101 Corvette Tech Tips

101 easy performance, restoration, maintenance & shop tips

Wayne Scraba Feb 8, 2005 0 Comment(s)

Working on and maintaining your Corvette is supposed to be fun, butthere are times when you run into a mechanical brick wall that seemsalmost insurmountable. Sure, you can throw $100 bills at the Corvettemechanic to overcome the obstacle, but that isn't always necessary.While there is no question that money and preparation are precariouslylinked on the path to improved Corvette performance, in many cases cubicdollars can be supplanted by ingenuity.

That's where we step in.

We've poked, we've prodded, and we've generally nosed around until wefound 101 ways to make your Corvette faster, easier to work on, and makethe details shine. Some of the ideas we discovered are safety-orientedwhile others are simply good, old-fashioned "time savers"; butnonetheless, they all make life in the Corvette fast lane a buncheasier. Pick and choose the tips that suit your Corvette. We're positivethat you too can work on your pride and joy without breaking the bank!

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When considering the compression ratio for a new Corvette normallyaspirated engine and factoring in today's gasoline octane, there aresome variables you should consider. Here's the rundown:

* A higher compression ratio requires higher-octane fuel

* More spark advance requires higher-octane fuel

* Lower humidity requires higher- octane fuel

* Higher altitude allows the use of lower octane

* Leaning of the air/fuel ratio requires the use of higher octane


The folks at NGK point out that torque is one of the most criticalaspects of spark-plug installation. Torque directly affects the sparkplug's ability to transfer heat out of the combustion chamber. A sparkplug that's under-torqued will not be fully seated on the cylinder head;hence heat transfer will be slowed. This will tend to elevatecombustion-chamber temperatures to unsafe levels, and pre-ignition anddetonation will usually follow. Serious engine damage is not far behind.

An over-torqued spark plug can suffer from severe stress to the metalshell which in turn can distort the spark plug's inner gas seals or evencause a hairline fracture to the spark plug's insulator. In either case,heat transfer can again be slowed and the above-mentioned conditions canoccur. NGK also states that the spark-plug holes must always be cleanedprior to installation; otherwise you may be torquing against dirt ordebris and the spark plug may actually end up under-torqued, even thoughyour torque wrench says otherwise. Of course, you should only installspark plugs in a cool engine, because metal expands when it's hot andinstallation may prove difficult.


Plenty of vintage Corvettes are equipped with drum brakes (actually,everything prior to '65, and even a few '65 models), and for the mostpart, servicing these components is pretty much a no-brainer. One thingto remember, however, is that when you replace the shoes, use a bit ofScotch-Brite to clean the contact points on the wheel backing plates.Next, lube these contact points lightly with white grease. This allowsfor smooth shoe action. Just be careful not to drop any grease on theshoes. If you do, use some spray-on brake cleaner to clean it.Otherwise, the friction material won't be too happy!


If you're encountering a tough brake bleeding operation on one or moreof your Corvette calipers, try this: A turkey baster can be used to pumpbrake fluid into the bleed screw to force the bubbles out of theirhiding places.

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If you're going to store your Corvette for months at a time, disconnectthe battery. This will reduce the discharge. On the other hand, you canalso charge the battery once every two to four weeks and leave it hookedup. If you have the battery stored and disconnected, a charge everymonth or two will help keep the self-discharge from draining thebattery. Also look for regulated trickle chargers that are designed forthis type of application.

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If you find brown, foamy residue in the coolant of your Corvette you mayhave also located a cracked cylinder head, which can cause overheating.Have your radiator pressure checked at your local radiator shop.Pressure loss can cause overheating. Before you start peeling apart theengine, give this some consideration: Many times a failed radiator capis the culprit. A cap that has failed to hold system pressure can causecoolant loss and overheating conditions.


The air pressure listed on the sidewall of a tire is not the correct airpressure for your Corvette. The number listed on the sidewall is themaximum air pressure for the tire. Follow Chevrolet's publishedrecommendations. You and your Corvette will be much happier.


Many vintage Corvettes came factory-equipped with Holley carbs (and morethan a few other Corvettes were retrofitted with Holleys). If the bowlscrew on the carb leaks (normally due to a torn gasket), find a commonroofing nail. Use the rubber washer from the nail to fix the leak.Problem solved.


Is your Corvette misfiring? Are you scratching your head trying tofigure out which cylinder is the culprit? If the car is equipped withheaders, here's a quick test. With the engine running, squirt a smallamount of water on each header tube (close to the exhaust port). Oncylinders that are functioning properly, you'll see the water evaporateinstantly. Not so on the dead cylinder(s).


Most cam break-in lubricants are moly-disulfide concoctions. Werecommend you use them when installing a new cam in your Corvette. Butremember: They can easily plug an oil filter within 20 minutes ofoperation. When the filter is plugged, it will typically bypass and theresult will be copious quantities of dirt inside the engine. Afterbreaking in the camshaft (or a new engine), replace the filter after 20minutes of running time. It's cheap insurance.


