Good racing engines, like...
Good racing engines, like this aluminum monster from Clements Automotive, don't come cheap. Make sure you are doing everything you can to help it provide all the power you paid for.
There are many scenarios that require you to lay out hard-earned cash for a race engine. Maybe you are new to racing and starting from scratch. Maybe you are moving up a class. Maybe you ran it hotter than a stove and blew it sky high (don't worry, we won't tell anyone). Regardless, we know you want a perfect home for your new engine to live and provide you plenty of power for a long time. With that in mind, Circle Track contacted some of the top pros in the industry for their tips on raising a happy, healthy engine.
Don't Get Double-Crossed
Wiring the ignition system can affect a lot of racers. MSD is kind of the standard in the industry, but the plug between the distributor and the ignition box isn't watertight. A lot of racers cut off the connector that MSD uses and install a GM weatherpack connector, which is definitely an upgrade in terms of keeping out water.
It's easy to get the polarities reversed when you do this, however. The connector is only composed of four wires-two from the distributor, which connect to two leading to the ignition box. The problem is that the wires don't match up. The two leading out of the distributor are black with a colored stripe. One stripe is orange and the other is violet. The two wires out of the distributor box are solid violet and solid green. You might think that the black-and-violet wire connects to the violet wire on the ignition box, but it doesn't. The black-and-orange wire connects to the violet wire, and the black-and-violet wire connects to the green wire. It's impossible to get it wrong because MSD's connector comes attached from the factory, and it's keyed so that you cannot plug it in if reversed. When you're splicing in your own connector, it's easy to get confused. We've seen a lot of people in this situation.
MSD wiring can be a little...
MSD wiring can be a little confusing. A lot of racers like to cut off the stock connector and splice a weatherproof connector in its place. If you do, just remember that the violet-and-black wire connects to the green wire and not the violet wire as you might think.
When the wires get crossed, it creates an error and 22.5 degrees extra advance. Plus, the ignition is firing sporadically because it's working on the wrong side of the pickup coil inside the distributor. The motor won't tolerate this. Then it gets worse because guys will drop a new engine in, get the wires reversed, and never check the timing because they assume it must be correct as it just came from the dyno. They end up bringing the engine back to the builder in a basket, wondering what happened. The first thing we'll check is the ignition system.
The good news is the fix is simple. If you are putting weatherpacks on your ignition system, just remember that the violet-and-black wire connects to green. Now you are home free.
The Break-In Blues
Oval track engines with big mechanical cams have to be properly broken in. I know it's tempting when you get that new engine installed to rev it up a few times to impress the neighbors, but if the engine hasn't been broken in on a dyno, that's one of the worst things you can do to it.
A new engine needs to be run at 1,500 to 2,000 rpm for 11/42 hour to 45 minutes. That's enough to get the rings to seal and break in the valvesprings so that they don't disintegrate as soon as you run the engine hard. I recommend using high-grade detergent oil, and don't put any strain on the engine. You need to keep the rpm between 1,500 and 2,000 to keep the oil moving through the engine. You need oil pressure at the camshaft and oil splashing up on the valvetrain, and you don't get that at the level you need at idle. Every two to five minutes, give the throttle a little rev to keep the carburetor cleaned out. You don't want the engine to stall because it's real hard on a new cam if you have to start the engine up again.
After you have run the engine for 30 to 45 minutes, shut it off and check everything. Check for water and oil leaks, and maybe change the oil. Now is also a good time to re-check your lash as well as re-torque the head bolts. Now you are ready to race.
Race EngineeringLake Worth, FL
LC Engineering has found that...
LC Engineering has found that the Toyota four-cylinder racing engines, which are catching on in Mini-Stock oval racing, do not like to be paired with a Chevrolet-style hydraulic throwout bearing.
Trust Your Builder
You put a lot of faith in your engine builder in terms of the money you spend on his product, so you might as well trust his judgement on the engine's settings. A lot of guys experiment with different things on their own and end up hurting power. Take, for example, spark-plug heat range. If an engine comes from the builder with plugs in it, I recommend using that type of plug. As an engine builder, I can get a lot closer to the ideal heat range than a driver can. It's the same with valve lash issues and other adjustable components on the engine. Before changing a lot of different things, make sure you check with the engine builder to see what he recommends. He's put in a lot of time and effort to dial in all the settings and maximize the engine, so if you go changing a lot of things just to see what will happen, you're likely to find yourself going in the wrong direction.
Racers are always looking for a better combination of components that will either give them an edge on the track or make their lives easier. Unfortunately, not every combination of parts from different sources works like you might expect. You have to be careful.
