Many manufacturers involved...
Many manufacturers involved in racing know the problems you are up against because they are racers too.
The basics of an automobile engine require lubrication. This means the role of the oiling system is critical to performance and especially critical for high-performance applications. To help you keep your engine in its best condition, we called some experts, who shared their advice based on daily experience in oiling system work.
Timmy Petty ; Maurice Petty and Associates; 336/498-2110
One thing we really get into is making sure all the oil passages are just as clean as we can get them. I know that sounds simple, but it's a step that often gets overlooked. We've even ruined a $15,000 engine once because of it.
One area that requires particular attention is the rear main cap. If there is any trash in the holes, that can ruin an engine really quick--especially if you are running an external oil pump. We polish every hole with 220-grit paper and chase all the threads to make sure every oil passage is perfectly clean. Even if the block is perfectly sealed from the time it is cast until you start machining on it, it's still going to have overcast, or casting slag, in there. We'll spend a day on the engine block, looking it over and polishing all the oil holes just to make sure we can eliminate potential trouble before it happens.
Do You Know Where that Pan has Been?
Steve Morrison; Milodon; 818/407-1211; www.milodon.com
I hear racers all the time say they lose oil pressure in the turns, but it comes back on the straightaways. They don't seem too concerned about it, but I think, "What are you saying? You are losing oil pressure at least two times every lap! Can you imagine what that is doing to your parts?"
After a little investigation, a lot of times we'll discover the culprit is a cheap, oil pan that has very poor oil control. If you are racing in a claimer class, I can understand the temptation to get out cheap with a $68 oil pan, but look at it this way: You can't get out for less than $2,000 for even a claimer engine. Isn't it worth another $60 or $70 to get a racing oil pan that's probably going to save you money in the long run?
There are lots of good racing pan builders, not just Milodon. The difference between them and a cheap $68 oil pan is the racing guys actually understand what you are doing to your engine. They understand you are diving hard into the turns, you are really pushing the g's to the right side of the car through the turns, and then accelerating hard out of the turn and all the way down the stretch. They know where the gates need to be and the pickup needs to be so oil is always available to the engine. That cheap pan may be a deal now, but when you have to replace that first set of bearings early because the engine was starved for oil you've just lost everything you've saved, plus potentially a lot more.
Make sure all the oil galleries...
Make sure all the oil galleries and passages that were drilled are clean and burr free before you plug the holes.
The Devil is in the Details
Jay Dickens; Jay Dickens Racing Engines; 662/369-2780
A lot of people will take an engine block out of the box, clean her off, and start bolting parts up. Sometimes, you can get by with that, but sooner or later you are going to end up getting bit. We try to minimize that problem by trying to eliminate any potential failure before it can happen. Before a block is ready, every hole on it that has been drilled or machined, we've massaged it or relieved it in some form or fashion.
Think of the oil galleries and other passages inside the block as the engine's arteries and veins. Just like in your body, junk in there is probably going straight to the places it doesn't need to be. When those oil galleries get drilled out, they leave a little sliver of metal where the drill bit stops. You've got to go in there with sandpaper or stainless brushes and hit all those burrs. We've got some pretty specialized tools to do it, but just use whatever you can to get in there.
These days, when it comes to engine building, it's the little things that seem to make the difference. Everybody has access to buy the good parts now. It's just a matter of taking the time to measure stuff, make sure it all fits properly, and all the little things like that.
Billy Godbold; COMP(R) Cams; 800/999-0853; www.compcams.com
Everybody has his or her own preferences when it comes to assembling an engine, but I like to recommend that people use the red cam lube that comes with most cams these days. A lot of people use white lithium grease on the camshafts and lifters. That stuff is good because you can put it on and it's still going to be there nine months down the road. But, it's not as good because, with the first revolution of the cam, most of it is going to be wiped off. That's why I like the red cam lube. It is superior because sometimes we'll get a cam back that has a thousand miles on it, and it still stinks from that stuff. If you get it on your hands, you will have to lose a few layers of skin before you can get it off, but at least you know it's going to protect your cam the first time you crank your engine.
When it comes to lubrication in general, you can say I'm for it--the more the better. Valvesprings are amazing heat generators. Every time they move up and down, they are generating a little bit of heat. Multiply that by the rpm today's race cars are reaching and you have a lot of heat. The only cooling they have is oil, so you should make sure you get plenty of oil onto the valvesprings. I am a big fan of spray bars. Also, I am against oil restrictors. If you are going to run oil restrictors, don't run a 0.020 or 0.030. Run a 0.120 or something; get oil up into the top of the engine. If you can run a spray bar, great. If you can't, at least don't try to make a bad situation worse by intentionally limiting too much oil to the top of the engine.
Gary Penn; General Motors; Performance Parts; 800/468-7387; www.goodwrench.com
A mistake we often see from all racers in all venues is they buy a high-volume oil pan that holds eight quarts, for example, and they put eight quarts in it. This is a big mistake because that brings the oil right up to the crank. The real beauty of a high-volume deep-sump pan or a pan with wide kick-outs is you can run the five or six quarts that the engine wants and still keep the oil level down away from the crank.
At GM, we are also big fans of synthetic motor oil after break-in. The stuff has really improved over the years and allows you to get by with things you might have never thought possible. A good example is our 385 crate engine, which is the same engine that our new 400hp circle track crate engine is based on. At the drag strip, we actually run the 385 engine out of oil at 1,000 feet and run it with no oil pressure across the finish line at 7,500 rpm. The pump has it all in the top of the engine at 1,000 feet because we only run three quarts of 0W-10 in the motor. That frees up a few horsepower because nothing is going through the pump, it just cavitates. Plus, there is no oil in the crankcase so you don't have any windage.