If you have a persistent squeak from your brakes and you've triedeverything to stop it, try this: Remove the pads and clean the back toremove dirt and dust. Brake cleaner works perfectly. It dries fast anddoes not leave a residue. After cleaning, spray or brush on a goodcoating of disc-brake anti-squeal compound on the back of the pads (mostauto parts stores sell it). Allow it to dry for half an hour, thenreplace the pads and anti-squeal shims (if used on your car). The squeakshould be banished for a couple of years.


The folks from Fel-Pro point out that a water-temperature gaugeindicates only the average temperature of the coolant in the engine. Awater-temp gauge does not indicate the cylinder-head castingtemperature. The casting temperature is what the head gasket issubjected to.


Believe it or not, nail-polish remover makes an effective andinexpensive small-parts cleaner. The polish remover is acetone, and themost potent, least expensive stuff comes without scents or oils. By theway, in diluted form it will remove bugs and tar from chrome, and removegrease and oil instantly. Just keep in mind acetone is also a wonderfulpaint remover, and, for a perfectly restored Corvette, that's the lastthing you need to spill.


Tire diameter of the metric or P-metric tire can be calculated by usingthe tire size nomenclature. The section width and aspect ratio aremolded into the sidewall. The section height (SH) of a tire is thesection width multiplied by the aspect ratio. The overall diameter (OD)includes two section heights converted to inches, plus one rim diameter.The following formula is valid for all metric and P-metric tires: OD =(2 x SH) + Rim Diameter


When it comes to brake lines, what size should you use? That's simple:Use 3/16-inch steel line wherever possible. Use flex line only wherenecessary.


If you're plagued with bulbs on your Corvette that constantly needattention, think about this: Is there corrosion at the base of the lightbulbs? If so, apply a wee bit of electrical grease to the bulb base.This goes for the prongs of blade fuses as well. Your problems should besolved.


If you have a dim headlight, the cause is a bad ground (and on aCorvette, there are plenty of them). Clean the ground and the headlightwill work well again.

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Don't take aftermarket wheel backspace dimensions with a grain of salt!When you buy new or used wheels, be sure to check the backspacedimensions of all of the wheels. This is particularly important when itcomes to multiple-part wheels (wheels where the center is bolted,riveted, and welded to the wheel rim). Why so? Simple. Some folks havefound that wheels can be out by as much as 3/16 inch. And that can causeyou nothing but grief when fitting wheels to your Corvette. Double-checkthe wheel backspace. You'll be glad you did.


Wheel bearings don't last forever (most grizzled Corvette owners canattest to that). To check wheel bearings, grab the wheel at the top andbottom, and push and pull to determine if the wheel will move in or outat the hub. If there is noticeable movement, it indicates the bearingsare loose and in need of adjustment. It could also indicate the bearingsare badly worn. Translation? It's time to tear things apart.

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While commercial drill stops are readily available, it's pretty easy tomake one by wrapping a piece of tape around a drill bit at the depth youneed the hole. It's cheap. It's easy. It works. What more could you askfor?


Plastic or nylon wire ties have countless uses on a Corvette (they'vebeen called the modern equivalent of duct tape). Unfortunately, they'reoften as sharp as a knife once the excess "tail" has been cut off. Tosolve the problem (and save your hide), simply touch the cut-off endwith a hot soldering iron. The end will be blunt, will never work loose,and, best of all, won't cut you when you least expect it.


When shopping for high-performance wheels for your Corvette, one thingmost people forget is the actual size of the center wheel hole. Believeit or not, the center hub holes in wheels are not all the same. In fact,certain vehicles have significantly smaller hub holes than others. Agood example is the late-model Corvette. A wheel designed for theCorvette often has a much smaller hub hole than a similar wheel designedfor use on a late-model Camaro. Check first before you buy.


There are two main types of lubrication in things mechanical: oil andgrease. Which chemical is used where depends upon the speed of rotation,the operating temperature, and whether heat must be removed from thearea concerned. If a function of the lubrication is to control or coolfriction-generated heat, then oil is the chosen product since it canflow away, dissipating heat while recirculated oil is introduced toinduce relative coolness. On the other hand, grease is used when thebearing operates under normal speed and temperature conditions.


Some people prefer to use "gasket in a tube" instead of header gaskets.While it seems like a good idea, think about the cleanup time requiredto peel the high- temperature silicone from the cylinder heads andheader flange once you remove the pipes. We've watched racers spend halfan hour or longer trying to scrape all of the goop clean. A simpleheader gasket can be replaced in seconds.


