Resto-Mod Restorations — Part 14: Exhausts
Resto-Mod builders have many choices when it comes to headers, exhaust pipes, mufflers, tailpipes, resonators and tips. There are different brands and designs, pipes made of different materials, different finishes, different installation methods (slip fit or welded for instance) and different price ranges.
The least expensive option for a Resto-Mod builder is a stock exhaust like this Waldron's system for 455-powered 1971 Olds Cutlass and 4-4-2 models.
The least expensive option is probably the "stock look" exhaust system, which works on muscle cars with their original engines and chassis. Although the stock look exhaust system follows the OEM's (original equipment manufacturer's) design, it could be made of stainless steel instead of mild steel and it could have less restrictive mufflers or be put together by welding, rather than slip fit joints.
A custom modified "hot rod" exhaust system is the Resto-Mod builder's other choice. This is the route you'll have to take if your car has a crate engine or a custom frame. In fact, if your using a ready-to-roll bolt-in frame like the ones that Schwartz Performance builds and you go with their power train package, the engine will come with a specific exhaust system made for the frame you chose.
Stock Look Exhaust
Even though the term "stock look seems self explanatory, there are at least four variations of this type of system according to muscle car collectors, dealers and parts suppliers. All of them are high-quality exhaust systems, but the best one for you to purchase depends on your own personal restoration goals.
There are concours style stock systems like this one that Mid America Motorworks offers for Corvettes with outside exhausts.
Mid America Motorworks also sells the OEM-style slotted covers for the factory style Corvette "off road" external exhausts.
There are concours style stock-look systems that are supposedly bent from the same pattern cards that original equipment suppliers used back in the '60s and '70s. These exhausts are usually sold only as complete systems and they are made for collectors who want their cars to be judged perfect originals. There is no reason, other than one-upmanship, to use these on Resto-Mods.
Secondly, there are stock-look systems bent from aftermarket pattern cards. These can be very close to factory perfect, but sometimes have manufacturing variances, such as indentations caused when the bending machine stretches the metal tubing. Also, many such systems use modern mufflers that are eyeball-matched to originals, but may not be identical.
Thirdly, there are reproduction stock look exhaust system components patterned off one part that fits multiple models. These fit and generally look OEM but they may have small differences. For instance, in a hypothetical case, an OEM Ford muffler might have looked like a Mercury muffler, but had a different part number. Today, the same reproduction part might be sold for both cars. Such parts may truly be "stock-looking," but might cost concours judging points.
Last, there are systems that are manufactured to OEM designs, but made of different materials like stainless steel. These pipes can be exact copies of factory parts, but stainless steel will virtually last forever. The stock look exhaust system made of stainless steel is probably the best options for the Resto-Mod builder who has only a mildly changed car and wants to keep exhaust costs low.
Hot Rod Exhaust Systems
Exhaust systems aid the smooth flow of spent gases out of an engine and reduce noise. There are three ways to muffle engine sounds: restriction, reflection and absorption. Restriction means the flow of exhaust gas is restricted. This makes for a really quiet exhaust, but chokes off engine power. Most factory exhaust systems use restriction to keep cars quiet for the average motorist.
Hooker was one of the pioneer makers of performance exhausts, but today makes this system for the Chevy LS1 V-8 that Resto-Mod builders love.
Exhaust gas reflection involves splitting the flow path of the exhaust gases within the muffler and using wave-cancellation techniques to help create a pressure drop that reduces sound pressure and, therefore, reduces the noise level at the muffler's outlet. Reflective-type mufflers use a series of baffles and reflectors that the exhaust gases wind around in order to set up wave reflection.
Straight-thu "glass-pack" mufflers with one straight tube inside another absorb sound. The inner tube is perforated with louvers. Between the tubes is a packing that is usually made out of fiberglass. As the exhaust flows through the muffler, the packing material absorbs the sound. However, the louvers restrict flow and rob power. While the pipe may have a 2-1/2 in. inlet and outlet, the smaller inner tube and protruding louvers make the diameter as tight as 1-3/8 in.
The first cars to get aftermarket performance exhaust systems were early Ford flathead V8s. Today, Egge Machine reproduces these flathead headers.
The first custom performance exhaust systems were designed for the Ford flathead V-8. When, hot rodding took off after World War, the overhead valve V-8 arrived and it became the focus of the performance and racing industries. Early manufacturers didn't think about tuned-length headers, materials other than thin wall tubing, collector boxes or varying the number of tubes in a header. Drag racing and "Stoplight Grand Prixs" prompted early rodders to build performance mufflers and exhaust pipes. They found that good headers use exhaust gases — that normally pass out the exhaust as heat — to improve induction efficiency.
