June 2012 Chevy High Performance Q&A

Chain Reactions

Kevin McClelland Apr 23, 2012 0 Comment(s)
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Have you ever noticed the number of parts that can be taken out in one shot when we break our hot rods? I have a great example of this. I was racing my roadster at one of our local races here in Fontana, California (luckily, I was close to home). I made my first time run of the day and rolled up to our pits and shut everything off, cooled the car, recorded the weather, and downloaded my data logger. Everything looked great, and we went up to make a run with Daniel’s wagon. I went back to my roadster when they called us for our second-time run. I hopped into the car and fired the engine. When it started it sounded like there were marbles in a coffee can being rattled around in the cockpit. I immediately killed the engine and thought to myself, did it have oil pressure? The RacePak dash in my car has warning lights and nothing lit up. I cranked the car and the pressure was right there. I jacked the car up and looked to the flexplate, hoping to find it cracked or the converter bolts loosened up. No luck. Next, I fired the car again and put the car in First gear. The noise was immediately gone. Well, like I said I was glad that we were close to home since I didn’t have a spare transmission.

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This past weekend I finally got a chance to pull the transmission and check out the damage. I had assumed that the planetary gearset had given up. This Powerglide trans had factory 1.76 planetary, with a 4130 carrier and output shaft, which is good for the 850hp range. I’m right about there with my pump-gas 524, and I was a little over 100 runs since I rebuilt the car and had around 250 passes on the transmission. After tearing it down, I found an unfortunate mess of broken components that were mostly self-inflected. Yes, the planetary gearset had lost two teeth off the sun gear, but I also found that the Torrington thrust washer that lives in the middle of the planetary had lost sections of its hardened race. This was from excessive endplay that hammered the thrust every time you lifted and got back on the throttle; this is nothing you would notice while driving the car. These hardened steel pieces had been running through the planetary gearset and made the teeth fail. If the endplay had been correct I would probably still be running today. Not only did the endplay kill the planets, it destroyed the front pump in the trans and the sealing rings, which transfer the fluid pressure to apply high gear. The endplay was allowing the direct drum to move back and forth, loading these rings and wearing out the sealing ring grooves in the front pump. Finally, the input shaft has a small spud that engages with a bushing in the output shaft. Because of the excessive endplay, the input and output shaft were being loaded and wore the spud of my 300M hardened input shaft. The bottom line to all of this is a ton of money for parts. Luckily, my good friend and racer Jim Galente is helping me out with my rebuild. He owns RaceTrans here in SoCal at www.racetrans.com.

Something as simple as proper setting the endplay killed a ton of good parts. The trans had over 350 runs on it, and everything else looked great. The clutches, bands, and bushings were in perfect shape. I guess what I’m getting at is that it’s all in the details. Keep an eye on everything when you’re assembling your toys to prevent chain reactions.

200-4R Rebuild

First of all I love this magazine; there’s so much good info and tips. I am in the process of making my ’87 Chevy Monte Carlo live once more. This car has been in my family since new, when my mother rolled it off the lot. Being a Canadian car, the stock 305 is being replaced with a 383 with Vortec heads, COMP cam, and an Edelbrock intake and carb. The tranny is where the fun begins, as it’s a 200-4R. I’m having a real hard time finding parts. I have narrowed it down to a few parts to finish, but they don’t seem to be found anywhere. To compound it, if I do find parts they can’t be shipped to Canada. The last parts I need (with original GM part numbers) are 8634853 3/4 pressure two-prong pressure switch, 25524921 and 25524923 speedo gears with 28/27 teeth (I’m still unsure of tire size). Thanks for your help.

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Rod Cooper
Via email

Rod, we’re glad to here that your mom’s Monte is still in the family and about to embark on a new chapter in its life. It’s sad to hear that you’re having difficulty finding components for the 200-4R. Many of our cool performance parts are becoming extinct. These transmissions were discounted for years as mundane underperforming transmissions. The Buick Grand National Turbos took care of that. The performance builders got their hands on them, and they are an outstanding transmission. In many cases they are stronger than the 700-R4. The gear ratios are also more desirable than the 700s. The First gear comes in at 2.74, Second 1.57, Third 1.00, and a steep 0.67 overdrive. The 700-R4’s ratios come in at 3.06, 1.63, 1.00, and 0.78 overdrive. The First gear ratio of the 200 is much more manageable from a traction perspective, and the 0.67 overdrive gives you the ability to run whatever gear you wish and bring the engine speed in line while cruising.