Worn idler-arm bushings cause front-end steering shimmy and can negatethe responsive "feel" the steering demonstrates. So what's the point?Never overlook the idler arm on an early Corvette when it comes tosteering maladies.


Here's another grease trick: It works well as a sealer for Corvette carbgaskets. If you use a small amount of grease on the gasket(s), it can bereused a number of times and it won't stick to either the carb or intakemanifold.

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Battery terminals have a nasty habit of corroding (even on Corvettes).That should come as no shock. A quick fix is a shot of GE Silicone II ora similar spray-clear product over the terminals. It will minimize thecorrosion and prevent acid from eating the terminal bolt.


Did you know there is more than one use for Rain-X? It can also be usedas a lubricant between door-glass and associated rubber window-glassseals on your Corvette. If you apply Rain-X to both sides of the sidewindows, you'll never have that not-so-pleasant experience of a sealtucking down and jamming the operation. Better still, Rain-X helpspreserve the rubber glass seals.


If you've had the front end completely rebuilt or restored (fresh parts,proper wheel balance and alignment) and still notice a vibration, trythis: There might be pebbles lodged in the tires. Check your tire treadsfor small pebbles. By the way, you should also consider washing thedirt, grime, and rocks from the inside of your wheels so the balancewon't be affected.

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Engine valvetrain damage is rather common, particularly if the engine ismodified. According to the pros, the majority of this damage can beattributed to weak valvesprings. Some enthusiasts believe a very stiffspring stresses the valvetrain and soaks up power as the springcompresses. That might not be correct. Very little drag is actuallyadded by stiff valvesprings. Why? That's easy: There are always the samenumbers of lifters opening as there are closing valves. Think about it.It makes sense.


If you have a close look at all V-8 engines (Chevys included) you'llfind the connecting rods can be installed in one of two ways. The bigend (crank pin) of the rod has one side finished with a healthy radius.The other side doesn't. The rod end with the radius matches the filletradius on the crank. The flat end faces the other connecting rod it'spaired with on the journal. To install them correctly, always face theradius end toward the crank fillet.


If you've swapped tires and increased or decreased the diameter, thenthe true axle ratio in your Corvette has changed. Perplexed? Here's aformula to help with the axle gear ratio: MPH x Gear Ratio / True TireDiameter x 336 = RPM


Universal joints that are equipped with a grease fitting should beinstalled with the fitting compressed. In other words, they should beinstalled so they are ahead of the driveshaft in the direction ofrotation.

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Have you noticed that as oil becomes dirty (prior to a necessary change)the oil pressure in your Corvette goes up? Similarly, have you noticedthat after the oil has been changed, the pressure seems to go down? Thereason is, clean (new) oil has a lower true viscosity than used oil. Asoil is used in the engine, it gathers contaminants and this causes theoil to oxidize. Simple enough, we'd say, but also a good reason to keepon top of the oil change schedule.


You know those little plastic clips that keep bread bags together? Youmight want to start saving them. Here's why: Think back to the time youmixed up the ignition wires when you swapped distributor caps on yourCorvette. If you had used these tags on the wires, and wrote down theappropriate cylinder number (for example, 1-3-5-7) on the tag, then youwould have saved oodles of time.


Fin count plays an important role in cooling. As a rule of thumb, aradiator will normally have between 8 and 14 fins per inch. When the fincount number is increased, the radiator can "radiate" more heat to boththe surface airflow and the surrounding air. Unfortunately, as fin countincreases, so does the opportunity for plugging, especially with bugs,dirt, and other foreign road junk. Bottom line? Keep your Corvetteradiator clean.

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It's pretty common to use a flat-blade screwdriver to remove interiorpanels in a Corvette (to pop out the retainers). Trouble is, the panelsare usually soft (and expensive). On the other hand, screwdrivers areusually small and sharp. If the screwdriver slips while you're prying apanel, things get expensive quickly. The solution is simple: Wrap theend of the screwdriver with electrical tape. You'll be much happier. Sowill your door-panel upholstery.


If you spy a tire with a foreign object such as a nail embedded in thetire tread, don't try to pull it out (we know, the temptation to dosomething like that is pretty compelling). Why? Remember that a tire isa pressurized vessel. If the nail is loosened, it could become ahigh-pressure-powered missile. Anyone and anything nearby is a candidatefor injury. In addition, the escaping air can also pick up debris (dirtand other junk) from the area of the puncture. It too will be forcedoutward. What's the solution? Deflate the tire before you yank outforeign objects.


We all know that neglected coolant can lead to a clogged cooling systemand a loss of cooling system efficiency, but it can also cause otherless obvious problems. If the coolant age or condition can't be easilydetermined, there is a quick check for coolant contamination using adigital volt/ohm meter (DVOM). Attach the positive DVOM lead to theradiator, then dip the negative lead into the coolant at the fillerneck. A voltage reading of 0.2 volt or less is good. A reading of 0.5volt should be considered borderline, and anything over 0.7 volt isunacceptable. If the coolant fails this test, the cooling system shouldbe thoroughly flushed and cleaned. Remove any engine temperature sensorsand inspect them for contamination or other damage.


