June 2011 Chevy High Performance Q&A

Love It When a Plan Comes Together, Part II

Kevin McClelland May 3, 2011 0 Comment(s)
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Last month I gave a recap of getting my Super Gas roadster back on the track. I plan on finishing my column on Saturday nights--between two-day races more often. Sunday went well, with us going seven rounds and winning Bracket 1 at the PSCA/Edelbrock World Finals. To top off a great weekend, the car ran 8.47 at 156.60 mph in the semis en route to the finals. The only thing that could have made it better would have been Daniel joining me in the winner’s circle photos with the wagon. Unfortunately, he fell during the fifth round of seven. After the race, we immediately started preparing the cars for the upcoming Vegas Bracket Nationals.

1106chp 01 O  June 2011 Chevy High Performance Q A Chevrolet 2/2

Our friend Ian Smith flew in from Australia to join us at the Vegas race. We had never met in person and had only communicated over the Internet and telephone. Ian and his son, Warren, are Super Gas racers in Australia, and Warren won the Australian World Championship several years ago. Back in 1998, the NHRA asked if I would help a fellow Super Gas racer in Australia and teach them the ins and outs of throttle stop racing. Ian was the chairman of the Australian NHRA and retired to start racing with his son. I was honored to be asked to help and gladly gave them my advice on how to pull your hair out Super Gas racing!

Ian wanted to come up to the United States to see how a big-buck bracket race was run to take that knowledge back Down Under to start, as they call it, Dial Your Own racing for good money. Most of their racing is class racing, and Super Gas is at the Sportsman level. There are bracket events and interest is building. Here in the States it’s the largest motorsport with participants from all over the world. On any given weekend, more people are bracket racing than any other form of motorsport.

Ian got a full dose of what Las Vegas had to offer. Mainly it was cold temperatures and nasty winds, giving us a very slick racing surface. The track was great on the starting line, but down the track it got treacherous. Sadly, over the course of three days of racing we lost six cars, five of them dragsters. Every crash resulted from trying to tighten up the finish line (eighth-mile) by getting on the brakes. With all my years of experience I found myself dead sideways in the lights when I hit the brakes and went for the slide of my life at 127 mph. No one in my camp thought that was fun--especially my wife, Lisa.

Ian is already back home, safe and sound, and I’m sure that his fellow promoters in Australia will look at him oddly when he explains what we do at these races. Hopefully, one day I can return the favor and drive a car at one of their races; it would be an honor and a lot of fun. Until next month, be safe.

Arm Strong

Q: I have owned an original ’69 Z/28 since 1974. I have rebuilt, replaced, and restored almost everything on the car except the steering gearbox. The steering is manual and seems to have a lot of play in the system now. Is there an adjustment I can make to eliminate the 4-5 inches of play in the steering wheel? Did the ’69 Z/28 come with a different steering gearbox than other Camaros? If so, how can I get a replacement for the steering gear? Can the original steering gearbox be rebuilt? What do you recommend?

The car runs like new, but the sloppy steering makes it feel like you’re herding goats.

Bob Moberly
Boyce, VA

A: Boy, do ’69 Z/28s bring back some memories! The ’67-69 Z/28s were equipped with a quick-ratio manual steering gearbox with a ratio of 16:1, which, with the addition of aftermarket wheels and tires, made them almost impossible to park.

On top of your steering gear there is an aluminum cover that is retained by 43/8-inch screws, and right in the middle of this cover is a nut and a slotted adjuster. This adjuster moves the relationship to the worm and sector gear in the steering box. You can try to loosen and turn the adjuster clockwise to engage the gears tighter together. The only problem with this is when you turn the wheel either left or right off center the gears will bind. You have picked up slop on center because of wear. Finding another 16:1 quick-ratio box is virtually impossible these days. However, Lee Manufacturing has the parts and know-how to rebuild your factory box correctly. It’ll cost a few bucks because the parts are becoming very rare, but it can be done.

Source: lee-powersteering.com

Gen III meets Gen IV

Q: Chevy High Performance articles have helped me install an Impala SS LT1 out of a ’96 into an ’88 Chevy Stepside short-box pickup. I have used a number of the advertisers for parts as well as information.

I have just purchased an L92, 6.2L engine with only 40,000 miles on it out of a Cadillac Escalade. I have also purchased the ’08 Corvette cam and complete LS3 intake assembly because the L76 is no longer available. When I bought the engine, I also received the ECM and wire harness.

