The Smoginator

A Clean Burning Stroker That Takes No Prisoners

Mike Petralia Nov 12, 2004 0 Comment(s)

Ah, to burn clean and run free. That's the spirit of California. Or, at least, it's supposed to be the reasoning behind our tedious smog laws. What were they thinking anyway? That by policing a couple hot rods and forcing us to install some ugly and lame exhaust recirculation systems that they could keep us down? Did they believe even for a second that by implementing the now infamous "Smog Check" program back in 1982 that it'd keep us high-performance hard heads off the road? No way. We may have stumbled in the beginning of the smog era, fearing what was then unknown territory. But we have since prevailed. And in fact, the motor we just built might prove that we've won the battle entirely. That's because it made some killer power, but it will also pass the sniffer with flying colors. The secret? None, really. It's just a well-balanced package using parts that have received the California smog board's seal of approval. And, if it burns as clean as we think it will once it's in plopped in between the fenders of the '79 Chevy truck that'll be its home, this thing might set the performance "smog" world on fire.

You might not know that the real reason California's Smog Check program began was because our free-living lifestyle meant that the state couldn't meet the 1970 Federal Clean Air Act. And any state that couldn't pass had to do something to prove they were trying to clean up their air, or lose their building and highway funds. So this was all really about California getting more money. And what's wrong with that? We all would like a few more bucks now and then. And if the money comes with cleaner air, then it's all the better. But some of us have to live and drive here, too. And since we all want to be good, law-abiding citizens, we must follow the rules. In the early days of smog checks, many of us would drive around all year without any smog equipment hooked up. Then we'd make a mad dash to reinstall it just before our smog check was due. Or, even worse, we'd find some sleezeball mechanic who would pass it for quick cash. Either way, we were polluting the air, and just further contributing to the problem. But the truth we didn't know, mostly for lack of seeking it, is that none of the smog equipment ever cost us any power at all. In fact, the stuff's not even operating at wide-open throttle, which is where we want the most power. So why'd we remove all of it? Probably because we didn't know any better and smog stuff's just plain ugly. But now, while the aftermarket still hasn't found a way around the ugly part, they've made sure that our performance doesn't have to suffer for it.

Shortly after the smog check program was launched, the aftermarket started looking for ways to get their parts accepted by the smog-police and granted what's known as an Exemption Order, or E.O. by the state of California. And since, in California at least, there's always been a visual as well as tailpipe inspection to ensure that all of our car's original emissions equipment is hooked up and operating, the aftermarket had to find out a way to get their parts exempted from the visual inspection as well as pass the sniffer test. And the only way the smog police would exempt anything is if it was proven beyond any shadow of doubt that the parts did not make more smog than the original parts they replaced. The exemption testing procedures are long and tedious and the aftermarket manufacturer making the parts is responsible for the costs involved, which could run into six figures. That's why even though a high-performance part may burn clean, it might not ever be granted an exemption order because the manufacturer can't make enough profit on it to overcome the cost of testing it for an E.O. (there's that money thing again). But, luckily for all of us, there's still a ton of parts that have been granted an E.O., and they come with a sticker that you can put under your hood to proudly proclaim it!

Now, for some time there's been resistance to running smog-legal, E.O. parts in hot rods. And this again probably goes back to our fear of the unknown and the idea that if it burns clean it can't make power, can it? Well, we're here to tell you that's totally wrong. In fact, some of our most powerful bolt-on parts like nitrous and blowers are almost always legal. That's because they don't pollute when cruising around town and some can even help the engine burn cleaner. But there are also a slew of internal engine parts that can build lots of power and still pass the sniffer test. Just pick up any aftermarket catalog and you'll find tons of parts that are 50-state legal. Which usually means they've been granted a California E.O. and pretty much every state accepts that as the golden key, since our smog laws are tougher.

Now, onto our smog-legal engine, The Smoginator. What we did, quite frankly, was fool the system. Like any savvy racer would do, we looked at the smog rules and found a loophole. There's nothing saying that you can't increase the displacement of the engine under your hood. Although there are strict guidelines that govern the size and type of replacement engine you can swap into your car, you can still stroke and overbore the original. So that's what we did. We yanked the tired-old 350 out of a generic '79 Chevy pick-up and went to town. We first had to get a new rotating assembly. And this assembly would not be the typical stroker kit you'd find at the swap meet. Nope, in order to squeeze every last ounce of legal power out of this thing, and flaunt the system to the max, we, along with the crew at Lunati and Speed-O-Motive, engineered a trick rotating assembly made up of a 3.75-inch stroke forged crank, 6-inch rods, and custom pistons with a compression height that actually put the pistons outside of the bores by 0.015 inch. Now, some of you might call this loony, but hear us out. There's really no reason not to run the pistons out of the bores. The amount they stick out is so little that they won't rock over and the ring package is not anywhere near the top, so it's not in danger. The only thing we had to change was to run a little thicker head gasket for safety. What's the reason we did all this? We wanted to minimize the quench area and the get rid of the dead, non-power producing gap between the heads and pistons. This squeezes every last drop of power out of the compression stroke as it eliminates the dead spots that are hard for the spark to reach. But, it's important to figure piston shape into this equation. We ordered a set of Lunati flattop forgings with two valve pockets cut a little deeper than normal to accommodate for the lack of clearance. And we informed Lunati of our plans, so they could place the ring pack in the proper spot lower on the piston. Since these pistons have a relatively short compression height of 1.155 inches due to the long stroke and rods, we had to consider everything before assembling this beast. And that also meant that we'd never be running nitrous or a blower on this thing, lest we damage our custom slugs.