When installing Corvette valve-cover gaskets, it's common to usesilicone for the sealing agent. Trouble is, the gaskets tend to tear ifthey have silicone on both sides. Try this instead: Use silicone to gluethe gasket to the valve cover, then use a bit of grease on the side thatmates to the head. The gasket won't leak and won't rip off the next timeyou lash the valves.


Here's another neat shop tip anyone can use: If you have some awkwardmetal bits that need more than two hands to hold in place, try using afew relatively powerful magnets to keep the parts in place. The magnetsfree up your hands and allow you to get the job done. Of course, thistip doesn't apply to Corvette body panels!

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People cling to rod ratios (rod-to-crankshaft stroke percentages) as ifthey are magical. Rod ratios or "l/r" ratios are for the most part thenaturally occurring result of other engine-design criteria. In otherwords, much like with ignition timing (spark advance) they are what theyare. Unless you want to completely redesign the engine (including yourblock deck height, piston compression height, rod length, and so on)don't worry so much about rod ratios. Your time would be better spentsearching for more airflow from the cylinder heads, but that's anotherstory.


If the engine in your early Corvette runs uneven or surges, thefloat-level setting could be the culprit. Remove the bowl, flip it over,and have a look at the float location. Adjust it (with the externalhardware) to a point where the top (now bottom) of the float is parallel(square) with the inside of the bowl. This is the preliminaryadjustment. Fine-tuning will be accomplished when the engine is running.Repeat the process with the second bowl. And if it's a Tri-power car,repeat once more.


When working on the electrical system of your Corvette and you need tosolder wire together, use resin core solder. It's the best bet for theapplication. Keep in mind this stuff isn't cheap. But in this case, youlikely don't need to buy it in huge quantities. It's an old tip, butit's still appropriate.

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How many of you have an oil filter wrench that slips? Plenty, we'll bet.Instead of buying another wrench and finding that it slips after a shortperiod of time, try this: Wrap several layers of electrical tape aroundthe circumference of the wrench. Then try the wrench. Magic! The wrenchdoesn't slip.


Let's say you don't use your vintage Corvette for some time,particularly in the summer. If that's the case, gas tends to evaporatefrom the fuel bowl (remember, these cars don't have an electric fuelpump as do late-model EFI models). As a result, you'll spendconsiderable time cranking the engine in order for the fuel pump to fillthe float bowl (mechanical pumps). To stop the strain on the starter andbattery, try this: Use a small funnel with an inner diameter of 3/8inch, place it over the float-bowl vent tube, and pour a small amount ofgas into the bowl. Bingo. The Corvette will usually start immediately.


When thinking about tools, the actual "fit" of the wrench is somethingmost folks ignore. Believe it or not, if you have trouble with wrenchesthat routinely slip off fasteners (and consequently give you a case ofbusted, bleeding knuckles) and regularly round off fastener corners, theproblem is likely the tool. You see, a good-quality wrench such as theMac combination wrenches have closer tolerances than some departmentstore tools. Keep this stuff in mind. You'll appreciate it if you'vebeen spending far too much time reaching for the first aid kit in yourshop.


See that weatherstrip seal between the fan and radiator? This high-temperature seal increases fan efficiency considerably. It's like addinga shroud to a conventional engine- driven fan. Try it. It could solve ahot-headed Corvette in a heartbeat.


If you have a vintage Corvette, flush the brake fluid! Years (perhapsdecades) of rust, scale, and crud manage to collect in the brake lines.In turn, this stops the brake system from working to its designpotential. The simplest way to flush brake lines is to open up thebleeder screws and let Mother Nature do the work. Keep the brakereservoir full with fresh fluid (DOT 3 or better). Repeat the processuntil the expelled fluid is clean. Expect to use a few cans of freshbrake fluid.


After the tires on your Corvette are cleaned, allow them to drycompletely before applying any dressings. Once the dressing is applied,allow it to soak for at least half an hour before you wipe off anyexcess. Of course, this doesn't apply to dressing overspray--wipe thatstuff off immediately!


When tightening any assembly held together with a number of fasteners(for example, Corvette engine parts), Mac Tools states that eachfastener should be tightened down a little at a time, going to eachfastener in turn, until the specified torque has been reached. Mac Toolssuggests you follow this practice when torquing fasteners:

* Apply 3/4 of the specified torque to each fastener.

* Reset the wrench and tighten each fastener to the specified torque.

After tightening all the fasteners, repeat the final tightening to makecertain all fasteners are at the specified torque.