Give our good friend Ken Casey a call at John Elway Chevrolet. If they don’t have the pieces in stock he will find the pieces for you. Also, they will ship into Canada to get your Monte on the road. When you talk to him, ask how his ’67 RS/Z28 is doing. It’s powered by a LT4 383 that is backed up by a T56 six-speed. He only brings it out when the weather is nice, and he wants to scare little old ladies. He’ll get a kick out of you asking. Good luck with your project

Source: elwaydealers.com

Final Wishes

I’m hoping you can answer a question that has had me stumped for many years. Back in the early ’70s, I purchased a stock crate 454/450hp engine from a local speed shop. I drove it on the street for a couple of years. I had to pull the heads off after I dropped a nut down the carb. I found the intakes to be 2.3 inch with closed-chamber square-port heads. I added an 800 Holley double pump, Edelbrock Torker, Engle solid lifter 0.600-inch lift 320-330 duration cam, Accel dual-point distributor, and S&S 2-inch primary headers. This was put in a ’70 SS Nova M21 four-speed with 4.56 12-bolt posi. I got a pair of 28x9 slicks but then my world caved in—with a baby on the way, I lost my job so I had to sell the car. I’ve always been curious as to the horsepower I was making and approximately what my e.t. and speed would have been. I’ve been dwelling on this ever since, as I was never able to build another one. Any info would be greatly appreciated.

Gary Hurd
Via email

Gary, this must have been bugging you all these years. The second-gen Novas were real sleepers. Many people went for these cars over the Camaros for dragstrip duty because of the light weight and the rear overhang of the body that helped the weight transfer.

With your collection of components I would target the horsepower in the 600-pony range with open exhaust. Back in the day there weren’t the performance mufflers available to make good power through capped exhaust. This, coupled with your low rear gears and slicks, should have been able to slip into the low 11s at low 120s. If you had a really good run, the car stuck, and you hit every shift point, it may have tickled very high 10s! These cars were a blast to drive and row through the gears.

Things happen to us in our lives that make us do the responsible thing. Unfortunately, you lost your pride and joy. Hopefully sometime in the future you can relive your Nova passion. They are still available and not too expensive yet. Good luck!

P.S. We’ve all dropped something down the carb. Only real men step up to the plate and admit it!

Air Dyno Lives

Thanks for the great tech. I have a 350-bored 0.060 inches with 4340 crank, H-beam rods, Mahle flat-top forged piston, and the block has been decked to 0. The camshaft is a Crane Cams (PN 118911) mechanical roller with a duration at 0.050 inches tappet life of 252/260, 1.6 rocker arm, at 0.020 inches lash the max lift is 0.652 inches. I have a set of Airflow Research 220cc heads, a Victor Junior intake, Performer RPM nitrous plate, a Holley 750, with 1.75 inch Hedman headers. How much horsepower should I be making on the motor? I know I’m down on compression a little bit and these are big heads for a 360ci engine. I have plans for a 388 with 12.6:1 compression. How much horsepower do you think that would make, and how hard would I have to turn each engine for peak horsepower. I run this engine in a truck and it weighs about 3,200 pounds with a TH350 with 4,000-stall converter and 4.88 gears, with Mickey Thompson 31s. I have not run the engine since the new cam and heads were installed.

John Parker
Via email

Boy, I haven’t officially fired up the Air Dyno in quite a while. Most readers I’m sure know what I’m talking about. The Air Dyno is when I pull power numbers out of thin air. I hope that my numbers are closer than the keyboard dyno operators on the Internet! Just ask anyone on a message board. If you don’t like the numbers I give you, I’m sure that there is someone out there who would give you the numbers that would make you happy!

Luckily, the air dyno should be pretty close; I ran a very similar combination before as a dyno mule. It was an original ’71 LT1 block, pistons, crank, and rods. It had the exact same camshaft that you’re running, flat-tops, Dart 220cc heads, Dart single-plane manifold, 4779 Holley 750-cfm carb, and 13/4- inch headers. We ran this engine on pump gas and it pushed out 540 hp all day long. It would make peak horsepower around 7,200 rpm. I didn’t like taking it that high with an all-stock rotating assembly so I would usually limit the high side of the test to 7,000 rpm. Now, on the torque side of things it was quite weak. It only kicked out 440 to 450 lb-ft and this happened at a high 5,600 rpm; the only thing that this engine had going for it is that it would carry the torque and make good horsepower.

