We asked and pleaded and finally got our stable of magazine car guys to open up and expound on some of the tricks and hot tips they use in their garages and on their own cool cars. There's only about a thousand years of experience around here and the SUPER CHEVY staff is from the "dirty knuckle" school of writing, so they actually get down and greasy and wrench on their own cars. With all of this supposed know-how, we can only hope that some of these can help you.
A Little Dab'll Do Ya
With RTV sealant, use only the thinnest bead that will do the job. Too much allows the excess to squish into the engine or transmission when the part is torqued. It will harden and could block oil galleys or fluid passages causing a malfunction.
Disconnected fuel lines can be hazardous. An easy way to block them is to use a wooden golf tee pressed into the end of the line. Tees have a wedge-shaped end, so they will accommodate various hose diameters.
Lock It Down
In recent years nylon locking nuts have been shown to be superior to lock washers, will work on anything not subjected to extreme heat (such as header-to-head-pipe installation), and won't back off. If you have the option of using the nylon nuts, do so.
Grease That Pushrod
When installing a stock fuel pump, use a small "dollop" of grease to hold the pushrod in the block while you insert the "foot" of the pump. This prevents the pushrod from sliding out and blocking installation of the pump.
This One Sucks
When doing service work on a carb, take an extra minute to inspect the rubber hoses for the vacuum advance and choke pull. If cracked, they can leak vacuum, destroy spark plugs, and generally ruin performance and fuel economy. Replace as needed; they're cheap.
We should all know this, but here's a reminder: Keeping a fire extinguisher handy in your garage is cheap insurance against losing your car or entire house because of a spark that ignites a fire.
Reversal of Fortune
If your car starts poorly, but idles all right and has decent power up to a point then starts running poorly again, check all the usual suspects: vacuum leaks, carburetor, points, condenser, dwell, and timing. Still without a cure? Look at the coil wires. A coil will function even when the positive and negative wires are reversed, but it won't run that well at higher rpm or during startup. The distributor should be wired to the negative terminal on the coil, while the positive terminal is the hot, or power, lead.
A hardware store turnbuckle, two bolts, and two washers can keep your engine from "torquing over." Run it from the engine to the frame or motor mount bolt on the driver-side.
Don't Drop Those Pan Bolts
When installing the pan on a trans that's mounted in the car, push three or four bolts through the pan rail and the gasket. You may have to smear some gasket sealer around the shoulder of the bolts to hold them in place. Now that the bolts are held in place by the gasket or the sealer, it's a simple task to screw them into the bottom of the trans. Then, you can thread the rest of the bolts in and snug them tight (not too tight as the gasket will push out).
Loctite It Right
Every toolbox needs at least a couple of bottles of Loctite thread-locking compound. Red Loctite (271) is the strongest and should be used on items that won't need to be disassembled any time soon, such as internal engine components. Blue Loctite (242) isn't as strong as the Red and should be used on items that you don't want to come loose but might need to removed at some point, such as brake calipers bolts. Green Loctite is the same strength as Blue but has an agent that penetrates threads that have already been assembled.
If a battery goes dead after only a few days, there may be a short circuit. For a quick test, disconnect either battery cable and connect the clip from a test light. Touch the battery terminal with the test end. If there's current flow, the test light will light. To find the bad circuit, disconnect various main circuits until the light goes out.
Two Will Do
Are four-bolt main caps really necessary for your hot rod? Several companies have done some serious dyno testing on the subject. Seems the magic number for a big-block Chevy is 600 hp. Below that figure, the factory two-bolt equipment will do just fine. But add monster power and four-bolt caps are mandatory.
The Plate Ran Away With...
Keep your license plates! Just attach a nut to the backside of the retaining screws. Thieves seldom carry a screwdriver and a wrench and will go someplace easier if you make it tough.
Squirt It Out
A carbon-fouled engine can be cleaned by spraying water down the carburetor while the engine is running. Run the engine at a fast idle and squirt a fine mist of water down the primaries. The water turns to steam during the combustion process and helps remove carbon from the combustion chamber and piston tops.
Here Kitty, Kitty
Of course, if you forget the tip above, you may want to keep a bag of kitty litter around. It's highly absorbent and creates fewer problems than using the good bath towels to soak up the spill. Dispose of the used litter at a recycling center.
