Jim Smart
April 1, 1999
Contributers: James Lawrence

Step By Step

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Coast High Performance will build you a smog-legal 347 Street Fighter short-block for only $3,095, and that includes a camshaft, complete blueprinting, and assembly.
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This is the secret to CHP’s smog-legal power in a stroker short-block—the reciprocating assembly. CHP equips the 347 with a 3.400-stroke cast-steel crank, heavy-duty Blue Thunder 5.315-inch rods, and Probe Pistons. This bottom end gives the 302 block nearly 350 ci of attitude.
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Here’s a closeup of the Probe piston and I-beam rod. With ARP 3/8-inch rod bolts, you can throw a lot of power at this combination without concern for failure. Dual eyebrows allow for either Twisted Wedge heads, or standard-valve–location heads like the GT-40, Edelbrock, or Dart.
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The long arm of the Coast cast-steel crankshaft requires slight notching of the block (arrows) to clear the rod bolts.
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Coast High Performance can fit your 347 stroker with a variety of different cylinder heads.
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Shown here and in the photos above and below is a set of ported TFS Twisted Wedge heads.
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CHP has a variety of other head and intake options as well.
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CHP gives the rod bearings liberal doses of assembly lube when assembling a 347 Street fighter.
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Notice the CHP CNC main girdle in the photo. It is an option with the 347 Street Fighter short-block. Once the main caps are torqued to spec, crankshaft endplay is checked. Endplay should be between .004 and .008 inch.
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Here, CHP installs the rings, making sure that the ring endgaps fit the proper specifications, and that the endgaps are positioned properly from each other.
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The cylinders are bored, then cleaned with transmission fluid, which serves as an excellent detergent.
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Then CHP lubricates them with Childs & Albert assembly lube prior to the piston/rod installation. Engine oil also works well.
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Connecting rods are mated to the crank journals and torqued as shown.
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CHP makes sure to check piston deck height. In the Street Fighter assembly we observed, piston-to-deck height came out well within spec.
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A Mellings high-volume oil pump is installed, taking extra care to check crankshaft counterweights and block girdle clearances. Check out the Coast block girdle, which is a nice upgrade for a small-block. The block girdle stiffens the block, which keeps things solid during high revs.
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This particular non-roller early block was to receive a custom hydraulic roller camshaft, so CHP fitted it with a Crane Cams hydraulic roller conversion kit. CHP installs a dual-roller timing set on all Street Fighter build-ups.
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Crane roller tappets are lubricated with assembly lube...
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...then fitted into the block.
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Lifter retainers keep the lifters aligned...
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...and the spider keeps the retainers and lifters in place.
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An important component of any precision engine build-up is degreeing the camshaft. CHP degrees every 347 Street Fighter that goes out the door.
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When installing head gaskets, make sure that you orient them in the correct direction. Up and forward means something!
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This particular 347 Street Fighter was topped with TFS Twisted Wedge heads.
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CHP offers the Edelbrock Performer RPM induction system for both 5.0 and 5.8 small-blocks.
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This is the complete 347 Street Fighter “E” from Coast High Performance. The beauty of buying an engine package from Coast is flexibility. CHP can build it any way you desire, and deliver it to your door anywhere in the nation.

As racers and performance enthusiasts, we like power--lots of it. The problem is that we can't get our power fix and stay smog legal in the Big Brother '90s. Nobody likes to roar down the street with a blatantly-illegal car, opening themselves up to the ticket-wielding Johnny Law. But we do it anyway, all in the name of speed.

Coast High Performance is changing this scofflaw behavior by introducing a new 50-state-smog-legal 347 Street Fighter short-block. Nowadays, getting anything approved as smog legal by the CARB and EPA is a chore, which proves the quality and attention to detail that CHP engineered into the 347 "E" stroker kit.

George Klass of CHP explained to us their year-long effort to get the 347 "E" Street Fighter short-block legalized. Beyond applying with the difficult and necessary paperwork, getting assigned a CARB approval station, and getting the car tested (before and after), there was the actual process of reconfiguring the 347 Street Fighter for it's new "Emissions-Legal" status.

Remember, CHP already has an excellent 347 Street Fighter short-block (also available in kit form) so they didn't have to start with a fresh sheet of paper. Klass explained that one of the best advantages CHP had with the 347 in the smog fight was the Blue Thunder 5.315-inch rod, versus the 5.400-inch rod normally sold in 347ci stroker kits. With the shorter rod, Coast was able to place the wristpin underneath the oil-ring land, allowing better oil control--an important factor when you have a sniffer checking for burnt hydrocarbons. Klass explained that Coast still sells the 5.400-inch rod for non-emission-conscious applications, and that it's a good, strong, viable combination. However, the shorter rod will provide better oil control, thus increasing engine longevity and ring seal. Another less visible advantage of the shorter rod is that a longer, fuller piston skirt design was possible. The 347 "E" short-block is only available with 9.5:1 compression, giving the piston a slight dish.

Of course, the really interesting thing about EPA and CARB legality is that a person can't see past cast-iron--meaning, how could anyone possibly know what kind of stroker or stroker short-block you really have under your hood? Well, a police officer, or visible inspection won't reveal the truth--but a smog test after 10,000 miles certainly can. The CHP 347 "E" has been tested and approved by CARB to be a smog-legal replacement for '88-to-'95 5.0-equipped vehicles.

When you buy a 347 "E" short-block, you also get an exemption sticker/certificate that you can present to anyone doing smog testing. As explained by Klass, there are some interesting aspects to the 50-state smog testing. Even if you purchase Coast's 347 "E" short-block, and bolt-on a set of 50-state legal TFS Twisted Wedge heads, GT-40 intake manifold, and smog-legal headers---the combination may not pass a smog test, although it's very likely that it will. The reason for this is because when CARB tests a part for smog legality (such as an intake manifold), it leaves the rest of the engine stock. So, by adding together combinations of emissions-legal parts, you are legal by the letter of the law, but it is no guarantee of actually passing a sniffer test.

Coast's 347 "E" provides plenty of twist for the masses without concern for the long arm of the law. And it's also very durable, constructed of top-quality components that can handle quite a dose of horsepower. The crankshaft is a cast-steel 3.400-stroke unit, and it is safe for 500 to 600 hp. Blue Thunder makes the 5.315-inch forged I-beam rods, and the Probe Industries pistons are 9.5:1 compression ratio and come with valve reliefs for both Twisted Wedge and Standard-valve-location cylinder heads. All of this is stuffed in a well-machined .030-over 5.0 block.

Klass told 5.0 Mustang & Super Fords magazine that a custom hydraulic roller camshaft is included in the 347 "E" package, and that it was specially designed and configured for use in an emissions-legal short-block. It is not an E-303 camshaft. If you want to retain the smog-legality, you must keep the CHP emissions-legal grind in the car, although Klass said that it is a pretty healthy stick and not as much of a crutch as you would think. Swapping in a Motorsports E-303 camshaft is a big legality question. The only way to know if it'll pass is to sniff it.

All in all, it's hard to believe you can order such a well-made package through the mail. Coast High Performance sells the 347 Street Fighter "E" in short-block form only (with a camshaft), in emissions-legal trim, for $3,095.99. If you aren't concerned with the smog aspect, CHP can still set you up with one of their non-smog 347 Street Fighter short-blocks, long-blocks, reciprocating assemblies, or complete Street Fighter engines. In today's world, all it takes is a phone call.