Engine Options Abound In The Street Rod Market - Engine Builder Magazine

Engine Options Abound In The Street Rod Market

By definition a street rod is an automobile of 1948 or earlier manufacture which has undergone some type of modernization to include any of the following; engine, transmission, interior refinements, and any other modifications the builder desires.
By definition a street rod is an automobile of 1948 or earlier manufacture which has undergone some type of modernization to include any of the following; engine, transmission, interior refinements, and any other modifications the builder desires.

The National Street Rod Association (NSRA) provides the best definition of what street rods are all about. “By definition a street rod is an automobile of 1948 or earlier manufacture which has undergone some type of modernization to include any of the following; engine, transmission, interior refinements, and any other modifications the builder desires.

In addition, according to NSRA, a street rod is a means of self expression for the creator. The builder of a street rod is not confined to guidelines set down by someone else. He can be his own man, and the street rod can be whatever he wants it to be, as long as the basic vehicle was manufactured prior to 1949. The street rod builder has the option of adding a late model engine and drive train from any make of car, he can modify the suspension to give better ride and handling characteristics, and he can incorporate whatever creature comforts he wants…

The key points here are that these are customized and modified pre-’49 vintage cars and trucks, built mostly for show and often for go.  Some are classic style “Hot Rods” (highly modified cars often with no fenders, chopped tops or no tops, custom frames and suspensions, and large V8 engines), some are “Resto Rods” (restored classic cars with light modifications), and some are “Rat Rods” (chopped, lowered bodies on open wheel frames with spray can paint jobs or even no paint job and almost anything for an engine).

Street rod engines can be virtually any year, make or size from mild to wild, naturally aspirated with single or multiple carburetors, to fuel injected, blown or even turbocharged.

The most popular engine choices for street rods have long been smallblock Chevy and Ford V8s, though you also see a lot of big block Chevy and Ford V8s, Chrysler Hemis, Oldsmobile, Pontiac, Buick and Cadillac V8s, older Y-Block Ford V8s, flathead Ford V8s, Chevy straight sixes, various Chevy, Buick and Ford V6s, late model Ford 4.6L V8s and Chevy LS V8s, even some late model overhead cam V6 engines and four bangers such as Chrysler 2.4L or Olds Quad Fours. Anything goes when it comes to building a street rod, so practically any engine is a potential prospect for engine work.

Many old school rodders prefer to stick with traditional (and much simpler) carbureted engines while others prefer the reliability and cold weather drivability of a fuel injected engine. The only drawback with the more modern approach is the added cost and complexity of the electronic fuel injection and ignition controls.


The street rod market has matured along with the Baby Boomers who make up the bulk of its ranks. Hot rodding had its heyday back in the 1950s and 1960s, but took a hiatus during most of the 1970s and 1980s as emission regulations and fuel shortages strangled the performance industry. The lackluster cars that Detroit built during this time did little to foster the car culture.

But as the Baby Boomer generation matured and had more disposable income to spend on hobby cars, they returned to their roots and reignited the market for street rods, muscle cars and other classic cars from the era of their youth.

The demographics of today’s street rod market reflects the people who created it. According to Bob Reynolds of the National Street Rod Association, 43 percent of NSRA’s 50,000 members are between the ages of 61 and 70 years old, and 11 percent are over 70. Another 33 percent are between the ages of 51 and 60. Only 4 percent are under 40.

There’s not a lot of fresh blood coming into the street rod market. Those of the younger generation who are into street rods are more likely to drive a rat rod and dabble in the “rockabilly” (’50s punk) lifestyle.  They can’t afford the high dollar, professionally built, billet aluminum Boyd Coddington-type of cars that their father’s or grandfather’s generation typically favors, so they build hot rods the traditional way out of parts they can scrounge and cobble together.

The “rat rods” that the younger guys build are not trailer queens, show cars or street performance cars, but custom rods that are often driven anywhere and in any kind of weather (a thought that makes the owner of most high dollar rods shiver!).

Street rodders (at least the older guys) also tend to be big spenders, with nearly one out of four having an annual income over $90,000 according to NSRA. They also spend a lot of money on their cars, with 67 percent saying they’ve invested over $40,000 in their rides. These are the kind of customers you want!

Low Miles

Regardless of what kind of engine ends up in a street rod, most don’t rack up very many miles. NSRA says 70 percent of their members put less than 5,000 miles a year on their cars, and 40 percent drive less than 3,000 miles a year.

