Mustang50 Magazine Homepage 5.0 Mustang & Super Fords

Smog-Legal Stroker!

Coast High Performance's 347ci Short-Block Is 50-State EPA Legal

By James Lawrence, Jim Smart
photographer: Jim Smart

http://images.mustang50magazine.com/howto/p84530_image_small.jpg
http://images.mustang50magazine.com/howto/p84531_image_small.jpg
http://images.mustang50magazine.com/howto/p84532_image_small.jpg
http://images.mustang50magazine.com/howto/p84533_image_small.jpg
http://images.mustang50magazine.com/howto/p84534_image_small.jpg
http://images.mustang50magazine.com/howto/p84535_image_small.jpg
http://images.mustang50magazine.com/howto/p84536_image_small.jpg
http://images.mustang50magazine.com/howto/p84537_image_small.jpg
http://images.mustang50magazine.com/howto/p84538_image_small.jpg
http://images.mustang50magazine.com/howto/p84539_image_small.jpg
http://images.mustang50magazine.com/howto/p84540_image_small.jpg
http://images.mustang50magazine.com/howto/p84541_image_small.jpg
http://images.mustang50magazine.com/howto/p84542_image_small.jpg
http://images.mustang50magazine.com/howto/p84543_image_small.jpg
http://images.mustang50magazine.com/howto/p84544_image_small.jpg
http://images.mustang50magazine.com/howto/p84545_image_small.jpg
http://images.mustang50magazine.com/howto/p84546_image_small.jpg
http://images.mustang50magazine.com/howto/p84547_image_small.jpg
http://images.mustang50magazine.com/howto/p84548_image_small.jpg
http://images.mustang50magazine.com/howto/p84549_image_small.jpg
http://images.mustang50magazine.com/howto/p84555_image_small.jpg
http://images.mustang50magazine.com/howto/p84556_image_small.jpg
http://images.mustang50magazine.com/howto/p84557_image_small.jpg
http://images.mustang50magazine.com/howto/p84558_image_small.jpg
http://images.mustang50magazine.com/howto/p84559_image_small.jpg

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.


Get Adobe Flash player
Get free and easy new car price quote in minutes.

Related Photos

Related Articles

 
S197 Mustang GT Intake - FRPP Bullitt CAI
We install the FRPP Bullitt CAI kit for S197 Mustang GTs in a 2007 Ford Mustang GT... more
 
Boss 340 Engine Build - Top Loaded
Our Boss 340 project engine receives high-rev heads, cam, and intake gear... more
 
Blown S197 V-6 Mustang - One Sick Six
Explorer Express combines economy and performance with its V-6 Ford Mustang supercharger kit... more
 
NASA American Iron Racing - National Treasures
A preview of the NASA American Iron National Championship Ford Mustang road race... more
 
S197 Mustang Supercharger - Shocked And Awed
An Iraq War Veteran's 2007 Ford Mustang GT receives Saleen Speedlab's 550 supercharger... more
 
S197 Mustang Shifters - Shift Exchange
Four Ford Mustang GT owners test and compare four popular S197 five-speed shifters... more
 
2008 NMRA Milan Race - The Motown Experience
Coverage of the Mustang drag racing action from the 2008 NMRA race at Milan Dragway... more
 
1995 Ford Mustang Cobra R - Home -Grown Horsepower
Darren Mag's takes on the competition with his 1000HP 1995 Ford Mustang Cobra R... more
 
Boss 340 Project Engine - Sonic Zoom!
We install a nitrous system and dyno test our Boss 340 Mustang engine... more
 
King of the Street 2008 - Day Two Dyno Runs
Day Two of King of the Street 2008 found us at HorsePower House using their dyno to see how much power our competitors were putting out... more

 

Get Adobe Flash player