For your high- compression 388, I would think that the power is going to be up about 70 hp for the added cubic inches and compression. This should put you in the 610 range. The peak power rpm should drop slightly too around 7,000 rpm and I would expect the torque to come up nicely into the low 520 range. The torque will be helped by the added inches, but the compression will give the engine more personality.

Hopefully, this has given you the information you need. I don’t know how happy you will be dragging around a truck with this engine. At 3,200 pounds that’s one light truck. At least you have enough gear that you should be able to stay out of the stall most of the time cruising. Have fun with your project.

Source: cranecams.com, airflowresearch.com, edelbrock.com

Can’t Keep a Good Man Down!

Kevin, can you help an old gearhead out? I’m 60 and have had everything from 10-second street cars to a 7-second dragster. I’ve been busting my knuckles since the late ’60s. I’ve stopped drag racing due to a medical condition, and NHRA will not renew my license, so now I’m back playing on the street.

My questions are about my ex-tow vehicle that now serves as my daily driver in the summer months up here in southern Ontario. It’s an ’86 Chevy C10 1/2-ton that came with a 4.3L V-6 and three-speed manual. I built a 511ci big-block (0.060-inch over/4.375-inch stroke), Eagle forged bottom end, forged 10.25:1 slugs, as-cast AFR 305s, Crane hydraulic roller (PN 139631), Edelbrock RPM Air-Gap, with a 750 mechanical secondaries. Holley, headers, and an MSD 6A box with an HEI. I put a TKO 600 behind it with a 12-bolt with 3.73s and 12.50x33 tires. I want to take the drivetrain out and swap it into an ’87 C10 short box that somehow found its way up from Arizona. The ’87 cost me less than it would to fix the rust and dents in the ’86. The ’87 has a TBI 305, air, dual tanks, and was a four-speed manual. I plan to remove all the A/C stuff. How do I get around the computer and still retain all the electrical components? I don’t want to lose the gauges/lights/wipers, and I want to keep the dual tanks functional. I was going to reuse the sending units and alternator from the 305 but what can I disconnect or bypass without causing headaches? Will the in-tank pumps feed my 511? What about the pressure regulator and return line? I have a mechanical pump on the 511. Can I use both (if needed)?

Finally, what does the air dyno make of the combination? Also, I found two pairs of bad lifters (one had a seized roller) and a bad lobe. I spoke with the people at Crane, and they will regrind the cam, so while it’s out I can have it re-ground to other specs. Would you change anything? I’m happy with it now. If anything it has too much low-speed torque. That’s why I went with the 33-inch tire to try to get it to hook somewhat, but now I find it will “buck” at anything under 1,800 rpm in Fifth. Before with the 31-inch tires, I could cruise at 1,400-1,500 in OD all day long. Thanks for your help!

Howard DeSchryver
Via email

As all of us with NHRA racing licenses well know that we have to pass a biannual physical to continue racing. Before I sit down to write next month’s column I have to go in for my physical to continue racing. Every time you go for the physical, you are just waiting for the doc to come in and say something stupid like you can’t race anymore. I feel your pain. At least you’re enjoying yourself with your 1/2 ton of fun. A 511-inch big-block and a TKO 600 gearbox must be a blast. Let’s get that engine swapped into your ’87.

I dug through the Crane master catalog CD and couldn’t find your camshaft part number. Then I checked on their website and the number’s not there. I wish I could help you with specs knowing what your current camshaft is. Unfortunately, down at the rpm you’re cruising at, the engine has a tough time with air/fuel distribution, and it only takes one cylinder that won’t fire to cause what we call a “chuggle” condition. The other issue is that at these engine speeds, the valve overlap can really affect the other cylinders that fire in sequence. Short of telling you that you need to go with a shorter camshaft duration that you’re currently running that’s about all I have to offer on the camshaft.

The good news is that the TBI computer only controls the “check engine” light on your dash. The dash gauges run off the engine harness and will function properly with the ECM disconnected and removed. The wiring harness for the TBI system and emissions controls is completely separate from the engine and body harness underhood.