Most street rods are only driven during fair weather from May through October, and spend the rest of the year as garage queens in storage. There are some diehard street rod owners who will drive their cars to various parts of the country to attend events such as the Good Guys car shows, regional NSRA shows or the granddaddy of all street rod shows the 43rd Annual Street Rod Nationals, which attract over 10,000 vehicles and will be held August 2-5 at the Kentucky Expo Center in Louisville, KY. Most street rods, however, never venture further than their local car shows and cruise nights. And if they do take an occasional road trip, it’s often in a trailer behind another vehicle.

Engine Options

Most of the miles that are put on most street rod engines are usually relatively easy miles. These aren’t race cars that are being flogged every weekend on a race track (unless they are into nostalgia drag racing). Nor are most of them daily drivers that spend a lot of time in stop-and-go city traffic or on the interstate.

Most street rod engines have a relatively easy life compared to other types of stock and performance engines you typically build for customers. Consequently, there’s seldom a need to use high end performance parts such as forged steel or billet cranks, forged steel rods, forged pistons, titanium valves, exotic cams or even four bolt main blocks.

Crate engines are popular with many street rod builders for a variety of reasons. In many cases, these reasons are simply the perception that a crate engine offers two things people are fans of: low price and high reliability. Granted, some crate engines sell for less than what it would cost to rebuild an existing motor. On the other hand, a street rodder can spend a LOT of money on a high end crate motor – probably much more than what it would cost to custom rebuild a good core.

Warranty coverage can be an attractive feature as well, but since these engines are typically not used for all-out performance, it’s unlikely the owner will exceed normal usage anyway.

There’s also a perception that crate engines offer convenience that solves the problem of matching an engine (new, used or rebuildable) to a body if a car is being built from scratch and there is no engine. Many of the desirable older engines that would make good street rod engines have either been melted down for scrap or have been rebuilt once or twice already.

Finding a good Ford Y-Block or flathead V8, Buick Nailhead, early Chrysler Hemi or other 1950s or early 1960s vintage engine that’s rebuildable can be a real challenge. It’s even difficult to find some of the better SB/BB Chevy engine blocks and heads.

A custom built engine, by comparison, has its own advantages. Assuming you can find a good block to start with, a custom engine allows you to build an engine that matches your customer’s budget, desires and expectations. You can tweak the engine however he wants it built, you can use the type or brand of parts he wants, and there’s no shipping or waiting for the delivery truck to arrive as is the case with most crate engines.

And, as Engine Builder Editor Doug Kaufman explains in his article in this issue, “crate engines” can be what you make it. If you find a niche, go after it with gusto.

Just remember, with street rods there is such a thing as too much power. These are relatively light cars that are driven on the street by card carrying AARP members.  Most street rodders want their cars to be quick and fun to drive, but not dangerous or difficult to control because the car has way too much power.

Street Rod Engine Work

Engine work that might be done for a typical street rod customer usually begins with the basics: cleaning, inspecting and reconditioning the block as needed, installing sleeves if one or more cylinders are too badly worn to be bored to oversize, line honing the block, regrinding the crank, installing new rings, bearings, timing chain and oil pump, reaming, replacing or relining the old valve guides, refacing or replacing valves and seats, etc. Nothing unusual here except for the challenge of finding replacement parts for an engine that may have been out of production for over 50 or 60 years!

According to a supplier of vintage and obsolete engine parts, Ford flathead engine parts are still the leading seller, followed by 1950s and ’60s vintage Cadillac engine parts. With pistons and valvetrain parts to fit such classics as Oldsmobile 215 Rocket motors, Buick 215 aluminum V8s, Chevy 235 straight sixes, Ford Y-blocks and Buick Nailheads, many other engines that might have been forgotten offer options to the intrepid engine builder.

Many of the pistons used in these engines are cast (though forged pistons are typically available on special order). Cast pistons are fine for most street rod and older car restoration projects because the engines are not being built for racing, but for everyday street use.

When modifications are made to a street rod engine, they may include balancing the rotating assembly (crank, pistons and rods), blueprinting the block and heads to certain specifications, overboring the block and/or installing a stroker kit to increase the engine’s displacement and power, or doing some mild performance work on the heads and valvetrain (cleaning up the bowls, matching the ports, reworking the combustion chambers, installing roller rockers, etc.).

