Room for Improvement Sep 17, 2010
Schrapnel sure sounds like a German word. Turns out Henry Shrapnel was the British inventor of the Shrapnel Shell, a hollow cannonball filled with shot that would burst in midair.
Check out the image of my Crower hydraulic roller lifter. You'll note that some important fragments are missing. Those pieces are now buried deep in the engine.
There's only one right way to handle this: The engine needs to come out so that we can gain access to the crap hiding in the Canton road race oil pan. Some people may have blindly installed a new roller lifter pair and hoped for the best, but that would almost definitely lead to catastrophic engine failure.
The big question is: Should this engine be reinstalled after freshening? It's a great powerplant based on a high-nickel-content 1971 400 block with Milodon billet main caps, a Scat 4130 forged crank, Manley rods, a JE/SRP piston, ported cast iron World Products Sportsman II heads with Manley Pro Flo valves, an Edelbrock Victor Jr. intake manifold, and a hand-built, custom-calibrated Holley carburetor. It also features 10.5:1 compression and a Crower 236 duration hydraulic roller cam. Output is reasonably estimated at 1.2 horsepower per cube--a total of 480 ponies. It's a great engine. The alternative is an "undesirable" and therefore affordable 5.3-liter LS engine with just enough boost to yield 550 horsepower.
Let's hear some feedback: Gen 1 406 rebuild or boosted junkyard 5.3?
Fishing for Fragments Sep 29, 2010
Who says no news is good news? We're thrilled to report that all of the crap formerly known as a roller lifter was resting peacefully in our oil pan.
Here's a tip: During the teardown process, do not turn your engine upside down to remove the oil pan. If you do, fragments will redisperse throughout the engine. Lie upside down, pull the oil pan, then rotate the engine.
Canton Racing Products supplied the oil pan and oil pump pickup in the photos. As you can see, the oil pan has trap doors and windage screens. Their primary role is to direct oil flow toward the pump. As an added benefit, the baffling system makes it difficult for large fragments to be swept up into the oil pump. Even better, the oil pump pickup is screened for added protection. Minute filings can make it past the screen, but they will get trapped by the oil filter.
Next up: cutting open the oil filter and replacing the damaged camshaft. We're confident that the bearings are safe, but we'll remove caps just to make sure.
Delivered From Distraction Jun 14, 2011
Almost one year ago, our muscle car's 406 small-block Chevy lunched a roller lifter during a track day. Damage was minimal, but the road to recovery was riddled with distractions. The crapcan Lincoln used up most of our time. That turd of a car kicked and screamed every step of the way, but it delivered miles of endurance racing fun. With the Lincoln project entering the "fine-tuning" stage, the Camaro is again top priority.
We'll show off key upgrades over the next few weeks, including Dart Pro 1 aluminum heads, Holley HP EFI and a track day-friendly hydraulic roller cam from our Daytona neighbors at Crane Cams. Crane also wants us to sample their NASCAR-derived distributor and Fireball ignition system. It's so nice to work on clean, high-tech Camaro parts after chasing the Lincoln around the shop for months.
Regardless of a car's make, model or year, weight reduction and improved efficiency are always desirable. In the case of our 1968 Camaro, a hand-built Holley HP 750 carburetor and ported cast iron cylinder heads sufficed for nearly a decade. Actually, the combination worked extremely well. Lap after lap, our small-block Chevy repeatedly screamed toward 7000 rpm. For a carburetor-equipped engine, street manners were excellent as well.
There's always room for improvement, though. We want more. The Dart Pro 1 aluminum heads will remove an appreciable amount of weight from the nose of our car. They also represent the latest in gen i head technology. Power, efficiency and weight reduction add up to a win-win-win. Likewise, converting to electronic fuel injection presents numerous benefits. Improved fuel mileage is big news these days, but we're way more interested in another application-specific benefit: Properly calibrated EFI will tolerate a more aggressive "Track Day" camshaft profile. The combined effects of cam and EFI should yield a broader power curve. Idle quality is in question, however. Will the Holley HP EFI system tame the aggressive cam profile? We'll find out soon enough.
In the next update, we'll discuss the minor machine work required to bring the block and crank back within spec. We'll also install and degree the new Crane hydraulic roller camshaft.