Popular replacement conical-style air filters used in some late-modelCorvette performance "kits" should be shielded from air movement createdby the fan, particularly in EFI applications (where they're the mostcommon). If they aren't shielded, the mass-air meter gives incorrectsignals to the computer.

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When dealing with aluminum cylinder heads and/or aluminum cylinderblocks, cold lash numbers can vary greatly from the hot figures. Why?Because aluminum moves around significantly more than cast iron whenhot. Because of this, you can understand why (and how) valve-lashfigures often become decidedly different with "aluminum" combinations.Although it's difficult to provide hard and fast numbers for all cam andengine combinations, Chevrolet offers this advice: "Cold-lashall-aluminum engines are 0.010 inch tighter than hot-lashspecifications." Generally speaking, you can use this as a startingpoint. Some aluminum-head/iron-block combinations are close to anall-iron engine in terms of cold lash while others might be anywherefrom 0.005- to 0.010-inch tighter. Do what we do: Contact your camgrinder and ask for a specific cold-lash number for your particularcombination.


Here's a tip from the ancient past, and it still works: If you have anengine that's filled with carbon, the best way to clean up the works isto flush it away with water. Fill a small squirt bottle with water (acommon sports-drink squirt bottle works great). Remove the air cleaner.Start the engine. With one hand on the throttle (lever), lightly tricklethe water from the sports bottle into the carburetor or throttle body.Simultaneously, keep the engine rpm to a point where it will run(remember, water doesn't burn). The idea here isn't to flood the enginewith water; the last thing you need to do is hydraulic the engine. Theidea is to steam the carbon free in the engine.


If at all possible, don't use spark-plug wires with brass terminalsalong with a distributor cap with aluminum inserts (normally a cheapcap). Why? Moisture will create corrosion. The result will be poor sparkand even worse performance.


There is a seal between the oil pan and drain plug on your Corvette. Ifthe plug is overtightened (for example, by the gorilla at the localquick lube), there's a good chance the seal (often plastic or copper)will be distorted. The result? A persistent drip. The solution? Buy anew seal.


Buy a number of alligator or spring clamps in several different sizesand keep them in your toolbox. They come in handy when sizing pieces(such as upholstery material) to be cut. They also hold things firmlyuntil adhesive sets up. It's like having a second pair of hands during aCorvette restoration.


Do you have a C4 Corvette with what appears to be a fuel-related hardstart or lean condition? Have a fuel sample test done to see if anywater has contaminated the fuel. If it has, check the rear fuel-fillcompartment seal to see if the drain is plugged. A clogged drain cancause rain or car wash water to back up into the fuel-tank filler tube.

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Valve stems are valve stems, right? Maybe not. Many Corvette enthusiastsforget about the actual size of the valve-stem hole. This might not seemlike a big deal, but given the differences in wheels, it's a good ideato grab your calipers and measure the diameter of the hole. Why? Mostscrew-in metal valve stems are sold in varying diameters.


Ring-and-pinion gears are matched pairs, and should never be mixed withgears from other sets.


Replacing a set of Corvette parking-brake cables isn't in most people'sfun dictionary. Avoid the drill of replacing rusted and frozenparking-brake cables by performing a wee bit of periodic maintenance.Every time you change the oil and lube the chassis, try squirting alittle grease or good old-fashioned penetrant into the parking-brakecable end. If a rubber boot covers the end of the cable assembly, pry itback and inject the oil or grease into the cable. Your problems withstuck or frozen cables will be over forever.


Why do so many aftermarket brake calipers for Corvettes use stainlesssteel for pistons and/or sleeves? Stainless is a good choice for theseapplications due to slower heat transfer than mild steels. Something toconsider when shopping for replacement calipers.


There are dissenting views on this topic, but many professionalrace-engine builders believe that engine bearings that are notaftermarket coated should be polished ("coating" refers to variousfriction-reduction coatings). The polishing process removes the shippingcoating, which in turn improves bearing life. The idea is to use acrosshatch pattern on the bearing surface with white Scotch-Brite(fine).


Here's an old concept that always seems to go unnoticed: In Chevroletapplications (for example, small-block and big-block), there is a needto shim the starter so it meshes correctly with the flexplate orflywheel. Here's how it's done: You need approximately 0.035-inchclearance between the peak of the tooth on the starter drive gear andthe valley of the flywheel ring gear. FYI, a good old-fashioned paperclip is approximately 0.035 inch. In order to check the clearance,disconnect the large wire from the battery to the starter (disabling thestarter). Leave the power to the solenoid so it will function when youengage the starter. A remote starter switch works perfectly for thisapplication. Shim as required.


