Stopping The LeaksI run a '78 Camaro in the Pure Stock division at my local dirt track. I have a few problems that I am hoping you can help me with. First, my 350 is stock with no modifications, and I am running a stock Quadrajet carburetor. My problems started my first night out. I got black-flagged three times (I left the track each time) due to smoke. Both my father and one of my sponsors told me that it was white smoke that was coming from under the car. They also said it would only happen when I was entering the corners off the throttle (but not every time). My first thought was that I was sucking tranny fluid into my motor, so I changed the vacuum modulator valve on the tranny with a new one. As I rolled onto the track for a feature race, I began to sense a black flag again. And, with four laps remaining and running in third, out came the black flag. I pulled into the pits, raised the hood, and saw I had an oil leak. Oil was all over the front of the motor and around the fuel pump, and the dipstick was wet too. Everything was dripping with oil! After bringing the car home and looking it over, it appeared to me that oil was coming from behind the fuel pump. So I siliconed the pump and let it dry for one week.
The next week, I was involved in an accident but believe it or not, I did not have any oil leak the whole night-just a little puff of smoke every now and then and a flooded carb. So I rebuilt the carb and went out the following week. When the heat races came up, I was running well-no smoke, nothing. Then all of a sudden, my temperature gauge was reading 240 degrees F, so I immediately shut the motor off.
Once again, as I lifted the hood, I found out that my oil leaks had returned, and I had a tranny fluid leak. I also threw a belt. At this point, I was running out of solutions, so I asked one of my friends for some advice, and he said I should block off my modulator valve on the tranny since I don't need it. I blocked off the valve, cleaned the motor, and put a new, wide cog belt on and went out for the feature race. Believe it or not, I finished the race without a problem. I had no fresh oil or tranny fluid anywhere except around my dipstick.
The motor runs very strong with 60-psi oil pressure and around 160-180 degrees F water temperature all day. After further inspection, I noticed that my No. 2 plug and the surrounding area was wet with oil. The area where the intake meets the head near the No. 1 plug is seeping water. Is it possible that I am blowing oil out of my No. 2 cylinder and/or the dipstick?
These problems come and go as they please, and any advice you can give me to what my problems would be greatly appreciated. By the way, I am running about 4,500-5,400 rpm.
Keep up the good work, guys!Chris HullPort St. Lucie, FL
Sounds like you solved the tranny fluid problem, so let's talk about the smoking issue. It appears to me that you have one of two problems. In your letter, you say that when you go into the corner and lift off the throttle, it starts to smoke. That makes me think of two different possibilities for the smoking problem.
One could be a vacuum leak. As you head into the turn, you are running a lot of engine speed, and when you lift, the carburetor butterflies close, which sets the stage for a lot of vacuum. This means you are creating a heavy vacuum signal on the intake system. If there is any vacuum leak under the intake manifold, between the intake manifold and the head, it could be a source of a smoking problem. The vacuum could be pulling oil out of the lifter valley, and if that were the case, smoking would occur. If a vacuum leak is the source, the solution is in a gasket change.
You also said water was leaking where the intake meets the head, so a gasket change would be a first option to solve that as well. This would be the most apparent solution if, as you state, everything is stock. If, however, you or anyone else has done any machining on the heads and or the manifolds (surely you wouldn't try to cheat!), then you may simply have a mismatched fitting between the manifold and the head. That could be a source of water leakage. Aside from that, it's advisable to make sure you have used a silicon sealer at all of your water outlets for maximum leakage prevention.
The second thought that comes to mind about your smoking problem is this: You say that you have a little oil around the No. 2 spark plug as well as around the fuel pump. That makes me think that perhaps you have a fine valve cover leak on the right-front corner. That's where all the oil goes when you go through the turns, so that's why my suspicions are aroused. If this is the problematic area, you need to work with your PCV valve (positive crankcase ventilation) to get a little vacuum drawn on the crankcase itself. If you don't have a PCV valve, then you need to have a couple of breathers open on the lefthand valve cover (on the driver side) to let pressure out of the engine.
