August 2010 Tech Talk
Putting My Whip on a Diet, Making the switch to an aluminum block
Most of you are just like me when it comes to racing technology. If a product comes along, even if it seems like a good idea, I think most of us are a little bit hesitant to try anything new until we see some data and results from other racers using the same or similar product. That, in fact, was exactly how I viewed aluminum cylinder blocks for the better part of the last decade. Sure, I understood there were some inherent advantages to aluminum: namely weight and repairability. That’s all fine and well, but I’d also heard the horror stories of blocks moving so much with heat that racers couldn’t hardly adjust the valves, and cylinders that wouldn’t seal up because the blocks moved so much. All in all, it just seemed like more of a hassle than it was worth for someone like me, who bracket raced almost exclusively.
Those of you who have followed the majority of the tutorial columns I’ve written here on ThisIsBracketRacing.com will remember that I talked a great deal about weight transfer in the columns pertaining to the consistency of our cars. For this reason, I had seriously considered going to an aluminum small block in one of my door cars many years ago. The folks at BRODIX offered a small block at that time, and the feedback I’d heard was pretty good. I could knock about 100 pounds off the nose of my Nova, and that sounded like a great plan. In the end, I elected not to go that route, basically just because I’m “thrifty” and didn’t want to come off the extra $3500 (at that time I was just running a stock GM block).
A few years ago, aluminum big blocks started to become a lot more prevalent in the world of sportsman drag racing. As racers began to see a slight advantage to having the faster car, we all started spending more money to upgrade our equipment. When BRODIX first offered their line of aluminum big blocks, the timing was just about right, and slowly sportsman racers have begun to change their opinion of the aluminum blocks as we’ve learned more about them. Obviously, we’re all intrigued by the weight savings. On a typical big block setup, the aluminum block can be as much as 130 pounds lighter than an aftermarket iron block.
In addition to weight, I think everyone understands the virtues of being able to fix aluminum blocks when disaster strikes. There are instances in which even aluminum blocks are not repairable, but BRODIX estimates that 90% of damaged blocks can be fixed without a monumental labor investment. That fact alone helps us justify the cost, which is still substantial at about $5100 retail. When building a new motor, however, that cost is only about $2,000 more than going with a standard aftermarket iron block. If you’ve got some time and want to check out something cool while you’re online, visit www.BRODIX.com
and watch their video of the aluminum block repair process, it’s fascinating.
I gave that summary, full of factual information that we’re all aware of on some level, so that I could tell my personal story.
As I said in my opening, I’ve never been one to jump on any bandwagon too quickly. Outside of toying with the aluminum small block idea for the door car, I had never seriously considered going to an aluminum block in any of my bracket machines, especially a dragster. I’ve been quoted before as the guy who said “Small blocks are for door cars, and big blocks are for dragsters.” I’ll stick by that, it makes sense simply from a weight distribution standpoint. In the dragster, I love having the big power and the big speed, and the added weight is on the rear of the car: it’s a win-win situation. For the door cars, I want the small block to get as much weight as I can off the front end so that we can transfer it more easily when we leave the starting line. Big blocks are for dragsters, small blocks are for door cars.
I basically took the same tact when considering the aluminum block option. I wouldn’t mind taking that extra weight off the front of the door car, but why on earth would you take weight off the back of a dragster? As a bracket racer, I’m much more concerned about the consistency of the car and it’s ability to get down a suspect racing surface than I am with the tenth of a second I can pick up by losing 100+ pounds on the rear of the car. With that theory in mind, combined with the myths and horror stories I’d heard about aluminum blocks (loss of power, substantial heat movement, etc.) I essentially swore off the thought of an aluminum block, and vowed to never use one in a rear engine dragster.
My how things change…
In 2008, I started running the 8.90 category in NHRA and IHRA pretty heavily. In that class, more so than in bracket racing, speed is viewed as a significant advantage (and I agree that it is to an extent, for several reasons). I agreed with this theory almost immediately, but I wanted to have a multi-purpose car: something I could bracket race week in and week out, and still run pretty good steam in Super Comp. Todd Ewing and the gang at Huntsville Engine helped me settle on a 582 cubic inch big block with a set of BRODIX 12* cylinder heads. We put the motor in a tall deck iron block, and I was fairly pleased with the results. In 2008, I ran 8.90 at 178 miles per hour in mine shaft conditions in Houston. And I ran mid 4.60’s in good air (low 4.80’s in the heat) when I went 1/8th mile bracket racing.