We specialize in Toyota four-cylinder engines, and last season we had a problem with a couple of customers installing Chevrolet-style hydraulic throwout bearings with the clutch. For oval track racers running the Celicas, we recommend a mechanical clutch fork. The hydraulic throwout bearing puts too much pressure on the crankshaft, which ends up blowing out the throwout bearing and seizes up the motor. You have to be careful when mixing different aftermarket components
Many of our experts noted...
Many of our experts noted that timing issues are a common problem encountered by new racers. If you aren't completely comfortable using a timing light, ask your engine builder for a primer.
In more general terms, one problem we've seen customers have is a failure to properly clean all the lines when installing a new engine. If you have a blown engine, it probably has sent metal throughout the oil system if it's a dry sump or remote filter. Some customers might clean out the fuel lines with carb cleaner, but they don't do anything to flush out anything else-the filters or even the oil pan. You have to be careful to thoroughly clean every system. We've started recommending Mag Filter for all our race engines. It is a magnet that mounts right on the oil filter, and it's amazing what it traps during the course of a race.
Finally, I suggest that you have your cam timing and ignition timing set up for the rpm range you expect to be running. We can have three cars with identical engines at the same track, but each driver has a different driving style, or maybe he or she has a different gear ratio. By finding out where the customer is most comfortable driving, we can tune the motor and cam for the appropriate rpm range. A lot of guys don't do that, and I don't think they understand the advantage of being able to adjust the camshaft timing, for example. I think our most frequent calls from our racers are in regards to camshaft timing, because people don't know what's possible. There is a misconception out there as to what advancing or retarding a camshaft does to an engine. Are you getting more top end or bottom end?
Again, the phone call I get is, "I've got six of my friends telling me one thing and six friends telling me something else." They want to know the truth, so they are asking questions, but they aren't always asking the right people. How do you know your friends really understand what happens if you advance the camshaft 2 degrees? I definitely recommend asking the industry leaders-don't depend on the guy in the pit stall next to you. Call the guys who built your motor or built the components that went into your motor, because they understand how it makes its power. We want to be able to support the guys who buy our engines because we want to make sure they run up front, and I'm sure other engine builders are the same way.
Lake Havasu, AZ
When checking lash on roller...
When checking lash on roller lifters, slide the feeler gauge perpendicular to the direction of the roller. If you run the feeler gauge in and out in the direction that the roller turns, it can give you a false feeling of lash clearance.
Timing Is Everything
A problem I see from guys who are new to racing is that they aren't sure how to set the timing on their engines. Let's say they have an aftermarket balancer with a degree tape on it that says 32 degrees. They also have an adjustable timing light whereby they can dial in 32 degrees on the back. Well, they've got 32 degrees in their heads, they set the timing light for 32 degrees, then mark the balancer on 32 and wind up with 64 degrees of timing.
Yes, the engine will crank and run with the timing set that far advanced. But when you go out on the track, it will knock the bearings out. I've seen it happen too many times.
Another tip I have for new racers is to always make sure you allow the engine to warm up properly. This is especially important for a new engine. You've got to let the water and oil temps come up to operating temperature before you start stressing the engine. When the fluid temps are still cold, that means that your bearing clearances are still tight also. Cold oil is thick, and when you combine that with tight bearings, you run the risk of not getting all the oil you need where you need it.
If you're racing an alcohol motor, it can be really tough to get that motor warmed up, especially early in the season when it's still cold outside. Guys will just let it sit and idle, and the motor will never warm up. Instead, it ends up running rich and milking the oil. If the carburetor has air bleeds on the side, you can actually lean out the air bleeds so that the carburetor won't run too rich while you are sitting at idle. Also, if you have a fan blade on the motor that's always spinning, I recommend putting a piece of cardboard in front of the radiator to block the flow of cool air. Both of those tricks help when you're trying to bring an alcohol motor up to temperature.
A third thing that you need to be aware of is how you service your K&N air filter. Filter problems are actually more common than you might think. Not too long ago, we had a guy bring his car back to us. He was down on power so we put his car on the chassis dyno to find out what was going on. He had already chased this power problem all over the place and replaced several thousand dollars worth of parts-ignition, carburetor, all kinds of stuff.
We finally found the problem almost by accident. I had taken off the filter because I wanted to watch the booster when we put the gas to it, and the engine suddenly picked back up. His K&N filter had gotten dirty, and he had decided to wash it with laundry detergent. That's the last thing you want to do because the detergent clogs up the gauze material of the filter, and then the filter won't breathe any air. K&N makes a filter cleaner that doesn't harm the filter material, and I recommend you use only that.
