Just for fun, this is a photo of the Olds Aerotech driven by A.J. Foyt that achieved 257.1
What's up, DOHC?
R. J. Wetak; via CarCraft.com: We just scored a '72 Vega on eBay, and for the first time, my boy got excited over a car-what a proud day. He just turned 16 and can't drive until he's 18, which gives us two years to get it on the road. He is not ready for a 6.0L V-8, but we are drawn to a turbo 2.0L Solstice-type swap. Fabricating is not an issue, but being a V-8 addict, I am not up to speed on the interchange on the different GM four-cylinder engines, transmissions, turbos, and the like. I personally would choose a five- or six-speed, but the kid may call auto. Any tidbits of info you could supply would be great, maybe contact info for a company that caters to car crafters by supplying complete drivetrain takeout assemblies. I think this has potential to be a great experience with a very entertaining outcome.
Jeff Smith: This is uncharted territory, but let's take a stab at it. It does sound like the least intrusive approach would be to pull the complete motor and trans from a wrecked Pontiac Solstice. The first year for the Solstice was 2006 with a base Ecotec 2.4L 16-valve four-cylinder rated at 173 hp at 5,800 and 167 lb-ft at 5,500. This is pretty tame power even for an Ecotec. The high-performance version can be found in the EXP beginning in 2007, a direct-injected 2.0L engine with an intercooled turbo that is rated at a much sportier 260 hp at 5,300 rpm and a boost-infused 260 lb-ft. That boost increase is almost 100 lb-ft or 60 percent more torque than the normally aspirated version. The transmission behind both versions is a five-speed manual gearbox with a 3.75:1 First gear with the turbo's rear axle ratio of 3.73:1. Don't make the mistake of putting an automatic behind either of these engines-that would be like draping Jessica Simpson in a burlap sack.
Issues with the turbo application may settle around fuel delivery, since the direct injection system will require a serious fuel system. But frankly, any performance engine will require a 3/8-inch minimum diameter fuel line and quality hardware. The only way this will work is to get the entire engine and trans, along with the computer, wiring harness, sensors, and anything else that will make the conversion easier. The biggest problem we see is finding an affordable package.
Another option is the all-aluminum 2.4L (146ci) or 2.3L (138ci) Olds Quad 4 engine. These motors were available in front-wheel drive (FWD) applications such as the Olds Calais, Pontiac Grand Am, and other GM FWD body styles from '87 to '95. These engines are much more plentiful and were rated at between 160 and 190 hp. These are especially cool since they are also dual-overhead-cam (DOHC) engines like the Ecotec. The hot dog Quad was the W41 engine with that code cast into the valve cover. Converting this engine to a north/south drive configuration isn't that big a deal since a company called Quad 4 Rods makes a Quad 4-specific bellhousing that will adapt to an equally plentiful GM T5 five-speed from an S-10 pickup. The bellhousing sells for $475.00, and if you insist on an automatic, the company also offers aluminum adapters to bolt several different GM automatics to the little four-cylinder. Quad 4 Rods also makes a stand-alone ignition system should you decide to convert to carburetors, as well as a header flange and stub kit that will set you up to build your own header. From a simplicity standpoint, it would probably be easier just to swap in a Quad 4 engine from a donor car complete with the ignition, injection, wiring harness, intake, and exhaust. Then you can adapt the engine to a T5 trans, and you're almost there. According to Quad 4 Rods, a complete Quad 4 with intake and exhaust manifolds, ignition, flywheel, starter, and alternator weighs 325 pounds. Compared with the '75 Cosworth Vega's dismal 110 hp, the Quad 4's 190 hp is downright impressive.
We talked with Ed Taylor, who worked with the late Jim Feuling on the Quad 4 engines back in the '90s, and he said with the log manifold (not the cute tubing intake), the H.O. camshafts, and a header, this little engine can make 200 hp-not bad for a tiny four-banger. So find one of these DOHC engines, stuff it in that Vega with a T5 behind it, and be glad you did.
