The art of the 75-minute rebuild
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Anyone who's ever taken some time to observe professional Top Fuel drag racing has probably marveled at the teams' ability to rebuild an engine between rounds. In less time that it takes most of us to TiVo through a week's worth of The Daily Show, the crews in charge of engine maintenance are able to swap out the parts required to keep these ticking time bombs together for another five seconds.
A mere thirty seconds after pulling the car into the pits after a run past 300 MPH, a specialized tool organizer is set into place on top the car's roll cage, and a team of about eight men goes to work. Less than 14 minutes later, the engine is torn down to a block containing only the camshaft, cam bearings, crankshaft, and upper crank bearings, and the reassembly process begins. The cylinder heads get dropped back on the block just a bit more than a half-hour into the overall process, and at five minutes past the one hour point, it's time for each crew member to man his station for the warm-up process.
Check out the Read link for a lengthier tear down of the the 75-minute rebuild.
[Source: Hot Rod]
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Reader Comments (Page 1 of 1)
chuck goolsbee 10:28PM (7/23/2006)
Good. Fast. Cheap.
(pick any two)
No disrespect to these guys at all (I should know.. I'm the world's slowest mechanic!) but it isn't like they are getting 250,000 miles out of it. ;)
--chuck
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gbh 12:19AM (7/24/2006)
Marveled at what? Bunch of yutzes slapping together some seconds-from-meltdown junk in under an hour? Gimme a week coaching your local highschool's auto tech class. I can get the same performance out of them.
Good thing those POS lumps only have to live for about 900 total revs.
Yeah, they make huge power. For all of 5 seconds. Wahoo...
C'mon, building an engine worth more than $1000 outside a clean room is just pathetic. Tolerances? They couldn't tell you to save their lives.
One of the many reasons that 'drag racing' is not considered racing by a lot of folks.
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dakota 12:59AM (7/24/2006)
"Marveled at what? Bunch of yutzes slapping together some seconds-from-meltdown junk in under an hour? Gimme a week coaching your local highschool's auto tech class. I can get the same performance out of them.
Good thing those POS lumps only have to live for about 900 total revs.
Yeah, they make huge power. For all of 5 seconds. Wahoo...
C'mon, building an engine worth more than $1000 outside a clean room is just pathetic. Tolerances? They couldn't tell you to save their lives.
One of the many reasons that 'drag racing' is not considered racing by a lot of folks."
Righttttt...and lets see you turn out an engine that can withstand that amount of power, torn down and put back together within that amount of time. Oh and drag racing has been around alot longer than more current motorsports in this country. Why don't you try doing something before opening your trap.
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carbuzzard 7:38AM (7/24/2006)
Horses for courses. A thoroughbred would make a lousy barrel racer. So what? The vehicle and the system to service it that has been developed for the needs of that event is impressive. No doubt the kind of tolerances that would make a good Prius would make a lousy drag racer. So what? Is Michael Schumacher's F1 ride a "POS" because it doesn't work very well taking Jr. to soccer practice? Is a race car whose engine is torn down after two hours of racing mechanically superior because, well, after all, it's not like it's being asked to go 250,000 miles. Sheesh.
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ron 9:41AM (7/24/2006)
If you haven't seen a top fuel pass, it is one thing you should see before you die. It ROCKS!!! When they go by it feels like your chest is going to explode. I've never been to NASCAR but when they go by it's just simply amazing. It's definitely racing. That’s my vote.
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kag 10:06AM (7/24/2006)
Right on #5. Also, because the pits are open to the public at any NHRA event, you can get right down there and watch them work between rounds. For the warmup they start the car on alcohol and then switch to nitro. Nothing quite like watching the crowd scatter from the nitro cloud... and that first throttle blip...
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gbh 12:52PM (7/24/2006)
"Righttttt...and lets see you turn out an engine that can withstand that amount of power, torn down and put back together within that amount of time. Oh and drag racing has been around alot longer than more current motorsports in this country. Why don't you try doing something before opening your trap."
You're right as far as the history goes, I'm sure the first race ever was a simple drag. However, I fail to see the relevance of that historical data point.
