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November 2010 Chevy High Performance Q&A - Performance Q&A

Kevin McClelland Oct 12, 2010
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Who Needs Stinking Instructions?
As an alpha male, there was a time in my life that I went by the mantra, "Who needs any stinking instructions?" I guess with all the gray hair I've accumulated over the years, I've begun to realize that the parts manufacturers are usually smarter than the consumers installing said parts. As you guys know, I'm not bashful about sharing when I kill some parts. If I can save you some pain-in either the wallet or by fewer busted knuckles-then I've done my job.

chp_01_o November_2010_chevy_high_performance_q_and_a Editor 2/2

Back in the day, all I ever wanted to be was a mechanic. All through my teenage years this was my focus, and I got my education based on this profession. When I graduated from LA Trade Technical College, I went straight into the field, first with a local private shop as its transmission man. I really took a liking to automatic transmissions and their complexity. Then I moved on to our local Chevy dealership as a heavy line mechanic. There I further applied my craft as a transmission rebuilder. Where I'm going with this is that if I've built one TH350 I've built hundreds!

So, instructions? As I was taking the Stocker combination out of our wagon earlier this year, I noticed a good amount of metal flake in the transmission fluid. I'd just installed a new A1 8-inch converter tuned for our 305 less than 30 runs before. All I could think was that there may be a problem with the converter. Dropping the pan on the trans to check everything out before putting the engine and trans back in the car, I came to find a ton of junk (metal shavings) in the bottom of the pan and around the filter. The last time I rebuilt the trans, I had just installed a lightweight aluminum front drum and Second gear sprag for better performance. The drum assembly came from the manufacturer with no instructions. At that point, I should have given them a call and asked if there were any special instructions for running an aluminum drum. But hey, I've built well over 100 TH350 transmissions, so how hard could it be?

Where did the metal shavings come from? You guessed it. The aluminum drum is not compatible with the Second gear band that applies to the outside of the drum. This band tore itself up and cut into the drum. It cut thin, fine, hairlike strands off the aluminum drum and dispersed them throughout the trans. Luckily, I caught the error soon enough that it didn't kill the $700 drum! In a drag-racing application, you don't need the Second gear deceleration and you omit the band.

The bottom line: If you get custom parts that are very specific to your needs and you don't get any documentation from the manufacturer, take the time and give them a call. I know I will next time.

Q: I'm a longtime subscriber, currently building my latest and greatest, and I need some engine advice. I purchased a GM LQ9 engine GM PN 89018179 to put in my '66 Chevelle hardtop with a Tremec TKO-600 trans with 0.64 overdrive. I'll be using full-length headers (Edelbrock stepped), 21/2-inch duals with an X-pipe. The car will have power steering and A/C with the GM Corvette pulley system. It will be for street use only, so what mods do I need to do to the engine to get an honest 340 rwhp and 350 rear wheel torque? From what I've read I believe I will only need a mild cam swap, something along the line of the LS6 cam. I am looking for a setup that gives me some low-end torque with good street manners yet has a nice, noticeable idle to it. I plan on topping the engine off with the FAST EZ EFI. What carb intake would you recommend? I think I have only two choices: the Edelbrock dual-plane or the single-plane from GM. Finally, does this engine have a 58X? Oh, and part numbers that would be great.
Mark Shirley
Overland Park, KS

A: What an awesome swap. Your Chevelle will be a kick in the pants to drive with the torquey LQ9 Gen III 6.0L and the Tremec manual trans. Achieving your rear-wheel horsepower goal will be very easy with your base engine. We just want to make sure it'll have the street manners you're looking for.

You mentioned the LS6 camshaft as a possibility for a cam upgrade. This would be perfect for the street manners and power accessories load that will be on the engine at idle. The only issue is that you will have a very mild (think stock) idle quality. The '02-04 LS6 camshaft produced 405 hp in those years. The camshaft specs out at 204/218 duration at 0.050-inch tappet lift, 0.550/0.550-inch max lift, and is ground on a 117.5 separation angle. Not only is the camshaft ground with very wide centers, the inlet centerline is installed in the engine at 120, which is very retarded. The wide separation angle gives you great idle quality but has very little overlap. Also, with the centers this wide you have a very broad torque curve. Now, if you're looking for the Saturday night hamburger stand idle quality with outstanding torque and power, check out the Comp Cams 275THR9 Thumpr. This cam specs out at 219/233 degrees duration at 0.050 inch tappet lift, 0.553/0.536-inch max lift, ground on a 109 separation angle, and installed at 103 degrees intake centerline. This camshaft will give you outstanding midrange torque in your LQ9 with an aggressive idle. This will work well with your manual trans car, and work with the EZ EFI you wish to use.