Even though the engine is running for about two seconds with no oil pressure, we really aren't seeing any undue wear on the engines. That's a testament to the quality of synthetic oils out there today. Now, I definitely am not recommending a circle track racer try this--those engines require more oil with more viscosity, and they require a lot more endurance--but you get the idea of how the envelope is being pushed. The advanced quality of the oils on the market means the old rule of thumb that you need 10 pounds of pressure per 1,000 rpm is not valid any more.
Overloading the Overhead Cam
Dan Esslinger; Esslinger Engineering; 626/444-4919; www.esslingerracing.com
For the Mini Stock guys, we offer a line of oil restrictors to put into the cylinder heads, because we have found the oil flow is way more than you need. The overhead cam does not need all the oil pressure it's getting. Where we like to see 60 or 70 pounds on the bottom end, you can get away with 35 pounds up on the top end. To get the restriction we are looking for, we will slide a certain size tube in an oil passage that restricts flow to the top. Otherwise, you tend to pack in a lot of oil up above and starve the engine on the bottom end.
The restrictor on the left...
The restrictor on the left is for a Ford block; the one on the right works with Chevrolet. Finding the right amount of oil restriction to the head is a delicate balance; too much wastes horsepower but run too little and you stand a chance of ruining springs early.
Jeff Broetzman; Peterson Fluid Systems; 800/926-7867; www.petersonfluidsys.com
A lot of guys these days are playing with creating vacuum inside the engine. Vacuum is very good for making horsepower, but it can also be very bad for some oiling systems. It causes a battle of wills in terms of physics inside the motor. The vacuum is trying to hold everything in, and the oil pressure is fluctuating and doing other things depending on how radical that disparity is between the negative pressure created by the vacuum and regular atmospheric pressure. It gets a lot of guys in trouble because it dries up a lot of surfaces that are relegated to being oiled by splash feed from other areas.
One good example is the wristpins, which are typically splash-fed off the side clearance by a set of rods connecting to the crankshaft. The centrifugal force created by the crankshaft throws the oil up there and lubricates the wristpin, but that stops when you create a vacuum. The answer Winston Cup guys have found is wristpin oilers, which are feed holes that run through the connecting rods. A guy needs to be aware of how creating a negative pressure condition inside the engine can affect how the oil behaves. He may be creating horsepower, but if he also isn't taking the precautions he needs to protect certain parts, he's also hurting the lifespan of his engine, which can be a pretty big investment.
Jerry Ehlert; Calico Coatings; 704/483-2202; www.calicocoatings.com
The dry-film lubricant coatings we apply to bearings provide a wide margin for error. It's what we like to call "insurance" in case of a momentary loss of oil pressure, say when the oil pump cavitates. Also, there's a lot more incidental contact between journals and bearing surfaces than many people realize. In theory, it should never happen because of the oil film strength, but it does occur. I've had customers tell me they have lost oil pressure and driven a half lap or more to get back to the pits. I've had one customer tell me that he was three laps from the end of a major race and broke an oil pump shaft. He lost oil pressure but elected to continue. The coatings were the difference between being able to hold on for a top finish in a big money race and not being able to finish at all.
The lines on this Ford block...
The lines on this Ford block trace the oil galleries that Ken Troutman of KT Engine Development mentioned. For all the other main bearings, oil flows in one hole and out another that leads to that main's corresponding cam bearing. Because of the horizontal gallery cut into the front of the block, the front main is fed from two holes. KT Engines plugs the leftmost hole and allows oil to feed directly to both the first main and cam bearing through the other gallery.
Steve Morley; Grenade! Racing Enterprises; email@example.com
My biggest tip is also one of the simplest ones: Warm up the engine before hot laps!
So many times I have seen racers going out on the track with a cold engine. The oil cannot possibly get back to the pan when it is like syrup. Besides, the engine clearances are all wrong when the engine is not up to temperature. The next time you have the intake off your engine, pour room temperature oil in the valley and see how long it takes to run back into the pan.
Also, I've noticed that oil pump driveshaft engagement has become an increasing problem. With everybody making trick-of-the-week intakes and different distributors, I've noticed some cars having trouble because the oil pump shaft isn't getting the engagement it needs. During mock-up, I will have the intake on the engine and bolt on the distributor. Then, I flip the engine over and check for total engagement of the oil pump driveshaft. Be sure to have some end play. The common complaint when this is a problem is, "It has 60 psi of pressure, then when the engine gets up in the rpm, the oil light comes on." Look at the ends of the shaft. It will be shiny from riding up on the end and not turning the oil pump--bad news!
Ken Troutman; KT Engine Development; 704/784-2610; www.ktengines.com
The galleries in the block can often be wasteful with oil. For instance, a Ford block has a spot in the front where the galleries cross. The factories make it easy on themselves. On the front of the Ford block, you've got one feed hole, and then you've got another big hole that crosses that feed hole and also runs to the crank. It's dumping so much oil right there to the front main bearing. It just doesn't need that much oil, so we plug one of the holes and close it off.
We are always looking at the engine as a whole and thinking about how we can be more critically stingy with the oil we are feeding through the block. Oil is horsepower: Tighten up the clearances, close off any unnecessary oil feeds and use a lighter viscosity oil. You can go with a lighter oil if you have tightened up the clearances because once the engine gets hot and opens up, clearances are still tight enough that you aren't hemorrhaging oil.