Currently, I’m in the process of acquiring an ’87 Camaro, and I’d like to know a couple of things about the swap. How would I go about using the electronic throttle body? Is the current TPI L98 350ci fuel pump usable or will I have to upgrade to a better in-tank pump? I know the LS3 is a returnless fuel system and the current system is a return fuel system, so any suggestions in this matter would be helpful. Will I need to buy an adjustable tranny crossmember even though I am using the 700-R4/4L60 automatic that comes with the car? Who can I get to reprogram the ECM for the new cam and intake with throttle body and injectors from the LS3, or can the original injectors be used from the Escalade?

I have gone through all of my back issues for LS swap articles, in particular the Nov. ’03 "Transplant Triumph." It explains a lot of the issues that I will come across. I’ll be doing most of the work myself and any information that you can help me out with would be greatly appreciated.

Shawn Clenighan
Windsor, ON, Canada

A: Third-generation Camaros are a fun platform to play with. In 1992, the last year of production, GM built what it called the Heritage Edition. It was basically an RS Camaro with a Corvette L98 and ZF six-speed. These were factory-built toys that had the 1LE brakes and suspension package. When we were playing with cars for Chevrolet, we got one before it was sent off to the crusher (no VIN, you know). We installed a highly modified LT1, which cranked out 440 hp at the time. This car was an absolute blast to drive and ran 12.30s in the quarter on 87-octane gas. The magazine editors beat this car to an inch of its life, but they couldn’t kill it. If we only could have saved it from the crusher!

Now we have LS-based engines to swap into all the early platforms. The 6.2L L92 will make this car a killer driver and scary fast. Let’s start at the top on your swap. As for the electronic throttle body, we’d suggest installing the throttle pedal assembly from the Escalade into your Camaro. The fuel pump from the L98 won’t keep up with your L92 in either delivery or pressure needed. The L98 ran on a regulated fuel pressure of 40 psi, and the L92 requires 58 psi. The L98, on a good day, produced 230 hp, and your L92 should easily double that. We recommend a Bosch electric fuel pump; the 044 pump is a quality OEM pump that was used on 930 Turbo Porsches and some of the Turbo-equipped Volvos. This pump will give you trouble-free service either in the tank or used as an inline pump with the production Camaro pump feeding it. Check with Jay Racing, which offers both stock Bosch and blueprinted 044 pumps for very high-powered application. Jay also has intake filter socks, AN fittings, and other useful hardware to make a very clean installation.

To finish off your fuel system you will need to install an inline fuel pressure regulator, which will return fuel back to the tank. You can use many of the aftermarket regulators on the market, or use the factory ACDelco filter/regulator used on ’99-03 C5 Corvettes. This is a very inexpensive part that is mounted back by the fuel tank and directly bypasses the fuel into the tank. Mount it right in front of the Bosch pump and run the return into the top of the tank. Make sure you run an adequate return line back to the tank. The factory Camaro return is only 1/4-inch tube. You’ll want to at least run a 5/16-inch return. If the return is a restriction, the regulator will not be able to control the fuel pressure at idle. You can pick up the combo filter/regulator under GM PN 10299146, or under the ACDelco PN GF822.

Finally, stick with the new LS3 injectors. These are 42-lb/hr injectors that were used on the LS7s before their life on the new LS3. Changing the injector size in the calibration is a simple code change. As for calibration, look up Mark McPhail at McPhail Performance. We worked with McPhail for years when he was an engineer for GMPP. He has years of calibration experience and his depth of engine swap information is invaluable.

You will want to stick with the factory transmission crossmember. The trans is going to need to stay in the stock location for the rearend torque arm to connect correctly. To use the original 700-R4 trans you will need to run the crankshaft spacer offered by GM under PN 12563532 and six bolts (PN 12563533). This spacer is bolted to the face of the flexplate to register the snout of the torque converter. You’ll also need to run approximately 0.400-inch-thick spacers between the flexplate and the torque converter lugs. The crankshaft flange on the Gen III/IV engines is 0.400-inch farther forward in relationship to the bellhousing flange. To use any of the early transmissions like Powerglides, TH350s, TH400s, and any of the overdrives, you need to run this crank spacer.

Let us know how your swap turns out. You should have a really nice driving package when you’re done. You will also be a couple of pounds lighter on the front end, which will help the handling. Installing the Gen IV engine will wake up your Camaro. Enjoy.