As for the intake, we recommend the Edelbrock Performer RPM. The dual-plane design will give you more midrange torque over the single-plane design. The open-plenum, single-plane will make more peak horsepower, but it sounds like you're looking for a great driver. Pick up a PN 7118 manifold and timing module kit, which includes the manifold and an MSD timing module and harness for the 24X-based Gen III LQ9 engine you're using. This timing module is a standalone unit with six preprogrammed spark curves, a rev limiter, and a two-step.

Finally, the EZ EFI is the neatest thing since sliced bread. The quick-learning fuel-tuning capabilities of this system are impressive. Since you are putting this into an early Chevelle we'd recommend going with the master kit PN 30227-KIT, which comes with everything you need: the ECU, wideband O2 sensor, wiring harness, fuel injectors, fuel pump kit, control relays, and the innovative 4150 throttle body. This will give you the best rounded performance and fuel economy out of your late-model-powered muscle car.

Shoot us come pictures of your Chevelle when you're done-we'd love to see your finished product. Enjoy the power and driveability of your Gen III.

Tuning In The 21st Century
Q: I read your column in the Jan. '10 issue with great interest and have a question. What procedure would you use with a UEGO to tune a street engine without going to a strip?
Bob Fuertinger
Via email

A: As always, we would never recommend or condone breaking any traffic laws or speed limits. Safety must be our first concern. That said, the wideband O2 sensor can be used for tuning on the street with no problems. Let's figure out some creative ways to get to WOT!

Before you perform any power tuning, make sure you tune your part-throttle fuel mixture in the 14.7:1 range. This is where the engine converts fuel the most efficiently for emissions and is very close to best fuel economy. In some engines you can even run the engine slightly leaner than 14.7 and still retain good performance and driveability to pick up a little more mileage.

Now for the fun stuff. You do need to pass cars on the freeway, don't you? Freeway on-ramps are perfect places to run the car at WOT in Second. Obviously, do this in a safe manner; we're talking straight on-ramps with a buddy reading the O2 sensor. As the driver, you need to focus on the road and the traffic around you. A nice power sweep in Second will give you all the readings you need to fuel the car accurately.

Once you have worked out your jetting, we're sure there will be times that you may forget about the speed limits. This will give you an opportunity to get different readings and different rpm and load points. The bottom line: Be careful!

Need Some 5.3l Beans
Q: I have been reading your magazine for a few years and love all the new tech for classic Chevrolet metal! But my question is about something a little newer. I have a '99 extended-cab Silverado with the 5.3L Vortec and an auto trans in it. It has a complete K&N cold-air kit, an after-cat dual exhaust, and a set of Kuhmo Road Ventures (285/75R16). I drive my pickup every day, and while the performance is decent for a 2.5-ton vehicle, I'm not satisfied. I've thought about possibly adding a blower or turbo, but I can't seem to find a lot of resources on how much power I can safely make without rebuilding the motor. The truck will see some track time, mostly just for fun once or twice a year. I need it to be completely reliable, as it is used to tow and haul on occasion. Thanks for any advice you have and keep up the good work!
Trevor Heinen
Hillsboro, ND

A: I spent quite a bit of time with an '00 standard-cab shortbed truck that was owned by a good friend of mine. This truck was used on many Hot Rod Power Tours with a K&N intake, cat-back exhaust, tire and wheels, and suspension. He got bored with the power so we installed a MagnaCharger supercharger kit and beat it within inches of its life!

The MagnaCharger kit uses an OE-based Eaton supercharger and an integral air-to-water intercooler. These packages are original equipment quality and durability. Can you find a higher output system? Probably. However, we don't think you can beat their durability. Check out the Radix Intercooled Supercharger system PN 1-12-60-001. This kit features a 60ci Roots-type supercharger with integral bypass valve, and a fully assembled inlet manifold with injectors, fuel rails, and intercooler. It also comes with a handheld flash programmer to install the supercharger tune right into your PCM that reflashes the factory ECU, including the spark and fuel calibration, transmission shift points, line pressure, and torque converter strategies are optimized to manage increased torque, horsepower, and mileage. This system will add 120 hp and 120 lb-ft of torque to your base 5.3L. This will wake up the performance of your truck and give you the towing capacity you're looking for. The best thing is that it won't leave you stranded on the side of the road.