Installing a fresh pickup on an oil pump can be a curse, especially ifthe pickup tube is a press-fit such as those found on most Chevy V-8engines. While there are special tools available to press the pickuptube into the pump, you can get Mother Nature to help during theinstallation process. Spray the end of the pickup tube with an aerosollube and slide it inside your freezer for an hour or so. In themeantime, slip the bare oil-pump body in a pan of water and householdcooking oil. Bring the pump to a boil and, with the help of some ovenmitts, 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 orany special tools.


When changing serpentine belts, count the number of grooves. In someapplications there are a couple types of belts: Some have seven groovesand some have eight, depending upon the year of the vehicle. Inaddition, vehicle accessories determine belt length. By the way, whenyou replace a used-up belt, keep the old one. It will usually havesufficient life left to get you back to civilization. One more thing: Ifyou have a problem routing a serpentine belt in your Corvette, pay closeattention the engine compartment. There's usually a sticker somewherewith a diagram showing the belt routing.

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When tracing electrical gremlins in a Corvette, keep this in mind: Wiresalmost never go bad. Connections do. Don't be tempted to run a new wire,thinking you're solving the problem. Quite often, if you trace a short,you'll find a bad or corroded connector that you can clean or replace.You'll save yourself time and, at the same time, you won't hack yourwiring harness.

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Have you ever come across a new clutch disc that doesn't want to slideeasily over the input splines on your Corvette transmission? If youhave, don't worry. You're not alone. The problem is a burr on either thegearbox input shaft or the clutch-disc splines. To ease the job, takethe time to carefully deburr the splines on both the clutch disc andinput shaft. From now on, the installation will be a snap. The problemis common on both well-used components and new clutch discs.


A quick way to check a charging system is with a voltmeter. For a12-volt system, it should read 12 volts with the engine off, and 13-14volts with the engine running.


Can't find small oil leaks in a restored Corvette engine? Check the PCVvalve and make sure it's functioning properly. If the PCV system checksout, try plugging up your PCV system temporarily. Start the engine andcheck for leaks. The crankcase pressure will build up and any small oilleaks will probably get big enough to find easily. Obviously, it alsohelps to start with a clean engine to make the leak more apparent.


Question any seasoned racer about brake fluid and one of the firstthings that will come out of his mouth is "Ford High Performance BrakeFluid" (sometimes referred as "Ford Heavy Duty Brake Fluid"). Let's backup for a minute: The really good racing brake fluid available today iscalled "Castrol SRF." It is a somewhat rare super-fluid designedprimarily for racing, but most people don't buy it because of the highcost. The reality is, Ford Motor Company purchases this fluid by thebarrel, repackages it, and sells it as Ford Heavy Duty Fluid to ownersof heavy-duty trucks. Anyone may buy it from a Ford dealer under PNC6AZ-19542-AA. The packaging states: "High Performance Dot 3," and thecost is considerably less than the Castrol-packaged fluid.

Another good quality brake fluid is Castrol LMA. It's good at rejectingmoisture and may be kept in your brake system for several years. The LMAstands for "Low Moisture Absorption." It is sold in plastic containersthat do not have a long shelf life. Do not purchase a large quantity ofthis fluid at one time, since moisture can make its way through theplastic containers. Ford Heavy Duty DOT 3 is quite inexpensive and ispopular (particularly among racers) because of its excellent dry boilingpoint. It absorbs moisture quickly, but the racers don't care since theychange their fluid frequently. It's sold in metal cans and, as a result,it does have a long shelf life (provided the seal isn't broken). Interms of specifications, Ford Heavy Duty is classified as a DOT 3 fluid.The dry boiling point of this fluid is 550 degrees F while the wetboiling point is 284 degrees F. Castrol LMA is classified as a DOT 4fluid. It has a dry boiling point of 446 degrees F and a wet boilingpoint of 311 degrees F. And by the way, your Corvette won't disown youfor using Ford fluid!

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If you smack a curb or hit a pothole with your Corvette, the front-endalignment can be thrown out (it's easier than you might think). Theresult, of course, is eventual tire damage. With the cost of tirestoday, it's good preventive maintenance to have the alignment on yourcar checked regularly. Some folks have the alignment checked every timethe tires are rotated, or at 6,000-8,000-mile intervals.


A number of Corvette folks report plug fouling problems when usingvarious octane boosters. If that happens, go straight to the spark plugswithout passing go! The solution is to clean and/or replace the plugs(and perhaps search for another octane booster).


How can you tell if a Corvette crankshaft is cast or forged? A castcrank will usually have a line on the counterweights where it was pouredinto a mold. A forged crank does not have the fine lines on thecounterweights.


Changing oil is a messy job. That's a given--but to make it less messy,try this: Slide a plastic bag over the filter after you break it loosewith the filter wrench. Hold the top of the bag firmly against theengine block with one hand, and use your other hand to unscrew thefilter. The oil slop will be contained inside the plastic bag.


