A lot of people ask me why I often contradict articles written in the buff magazines, or that I blithely poo-poo some "Experts" advice on what you "Gotta Have". Here's why. My dad was a gearhead and restored and raced cars for many years. My mother says-not joking-that I could swap valvesprings in a small-block Chevy cylinder head before I could ride a two-wheel bike! I worked in car dealers and independent shops for 38 years, and my friends and I drag-raced cars, ran "Street Stock", "Hobby Stock" and "Super Stock" cars on circle tracks for 20+ years. You learn quite a bit from your own experiences, and from talking to other people about theirs. That's why I'm confident, and yes I'll admit-sometimes even arrogant about my opinions. Anyhow-today I'll play "Mythbuster", and tell you why you don't need many of the "Gotta Haves" that you read about in the buff magazines. # 1. Drivetrain and Suspension / Brake Upgrades. Have you noticed that every single magazine project car of late has a custom Currie-built 9 inch Ford rear end, a Richmond or Tremec 5 or 6-speed stick, or a beefed up 700R4 or 4L80E overdrive automatic and a Wildwood 4-wheel disc brake setup worthy of a NASCAR Nextel Cup car? I'm all for safety and reliability, but honestly-let's take a look at Hot Rod's "Project Disco"-a 1978 Z/28 Camaro. First off the name implies that they were going to do a late '70's style project. Which would have been cool, with flared fenders, Minilite Wheels, and a snarling small or big-block Chevy. No-like all the mags-they should change their name to "Modern Fuelie Swap Monthly"-they put an LS3 and a six-speed in it!! That's not very "Disco-era" at all!! However-even choosing the modern LS motor-they spent a ton of money they didn't need to. '78 Z/28's had either a BW T10 4-speed manual or a TH350 automatic as standard equipment. Either one would have bolted up to the LS engine, and worked just fine. They didn't need to spend an extra 3 grand on the six-speed conversion. For what? To reduce freeway crusing rpm by 500 rpm? Ditto for the rear axle. '78 Z/28's have an 8.5 inch ring gear positraction rear end with either 3.42:1 or 3.73:1 gears. Perfect for a street / strip machine. And their tough. I've had 400 and 455, 4-speed Trans-Ams with this rear end, and popped the clutch at 4,000 rpm many times drag racing or just screwing around and never broke the rear end. As for the brakes-are they saying that the factory front disc / rear drum setup isn't adequate to stop the car safely in daily driving or on a weekend trip to the drags? I have a friend who Autocrossed a '76 T/A ( They use the same braking system as the Camaro ) very successfully with the stock brakes. He figured out that if he used Bendix or Ferodo Police-Spec Semi-Metallic D52 pads and Dot 5 fluid, that the brakes would not fade, even after back to back to back runs!! In fact-the main problem was the Dot 3 fluid boiling and causing a mushy pedal. With the Dot 5 fluid-everything was peachy. Same thing for a Circle-Track racer who had a '70's Camaro front clip on his "Super Stock" champion car that ran on 1/4 mile and 1/2 mile tracks. Even on a 50 lap main event on a 1/4 mile track-his stock braking system never faded-if he used Dot 5 fluid and the Police-Spec pads!! So this project car in no way "needed" the additonal 10 grand that they spent on the Currie 9 inch rear,Wildwood 4-wheel disc setup and six-speed conversion!! They do that stuff to sell their advertisers products. They have to to stay in business. But honestly-I have never seen anyone break a Chrysler 8 3/4 inch rear, ( Even with a 505 stroker with nitrous in a 9 second Duster! ) or an 8.5 Gm 10 Bolt. Does that extra 1/4 inch or 1/2 inch on the ring gear really make that much difference? I guess if you were running a 720 hp GMPP 572 with a stick or a TH400 with a 5,000 rpm converter and a trans-brake and wrinklewall slicks bolted to the rims, it might. But for the other 99% of you-you probably don't NEED a Dana 60 or a custom 9 inch rear!!! Same thing for transmissions. Unless you have over 500 hp-a TH350 or a C4 will work fine with a shift kit and the proper cooler. You don't "Gotta Have" a TH400 or a C6. Some of the newer T10s advertised in Summitt may only show a 375 lb torque rating. Puhleeze. GM used the T10 ( the design