Quad 4 Rods; Denver, CO; 303/287-9093; quad4rods.com, quad4forums.com
This is Loren's Chevelle. With a Rat and a decent gear, it has most of what it takes to ma
Loren Coate, via CarCraft.com: I'm a retired school principal with a stock 502 H.O. crate motor in my '70 Chevelle. It has Hooker 2-inch headers, an 850-cfm Quick Fuel double-pumper carburetor, 3:73:1 gears, and a 2,800-rpm converter. The car weighs 3,800 pounds with consistent 1.80 60-foot times and has run 12.50 at 109. The tire size is 275/60R15 MT ET street radials that are 28 inches in diameter. This is a stock 502 H.O. with rectangular-port iron heads and a nonadjustable valvetrain. I've noticed that acceleration tapers off noticeably after 5,000 rpm. Could you help me get to 11.99?
Jeff Smith: Don't you just love letters that get right to the point? I have lots of suggestions, but let's start with more background. The 502 H.O. (High-Output) GM Performance Parts crate engine is a 450hp big-block with 550 lb-ft. The engine uses an excellent steel 4.00-inch stroke crank, forged 8.75:1-compression pistons, iron rectangle-port heads (2.19/1.88-inch valves), and a conservative hydraulic roller cam with 211/230 degrees at 0.050-inch tappet lift, 0.510/0.540-inch valve lift, and a conservative dual-plane intake. The easy answer is to just dial in an Edelbrock Performer RPM Air-Gap intake and a cam with about 20 more degrees of duration and lift of around 0.550 inch. This will also demand better valve-springs and an adjustable valvetrain with good roller rockers. This will raise the H.O.'s horsepower peak from 5,250 rpm to around 6,000 rpm, and the horsepower will probably jump to more like 480. This is a good idea, but we have more.
Based on stated power and weight, our copy of Patrick Hale's Quarter Jr. dragstrip simulation provided some interesting information. The simulation estimates the Chevelle should run around 12.40 at 108 mph, which is very close to your current performance (I had to estimate weather and track altitude). However, the simulated 60-foot time was 1.63, and yours is 1.80. It also appears that the tall Mickey Thompson DOT drag radials tend to reduce the gear ratio a little. According to our simulation (and your mph), the engine is barely turning 5,000 rpm in the lights. At first, it might appear that adding a gear ratio such as 4.10:1 would help, but we tried that and saw barely a 0.10-second and 1-mph improvement, making it difficult to justify the cost. This minor improvement in e.t. and speed is because the engine is already making excellent torque but no horsepower to push the trap speed. That's why adding gear doesn't help the acceleration on the starting line. To take full advantage of the gear change, we have to make the above engine changes as well.
A better way to improve e.t. without spending money on the engine is to reduce weight. At 3,800 pounds, the car is heavy. If you are creative, there are many ways to reduce weight at very little cost. Pull out any unnecessary pieces. If the car has A/C, yank it all. Try a pair of inexpensive plastic bucket seats to replace those factory seats, and while you've got the seat out, rip out all that sound deadener under the carpet-that's probably 20 pounds. Does the engine use a clutch fan or-worse yet-a plastic flex fan? Those clutch fans are monster heavy, and the plastic ones are notorious power bandits. Replace the fan with a big OE electric-look for one of those huge 12-inch electric units used on a Lincoln MKVIII. They move a ton of air, and you could get a junkyard piece for next to nothing-saving weight and maybe freeing up some horsepower. Every 100 pounds you can pull off the car will trim 0.10 second and add 1 mph to the trap speed.
One way to get a double hit off any weight reduction is to run as light a rear wheel as possible. Your other photo shows you are using the 15x8-inch steel GM Rally wheel in the rear. Those are really heavy-on the order of 40 pounds for the pair. Find a light aluminum race wheel. If you're willing to buy some parts, a fiberglass front bumper isn't expensive and will pull a solid 20 pounds off the car. That's a good dollar-per-pound investment. A fiberglass hood like the one we used on our Chevelle last month from Glasstek will also remove 25 to 30 pounds.
Overall, unless you can remove about 300 pounds from the car, it will be tough to lower the e.t. to 11.99 without resorting to engine improvements. It appears it will take around 500 hp to push this Chevelle at 3,800 pounds into the high 11s. If you're really serious, pull 200 pounds, add the cam and intake, and you'll probably be close. Of course, the quickest, easiest way to get there is with a nitrous system-but you already knew that.