Believe it or not, too much oil in the pan of your Corvette is just asbad (perhaps worse) than too little. If the oil level is too high, itcan be above some windage trays. At the least, the oil can be picked upby the rotating assembly. Next, it is whipped into a frenzy--creatingfoam, which really means the oil becomes aerated. Hot, aerated oil willnot maintain pressure and, because of this, will definitely createlow-pressure problems.


Some intake gaskets purposely block off coolant ports to enable theengine coolant to flow in a predetermined path through the engine. Ifthese ports are not blocked off it could create a short circuit in thecooling system. So what's the answer? Buy the right gaskets for theapplication. Otherwise, the temperature gauge in your Corvette could beheaded toward the stratosphere.


It's common knowledge that it isn't a good idea to break in aflat-tappet-cam engine with synthetic lubricants. Did you know thatapplies to all engines? According to the pros, all engines, no matterthe camshaft type (roller or flat tappet), are best served by usingmineral oil during the break-in. Why? The experts claim that thecylinder-wall finish/ring combination used today still needs some timeto get acquainted and effectively break in. If it's good enough forprofessional racers, it's good enough for us.


When polishing and detailing custom Corvette billet wheels, be sure touse only extra-soft polishing cloths. Old fleece sweatshirt material isperfect. Do not use cross-weave materials (for example, T-shirts and/ordiapers) on soft metals, since they can easily scratch the surface.


Never add air to a tire and rim assembly that has been operated in aseriously under-inflated or flat condition. Why? The condition justmight provoke the tire to separate (often explosively). The result canbe serious injury. The real solution is to have the tire deflated andcarefully inspected by a professional. By the way, we're talking fromexperience here, folks. Be extra cautious.


If you're plagued with bulbs on your Corvette that constantly needattention, think about this: Is there corrosion at the base of the lightbulbs? If so, apply a wee bit of electrical grease to the bulb base.This goes for the prongs of blade fuses as well. Your problems should besolved.


According to several fuel-pump manufacturers, one of the leading causesof in-tank electric fuel pump failure is fuel starvation. Most tankshave baffles or a built-in sump that keeps the pump pickup submerged infuel. These pumps use the fuel as a cooling agent. So far, so good; butif the gas tank contains only a gallon or two of fuel and the vehicle isdriven hard around a corner, the fuel may slosh away from the pickup andmomentarily starve the fuel pump. Repeat this process a number of times,and the pump will ultimately suffer (no more cooling and it willeventually expire).


Spark-plug gap size has a direct effect on the plug-tip temperature andon the voltage necessary to ionize (light) the air/fuel mixture. Becauseof this, gaps are important. Plugs are not pre-gapped at the factory,and the gap must be set and adjusted for a specific Corvette. NGK pointsout that a modified engine with higher compression or forced inductionwill typically require smaller gap settings (to ensure ignitability inthese denser air/fuel mixtures). As a general rule, the more power youare making, the smaller the gap you will need. NGK also states that aspark plug's voltage requirement is directly proportionate to the gapsize. The larger the gap, the more voltage is needed to bridge the gap.Most experienced tuners know that opening up gaps to present a largerspark to the air/fuel mixture maximizes burn efficiency. It is for thisreason that most racers add high-power ignition systems. The added powerallows them to open the gap yet still provide a strong spark. With thismind, many think the larger the gap the better. In fact, someaftermarket ignition systems boast that their systems can tolerate gapsthat are extreme. Be wary of such claims. In most cases, the largest gapyou can run may still be smaller than that claimed.

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If you're plagued with a vintage Corvette engine that starts, thenstalls, check and reset the idle-mixture screws. Turn the screw in untilit seats. Repeat with the second screw, then back both out 11/2 turns.This should provide a baseline so you can set the idle mixture on arunning engine.


When servicing K&N filters, be sure you do not over-oil the element.Aside from restricting airflow, excess oil can migrate into the intakesystem where it can coat electronic sensors. The result, of course, canbe catastrophic. When servicing the filter, if oil drips from it, washthe filter and start over. Use only K&N oil. Follow the oilinginstructions included with the filter or, if you've misplaced them,refer to the instructions listed in the back of the catalog.


Speaking of the "old days" and ancient tricks, here's something youshouldn't do: It was once common to pull off a battery cable when aCorvette engine was running to check the charging system. If thealternator was working, the engine would continue to run. If it wasn'tcharging, the engine would stall. Some people think you can do thattoday. Not so! Those old Corvettes had relatively robust mechanicalvoltage regulators. Newer examples have internal voltage regulators, andif you yank the cable, you'll create a spike or surge in the system.Everyone knows what that will do to a computer.

The modern automotive electronic voltage regulator has some of the samecomponents as a computer. Pulling a battery cable while the engine isrunning will send a voltage "spike" throughout the electrical system ofthe automobile. This can, and often does, damage the voltage regulator.But it can also take out other electronic bits. Included in the mix arecomputers, ABS control units, electronic instrument clusters, soundsystems, and so on. Bottom line? Don't mess with the electronics.They'll come back and bite you.