So like we said, you can buy more power, but will it get you home. Look at other options, but we think you will be happy with the MagnaCharger.

Q: What is the reference plane for measuring valve angle? I assume (I know that's dangerous), it's the horizontal axis. Is 7 degrees flatter than 23 degrees? I can't remember seeing you define this either in print or via an illustration. Looking at a picture of an assembled engine, however, doesn't back my assumption up. If you measure from the vertical axis, wouldn't 7 be steeper than 23? Is this measurement made with the head not mounted but on a surface table?
Bill Bodell
Farr West, UT

A: Now you've got us confused! Reference plane from the tangent from the vertical axis? The easiest way to put valve angle into perspective, at zero angle, the head of the valve is flat to the piston head (or deck surface of the block or head). As you roll the valve toward the intake side of the engine, you are increasing the angle of the valve in relation to the piston head or deck. A 23-degree valve angle head will have the valve head angled from the piston head 23 degrees toward the intake. Now, let's shift gears for a moment. A big-block head has two angles based on the intake and exhaust and the amount of canted angle off on the crankshaft centerline. For instance, the intake valve on a Edelbrock RPM Xtreme big-block cylinder head has the intake valve rolled to the intake side 24.5 degrees, and is 4.4 degrees off of the crankshaft centerline. The exhaust valve is rolled 15.5 degrees toward the intake side, and 4.2 degrees off crankshaft centerline. These canted valve angles allow for larger valves in a smaller bore size than a standard wedge head.

Hope this clears up your questions about valve angles. We find the easiest way to keep the valve angles straight is to go off the head of the piston. Keep this in mind when referencing valve angles.

Lash Games
Q: A few years ago there was an article written on how to simply adjust valves on a newly rebuilt engine. It started with the No. 1 cylinder and it had you work your way around by rotating the engine manually a few degrees to set the valves on the different cylinders. I have lost the magazine so my first thought was you-can you help me? Thanks and keep up the good work.
Fred Evenson
Bakersfield, CA

A: Adjusting the valves has been covered by every magazine at some point. Also, every camshaft manufacturer lists a procedure on its website. Let's take a look at my favorite method and maybe a couple of tricks to ensure that you don't have those valve covers back off your fresh, clean engine.

There are many methods for adjusting the valves with hydraulic lifters. In some manuals, you will find that you can set the engine to top dead center on cylinder No. 1 and adjust four of the cylinders. Then you rotate the engine 180 degrees and adjust all the other cylinders. This method will work on a totally stock camshaft with very little duration. The bottom line is that you want to adjust the valves of any given engine when the tappet is on the base circle of the camshaft, preferably when it's directly opposite the nose of the lobe. The best method we know of to achieve this is the Intake Opening/Exhaust Closing method. What this means is that on any given cylinder you will adjust the exhaust valve lash when the intake is just starting to open on that cylinder. Then you would adjust the intake valve lash when the exhaust valve is just closing. Of course, this is with you turning the engine in its natural rotation.

As for the amount of preload to put on a new tappet with no oil is a little tricky. You will need to do this by feel, and the easiest way is to slowly rotate the pushrod with your fingers and tighten the rocker adjusting nut until you take up all the clearance and feel a slight drag to the rotation. Loosen and tighten across this point a couple of times to ensure you have found zero lash. Then you can preload the lifter to a specified amount. The factory setting is one full turn past zero lash. Plunger travel in the tappets varies by manufacturer, but GM with its factory tappets, the one-turn setting puts the plunger in its midpoint of travel. This gives the most leeway for wear and temperature variations that affect the lifter preload. Now, for performance use we'd prefer the tappet to have less preload. You wish to run less preload because when the engine gets up at high engine speeds, the lifter may try to pump up and keep the valves from seating! You will find that most performance camshaft companies will recommend adjusting the valves to a half turn preload. In some very high rpm applications, I've run the pre-load down to as little as an eighth to a quarter turn. You must be very accurate in your adjustment with this type of setting-and willing to adjust the valves frequently. The best compromise is to adjust the valves to half turn preload.