That was all fine and well for a little while, but toward the middle of 2009 I felt like I was giving away some advantages in both spectrums: I wanted a little bit more speed in Super Comp and I felt like the weight of my car (nearly 2100 pounds) was making it inefficient on the throttle stop. In bracket trim, I didn’t like the constant maintenance on the motor, and while I didn’t mind getting chased as much, I hated the idea that I had so much money tied up and so much power to only be in the middle half of the field in terms of ET.
In August of last year, I went out on a bit of a limb, and I built a second dragster with the sole intention of having two purpose built race cars: One for 8.90 competition and quarter mile bracket racing, and another for 1/8th mile bracket racing. I built the new car as a flyweight special, and I even let Todd and the guys at BRODIX talk me into putting that same 582 into a BRODIX tall deck aluminum block. The folks at American Race Cars made some small weight saving changes, and I was a lot more conscious of the weight of the components I bolted onto the car. In the end, I emerged with a new Super Comp ride that weighed in at 1775 pounds.
Meanwhile, I installed an iron block, conventional head motor in my ’08 Dragster, and made it my 1/8th mile bracket car.
In Super Comp, I had a rocket ship. My same old combination was now running 8.90 at 183+, and I went 7.02 @ 189 mph in Florida at the winter series. On the few occasions where I did go eighth mile bracket racing, I was dialed in the 4.4 second range. I was still concerned about the lack of weight on the rear of the car, but I didn’t figure it mattered for what I was doing. 90% of the racing I would do in this car would be done in Super Comp, on the throttle stop, and at national event facilities where traction shouldn’t be much of an issue. When I wanted to go double-enter an eighth-mile bracket race at a lesser facility, I could take the old car, run 4.90’s down a dirt road, and not feel like I was beating it up.
When I started messing with the combination in the aluminum block, I learned some things that I was really impressed with. First of all, the loss of power myth is just that. Maybe in the early days of primitive aluminum blocks the cylinders got far enough out of round with heat to cause an issue, but technology has come a long way. The blocks that are currently on the market, like these from BRODIX, don’t have issues like that. I’m not big on dyno numbers, I’m big on time slips. I picked up nearly .3 of a second in the quarter-mile by losing 300 pounds. I don’t think the aluminum block slowed me down at all. I was also pleasantly surprised by the ease of maintenance on the motor. Those of you who have made the switch to big headed motors (18*, 14*, 12*, 11*; anything without a conventional head design) know that the weak link to the combination is roller lifters. As such, I’m a nut about running thru the valves, because I’ve caught so many potential lifter problems before they became an issue (by finding a valve that lashed .004 or .005 loose). My fear with the aluminum block was that the heat dissipation would make these routine checks a lot less accurate. That couldn’t be farther from the truth.
At the recommendation of the guys at Huntsville Engine, I took the motor home, installed it, started the car, and brought it thru a heat cycle. With the engine hot, I set the valves at .024”, just as I’d run them with the iron block. Then, I let the car cool overnight. The next morning, the valves all checked at about .015” cold. Granted, this is a little bit more discrepancy than I saw with the iron block (they moved about .004-.005” from hot to cold), but the consistency of that movement is incredible. I run through the valves every morning with the engine cold, and I’ve caught just as many potential lifter problems since switching to the aluminum block as I had before.
A little technical info here… In researching this story, I asked the guys at BRODIX why the original aluminum blocks got such a bad reputation for robbing horsepower. The truth is, that the early aluminum blocks did just that. The problem was due to the metal used in these blocks nearly two decades ago. The casting would move around, as would the sleeves, thus keeping the rings from sealing and robbing horsepower as an end result. In those days, the block couldn’t even be decked flat from new because the sleeves would sink after initial fire up. Basically, the heat would move the metal around and drop the sleeves allowing compression to leak and lose horsepower. These problems in the primitive days of aluminum blocks were the cause of my initial trepidation to making the switch.
The metal used in today’s blocks, like the one I purchased from BRODIX is superior to anything on the market. Now, blocks are decked flat just like an iron block before assembly, and the movement in tolerances is minimal. Plus, when ordering a new aluminum block from BRODIX, we as racers can specify some factory options that would cost a mint in machining with a conventional iron block. A few of those include roller cam bearings, raised cam, oversized lifters, and more.