There was a boom in high performance exhausts in the muscle car era. This is Waldron's reproduction of the '67 Fairlane 427 exhaust system.
There was a boom in header popularity in the '60s, when factory muscle cars arrived. Performance type factory cast iron manifolds were the hot ticket. Tube headers of the day tended to flex a lot as they expanded and contracted, causing small cracks around welds. Today you'll find mild steel and stainless steel tube headers that never crack due to improved metallurgy and technology.
There were differences between early competition exhaust headers and street type exhaust headers. The early competition style headers often included a collector box and a collector box block-off plate. Street headers designed for everyday use cars must comply to a wide variety of regulations and noise codes.
One thing that hasn't changed from the old days is the fact that the wrong headers—no matter how kool they look—can make a hot rod run slower. Since the Resto-Mod's engine is basically an air pump, headers have to be "tuned" to a motor's induction system to make the pump function right. If the mixture is set too lean, the headers will try to collect more spent gases than the cold air intake system provides. The engine will start to gasp or choke. When headers are properly tuned for a specific engine, power gains up to 40 percent are possible.
In good headers the shape and diameter of the tubing has to match the size and shape of the cylinder head openings. You can't bolt a three-inch-diameter tube to a larger or smaller opening and expect a smooth flow of spent gases. Likewise, you can't bolt a round tube to a D-shaped port and get good performance or sound due to poor sealing of the exhaust gases. This is important to keep in mind when you are fabricating homemade exhaust systems.
Header pioneer Gary Hooker always insisted that no single exhaust system combination was right for every application. He found that Chrysler wedge and Hemi V-8s ran best with a 12 in long. x 3-in. diameter collector behind a six-in. transition pipe. However, smaller-displacement Mopar V-8s worked better with a 12 x 2.5-in collector. He also found that 4-tube headers worked best with perfectly tuned engines, but Tri-Y designs were best for other engines.
Hedman. One of the best known brands of headers today, makes "tight tuck" headers for the LS1 SBC (small block Chevy) V8.
Through racing, experiments, feedback and tests, early manufacturers like Hooker, Doug Thorley, Ed Iskendarian, Jardine, Clifford, Cyclone, Mickey Thompson and Howard Douglass learned about headers. Douglass, for instance, discovered that any time an equal-length header design was developed, he had underhood clearance issues. His answer was to use special programmed mandrel tubing benders to get compound curves of extremely short radius.
Hot rod exhaust systems are hot with Resto-Mod builders—and not just if you accidentally touch them. Damon Lee of Speedway Motors says that his company, which is known as "America's Oldest Speed Shop," is expanding its line of Resto-Mod exhaust parts and has more exhaust pipes in the pipeline.
Del Austin, Director of Sales for Egge Machine and Speed Shop sees a growing trend—especially among West Coast Resto-Mod builders—towards using vintage engines like the Chevy 327 or Pontiac 389 in Resto-Mods. Del defines a vintage engine as any post World War II to 1970s pre-catalytic converter engine, as used in Resto-Mod versions of the earliest muscle cars.
Egge Product Manager, Neil Matranga, believes such engines are "kool at a car show." Neil says building a vintage motor isn't expensive, but notes such power plants require exhaust parts with the right look and sound. Egge even sells split manifolds for the "something different" engines like Chevy and GMC sixes.
Revived Porter mufflers have a history dating back to the '30s and a distinctive blue color.
Clark Babler has a unique muffler for Resto-Mods. He manufactures Porter Mufflers, originally developed by the Porter Brothers, of Los Angeles. When they retired, the Porters sold the rights to Gene Fechter of Minneapolis. Fechter retired in 1989 and Bablers took over to make improved Porter mufflers. Clark handcrafts each of the classic mufflers from 14-gauge tubing with 12-gauge end caps. They have coil spring cores and stainless steel packing. The premium Porter Mufflers come in a distinctive ceramic blue color or stainless steel. They have a throaty rumble that was popular in the day and with Resto-Modders, too.
Vic Wood of Hedman Hedders says he has new Tight Tube headers available for Chevy engines. In addition to standard chrome-metallic finish, the Chevy headers are available with an HTC thermal coating that won't "blue" like chrome does. Hedman's offers kits with all hardware, flanges and gaskets.