We hope this gives you all some clear guidelines for adjusting your hydraulic valves. This method can be used on any engine big or small, or cylinder count. Also, this is the same method you will want to use for finding the adjustment point on solid lifters. Lash on!

Aussie Racer
Q: First of all, thanks for your magazine. It was the inspiration for the '83 Holden Commodore I'm currently building. I built a 383 with a 3.75-inch stroke, 5.7-inch rods, 10.8:1 compression, Victor Jr. 64cc heads, and 750-cfm Holley HP carb. The cam is a solid flat-tappet with 0.518/0.536-inch max lift and 290/298 duration. Here in Australia, 98-octane fuel is premium and available everywhere. What ignition timing would you recommend? Also, I'm running MSD everything, including the 6AL and distributor with vacuum advance. Do you think you could shoot me an output estimate? Thanks for even reading this.
Jason Lacey
Victoria, Australia

A: Glad to read neat stories about our gearhead friends from Down Under. You guys have some very cool cars to mod, and with 98-octane at the pumps, you can get very entertaining with your engine builds. Thanks for the photos-love the yellow paint!

With the good fuel you have, we'd start at 36-38 degrees total timing without the vacuum advance connected. After setting the timing, connect the vacuum advance to a ported vacuum source on the Holley carb. Limit the vacuum advance to 10 degrees. This will get you right in the ballpark for spark advance.

As for power, from the photos it looks like you're running a Victor Jr. single-plane intake. The headers appear to be in the 15/8-inch primary range. With these cylinder heads and the generic cam specs you supplied, you may be in the 480-500 hp range. We'd put the torque in the 450-470 lb-ft range and should push your Commodore nicely. The Commodore looks to be a unibody construction and looks rather light, so the 383 should give you quite a thrill ride.

Body Pains
Q: I need help putting my '69 Camaro back together, since I didn't take it apart. I need an assembly breakdown of the steering column and another for under the dash (hoses, wires, cables, vents). I have a factory assembly manual, which has neither of these. I'm hoping you have an answer.
Via email

A: Putting a basket case back together can really get on your nerves, even if you've been working on them since they were built. The factory assembly manual you have gives you general specifications that GM used as the car went down the assembly line (e.g., measurements for moldings, emblems, body gaps), but to get the hard-core info you're looking for, you need a Fisher Body Manual for '69 Chevrolet passenger cars. The GM Fisher Body Service and Construction Manuals are very helpful when doing a total rebuild, showing nearly everything from the upholstery styles to the dash and door assemblies. They also include adjustment and installation procedures-this is going to be your best source of information for assembling your Camaro. Check with Greg's Automotive for the Fisher Body Manual, PN 69FB. They are very reasonably priced at $25 and can be ordered online.

Dual 4 Pots
Q: I recently built a 383 stroker motor with a 9.4:1 compression ratio. It consists of the following: a 3.750-inch stroke cast steel crank with 5.700-inch CNC forged I-beam rods, forged flat-top pistons, and AFR 195cc heads. Up top, I'm running an RPM Air-Gap manifold with a Holley 750-cfm vacuum secondary carb. The camshaft is a Comp hydraulic roller with a lift of 0.502 inch intake and 0.520 inch on the exhaust. At 0.050 inch tappet lift it has duration of 224/236. This combination on an engine dyno turns out 491 hp at 6,000 rpm and 489 lb-ft of torque at 4,600 rpm. I would really like to use a dual-carb setup just for something different, plus they look way cool-does it run off just one carb at cruise or is it working off both? Edelbrock offers a kit with 600-cfm carbs. I just wonder if this would be too much carburetion for this engine combination? Thanks in advance for your help, Great mag!
Lon Ketchum
Via email

A: Dual quads would be way cool on your 383. Edelbrock offers two kits for small-block Chevys. The original C-26 Dual Quad manifold is still around after some four decades! Several years ago, Edelbrock stepped up to support the vintage market by producing an RPM Air-Gap Dual Quad version, which features the distinctive Air-Gap design to give you cool, dense intake charges, and larger and taller runners for great airflow. The RPM Dual Quad is 15/8-inch taller at the carb flange over the C-26, which could cause hood clearance issues. This manifold and dual quad setup will not perform as well as the single four-barrel RPM Air-Gap, but I don't think that's what you're about. With the new RPM design you should see minimal power losses.