Sources: mcphailperformance.com, jayracing.com, gmperformanceparts.com

Go Large

Q: I have a ’72 Chevelle SS with a 355 ci. My rotating assembly is basically stock except for a decent set of forged pistons. For heads I have the 23-degree Trick Flow aluminum with 195cc intake and 64cc combustion chambers. I want to build a stroker engine but would like to keep my current heads to save some money. Any suggestions on what’s too big for these heads would be appreciated. This car is just a street cruiser that needs more grunt.

Mike Lewis
Dayton, OH

A: We would have no problem using 195cc inlet port heads on 400-plus cubic-inch engines. You said you’re looking for grunt to move your heavy Chevy. Going with a 3.75 stroke keeps everything simple. However, we would look to a new block to get the bore out of 4.125 inches. A 406 would be a nice addition to your displacement. The 195cc heads will make great midrange torque, and when it starts running out of steam from the stroke, the heads will run out of air. Good luck and enjoy your engine build.

Used Corvette Parts?

Q: Hello CHP! I have a cooling issue in my ’95 Chevy S-10. It just so happens that I’ve committed the greatest sin of all with this truck and dropped a small-block 350 in it with a TH400 backing it up. The 350 has a 0.512-inch lift hydraulic flat-tappet cam advance of 4 degrees, an Edelbrock Quadrajet atop a 1-inch spacer, and a cast-iron intake. MSD Street Fire HEI distributor and 8.5mm super conductor wires handle the ignition. The 350 exhales through Patriot conversion headers to 2.5-inch Flowmaster 40s. The TH400 has a B&M 3,500-stall converter, shift kit, and an adjustable-vacuum canister on the housing. The trans is still fully automatic, and shifts seem a little delayed after I shift up. There is a stock replacement Corvette radiator trying to keep it cool, and it still likes to climb up toward 250 degrees. I can never seem to keep it cool enough to get it streetworthy let alone track ready. Any advice to help my truck see the street?

Kory A. Schultz
Two Rivers, WI

A: Kory, there are many greater sins. We’re going to take a shot here; for the coolant temperatures to climb to the 250 range there are few possible culprits. Yes, there could be cracks in the heads or block, but we think it may be something simpler. You said you’re using a Corvette stock replacement radiator. By chance, are you using one of the nice aluminum water pumps off a Corvette donor car? The pumps are very nice as they are the short water pump design giving you more accessory drive and radiator room in front of your small-block, but they’re designed to run with a serpentine drive setup and in a reverse rotation from the crankshaft clockwise rotation looking at the front of the engine. If this is the case, your water pump is moving next to nothing. Make sure you’re running the correct rotation water pump for the front accessory drive system.

Next, you didn’t go into what type of fans you’re running. Climbing to 250 in quick fashion isn’t going to be stopped by a fan. You could drive the truck down the freeway at 60 mph, and the airflow through the grille should keep the engine cool if everything is correct with the engine and water flow. Make sure how you have the radiator mounted keeps the hot air in the engine bay, and cool fresh air in front of the radiator. If the hot used air has a chance to bleed in front of the radiator, the temps will continue to climb.

As for your transmission shifting, it’s not uncommon that a manual shift may be slightly delayed. You didn’t say if the shifts are firm when they occur. If the shift is solid and firm we wouldn’t worry about the slight delay in shifting. You can always compensate when you shift the truck to hit your rpm target.

Couldn’t Have Said it Better!

Q: Thank you and CHP for keeping us up on the latest this great hobby has to offer as well as protecting it for our children. Just because we trade gas for horsepower doesn’t mean destroying our sport would make any difference in the national usage of fuel or creation of pollution, but it would drive thousands more average income, but exceptional, Americans out of work. The trade-off would not be worth it. More gas is probably used driving to football games, so where does it all stop?

My son and I built a ’73 Camaro and have a current best time of 12.69 in the quarter-mile. We are running P255R50-16 Mickey Thompson Drag Radials on heavy steel rims. We bought some much lighter alloy rims in 15x8 with a 4.5-inch backspace. I am focusing on 275R50 or 275R60 drag radials. Which will give us the best bang for the buck, the taller 60 series or the wider 50 series? Or do you have a better pick based on the following information?

The car is close to stock weight and has a stage three TH350 transmission with a 3,000-stall converter, 8.5-inch 10-bolt with 3:73:1 Richmond gears, factory Positraction, and West Coast Machine lift bars. The motor is a BP 383 with 405 hp and 440 lb-ft of torque. This is all topped with a 770-cfm Street Avenger, DUI distributor, and COMP Pro Magnum roller rockers. The long-tube 5/8 headers had open cutouts during the best time and isolated cold air intake on the cowl-induction hood.