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Here's a quick tip: In order to measure a wheel-bolt pattern, measurefrom the center of the No. 1 lug hole to the outside of the No. 3 lughole. The number you get is the bolt circle size.


Do you have an impossible-to-find whine originating from the undersideof your Corvette? If you do, think about adding a small amount of greaseto the splines on the transmission slip yoke. This eliminates themetal-to-metal contact from the splines in the yoke to the splines onthe output shaft.


Never add air to a tire-and-rim assembly that has been operated in aseriously underinflated or flat condition. Why? The condition just mightprovoke the tire to separate (often explosively). The result can beserious injury. The real solution is to have the tire deflated andcarefully inspected by a professional. By the way, we're talking fromexperience here, folks. Be extra cautious.


Squealing Corvette disc brakes are a pain in the you-know-what. In orderto stop the ordeal, try these two tips:

* After resurfacing a rotor, hand-sand both sides smooth and flat, using120- or 150-grit sandpaper on a sanding block.

* After sanding, clean the rotor thoroughly with detergent and water.This serves to demagnetize the rotor and remove all of the fine grit anddust that can cause chatter.

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Car wash sponges are cheap. Dedicate a sponge for tire cleaning only anddon't use this pad for anything else. This way, the tire residue canstay in one spot, and you won't contaminate your car's paint withwayward tire dressing, small rocks, and so on.


On vintage Corvettes, rear drum-brake wheel cylinders should be replacedas pairs. Why? Simple. It will equalize the hydraulic pressure pulse. Ifyou don't, you run the risk of replacing brake shoes that can becontaminated by brake fluid leakage from the cylinder.


Have you ever had one of those moments when you're searching for thatelusive problem on your Corvette only to find out it was a painfullysimple fix? Here's one more to add to your collection: a crimped fuelline. The fuel line is important to fuel delivery but often overlooked.If it's crimped, your car will have no fuel (or much less thanrequired). The maladies perpetuated by this can be numerous. Give it alook before ripping apart the car.


Don't you just hate a squealing fan belt? If the belts on your Corvetteare tight and still squeal, try this: Buff the inside of the pulleyswith green Scotch-Brite. The abrasive pad gives the fan belt a morepositive surface and should eliminate the noise. It's also a good ideato use a new belt once the pulleys are "deglazed."


When bleeding Corvette brakes manually, be careful not to overextend themaster-cylinder piston. This can rip or tear piston-cup seals that, inturn, can result in master cylinder failure. It's simple to cure thisproblem: Just put your free foot under the brake pedal during thebleeding process to act as a stop.


Pretend you have aftermarket wheels on your Corvette (not a bigstretch). And pretend they use different lug nuts from those fitted toyour car by the OEM manufacturer (similarly, not a big stretch). Whatabout your spare? If it's stock, make sure you have a spare set of lugnuts that fit the spare. Otherwise, you might not be too happy if you'reout in the middle of nowhere with a flat.


Fan clutches lose speed over time because the silicone fluid insideloses shear strength. After six or eight years of service, the clutchmay be slipping to the point it can't spin fast enough to keep up withthe engine's cooling requirements. This in turn may cause the engine tooverheat during hot weather, when idling in traffic, or when using theA/C. Any fan clutch that's wobbling, making noise, leaking, or turnswith little or no resistance is overdue for replacement.


Believe it or not, good old-fashioned, standard rubber fullsize coolanthoses should be used to ensure maximum flow. Smaller-than-stockbraided-steel AN hoses decrease flow and, as a result, can hinder propercooling.


If you have roller rockers on your Corvette engine, be sure to installthem with the flat side of the seat facing up. If you don't, it willkill the polylock (and quite possibly the rocker). Just make certain theflat surface on the rocker-pivot mechanism faces up. You'll have nobroken parts or "missing lash" with this tip.


Poor fuel economy can be caused by a defective jet, an incorrect jet, ora loose jet (more common than you might think). Use a large, flat-bladescrewdriver or, preferably, a dedicated jet driver to tighten the jetsso they aren't damaged in the process. Tighten the jets (Holley torquespecs call for 30-40 in-lb of torque). If the carb is a Holley, and ithas a secondary metering block, repeat the process.


What isn't generally known or understood is that break-away orbreak-loose torque is considerably less than the applied torque. Thismeans the torque required to loosen a bolt previously tightened to 90lb-ft would be considerably less than the 90 lb-ft of applied torque. Atorque wrench should be tested on a torque-wrench testing machine todetermine its true accuracy.


101 ways to make your Corvette faster, easier to work on, and makethe details shine
Wayne Scraba Feb 8, 2005


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