Edelbrock offers a complete RPM Dual Quad manifold and carburetor kit under PN 2025. This package features their Thunder Series AVS 500-cfm carbs, progressive throttle linkage, fuel lines, and intake gaskets. These 500-cfm carburetors will be perfect for your application. The secondaries on these carbs feature an air valve that tailors the airflow to the demand of the engine. The high-tech progressive linkage offered can be set up for either progressive or 1:1 ratios. In the progressive mode, the rear carburetor is for slow-speed driving (up to 20 degrees of throttle opening). Past that point, it brings in the front carb as well, until you reach wide-open throttle. If you're looking for a more aggressive throttle response you can set the linkage to 1:1, which opens the carbs in unison.

Check with Edelbrock for more information. Have fun-your 383 will have some real authority with dual quads atop it.

LS Monte
Q: I'm in college and your magazine is the only thing I insist on reading cover to cover. A few years ago I bought an '85 Monte Carlo CL from a junkyard and have been converting it into a purely dragstrip car. I have a good Turbo 350 transmission and 12-bolt GM rearend (I need to remove the posi and install a full locker). The engine is where I fall short.

Right now, I have a borrowed 305ci, Summit cam and lifters, and a set of 305 heads with larger valves installed. I am in the hunt for more power and since I don't own the motor, I'm not going to tear it apart and rebuild it. I have been looking around for information on swapping a LS-series motor in. With the factory roller valvetrain and stout bottom end, these are great power engines for the money. I want to steer away from EFI-too much headache for tuning. Could you guys help me out with a very tight-budgeted swap of a LS motor into my Monte? Also, could I get away with swapping out cams and not the roller lifters? My budget isn't much to work with, but I've got to go faster.
Alex Tipton
Chester, NE

A: I know we all have a need for speed, but focus on your education right now. Yes, you can work toward swapping in a new engine, and this is a perfect way. Get all your ducks in a row and then pull the trigger. Swapping in an LS-based engine will be the best upgrade you'll ever do to your Monte. Doing it on the cheap may be a little difficult. If you're willing to make some of your swap components, it can save you a ton of money. However, you need the space and facilities to do this. I'll try to be gentle choosing the parts to make your speed fix real.

First, you need to find an affordable engine. LS1s are very plentiful for very reasonable prices. We would look for either an LQ4 or an LQ9 6.0L truck engine. These had a cast-iron block with aluminum heads. The blocks are about 50 pounds heavier than the aluminum LS blocks, but the engines are cheaper and have more displacement. Also, it gives you a 4.00-inch bore for upgrades in the future. You can swap out for a higher performance hydraulic-roller camshaft without replacing the factory roller tappets. You'll need to install the appropriate valvesprings to match the lift curve of your new stick.

Next, you need to get the engine in your car. For a very nice swap package, check out BRP Hot Rods for very well-engineered engine mounts, trans crossmembers, and header packages to drop your new LS engine right into your Monte. BRP also offers what it calls the LH8 oil pan package, which consists of an OEM pan, oil pump pickup, and correct windage tray. Again, this works with the swap package for a no-drama install.

Edelbrock offers dual-plane Performer, Victor Jr, and Super Victor intake manifolds for the LS engines based on your cylinder heads of choice, satisfying your needs from idle to 8,000 rpm. Milodon has a complete line of LS swap oil pans, from the street swap pan to its racing pan for early to late Chevy iron. These pans are shallower than stock at a 6-inch sump; however, they have a 7-quart capacity.

To give you the spark you need, check with MSD for its stand-alone 6LS ignition system and harness. This makes the spark side of your swap a snap. The controller allows you to map a timing advance curve with MSD's easy-to-use Pro-Data+ software. Other programmable features include a two-step rev limiter, a vacuum advance curve for cruising economy, and even a step retard in case you want to add a little nitrous to the mix. MSD offers two systems that will support either the 24X or 58X crankshaft reluctor wheels.

Last but not least, to use an LS engine with an early (non-LS) transmission, you'll need to run a flexplate spacer. The crankshaft face is 0.400-inch farther forward in relationship to the bellhousing surface of the block. GM Performance Parts makes a spacer sold under PN 12563532, and you need six new flexplate bolts (PN 12563533). This will space the flexplate back to the proper dimension to engage properly with your torque converter. Good luck with your Monte upgrade.

Technical questions for Kevin McClelland can be sent to him at



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