Since this is not a forged motor, and we want to drive home from the track, we want to limit the revs to fewer than 6,000 rpm. If you can expand on your answer and give us your estimated potential for the car, what you would do next? Also, what’s the best tire selection?

Walter Drysdale Via email

A: Thank you for a very good analogy on the fuel and pollution issue. The SEMA Action Network is a national partnership of car clubs and individual enthusiasts (like you) who work together to impact legislation that affects car and truck hobbyists of all kinds. SAN is a very good way to make a difference. Speaking with Jim McFarland, one of the writers of the SAN article (Dec. ’10), he tells us that more than 6,000 people joined the cause after the story ran. Writing to our elected officials, letting them know that we are not going to stand for them taking our sport and livelihood away, is one of the very strongest tools we have. Check out the latest movement that SEMA is supporting to keep our hobby alive on the website and link to the SEMA Action Network page.

Normally, we’d recommend going with the taller 60-series tire to gain more sidewall in the tire. However, with your 3.73 gears, go for the shorter tire to gain a gearing advantage; we’re going to assume you’re having traction issues with your current combination. The 12.69 e.t. isn’t all bad for a dual-purpose street/drag car. We wish you would have given a few more pieces of information, such as your quarter-mile speed, and we’re going to guess that your 60-foot is in the 1.80 range.

After figuring out what a BP 383 was, we found that this is a crate small-block offered by Summit Racing. It’s dressed with a Professional Products dual-plane similar to the Edelbrock RPM Air-Gap. The engine is topped with iron Vortecs with 2.02/1.60-inch valves installed in them. Our experience is that stock 1.94/1.50-inch valves with the factory valvejob are very hard to beat. Also, Summit doesn’t offer up the camshaft specs for this engine. We guess it’s somewhere in the mid 220-duration range at 0.050-inch lift, based on the power curve of the engine. Our next step would be to install a set of aftermarket aluminum cylinder heads in the 180-190cc range. Also, mill the heads to reduce the combustion chamber size down from 64 cc to raise the compression over the current build of 9.5:1. With a cylinder head and compression change, your power could go from the 405 to the 440 range and the torque up around 460 lb-ft. This would give you several more tenths on the track without changing the manners of the engine.

I hope this helps with a direction for your son’s Camaro. Keep instilling the proper values into your son and his friends. Fewer of us are passing our knowledge down to the young people. Also, please check out the SEMA Action Network and join. It is free and it helps keep our passion alive.

Source: semasan.com, summitracing.com

When Mice Attack

Q: I have a ’98 Z28 with a manual trans, and completely stock. A rodent found its way into my garage and chewed through a lot of wires, many located between the left cylinder bank and the firewall. I’ve been trying to figure out how to pull this wire bundle up through the engine bay so that I can splice wires together and make everything functional again. I can’t get my hand down there to try to free things up. I’m thinking that moving the engine down and forward might give me enough room to get to the damaged section of the wiring harness.

Do you think it would be possible to shift the engine and trans enough to give myself a few more inches without going through the whole engine removal procedure?

Steve Burger
Amado, AZ

A: Mice can be a real problem when it comes to eating wires and building nests in the most unwanted places. We’ve seen them build complete homes over the winter in the heater box of early Chevys. And back in 2003 they ate through the injector wires on a friend’s brand-new Z06 Corvette. The local Chevy dealer didn’t have any humor about this and wanted to charge my friend $2,500 for a complete new engine harness!

Moving the engine forward and down to extract the harness sounds like a great plan. Removing the engine from fourth-generation Camaros can be a real pain if you do not have a vehicle rack to work with. The proper way to remove the engine in these cars is from the bottom. You can sneak the engine out the top, but it requires you to trim on the firewall lip and hold your mouth just right to get it out. Disconnecting the radiator lines, removing the radiator, pulling the driveshaft, removing the shifter tower, and removing the side engine mounts and cups should allow you to drop the engine several inches and move it forward a couple also. You will also need to remove the exhaust crossover pipe from the exhaust manifolds. Support the engine with an engine hoist and place a floor jack under the transmission to roll it forward.

If only mice didn’t like the taste of the wire insulation! CHP

Technical questions for Kevin McClelland can be sent to him at chevyhi@sorc.com.

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