Both the intake and exhaust ports have been heavily worked by the engineers and machinists at AFR, and the results speak for themselves. 280cfm of flow on the intake side at .550-inches of lift and 218-cfm on the exhaust port (with a 1.75-inch pipe) is great for a 195cc street head.
22 New cylinder heads require new cylinder head gaskets, and we chose to run a complete 4.165-inch top end gasket kit from Cometic (P/N PRO1003T; $285.55). These Multi Layer Steel (MLS) gaskets will handle big cylinder pressure for years to come and ship complete with practically any bore size and compression height that you may require.
23 The new AFR 195cc Street heads dropped right in place and bolted up without any issues. Here you can see Greg torqueing the head bolts to 75 ft-lbs using Permatex thread sealant.
24 AFR also included its adjustable guide plates, which makes centering the pushrod and rocker arm a breeze. Greg prefers to loosen the guide plate bolt, center up the rocker arm, then tighten everything down. Once set, it's time to set rocker arms, and get ready to fire the engine up.
25 But first we had to install our new AFR aluminum CNC engraved valve covers (P/N 6704; $169.00). These beauties easily cleared our Crane rocker arms and included rubber grommets for installing breathers. Always a nice way to spruce up an engine bay, and they'll keep our valvetrain and engine happy for years to come.
26 Drumroll please … and wow! The new AFR heads took our 383 from a 295-rwhp driver to a 343.10-rwhp rocket. That's a gain of 47.9-rwhp from an already decent set of aftermarket heads. Not to mention the 373.64 lb-ft of torque, which was way up from the 344.09 baseline with the new camshaft. That's a 29.9 ft-lb gain at peak torque, which is awesome. Overall, with the new AFR cylinder heads and the Crane Cam package, our 383 was up 57.69-rwhp and 38.56 lb-ft of torque. Now that's what we're talking about! Look at the improvements under the curve and the difference past peak power. Huge gains.