has never changed, only the metallurgy of the gears and the modern ones are a lot stronger than the old ones ) behind Super Duty 421 Pontiacs and 409 Chevys-that easily had over 500 lbs ft of torque!! The T5 BW 5-speeds used in '80's Camaros and Mustangs supposedly only have a 300 lb torque rating. I know a guy that swapped in a STRONG 350, and it lasted 13 months with him going to the drags every weekend and powershifting through probably 30 hard passes a week! If he'd drove the car normally ir probably would have lasted 5 years! I know Mustang racers with nitrous that run 10s and have never blown their T5. I wouldn't put one behind a 454 or a 392 stroker, but you get the gist. You don't need to upgrade your tranny on your 302 'Stang or 305 IROC-Z because you installed an Edelbrock intake and matching cam!! # 2. Bottom-end and Valvetrain Beef. "You gotta have a 4-bolt main block" "You gotta have a forged crank." "You gotta have screw-in studs" "You gotta have forged pistons" and so on. These "Experts" are half-right. If your building a NASCAR engine that has to go 7,800 rpm for 500 miles at Daytona, yes you need all the beef you can get. But for a STREET engine, that will never see the high side of 6,500 rpm, and only maybe get the occasional weekend trip to the drags-you don't need all that stuff. Save your money for cams, headers, carb and intake, gears, etc-stuff that really gives you "bang for the buck". Here's why. People don't know-it's not load or rpm that breaks things. It's SUSTAINED load. That's why through the '70's and '80's GM medium and heavy-duty trucks with 350 Chevys in them always had 4-bolt mains and steel cranks, even though Camaros and Corvettes often had 2-bolt main blocks and cast cranks. Huh? The reason is the trucks were going to be constantly loaded and or towing heavy loads which put much more strain on the crank than the occasional full-throttle blast of the Camaro and Corvette owner. Ford NEVER had a forged crank for 351 Cleveland engines. And neither did the aftermarket. Yet drag racers like "Dyno Don" Nicholson and Bob Glidden ran 9 second 1/4s in Pro Stock, often shifitng at 8,000 rpm with stock 351C cranks!! Bud Moore and Bobby Isaac campaigned a 351C Torino in NASCAR with a stock crank. They were that tough. As for rods-most people don't know it-about 97% of rod failure-even in racing engines occurs AT THE BOLT. So if your rebuilding an engine-you don't need an ultra-expensive set of Eagle or Milodon forged rods. A set of chrome-moly rod bolts is good insurance. Even on supposedly "weak" factory rods. Pontiac rods ( Except for forged Super Duty's ) have a reputation for being "weak". However my friends and relatives have had numerous GTOs and Firebirds and Ventura project cars over the years-many which ran in the 11s or 12s-so they had SERIOUS power-and as long rpms were limited to 6,400 on a 400 or 5,800 on a 455-we never had a rod failure!! Ditto for forged pistons. Their noisy, and they require loose clearances ( they expand when hot ) so they use some oil. Cast pistons run quiet and are dead-reliable. I'd recommend forged pistons only if you going to run a blower or nitrous. And to that I'd ask-if you have that much money and need to go that fast-then why aren't you building a 454 instead of a 350? Or a 440 instead of a 360? Or whatever-you get the point. As for valvetrain-people will tell you you have to have screw-in studs, or roller rockers, or chrome-moly pushrods, or a stud girdle, or whatever. Again-if your buidling that NASCAR engine, yes. A street / strip machine or even a short-track racer? No. I know guys who have ran small-block Chevy and Ford engines in circle-track racing classes for years with two-bolt main blocks, cast cranks and pistons and stock heads and have run the engines two whole seasons without a problem. And these engines are under much more sustained load than your street car will ever be. As for failures-I've seen broken valve springs, broken pushrods, broken rocker arms, and jumped timing chains. But in 40 years I have NEVER seen a stud pull out of a head!! So before you spend your hard-earned money on a bunch of beef and machine work that you don't really need, talk to some of us old guys. We might be able to save you big bucks. Mastermind
No comments:
Post a Comment