In a Clutch
A clutch-type fan works with a heat-sensitive spring letting the fan turn freely until reaching a certain temperature, then it engages the clutch and fan to help cool. A good clutch fan should turn freely by hand when the engine is off and cool. If the engine is hot, try to turn the fan by hand (with the engine off!). If the clutch is good, the fan should still be engaged and hard to turn.
Boys & the Hood
If you have to remove the hood, run a strip of masking tape over where the hinges attach to the hood. Then, slit the tape with a razor blade and remove the portion on the hinge. Presto! The remaining tape now provides a perfect alignment line for reinstalling the hood. Oh yeah, remember to do it on both sides.
While the negative battery cable may provide enough ground to run the lights and radio, it isn't always sufficient to provide proper ground and peak efficiency for things like hot, high-voltage ignition systems and other items. Make sure you have a good ground strap running from the engine to the body of the car. Braided wire is best.
The Acid Test
You can easily prevent acid buildup on your battery terminals. Clean the terminals with baking soda and water and a fine wire brush. After they're dry, coat the terminals with Permatex Aviation Form-A-Gasket. Just brush it on and let it dry, and it does the rest.
Getting the Juice
If you're using a GM HEI ignition and have poor performance, it may be caused by inadequate power to the HEI unit, which requires a full 12 volts to perform properly. Sometimes they're mistakenly hooked up to the existing resistance wire in older cars. With less than 12 volts available, the HEI barely gets the job done. To ensure proper operation, make sure it's connected to a full 12 volts from the ignition switch.
Cold lash numbers on aluminum cylinder heads and/or aluminum cylinder blocks can vary greatly from the hot figures. When hot, aluminum moves around significantly more than cast-iron, causing valve lash figures to become decidedly different. Chevrolet offers this advice: "Cold-lash all aluminum engines .010 inch tighter than hot lash specifications." Generally speaking, you can use this as a starting point. Some aluminum head/iron block combinations are very close to an all-iron engine in terms of cold lash while others might be anywhere from .005 to .010 inch tighter. Do what we do: Contact your cam grinder and ask for a specific cold lash number for your particular combination.
No Fire in the Hole
A quick test for a misfiring cylinder on a header-equipped engine is to spray a little water on each header tube up near the exhaust port while the engine is running. The misfiring cylinder will have a lower temperature, which shows up on the cylinder where the water evaporates the slowest.
All the engine "how-to" stories say to always run a tap through the head-bolt holes when swapping heads or rebuilding an engine. There are, however, a number of different taps. ARP offers taps that clean the threads but don't remove material, leaving more iron in the block for thread overlap with the head bolts, which will prevent pulled threads.
The Big Bang
If you're running nitrous on your engine and you inadvertently fill the cylinders with nitrous while the engine is off, don't try to start the engine-an explosion can occur! Remove the coil wire, fully open the carburetor throttle blades, and crank the engine for 10-15 seconds before starting it. This purges the engine of any nitrous.
Having trouble keeping your floor mats in place? Glue a couple of small pieces of Velcro(r) to the backside. The Velcro(r) will bite into the carpeting and keep the mat where it's supposed to be, instead of bunched up under your gas pedal, or worse yet-under your brake pedal.
If your radio crackles every time you change the volume or the station, take the knob off and spray some aerosol tuner cleaner in along the control shaft. Tuner cleaner evaporates after it does its job and leaves no residue. You can buy it at most electronics stores
Most cam-break-in lubricants are molydisulfide concoctions. We recommend that you use them. But remember that they can easily plug an oil filter within 20 minutes of operation. When the filter is plugged, it will typically by-pass, and the result will be copious quantities of dirt inside the engine. After breaking in the camshaft (or a new engine), replace the filter after 20 minutes of running time. It's cheap insurance.
You Are Getting Sleepy
Common aerosol starting fluid (like ether) makes a great grease and wax remover, after sanding, in preparing small parts for painting. Simply hang the part with a piece of wire, spray it, and let it dry while you shake the can of paint. Make sure you use it in a well-ventilated area, away from any source of flame. In other words: No smoking!
When installing steel connecting rods, measure bearing surfaces at least twice-once at the 12:00 o'clock position and again at the 6:00 o'clock position. Remember that clearances vary, according to the application. Typically, you need 0.001 inch clearance per 1.000 inch of crank pin diameter.