The dipstick problem can also be crankcase pressure-related. If the PCV valve is not operating properly or there is no PCV valve and the engine is not ventilated properly with breathers, then the engine is trying to push oil out anywhere it can, such as through the dipstick opening.
Regarding your carburetor-flooding problem, you don't say if rebuilding your carb solved that issue. If not, it's really important to stay on top of that. Continual problems in that area will eventually wash the rings down, then you will really have a crankcase pressure problem. And that is certainly not a good thing.
I hope this helps you in your quest for a solution. Having been bitten by the same race bug as you, I know how frustrating all of this can be. But hang in there, 'cause it's gonna get better!James Fry-Engine SpecialistCompetition CamsMemphis, TN
Stock Setup WoesAs a major race fan, I wanted to try out racing for myself. Enduro racing is popular where I live, and being budget-minded, that's where I decided to race.
The rules were simple-stripped cars on 75 series tires, no spring jacks or turn screws. So I stripped my '86 Olds Cutlass and went to the 250-lap asphalt war with my all-stock chassis. Needless to say, I had my hands full.
The front end stuck well, but the rear was all over the place. Every time I lifted off the gas heading into a corner, the rear slid out or the wheel hopped. I got a lot of tire spin coming out of the corner when I got back onto the gas.
I soon found out most "Street Stock" cars on the track had various spring weights and heights to help them, and this was legal as long as they were in stock location and appearance.
Do you have any suggestions on spring weights and height setup? I also need help with tire-stagger baselines, and I would like to know wheel offsets that will help me. How much do I need, and where should they go?
I would also like to know of any literature that is available that can help me on any of this. Thanks.Mark NadolneyPinconning, MI
Let's see how we can help you. First, since you don't say much about the kind of track on which you are running (banking and so on), I will give you some advice on setting a suitable baseline. This may not be the absolute optimum for you, and you may have to make some changes depending on the track where you compete. However, the basics that will be supplied here will be a good foundation from which to make any alterations.
In the class you are running, we need to talk primarily about dealing with the frontend of your car. Working on the front is where the most can be gained, and you will be amazed at what you can achieve.
Let's begin by talking about spring rates, because there are a couple of things to think about here. First, you need to start out with a rate of 900 for the left front and 1,000 for the right front. In addition, it's advisable to run a sway bar. Something like one out of an old station wagon would be ideal. Since you can't run weight jacks, a sway bar will give some of the same effect. We normally run the biggest sway bar possible, and adding preload to the sway bar will cause it to act like a weight jack device, which has the net effect of increasing the spring rate.
Next, you need to check out the caster setting on the frontend of the car. Increasing the caster will definitely help the directional stability and generally make the car more maneuverable. When you set the caster on the left front, you will want to achieve a caster split on the right front. What I mean is, let's say you set the caster on the left front at 3 degrees positive, then you would want the right front to be set at 6 degrees positive (the top ball joint is behind the bottom ball joint). This is a good rule of thumb to shoot for so that you can have a good baseline. Since you have a stock setup, getting the split exact will be an inexact science, but get it as close as you can.
Next, deal with tire camber. The basic set I suggest is 211/42 degrees negative camber for the right front and 211/42 degrees positive camber for the left front. One of the best ways to keep an eye on how you are doing, as far as camber setting, is to check your tires with a pyrometer. Otherwise, just keep a close eye on the tire wear. Running on asphalt, you will see negatives very quickly.
On the rear end of a stock setup like yours, there is not a whole lot you can do. But, to make sure the car is set right, I suggest using a 175-pound spring on the right rear and a 200-pound spring on the left rear.
When it comes to shocks, you should consider going to an aftermarket company to replace your stock ones. A company like AFCO has a great selection to meet your needs, and they have stock mounts, so it conforms to your rules.