Edelbrock is another name famous in racing and hot rodding. Vic Sr.'s first product was the "Slingshot" intake for mounting dual Strombergs on flathead Fords. Today's exhaust products include accessories, Block-Hugger headers, tips, LS Series retro-fit kits, mufflers, shorties and Tubular Exhaust System (TES) headers. Most Edelbrock exhaust systems are suitable for Resto-Mods using late-model engines like the Chevy LS Series V-8s that are popular with builders.
Not all popular hot rod exhaust system suppliers are big mail order houses. Patrick's Antique Cars & Trucks is a place where enthusiasts get great products and one-on-one service. The company has a catalog aimed at Chevrolet/GMC trucks. Patrick's is famous among builders of 1947-1955 first series Chevy Resto-Mod pickups for its stainless steel exhaust system with exclusive 2-in/2-out stainless steel muffler and "shot gun" style stainless steel tailpipes. The system bolts up to Fenton cast iron headers and includes header pipes, a muffler, tail pipes, hangers and clamps made of stainless steel.
Doug Thorley was one of hot rodding's pioneer header manufacturers and today his Doug's Headers brand is part of the Petronix Performance family that also includes Patriot and JBA exhaust parts. The company markets a wide range of headers for cars including small-block Mustangs and makes Model D104 headers for 1968-1974 AMC Javelin/AMX cars with 1-7/8-in. diameter exhausts.
Hooker Headers is now part of the Holley family and offers exciting products like its Super Competition headers for retro fitting a new 5.7-liter Hemi into 1968-1974 B-body and 1970-1974 E-body Mopars. They utilize lightweight 16 gauge 32-in. tuned length 1-5/8-in. primaries merging into a 9-in. long 3-in outside diameter smooth transition collectors with a three-bolt flanges.
The "Tight Tuck" collectors provide maximum ground clearance for ground-huging Resto-Mods with dropped spindles. Thick 3/8-in. machined flanges give a leak-free seal against cylinder heads. All fittings remain for vehicles with emission controls. The headers fit most manual and automatic Mopar transmissions and use motor mounts that keep the tranny in its original location. All hardware and gaskets are included. Baked-on high-heat-resistant black paint and Metallic Ceramic Thermal Barrier Coating finishes are available.
Ray T. Flugger founded Flowmaster in 1983 and the company's exhaust systems fit cars from late-model Chrysler 300s to those with Chevy LS V-8s. Perfectly suited to Resto-Mods requiring limited-space installs is the Hushpower II, which is four inches thick, 5.5 in. wide and 23 in. overall with an 18 in. case length. Hushpower IIs come in 409 steel and ready-to-polish T304 stainless steel and take up limited space. Several mufflers can fit in one system. The "Flowmaster Magic" design with stainless steel internals and Cool Shell technology controls heat and sound. They can be used in cars with up to 400 hp.
Parts Place is a good source of Gen 1 Camaro exhaust systems and does a great job of making a just-like-OEM design.
Jeff Noll's orange Camaro coupe is powered by a Chevrolet ZZ4 H.O. 350-cid crate engine. Jeff added a set of Hedman Header's Jet Hot ceramic coated shorty headers. He then bolted on a Magnaflow 2-1/2 inch stainless steel exhaust system with an X-pipe arrangement.
Jim Mokwa's burgundy GTO convertible uses its original 400-cid block with a custom engine build by Butler engines. To exhaust hot gases, Jim used a set of Pontiac headers made by Doug's Headers that flow to a Pypes 2-1/2-inch X-pipe. Pype's "Street Pro" mufflers were fitted to quiet things down a bit.
Confessions of a Muscle Car Pipe Bender
In the back shops of an old-time auto parts store on the main drag in Antigo, Wis., Bob Andres uses his 15-year-old Huth bender to make stock-look muscle car exhaust systems that he ships all over the country. If a customer's car isn't covered by Bob's massive collection of "pattern cards," he or she can make a pattern with copper tubing or even hanger wire, mail it to Bob and he'll copy it.
"As long as they bend it to match the approximate center of the pipe, I can make them an exhaust system," says Bob. "The only difference is, if we bend up a stock system from my cards and it doesn't fit, we'll take it back, but if a customer's pattern is off, we make it clear that's not our responsibility."
Bob has been bending pipes with his ancient and scratched up exhaust pipe bender for decades. At one point, his boss went to a trade show in Las Vegas and bought a computerized bender for $40,000. Bob didn't like it as much as his trusty old Huth and it didn't earn it's keep at the auto parts store, either.