This Old Block: Rebuilding the Engine on Our 1968 Camaro Jul 12, 2011
Before we delve into the exciting part of our 406 engine project (like heart-shaped chamber design and cam lobe separation), we need to highlight the foundation of our 406. The engine block started life as a 400 from the good old days, when men were men and cast iron blocks had high nickel content. In 1971, the bean counters had yet to figure out that blocks could be made thinner and weaker in the interest of cost savings. So this old block is really strong. This is not a LeMons car, though. We don't skimp on anything. Milodon billet steel four-bolt main caps hold the bottom end together to limits that far exceed our 6500 rpm redline.
Remember, though: This is a rebuild. As cool as they are, those caps have been in place for eight years. We're here to talk about how Express Racing Engines offered to make the engine assembly idiot-proof. For some reason, Johnny at Express looked directly at Tom Heath and Steve Chryssos as he said the words "idiot-proof." We picked up our engine with Total Seal rings already fitted and gapped on their respective pistons. Likewise, crank and rod bearings were already in place with correct main and rod journal clearance. We went ahead and double-checked clearances just to be safe. The Federal Mogul bearings feature a dry film lubricant coating. The delicious-looking red goo is assembly lube from Red Line Oil. Our shop neighbor, Jeremy from Aggressive Auto Parts, helped out so that we could be free to shoot photos. Jeremy is quickly learning how we operate. "Can we borrow a tool?" really means, "Can we borrow a tool as well as the arm connected to the tool?"
Breathe and Burn: Dart Heads for Our Hotrod Aug 19, 2011
With work progressing nicely on our 1968 Camaro, we have some time to reflect on the wonders of modern cylinder heads. During the last 15 to 20 years, race engine builders have accelerated the head development process through a mix of science, experimentation and good ol' competitive spirit. Lessons learned on the dyno and at the race track find their way back to cylinder head manufacturers who literally cast knowledge into their products. Manufacturing technology plays a key role as well. CNC machines greatly improve repeatability, while "hard" metal tooling improves casting consistency over its predecessor, wood tooling.
While the high-performance cylinder head industry has improved as a whole, some brands—like Dart Machinery --still maintain a competitive advantage. A recent tour of Dart's Troy Michigan facility turned up some specialized (and crazy expensive) tools and equipment. So while flow benches are now everywhere, Dart has a proprietary wet flow bench that better emulates the movement of true air/fuel mixtures. If that sounds like ad speak, think again. Dart's wet flow bench is as big as your kitchen, and advancements made with this device are equally monumental. Some very interesting lessons have been learned regarding runner shape. Geek Alert: Some folks refer to runners as "ports." "Port" is a scalar, two-dimensional term, whereas "runner" is used to describe a cylinder head's three-dimensional, volumetric shape. Intake gaskets and heads both have ports, but only cylinder heads have runners. Anyway, advancements abound, but most are too subtle for photos. The most noticeable wet flow improvement can be seen in the contours surrounding each intake valve guide. Check out the the chamber picture to take a look.
Our particular cylinder heads, Dart Pro 1 Platinums, make the most of the old, conventional "Siamese" port location and 23-degree valve angle. These days, a fresh symmetrical port/shallow valve angle LS head is squirted off a GM foundry line every 5 seconds or so. The Internet makes it seem as though everyone is switching to LS technology. So why run the old stuff? Adaptability. LS engines can be had for cheap, but expect to use up a good amount of money, resources or both to accommodate mounting variations, cooling, accessories, exhaust, and more. Be sure to factor in conversion costs before taking the LS plunge. We queried smart people at GM Performance Parts, and it turns out that first-generation parts still outsell LS stuff by a wide margin. Long live the original.
In the meantime, Dart Pro 1 Platinum heads, along with Holley's HP EFI system and an aggressive but streetable Crane Cams camshaft, will take our 406 well above the 500-horsepower mark at 10.5:1 compression. By sticking with first-gen architecture, we're sacrificing some weight bias and fuel efficiency gains in the name of expediency. These engines also look kickass, while the typical LS engine looks like the oil burner in my basement. The dream scenario is to gather comprehensive performance data on this first-gen 406 combination, then swap in a 5.3-liter LS turbo engine for comparison. A few trips around the road course could make for the ultimate real-world dyno shootout. Wouldn't that be cool?
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