More Solid Steel Info
Clean all steel connecting rod reciprocating parts thoroughly. The idea is to remove all dirt and foreign oils. Spread the rod bolt assembly lube on the threads and be sure to spread the lube under the head of the bolt prior to beginning the tightening sequence.
When You Get to 9, You've Gone too FarDon't use metal stamps to number connecting rods! They may disturb the roundness of the connecting rod bore. Instead, paint toolmaker's layout die on the rod and rod cap. Inscribe the numbers.
Enough Steel Rod Info
Do not use rod bolts to draw the cap down the rod. The correct method is to locate the cap dowel sleeves into the counterbores of the rod. Then, very, very carefully, tap the cap into place.
Too Hot to Handle
Don't carry a micrometer around in your pocket and expect to have an accurate measurement. Body heat can ruin this relationship. Additionally, micrometers are sometimes supplied with "standards"-they're used to set the micrometer. When using a standard, don't allow the heat of your hands to heat the standard. You'll influence the calibration.
Installing a fresh pickup on an oil pump can be a curse-especially if it's a press-fit such as those found on most Chevy V-8s. While there are special tools available to press the pickup tube into the pump, try this: Spray the end of the pickup tube with aerosol lube and slide it inside your freezer for an hour or so, after which you slip the bare oil pump body in a pan of water and household cooking oil. Bring the pump to a boil and (with the help of oven mitts) quickly slide the cold pickup tube into the hot oil pump body. It's a slippery fit and usually doesn't require the use of a hammer or any special tools.
While we're on the subject, make sure your oil pump pickup tube and screen matches your oil pan and is about 1/4-3/8 inch above the bottom of the pan. For some applications it may be a good idea to weld the pickup to the pump body or add a support bracket to make sure the pickup can't fall off.
There's nothing like jumping in your car on that first hot day of spring, flipping on the A/C, and getting a face full of hot air. This can be avoided by periodically running the A/C in winter, which will keep all the lubricants circulated through the compressor and prevent a seal from drying up. The same thing applies to the heater in the summer. The heater core should be flushed with fresh coolant to keep it from developing a leak that can quickly ruin your car's carpet.
For those one or two bolts that are nearly impossible to start during header installation, thread a 3/8-inch stud in the back hole and let the header rest on it. Thread in the rest of the bolts and finish up by installing a nut onto the stud.
Rock Around the Clock
When installing an aftermarket high-lift camshaft with stock stamped-steel stud-mounted rockers, be sure to check the rocker arm slot that allows the rocker to pivot at maximum lift. According to Crane Cams, there should be approximately 0.60 inch of additional travel left in this slot when the valve is at maximum lift. At the same time, be sure that the rocker arm contacts only the valve tip, and not the valve spring or retainer.
Thread lubricants are critical since they are the primary element when determining friction. It's common to use good old-fashioned motor oil for lubricating threads (engine, powertrain, chassis, etc.). Unfortunately, there's a catch. When using specially formulated, low-friction lubricants designed for a specific task, the required torque can be reduced as much as 20 to 30 percent. The reverse is also true. The folks who make Oliver connecting rods point out that if the recommended tightening specifications are based on the use of a special lubricant, the use of motor oil or other non-specified lubricant will result in insufficient pre-load. Engine oil is a good hydraulic-bearing material, but it is a poor extreme-pressure lubricant. If used on bolts, the torque required will actually increase, due to galling which makes the surfaces rougher. Essentially, the torque must be increased to compensate for the added friction induced by the non-specified lube. If a specific assembly (a good example is a connecting rod fastener) demands the use of a specialized thread lubricant, don't use motor oil-use the proper lube.
To keep heat out of the carb, use a thick, insulating-type gasket with plastic anti-crush washers built into it. Fel-Pro has them for spread-bore and square-bore carbs. They will only raise the carb about 1/4 inch, so hood clearance shouldn't be a problem.
Torquing Engine Fasteners
When torquing an engine (e.g. head bolts), it is always advisable to torque the fastener on the last full rotation of the nut or bolt. Using a socket wrench (ratchet), tighten the fastener until you feel there is approximately one more full rotation left before it becomes fully secured (in this case, it's better to estimate looser rather than tighter). If using a "click" torque wrench, set it for a figure less than the required torque. All fasteners should be brought up in equal torque values in stages. Pick a set of figures such as 20, 40, 60, 80 percent (these are percentages of the full torque figure) and then full torque. Follow the torque sequence determined by the OE manufacturer. The idea is to equally tighten the fasteners (such as those found in a cylinder head or intake manifold sequence) in a similar manner, effectively "sneaking up" on the desired torque value.