Since most street rod engines should deliver good drivability as well as power, building an engine that can deliver lots of low end torque is much more important than building an engine for maximum horsepower. Most of these cars are fairly light, so it doesn’t take a lot of power to get them moving or to break the tires loose. The engine should have good throttle response and low end torque, so that requires a cam that doesn’t have too much overlap and duration.

The most common mistake that’s made when building a street rod engine (or any street performance engine for that matter) is over camming it. Everybody loves the lope of a wild cam, but a cam that’s overkill for the engine and car that it’s going into can also be a pain to drive.  It’s better to go with a cam that delivers most of its power from off idle to 4,500 rpm.

What’s important here is matching the breathing capabilities of the cam to the displacement of the engine, the valve and port sizes in the cylinder heads, the intake manifold and carburetor(s), the type of drivetrain (stick or automatic) and the final drive ratio and tire size.

A street rod engine that doesn’t rev much higher than a stock motor doesn’t need a lot of valve spring pressure either – especially with a flat tappet cam. Too much valve spring pressure combined with today’s low ZDDP motor oils can wipe out cam lobes and lifters.  It’s not an issue with roller cams, but with flat tappet cams it is. So if your customer wants you to build his street rod engine with a flat tappet cam, make sure you both understand the lubrication needs and options, and select your oil based on the customer’s (and the engine’s, of course) needs.

A hydraulic cam and lifters are usually the best choice for a street rod because hydraulic lifters require no adjustments. They’re also quieter, which may be a concern with an open engine compartment. On the other hand, some people like the clatter of a solid lifter cam, and want the ability to tinker with the valve adjustments to “fine tune” the engine.

The same advice that applies to camshafts also applies to cylinder heads, especially aftermarket performance heads. Don’t get carried away with huge ports volumes, valve diameters and CFM flow numbers. Bigger is better for top end power, but for everyday drivability and low end torque stick with street heads that have smaller, high velocity ports.

Compression ratios for naturally aspirated street engines should be kept to less than 10:1 for pump gas, and probably no more than 8:1 for a blown or turbocharged engine to avoid detonation problems. On boosted applications, there’s probably no need to go beyond 8 to 10 lbs. of boost for a street rod.

A lot of street rodders like a three, two barrel carb setup on a small block Chevy or Ford V8. With three duce manifolds and old style 2bbl. carburetors as well as other vintage models available from a growing number of aftermarket suppliers, these are easy bolt-on upgrades that require few if any modifications to the rest of the engine. The only drawback with a three duce setup is that three carburetors are trickier to tune than a single four barrel.

As for intake manifolds, a 180 degree split plenum manifold will usually provide better drivability and throttle response on the street than a 360 degree open plenum style manifold. The taller the manifold, the better the air velocity and low end torque.

Most street rod engines don’t need killer ignition systems. A stock distributor, an aftermarket electronic ignition conversion kit or an electronic replacement distributor should provide more than enough voltage for reliable ignition performance.

Engine cooling shouldn’t be an issue with most street rods unless your customer is trying to run a vintage stock radiator that was intended for a small displacement four or six cylinder engine. A more powerful V8 will likely require a higher capacity radiator.

Catering to the Customer

Any machine shop that does engine rebuilding work or custom engine building can potentially cash in on today’s street rod market. As with any kind of engine work, word-of-mouth advertising from satisfied customers usually generates the most business.

Engine builders who cater to circle track racers or drag racers in a given area typically create a customer base by building a reputation within that racing community. You build a competitive motor for one guy, and pretty soon word gets around and other guys start bringing you their engines to work on. It’s the same with the street rodders. You do an engine for one guy, and hopefully he tells his buddies what a great job you did.

Depending on the level of street rod activity in your area, you then pick up some additional business.

Attending events that attract street rodders is probably the best way to actively promote your engine building services to this type of customer. Dropping an ad flyer in the front seat of every car at an event is one way to let people know who you are and what you do.

But many vehicle owners find this tactic to be really annoying (though every car show promoter does it). Nobody wants to come back to their car to find the interior piled high with junk flyers and announcements. Most of the paper gets pitched.

A much more effective way to promote your services is to strike up conversations with the vehicle owners and talk to them about their engines and what you can do for them. Then personally hand them a business card or flyer with your shop’s information on it.

Finally, if you like hobby cars, have owned a classic car, muscle car or race car, but never owned or built a street rod, consider doing a street rod as your next project car. That’s probably the best way to jump into this market, meet new friends and hopefully generate new business opportunities for your shop.

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