According to your letter, you are having a little trouble into and off the corners. The description that you give sounds like a braking issue. If your rules permit, a brake-proportioning valve can really help on the problem you describe. It will allow the brake system to be split proportionally between the front and rear. By giving you control over braking force, you can reduce rear braking which in turn will help you on the sliding and wheelhop issue. That's because a reduction of braking force on the rear will make the car tighter going into the corner, and it will not want to come around so easily. The real beauty of this adjustable system is that you can adjust the braking while you are racing. Just as a rule of thumb, remember that more brake force in the rear makes the car come around easier, and more front brake pressure makes the car tighter.
Now let's talk about stagger. Front crossweight is what you are shooting for, so to get there, you want to run a larger tire on the right front. That obviously means you want a smaller left-front tire. The front stagger is important and is used more as a tuning method. The more direct effect regarding stagger is on the rear. Depending on the type of track you are running, the rear stagger will vary the most. If, for instance, you are on a track with long, sweeping turns, a stagger of 1 or 2 inches will work best. On the other hand, if the track has tight corners, you may go up to 4 or 5 inches of stagger. Remember, the larger tire does the most work.
Now to your question about wheel offsets. In your class and running on asphalt, you want to get offsets of the following: For the left front, run a 3- or 4-inch offset (this measurement is taken from the back of the wheel to the center), and for the right front, run a 2-inch offset. For the left rear, I suggest a 3- or 4-inch offset, and for the right rear, go with a 3-inch offset. This will make the rear narrower than the front, which is best for handling.
I think that covers your questions, and as a finishing statement to everything that I have written, I want to repeat that this information is what we would consider a generally good baseline for the stock-type car you are racing. However, depending on the track you are running, you may need slightly different settings. Checking with your competitors is a source for that, or companies like ours can help you get the right setup. What I have supplied here is simply a good starting place.
I hope this has helped you. Since you have decided to take up the call to race, you would definitely be well served by looking into as much information as you can find on any number of racing subjects. And to answer your question on such publications, my first suggestion is to find as many Circle Track issues as you can get your hands on. Spread throughout the years, it has good basic tech articles that can serve you well. There are, of course, other books too, and while I cannot list all of them here, you can find them in a variety of ways. I suggest that you go online and track down what you need.
Actually, the folks at Circle Track have informed me that in this very issue, they have listed several Web sites that may help you in your continuing education. Look at them and then dive in. Many of these companies may be a source of such information, or at minimum, they may be able to direct you to additional sources for the information you seek.Tom CarpenterChassis SpecialistSmiley's Racing Products
Getting On TrackWhat is a track bar? Is there another name for it, and what does it adjust?Ben Williamsvia e-mail
A track bar, also known as a Panhard bar, works like this: when you move a track bar up and down, you change the rear roll center on the car, which helps make the car turn better. A track bar works very similarly to A-frame angles in the front end. The A-frame angles basically control your front roll center, and the Panhard bar, likewise, controls the rear-end geometry.
The bar is just a straight piece of round steel with bolts on each end to hold it in place. Usually whatever the bar bolts onto will have different holes for mounting the bar at various heights so it can be adjusted up and down (in relation to the ground).
A track bar is found in the rearend. It keeps it from shifting from side to side; in other words, the track bar will mount on one side of the rearend, and on the other side, it will mount on the chassis. In its simplest function, the Panhard bar keeps the rearend from going left to right in the car.
For racing, the track bar is used to change the roll center on the car's rearend. This adjusts how weight gets from the left-rear to the right-rear tires. It works basically by how the body rolls going into the corner. Usually when the bar is higher on the left side, it will loosen the car up, and conversely, when the bar is lower, it tightens the car. This is achieved simply because the higher the bar is mounted, the more it will allow the rear-end weight to shift from side to side, thereby causing more roll.
Understanding how a track bar works and learning how to properly adjust it for varying setups can help you go faster.Mario GosselinDGM RacingLake Hamilton, FL