Glasstek; Naperville, IL; 630/978-9897; glasstek.com
Racing Systems Analysis (Quarter); Oshtemo, MI; quarterjr.com
Norm's information indicates that it's impor-tant to follow the 20-degree rule when using
More Info on Alignment
Norm Peterson, Cherry Hill, NJ: In your home alignment how-to, it is stated that the 20-degree turn-in/turn-out angles are not critical and the 20-degree figure is popular for reasons of accuracy. Neither is particularly true.
In truth, the 20-degree turn angles are specific to the commonly available caster-camber gauges such as the one you used. The short explanation is that when you make your caster measurement with this tool, you're actually measuring the camber change over a given amount of steering. The camber range becomes caster as you steer the wheels either way from straight ahead at roughly 1 ÷ (2 x sin ([turn angle])), where [turn angle] is 20 degrees in this case. Accordingly, the caster scale on the caster-camber tool is calibrated to use a factor of 1.5 for your 40-degree total sweep. Being off by a degree or possibly two in your turn angles probably won't make enough difference to matter for most street alignments, but if for any reason you could only get a turn angle of 14.5 degrees, you should be using a factor of 2.00 instead.
At least some of the commercially available caster-camber gauges are beveled on the end at the 20-degree angles for visual reference. I'd take this a step further and fabricate a 20-degree-angle jig from steel strip, as it will help to hit the 20-degree angle more reliably.
For those interested, there is an SAE paper readily available from Hunter Engineering (the alignment equipment company) at hunter.com/pub/under car/2573T/index.htm that goes into this in a lot more detail.
Jeff Smith: Thanks to Norm for this update. We were not aware that the bubble-type camber/caster gauges integrated this 20-degree requirement. Now we do.
This is Scott's orange '64 Olds F-85. His reference to being plagiarized is in regards to
Question that Sucks
Scott Renzenbrink, Massillon, OH: I have a '64 F-85 with a warmed-over 455 cam and a vacuum-secondary Demon 750. I noticed the vacuum gauge tends to bounce a little at idle, bounce a bunch at tip-in, and become steady once I am under way. I checked for leaks and adjusted the carb and the results are the same. Then last week I slapped the Q-Jet back on the motor and the gauge reads steady as a rock. Do you have any ideas why this would be occurring with the Demon? The car seems to be running fine, but I need to know what I am looking at. Is it just me? When I look at page 85 of the Oct. '09 issue, I feel like I am being plagiarized.
Jeff Smith: In the past when we've run into the situation, Scott, where the engine idle vacuum bounces around, it generally indicates that the engine is running lean. To get a little more feedback about this, we talked to Sean at Sean Murphy Induction (SMI) in Huntington Beach, California. Sean says it sounds like the engine is still suffering from a mild vacuum leak even though you did not immediately find one. Since you changed the carburetor and discovered that the engine runs fine, this indicates that the leak is located in the carburetor itself.
Vacuum leaks are one of the most common forms of engine idle and off-idle driveability problems. This is because the air that is introduced into the engine is not metered, which means the proper amount of fuel is not mixed with this air, and the engine will run lean. Depending on where this unmetered air enters the engine, it can affect all the cylinders or possibly just the front half or back half of the engine. A too-lean air/fuel ratio at idle is generally characterized by a rolling or inconsistent idle speed. Often this is described as an idle that hunts and is not consistent. The most common place for this to occur is the seal between the intake manifold and the heads. Loose intake manifold bolts or just a porous seal between the intake and the heads will create this same ragged idle quality.
There are several situations that can cause any carburetor to display these kinds of poor idle quality symptoms. Some areas to look out for are a rubber manifold vacuum port plug that's cracked. We've seen ones that look fine on the outside but once removed are actually split quite badly. We've also seen base gaskets between the carb and the manifold that do not completely seal the carburetor but only leak after the engine is completely up to temperature. We've also seen metering blocks on Holley and Barry Grant carbs that have been subjected to the gorilla-finger tightening technique. This is where the bowl screws have been overtightened, which tends to warp the sealing surface of the carburetor main body. It can create vacuum leaks that are not only difficult to locate but are also inconsistent, meaning the engine will not always exhibit these poor idle quality symptoms.