"It was designed for production work and could do 10 systems an hour," Bob recalls. "But it wasn't that good for the onesy-twosy custom exhaust system jobs we normally do, so we wound up selling it and going back to the Huth." Bob says it takes him about an hour and a half to two hours bend a typical stock-look exhaust system. Bob guesses that his muscle car systems are at least 95 percent factory perfect and 99 percent correct fitting.
Bob Andres uses his 15-year-old Huth bender to make stock-look muscle car exhaust systems that he ships all over the country.
10-Step Exhaust System Install
If you purchase a quality made ready-to-go exhaust system kit for your Resto-Mod muscle car, you should have no problems installing it. With such kits you probably won't need special exhaust installation tools like a pipe expander or chain-style pipe cutter. You should be able to do it with regular hand or air tools.
- Safely raise the car on a lift, ramps or sturdy jackstands (not a bumper jack). To keep the car in place, apply the parking brake and block the wheels.
If it is on a lift, put on a hard hat and stand under it. If it is not that high off the ground, safely slide under it. Check and inspect your old system and make sure you have all the parts you need before removing it. Wearing protective goggles, squirt all nuts, bolts and fasteners with penetrating oil
After letting your penetrting oil soak in, work from the back of the car to the front to unbolt the old stock exhaust system parts. If you are not installing headers, try to remove the studs at the end of the exhaust manifold by hand without breaking them. An impact gun is handy for removing the other rusty fasteners. Don't worry if a couple of these break, as they won't be re-used. Once you have the fasteners loose, remove the old exhaust system parts.
Next, remove all the exhaust hangers. It is false economy to try to re-use these as the heat has already affected them. They are relatively cheap and using all new ones will make your new system look better and last longer. Install the new hangers on the new parts before installing the parts on the car.
Starting from the engine or exhaust manifold (depending on if you are installing headers) start bolting the new parts in place. Do not tighten the fasteners completely until you have the whiole system hanging on the car. If you are installing headers, you will install the new gaskets first. Hang them on the studs. Sometimes you must use a sealer to hold them in place. Then install your headers over the studs and torque all the bolts properly. You may need a curved exhaust manifold wrench to get at some of the fasteners between the pipes.
Gaskets may be required at pipe joints or check out the new Pro Clamp (www.julianos.com) spin-on header and muffler coupling system.
With all parts in place, begin tightening fasteners. Make them very snug.
For a proper look you want your tailpipes even with your bumper when you are viewing the car from the rear. Make adjustments prior to final torquing.
Go over all bolts for tightness.
Start up the engine and listen for any stubborn exhaust leaks.
Jim Mokwa's 400-cid Pontiac V-8 has a set of Doug's headers that snake back alongside theTremec six-speed transmission.
As you can see, the Doug's headers mate well with the Edelbrock 87cc ported cylinder heads.
Headers are tight to the block and the four tubes collect into a huge single pipe.
Jim Mokwa got hold of a Pypes 2-1/2 inch exhaust system with cross over pipes.
Dual Pypes Street Pro mufflers are used in the car.
This is a view of Jeff Noll's Camaro exhaust system after it was installed.
Popular Exhaust System Suppliers
Doug Thorley Headers
1180 Railroad Street
Corona, CA 92882
Toll Free: (800) 347-8664
General Info: (951) 739-5900
2700 California Street
Torrance, CA 90503
11707 Slauson Ave.
Sante Fe Springs, CA 90670
100 Stony Point Rd.
Santa Rosa, CA 95401
12438 Putnam St.
Whittier, CA 90612
Hooker Headers (Holley Tech Service)
P.O. Box 10360
Bowling Green, KY, 42101-7360
MagnaFlow Performance Exhaust
22961 Arroyo Vista
Rancho Santa Margarita, Ca 92688
Patrick's Antique Cars & Trucks
1079 W. Main St.
Casa Grande, AZ 85222-9329
Pertronix Performance (Doug's Headers)
440 East Arrow Highway
San Dimas, CA 91773
Porter Mufflers Manufacturing, Inc.
4844 Bartlett Blvd.
Mound, MN 55364
Pypes Performance Exhaust
2705 Clemens Road
Hatfield, PA 19440
31-410 Reserve Dr. Suite 4
Thousand Palms, CA 92276
PO Box 81906
Lincoln, NE 68501-1906