Finally, the electric fuel pump in the tanks that fed the TBI “will not” keep up with your 511. I would recommend dropping the tanks and eliminating the electric fuel pumps and use your mechanical fuel pump. The truck is equipped with 3/8-inch steel fuel line. You will need to reroute the pressure line from your tank-switching valve down to your mechanical pump. The factory TBI lines run up the back of the trans and into the back of the throttle-body injector. As for the return line, you can cap these at the electric tank-switching valve. This is the simplest method I can work out.

Enjoy your truck and keep wrenching. It keeps us young. We may take a little longer these days to finish a project, but I’ll bet that you don’t have to re-work many things. That’s why we have gray hairs!

Source: cranecams.com

She Goes, Now Make her Wow

I am installing a big-block in my ’84 G-body (Monte Carlo) and would like to upgrade the front brakes. If I were to install spindles from a Camaro (second-gen) for 11-inch rotors or B-body spindles for a 12-inch rotors I know I’ll need to change at least the upper control arms or alter their mounting point. What control arms do you suggest or how do I determine where to mount the upper control arm? (If stock uppers are used I’ve heard that you need too many shims to correct your alignment and your handling still isn’t right.) I’ve installed Ford ends on my 12-bolt (slightly narrowed and mini-tubbed) and plan to use Explorer rear discs. Thanks for what is the first-read part of the magazine.

Terry
Via email

As always, it’s much easier to make them go, but when you get things in motion you must bring them to a stop. Brakes are usually the last thing that people think about in their project upgrade. Many builders think that they have the whole dragstrip to stop their iron. Well, if it’s a strip-only vehicle it may not be a problem. But if you have ever been in the position to get your pride and joy up to speed and find yourself closing fast on a stationary object, your brakes are your best friend.

There are many benefits to swapping out either the ’70-76 second-gen F-body or ’78-and-up B-body spindles. The spindles lower the car by about 3/4 inch, and give you really nice camber gain as the suspension is jounced through its travel. The stock G-body upper control arms will not work as you noted and the upper ball joint is smaller than the spindles above. The easiest way to install the upgraded spindles is to pick up a set of Hotchkis Sport Suspension tubular upper control arms. Their control arms for your application are sold under PN 1101C. Their tubular controls arms feature improved suspension geometry by creating a negative camber curve and give you increased caster. The fully TIG-welded tubular control arms come completely assembled with greasable polyurethane bushings, upper ball joints, and chromoly offset cross-shafts.

To upgrade the brakes, these spindles allow you to either use the 12-inch Police package rotors from the B-cars, or the third-gen Camaro 1LE brake package 12-inch rotors. The Camaro rotors are the easiest route as they are a direct bolt-on. On the 12-inch B-car rotors you must re-drill the lug stud holes to the proper 4.75-inch bolt circle to match your Monty wheels. You will also want to pick up the brake calipers from your donor B-car. This package of spindles and rotors will increase the track width of the front by 3/8 inch on each side.

For more information, contact Hotchkis. They can fill you in on the finer points of the installation, and recommended alignment settings for your type of driving. Enjoy your new handling, and most importantly, the “wow” factor!

Source: hotchkis.net

Shifty Business

Thank you for the valuable information you provide every month on Performance Q&A. I need your help selecting an automatic transmission shifter that will fit my car. I have a ’96 Chevy Camaro Z28 with a Gen II 5.7L engine. The transmission is a 4L60E, and I want to preserve the console. Does the B&M shifter PN 80692 fit, or does TCI make one that fits without removing the console cover? Thanks for your help.

Rafael Hernandez Raymond
San Juan, Puerto Rico

Thanks for the great question. No, the B&M shifter you listed will not fit your Gen IV Camaro. The shifter you listed fits the ’82-92 Gen III platform. After looking around for a while, I think I’ve figured out why no one makes a direct replacement performance shifter for your application. It’s all about the electronic-controlled transmission and that the computer shifts the car! The interface of the factory Park/Neutral switch in the factory shifter must be retained for the computer to be happy. Also, the shift cable that runs down to the trans in your car moves a simple manual valve in the trans, and applies the parking paw to keep the car in place while parked. You would have thought that by now one of the manufacturers would have stepped up and produced a nice shifter that replaces the mundane factory shifter. They could have integrated the factory Park/Neutral switch to keep the computer happy, and given you a nice performance feel with positive detents. Wish I had better news.

Source: bmracing.com

We love letters, especially technical questions. Submit your tech questions to Kevin McClelland at chevyhi@sorc.com. Regular shout-outs and good tidings are also always welcome.

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