Another situation we've run across is when a chunk of dirt or solid debris tends to lodge in one side of a carburetor's idle circuit. One time that comes to mind was way back when Scott Sullivan and I drove his Cheez Whiz '55 Chevy from Ohio all the way to California. Somewhere in Utah, the Lingenfelter-built 496ci big-block began running very poorly at idle and part-throttle. After much messing around with the carburetor, we realized the black chroming of the carburetor had apparently deposited or dislodged something into the idle circuit. If we removed the metering block and blew it out with compressed air, the engine would run fine-sometimes for days and other times only for hours. The fix is to drill out the idle-feed restrictor and remove the offending debris. This is a rare occurrence, but it does happen. Somewhere in the middle of these suggestions is probably where the problem lies. We'd suggest going through the BG carb with a good cleaning, new gaskets, and a shot of compressed air through all the various metering passages and see if a more stable idle returns. My guess is this will solve your idle stability problem and let you go back to enjoying your 455ci Olds.
Sean Murphy Induction; Huntington Beach, CA; 714/843-9169; smicarburetor.com
This is Editor Glad's dad in front of a twin of his high school car, which we found at the
Big-Blocks and Small-Blocks
Mark Edwards, Richwood, OH: I have a question regarding engines. I see articles that mention 400 and 454 big-blocks and small-blocks and would like to know what the difference is between them.
Jeff Smith: Thanks for writing, Mark, because it's important that we take the time to bring our new readers up to speed. Even you old-timers (and I include myself in that description) need to take a moment every once in a while to remember how little we knew when we started in this hobby. These are generic terms that relate to the physical size of the engine and to its displacement as expressed in cubic inches and more often now in liters. Let's start with a simple description using the small-block Chevy. This engine started out at a minuscule 265 ci in 1955 and expanded in production form all the way up to 400 ci in the '70s. In 1965, Chevrolet introduced the production 396 and 427ci big-blocks that were physically larger in external size and displacement. But you can see that by 1970, Chevy had built a 400ci small-block that was larger in displacement than the 396ci big-block. The monikers have remained the same despite the displacement overlap.
This is a 505ci stroker Pontiac built by Butler Performance. It could easily be considered
Like most things in our sport, other engines can make this distinction downright confusing. The most popular of all Chrysler big-block engines, the '70 426 Hemi (for example), can trace its roots back to the original Hemi-headed engine used in Chrysler, Dodge, and DeSoto vehicles. The Dodge version was called the Red Ram but only displaced 331 ci despite its lineage as a big-block. Pontiac also gets a little confusing. Take the 389 engine originally introduced in 1959 that many would consider a big-block engine; Pontiac engineers later developed a lower displacement 326 using a smaller bore that would be closer to being considered a small-block in terms of displacement. As you can see from these relatively few descriptions, the distinction between small-block and big-block can be a bit confusing sometimes. But hang in there, Mark, continue to read Car Craft, and you'll be an expert car guy in no time.
LS Rod Bolts
Tim Wusz, Anaheim, CA: I bought a relatively new LS1 engine that has an unclear history. I've changed the cam and decided to make sure that the bottom end is properly torqued before it goes in the car. I know that the head and the harmonic balancer bolts are one-time use but I'm not sure if that includes the rod bolts. What should the torque spec be?
Jeff Smith: According to all of our sources, this is a one-time-use fastener. Early LS '97 to '00 engines used odd-looking bolts with a sleeve and an undercut that LS engine builder Kurt Urban (kurturbanperformance.com) says was cause for many early engine rod bolt failures. GM created a second design, stronger capscrew around 2000. Where much of the confusion lies is with the torque angle spec that is now common with many modern engines. Torque angle, for LS rod bolts as an example, specifies 15 ft-lb of initial torque and then using a torque angle gauge, tightening the bolt another 60 degrees (first design) or 75 degrees (second design). The angle eliminates the effects of friction on bolt torque. Urban says if the engine has run and the rod bolt is loosened or removed, it should be replaced. If you are in doubt, try Urban's trick. Given the initial torque spec of 15 ft-lb, he sets his torque wrench to 35 ft-lb and runs back over all the rod bolts. As long as each factory rod bolt achieves that torque spec, he feels the bolts are sufficiently stretched. If you plan on rebuilding the engine, ARP (arp-bolts.com) and KaTech (katechengines.com) offer superior, high-strength replacement capscrews.
You've got problems? We've got solutions!
Car Craft Mag
6420 Wilshire Blvd.
Los Angeles, CA 90048