How much volume will a head lose when milled? Generally speaking, a Chevy engine will lose 1 cc of volume from the combustion for every 0.004-0.005 inch of material removed through a standard milling operation. Something to think about.
When degreeing a hydraulic camshaft, don't attempt to run through the steps with a hydraulic lifter in place. The clearances inside the lifter are too large. As a result, accuracy is impossible. You can make a special "solid" test hydraulic lifter by reworking the piston and cup, but why bother? Instead, use a new solid lifter for the job. Simply replace it when the degreeing job is done.
How much oil pressure is required in a high-performance application? Here's the guideline used by several successful engine builders: A typical Chevy needs 10 psi for every 1,000 engine rpm. So, if it runs a maximum of 7,500 rpm, it needs 75 pounds of oil pressure at that rpm level. How is this achieved? Don't run excessive clearances. Stick to the factory recommendations for connecting rod and crankshaft main bearing clearance numbers. Think about using a standard-volume oil pump. For most street car applications, there is simply no need to run a super high pressure, super high volume pump. Simply check the oil pump end clearance to determine if it is on the money and use it. Just remember: Don't goof up on the internal engine clearances.
If you have a close look at all V-8 engines (Chevys included), you'll find the connecting rods can be installed in one of two ways. The big end (crank pin) of the rod has one side finished with a healthy radius. The other side doesn't. In operation, the end with the radius matches the fillet radius on the crank. The flat end faces the other connecting rod it's paired with on the journal. To install them correctly, always face the radius end toward the crank fillet.
Air density decreases inversely with temperature. Hot air is less dense than cold air. The air/fuel ratio in the engine has to be changed to compensate. This is accomplished by reducing the jet size or jet number (lean the engine). An old racer rule of thumb states you should reduce one jet number for every 20 F of temperature increase, but it isn't cast in stone. The best way to compensate is to decrease jet numbers one at a time until either the performance improvements cease or the spark plugs show that the mixture is too lean.
Up, up in the Air
When it comes to jetting, there's another rule of thumb that states for every 700-800-foot change in altitude, the jetting should be adjusted. Basically, this is the same thing as an increase in temperature. As altitude increases, the available air molecules in a given volume decrease. The solution? Decrease jet size as the altitude increases. Just be positive to use the same "one jet number at a time" methodology, and always double-check the spark plugs.
If you know or suspect you've got a vacuum leak but can't seem to locate it, try this: Mix three parts water and one part dishwashing liquid together. Put the mixture in a toy squirt gun and squirt all the vacuum connections, one at a time. When the idle smoothes out-you've found your leak.
If you cut the header-to-cylinder-head flange in one or more places, between the bolt holes, it will help the flange conform to the head more evenly and reduce gasket failure. Once the bolts are tightened, retorquing them after a few heat cycles, and periodically thereafter, will extend gasket life. Tighten them when cold-not hot.
Step Up to the Pump
If your Carter AFB or AVS develops a hesitation after the car has been sitting for a while without being run, blame it on the leather accelerator pump. The material dries out, contracts, and no longer seals properly to the pump well. The fix? Install a marine application neoprene pump and the problem is gone for good.
If the water in your area is hard or contains lots of mineral deposits, use distilled water to fill the cooling system of your car. It will prevent deposit buildup and keep everything running cooler and longer. Use it to create the 50/50 mix of water and antifreeze, and add a can of rust inhibitor/water pump lubricant while you're at it.
Having a Seizure?
As technology and engine materials have changed, it's almost mandatory to use an antiseize compound on the spark plug threads in an aluminum head. So what's stopping you from using it on the plugs in your cast-iron heads as well? It will lubricate the threads and make the plugs a whole lot easier to remove in several thousand miles.
If you suspect you have a rear axle bearing about to give up the ghost, but you're not sure which one it is, there's a simple and reliable test: If it makes noise on a right-hand turn, it's the left side gone bad. If the noise rears its ugly head on a left-hand turn, then the right side bearing needs a replacement. Some things are just too simple, eh?
If your taillights or backup lights are doing some weird things, and you've already checked all the wiring, then there's one thing more to check. The ground between the light's housing and the car's body may not be good enough. Scratch a little paint off where it won't show and reinstall the housing.