For the top end of our smogger, we called the guys at Holley and ordered some of their 20-degree, small-block aluminum heads. These heads are often ignored and we can't figure out why, because they're trick aluminum castings with a 20-degree valve angle, (that's rolled over 3-degrees from stock), and they accept all the original 23-degree stuff on the market. That means that you can have heads with rolled valves, but still use the same rockers, intake manifolds, headers, etc. It turned out that these heads had perfect numbers for our smogger too. They flow 223 intake and 173 exhaust, which is right in line with the under 5,500 rpm power peak we were looking for. And those small valves and ports will increase velocities through the heads, meaning power will be good at all rpms. Speed-O-Motive also installed a Weiand PN 8000 manifold and Holley's 600-cfm smogger carb to make sure the heads would not run out of air and fuel.

Camshafts are a big concern with smog engines. Too much cam and you'll surely never pass the sniffer. And too little cam won't help make power either. This is an area where the aftermarket has made tremendous improvements by investing in R&D to make smog-legal cams that work. The Lunati hydraulic flat-tappet cam we choose might be considered big for a smog cam, if it were in a 350-cid engine. But, it comes as part of Holley's 50-state legal SysteMax II kit (PN 300-504-1) and we put it into 383-inches so it was just right. The flat-tappet hydraulic cam specs out with 216/228 duration at .050 and 272/284 advertised. Lift tops out at .454/.480 with 1.5:1 roller rockers and the cam's lobe separation angle is a smooth 112 degrees with 5 degrees advance ground into the intake lobe. Note the large difference between intake and exhaust figures. That helps a motor like this breathe to its fullest extent and makes good power doing it.

All of this equates to one bad little bruiser. It'll be a killer street machine as well as be able to haul big loads down the highway. When we really think about it, The Smoginator may be one of the coolest engines we've ever created.

10

The heart of the this motor had to be its custom-made Lunati pistons. The 2618 forgings have two valve reliefs and were built to our specs, sticking .015-inch out of the bore at TDC. Final compression for The Smoginator was 10.6:1, which kind of negates the option of running 87 octane.

Holley's smog-legal truck carb is rated to flow only 600 cfm, which we thought might turn out to be a bit small. But, strictly for testing purposes, we bolted on a larger, non-smog carb and guess what? The engine didn't run any better. This little smogger carb should not be ignored any longer.

Of course, as in any good dyno session, we optimized the fuel and ignition timing curves through repetitive testing. This carb only has replaced jets on the primary side, so we stuck to messing with them until we found the perfect fuel curve.

The Weiand intake manifold is a dual-plane design that dates back quite a few years. But time has not passed it by and it was able to crank out some serious power figures, much more than we would've expected even. Also note that Weiand casts the California E.O. number right into the front of the manifold. No need to put a sticker on your car for this part.

To keep this dyno session real for the street, we even ran a Weiand mechanical water pump, where as we know an electric pump is worth a few more ponies, but can't live in a daily-driven pickup truck.

Also for this test, since we didn't have a car's complete exhaust system hooked up, we couldn't make use of the EGR valve, so it was capped off, (black triangle). The Weiand intake also ahs provision for the factory-equipped hot-air choke that came on some earlier cars. But this Holley carb has an electric choke, so we capped off the heat-riser block also.

Danger Mouse has proven the power and reliability of the Pertronix HEI and since it's California legal, we decided to run one in this motor, too.

Typically, vacuum secondary carbs don't work as well on the dyno as they do on the street, but we had no trouble with this one today.

Our only hot spot was found midway through the day when we saw this burned plug wire. It didn't seem to be burned all the way through and power was not affected, so we left it alone and will replace it only after the engine's installed in the truck.

One thing we did have to modify on the Holley carb to work on the dyno is the choke. In order to keep it open, we wire it tight because the engines never really get cold during a day's dyno sessions.

Truck engines live tough lives and they need tough oiling systems, too. Milodon helped in that area by supplying a complete oiling system with windage tray, too.

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