Quick and easy ways to catch small engine problems before they become big ones.

By: Jeff Huneycutt

It is a simple fact that engines wear over time and require maintenance. And when high horsepower engines begin pushing the output even higher, the extra stress on components makes regular checks and maintenance even more important.

The ideal situation is to catch any small engine problems while they can still be easily (and cheaply) fixed before they become big, expensive repairs. It’s sort of like going to the dentist to get your teeth cleaned so you can avoid a root canal later on. The difference is working on your car is always better than a trip to the dentist.

David Ising, Technical Services Manager for COMP Cams®, offered a few tips for quick checks that you can make in order to give you a better idea of your engine’s overall health. If your engine is in a race car, either on a circle track, at the drag strip or on a road course, you may need to perform these checks after every event or two. However, if you are simply looking to take the best possible care of your hot street engine, you can probably get by with doing these checks whenever you change the oil.

We won’t get into the specifics of how to actually perform some of these engine checkup tasks. For example, good directions for checking the valve lash on an engine equipped with a solid cam setup would need an entire article for itself. But COMP Cams® has resources for everything you will read about here. If you aren’t sure how to do any of the following tasks, or lack the proper tools, all you have to do is call your COMP Cams® tech support representative at 1.800.999.0853, and he or she will answer any questions you have and get you going with confidence.

                                                        Check Your Timing

A quick timing check is one of the easiest ways to make sure your valve train is healthy and running like it should. This is especially important with traditional style engines that employ a distributor driven off the camshaft.If the timing mark jumps around when checking your engine timing, it could be a sign that the timing chain has stretched.

Checking the timing isn’t necessarily about making sure the timing is still set correctly—although that is also important.

You can also use the timing light to make sure your timing mark is steady and not jumping around. If you notice your engine isn’t holding its timing consistently, it is probably the result of a stretched or worn timing chain.

Other possible problems that can affect your timing can also reside inside the distributor. An excessively worn distributor can suffer from spark scatter, which is when the spark jumps from the reluctor to the wrong terminal. Or, if the gear on the bottom of the distributor is worn it can also affect engine timing. Sometimes a check of the oil filter media (which we’ll get to next) can also warn you of a worn distributor gear—especially if you are running a softer brass gear.

Inspect Your Filter

It is a messy job, but one that can really pay big dividends when it comes to catching developing engine problems before they result in big-time damage. The oil flowing through your engine not only provides lubrication, but it also sweeps away smaller contaminants and debris before they can damage bearings, cam lobes, cylinder walls and other delicate surfaces.

When an engine has a problem, such as the babbit material separating from a bearing, small particles of metal will often get caught in the flow of oil. Those particles will eventually get filtered out and separated from the oil by—you guessed it—the oil filter. Cutting up the oil filter to get a good look at what has gotten stuck in the filter material can give you a good idea of the health of your engine.

Since oil filters don’t come with zippers, you will have to cut open the canister in order to get to the filter element. Don’t try to do this with a pair of tin snips or a powered saw, you will only wind up with a huge mess of oil all over the shop. By far the easiest, neatest and safest method is to use a dedicated oil filter cutter. Powerhouse® Products sells one that is very reasonably priced and easy to use (pn POW351646). It is actually similar to a giant brake tubing cutter. The idea is to cut the metal canister around the base so you can lift it off without spilling any oil and easily inspect the filter media.

When your engine is new, you will probably see quite a bit of material caught in the filter media. That’s normal and shouldn’t be a concern unless you see a lot of the same type of material. You will probably see small flecks of silicone from the build, some aluminum from the pistons and maybe even lint left behind by the rags used to clean the engine. This is all part of the break-in process as the many components of a new engine work through the process of mating together. There may be a few small pieces of steel, but if there are large chunks or you continue to see flecks of steel after several runs, you might have a problem.

The most common source of steel in the filter element is the bearings flaking. But it can also be from just about anywhere else in the engine. It can often be tough to tell aluminum from steel—especially when they are coated in oil—so to make sure you use a magnet to separate the materials. Steel is ferrous, which means it will be picked up by a magnet while any aluminum pieces will be left behind.

                                                              Monitor Valve Lash

This tip is mainly for pushrod engines. Solid valve trains, either flat tappet or roller, will need to be periodically lashed. Unlike hydraulic lifters, which use oil pressure activating a plunger to take up any gaps in the valve train, solid lifters do not adjust for lash. To keep the valve train healthy, the lash, which is essentially all the gaps in the valve train components when the cam is on the base circle for that valve, must be precisely set and maintained.

Instead of simply checking your valve lash and resetting it if necessary, carefully monitoring any changes in lash over time can also give you a good clue to the health of your valves, seats, lifters and camshaft. As the miles and/or laps pile up, you can expect the valve lash to slowly decrease as the valve train tightens up. This is because of wear on both the lip of the valve and the valve seat in the combustion chamber. This wear will allow the valve to move up higher in the head and that, in turn, will reduce the available lash. This should be considered normal wear with practically any engine and isn’t cause for concern unless you notice one valve suddenly moves a couple thousandths more than the rest in the engine.

Checking valve lash on valve trains with solid lifters is a regular chore, but monitoring how the lash changes over time can give you a clue to the health of your valve train.

If you find the lash in one or more of the valves opening up, that is a sign that you should investigate further. The most common reasons for the valve lash to open up are problems with either the valve lobe or the lifter itself.

If you are running flat tappet lifters, which are still common in stock car racing and classic muscle car engine builds, there’s always the risk of killing a lobe. This is especially true now that most modern oils are no longer formulated to deal with the sliding friction you get with a flat tappet lifter. Of course, the lash is checked with the lifter against the back side of the lobe, which is unlikely to be ground down. But if the nose of the lobe is damaged, that means the crown of the lifter has also been ground off, which will create the extra lash that warns you that something is wrong.

A roller lifter is much easier on the camshaft, so a dead lobe is much less of a problem in this scenario. In this case, noticing the lash has opened up is usually the result of a lifter problem.

This can happen when the axle for the roller breaks or the needle bearings supporting the roller get crushed. Either problem will allow the roller to sink lower into the body of the lifter and open up the lash. When this happens the lifter is very likely to damage the camshaft as well, so make sure to pull and check both. Still, that’s a lot better—and cheaper—than having to completely rebuild an engine.

Track Spring Pressure

Valve springs themselves aren’t all that expensive in the grand scheme of things, but a broken valve spring certainly is. A broken valve spring will allow the valve to bang into the piston; pretty soon one or both are broken. Not long after that, the entire engine is only useful as a giant paperweight. Fortunately, valve springs almost always tell you when they are going to fail. The trick is that you have to listen.

For street motors valve spring technology is so advanced that they can last a very long time. Simply swapping them out at a given interval is about all you need. But if you are racing or building an extremely high horsepower engine with aggressive lobes, keeping a check on your spring pressures can clue you in before one is about to fail.

Most valve springs will go through a drop in pressure as they break in. With quality valve springs, this number should represent five percent or less of the spring’s total pressure. After the springs break in, that number will hold steady, so your readings should be the same within a pound or two every time you check them. But when a spring—or springs—start to lose pressure again, that’s a sign that it is about to fail. When you notice this, pull that spring or springs and replace them. If two-thirds or more of the set begin failing at the same time, that’s a good sign that the springs have reached their designed limit and the entire set should be replaced.

Once again, replacing a valve spring that otherwise looks perfectly good might be a tough pill to swallow. But just consider how much a few bucks spent on new valve springs will save you compared to a complete engine rebuild if one of them fails.