Make sure your air filter is properly sealed. This is vital if you are racing on dirt. Sometimes you won't get a good seal all the way around, between the filter and the filter cover, and it will allow dirt to be sucked in through that crack. You can seal that off by running a tiny lip of grease all the way around the filter on both the top and the bottom. This helps seal the filter to the cover so that the only way air can get into the engine is through the filter material.
Wells Racing Engines
Electric Power Equals Horsepower
Make sure that your engine is getting at least the 12 volts it is designed to run on. If you are running an MSD ignition, and the alternator is down and you aren't getting the voltage you need, your power is going to suffer. We encourage our customers to purchase a voltmeter and check regularly to make sure the alternator is putting out around 13.5 volts. All you have to do is ground one of your leads and then hold the other one to your alternator output. You have to rev up the engine a little. Those things don't start putting out until about 3,000 rpm. If you aren't getting around 13.5 volts, you probably need to replace your alternator.
Overall, electrical problems are something that new racers often struggle with. A lot of times, they are looking for a mechanical problem and missing the real cause because it's electrical. Often it's something as simple as a poor ground. We've had occasions when somebody brought an engine back, claiming that it didn't run like they thought it should, and it turned out that the engine wasn't properly grounded. You would think a race car with metal all over it would be a good ground, but nowadays, with the tough powder coatings that people are putting on the chassis and the zinc-coated motor mounts, it can be tough getting a good ground. We recommend running a ground from the back of the cylinder head to a rollbar. Before bolting it on, grind off any powder coat or paint so that you have a clean, metal-to-metal contact.
We've also had problems in the past with racers not getting their engines full of water. About everything that races on Saturday night these days is designed like a Chevrolet Monte Carlo that's low-slung in the front. As the radiator has been lowered over the years, it has become common for the highest point in the cooling system to be somewhere in the engine and not the radiator fill cap. If you simply fill the radiator with water, and if the top of the engine is higher than the fill point, you will trap air pockets in the engine and have serious cooling problems.
You can fix that by mounting what we call a surge system-basically an overflow tank-on the firewall a little higher than the engine. When you fill the coolant, fill from the surge tank. That will flow from the tank, to the radiator, and onto the engine. As long as the top of the tank is the highest point in the system, you shouldn't have a problem.
Cox Race Engines
Contrary to popular opinion, I believe that adjusting the valves should be done with the engine at room temperature whenever possible. We have run several tests, both in the shop and on the dyno, and we have found that adjusting valves on a "hot" engine isn't always ideal. During the time it takes to adjust the valve lash, or just check them, the engine cools off significantly. This change in temperature leads to a variation in component expansion and clearances. Allowing an engine to cool down for the few minutes it takes to check 16 valves can change valve lash significantly from cylinder to cylinder.
Because of this unpredictability in temperature and component expansion, I believe the best way to check and set the valve lash is with the engine at a constant temperature-and the best way to do this is with the engine at room temperature. The general rules of thumb for adjusting at room temperature are as follows:
Cast-iron block with cast-iron heads: Adjust 0.002 looser than specs
Cast-iron block with aluminum heads: Adjust 0.004 tighter than specs
Aluminum block with aluminum heads: Adjust 0.010 tighter than specs
This is just a baseline. With a new engine, I usually check the valves at room temperature, then bring the engine up to operating temperature and check them again to verify the difference between the hot and cold lash. Now I know the difference and can make my adjustments on a "cold" engine accordingly.
Also, on roller rockers, do not run the feeler gauge in and out in line with the roller. The roller will give you a false feeling of lash. Always run the gauge sideways when checking lash. And it's always a good idea to keep records of what valve, or valves, required adjustment during each check. This could be a telltale sign that something is about to fail.
If the valve lash is too great, a cam lobe may be failing or a roller lifter axle bearing may be worn. If the lash is too tight, it may be a sign that the seat is getting beat up or the valves are sinking in the head. All in all, it's a good way to catch a problem before it gets ugly.
I have found that the easiest way to adjust valves is to start on the number one cylinder (firing order) and adjust both valves on this cylinder. Then rotate the engine 90 degrees, go to the next cylinder in the firing order, and adjust both valves on it. Continue this pattern all the way through the firing order. By following this method, you will adjust each cylinder on TDC when both valves are closed-no guesswork. Most balancers are marked 270/180/90/TDC. If your balancer isn't marked, it's easy enough to do yourself.
Also, when breaking in a new flat-tappet camshaft, it's a good idea to leave the valves a little on the "loose" side to help the cam, lifters, and spring survive the break-in period.