BRODIX offers aluminum cylinder blocks for a variety of racing applications with seemingly unlimied options.
An added bonus to the aluminum block that I’d never really given much thought to was how much easier it is to keep the motor cool. With the exception of frying a water pump in Norwalk this season, I’ve run that car for nearly a year now and never seen the water temperature gauge exceed 165 degrees (and I stage at 150). It’s so much easier to get to a desired temperature. That’s the nature of aluminum, it’s easier to heat and it’s easier to cool, so you’ve got a lot more flexibility in getting the engine to proper temperature.
As it turned out, I got everything that I wanted and more from my switch to an aluminum block. I picked up ET and MPH from the reduced weight, I have the added peace of mind knowing that if I do have engine failure I should at least be able to salvage the block, and I was pleasantly surprised by the consistency of heat displacement and the ease of maintaining temperature.
That’s all good stuff, but I don’t think you needed me to tell you any of that; it’s kind of common sense. This is the part where I let you in on my dirty little secret. I built this car to run 8.90 and select quarter-mile bracket races. I thought it would be fast, but extremely track sensitive so I started off being very selective as to where I raced it. The truth is, as much as I hate to admit it, this is the best bracket car I’ve got.
This combination has brought the Super Comp results I'd hoped for: we've combined for a Lucas Oil Series victory and a pair of national event wins. What I hadn't really bargained for was success on the bracket racing level, where we've also won a handful of big events, like the Bradenton 5-Day last winter pictured above.
I’ve taken this machine to tracks I’ve thought it shouldn’t go down, and it does. It was so consistent last season that I couldn’t leave it home for the Million Dollar Race. There, it went 4.49 eight runs in row before I had a freak problem to end my day in round six (a bolt fell out of the throttle stop and it closed… Sick, sick, sick!). Just a few weeks ago, my buddy Jason Lynch drove it to a runner-up finish at the $50,000-to-win Great American Race in Belle Rose, LA. There, it was stuck on 4.54 all day, in New Orleans, in July. It’s a bad whip; it’s crazy fast and it’s incredibly consistent. And the scary part is that it’s my 8.90 car. I don’t bracket race it much, and I haven’t really fine tuned the combination for wide-open competition at all (not that it needs it). All I’ve done is turn the stop off and let it eat.
Like anything else, I want to know why… Why does this 1775 pound car with 1200+ horsepower go down the race track better than my 2000 pound car with 850 horsepower? The only explanation that I can give is that the nature of a dragster still allows the weight to be proportioned correctly, even though it’s lighter in the back of the car. Even with the aluminum block, the new car has over 75% of its weight on the rear wheels, which isn’t much different from the iron block car. It took a little bit different suspension and shock set up than the iron block car, but my theory is that the lighter combination actually let’s the 4-link work a little bit more efficiently, and the added power actually helps the car stay stuck in the middle of the track. I’m no suspension guru, but I’ve driven a lot of cars and I’m not afraid to turn wrenches and try things, and that’s really what I think. Plus we get back to the inherent laws of physics I’ve discussed before. Assuming that the car works well and traction isn’t an issue, a 4.50 car has to be slightly more consistent than a 5.0 car. It’s on the race track for less time, so outside variables simply can’t have as much effect.
All I set out to do was to build a great 8.90 car. I wanted a ton of mile per hour, and I thought I could make it consistent for that style of racing. In doing so, I stumbled upon a combination that I always said wouldn’t work: a lightweight, fast, all aluminum bracket motor. I’m not saying this is the only way to go; for weekly competition this combination may not be cost effective. I’m just saying that it opened my eyes. You can rotate the earth and print tickets. You can have the fastest car and the most consistent car at the track.
And that’s how the guy who said he’d never have an aluminum block in a dragster came to eat crow and admit he can no longer justify building a car without the advantage of an aluminum block!
I want to thank Jeff Brotherton and Jennifer Brotherton Woods at BRODIX for their help in assembling this column. A lot of the technical information and feedback comes directly from their research and development. There are a number of aftermarket companies that offer competitive cylinder heads and blocks, and I’m sure most are great products. I use BRODIX because of the people. They’ve got a background in racing, they’re constantly testing new products and ideas either on track themselves or through a great network of engine builders like Huntsville Engine, and they’re constantly in touch with racers like me to get feedback on products. Without trying to sound like a complete sales pitch, if you’re entertaining the idea of going to an aluminum block I urge you to give the crew at BRODIX a call.