As far as opening my trap, if you have the money (and it'll be over 50K), I'll build you a 6000HP+ Nitro-grenade powerplant. If you have some more money, I'll set you up with the tools and a little coaching. This is not some V12, EFI DOHC turbocharged high-tech powerplant we're talking about. There are only about 10 discreet steps to take one of these pushrod primates apart to the level that this article talks about. That's why it takes 75 minutes. If you knew anything about engine building, you'd know that. You can overlook a LOT of precision (and dirt!) when the engine only has to last about 900 RPMs.
Most of the parts in those engines are (relatively speaking) off the shelf items. These are not bespoke F1/Indy/WRC/Whatever pieces. Most parts in Top Fuel engines are basically catalog items, if you know who to call. I can pick up the phone and have most of it shipped to me rather quickly. There is some finish machine. Otherwise, in short order, you'll have the bitchenest Camaro on Main Street. For at least 10 seconds.
My terms are 50% non-refundable down. Balance on delivery. I accept checks and all major credit cards. Yes, there is a cash discount. (Most of my clients who spend larger amounts just pay with a check.)
Not the kind of engines I like to build, but any builder worth his salt can do it for you. If you have spent any time with the folks who full-time build this drag stuff, you'd know what I mean.
After 30+ years of being in and around motorsport, I find it really easy to be bored and unimpressed with drag racing. Especially what happens in the drag pits. Yeah, it's noisy. Yeah, there's flames. Yeah, they're slappin' a motor together. There's no mad rush of analyzing the data from the last run to reset the traction controls, torque splits, retune the injection and ignition maps. For god's sake, people are wasting time with temps and humidity so they can guess on how to rejet their carbs...
As a spectator, I'm not 9 years old anymore. If loud and noisy for a tiny fraction of time still did it for me, I'd go sneak onto an airport outfield, and wait for the big jets to takeoff and land. A little nitro smell and some noisy flames? You really ought to get out more.
It only lasts 5 seconds. They go (hopefully) in a straight line. There is no cornering, braking, re-accelerating. Yep, getting that one launch down as perfect as possible is a skill. No doubt about it. No, I won't suggest for a second that just anybody can do that. Nor will I suggest that I can outdrag Force. But it is only one very limited skill.
Carbs? Roots blowers? Pushrods? Quaint museum pieces and paperweights - not anything that belongs on a racing vehicle.
The NHRA has kept drag racing in the past for two reasons. The main one is money- Holley, Weiand, and a few other companies would have their business evaporate in a matter of days if modernity were allowed in. Second, is safety - speeds would greatly increase and ETs would drastically drop. Imagine 7000+HP with AWD, traction control, and a host or refinements. Now THAT might be exciting. Especially if the track were longer than a 1/4 mile.
Sadly, the paranoia over danger has hamstrung most all forms of racing. If they allowed modern tech and removed the multitude of restrictions on NASCAR, at 300MPH even IT might be interesting enough to watch.
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Non-Bizarro Adam 2:57PM (7/24/2006)
GBH,
I understand your disdain for NHRA drag-racing to a certain extent, and I am not going to bemoan the conversion to FI from carbs, but I must object to your demonization of pushrods in modern racing. If you look at the ALMS racing series results posted here, the Corvettes did quite well in spite of their weight penalty and restrictor plates, and have proven quite durable throughout their complete dominance of the GT1 class in recent years. Done right, pushrods have proven capable of ridiculous power, rock-solid reliability, and even pretty good mileage, all things that can be useful in a racing series, no?
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Tim C 4:42PM (7/24/2006)
Pushrods are archaic, like sidevalves and siamesed ports. We know better now. GM has bravely soldiered on with the Corvette. While using pushrods reduces the height of the engine it's no coincidence that all modern engines use overhead cams. Carbs and cams were the business in their day. That day has passed.
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Eric Bryant 11:07PM (7/24/2006)
gbh,
As is the case in any form of top-tier racing, underestimating the difficulty of the task is ill advised. I also highly doubt that you could build such an engine from "off the shelf parts" or for $50K, but, hey, I could be wrong.
I do, however, agree totally on your comments regarding the hamstringing of drag racing to satisfy the safety weenies. The lack of progression in the last two decades is indeed disappointing, and the whole affair seems to be regulated by some sort of backwoods fear of electronics and other "modern" technology.
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gbh 1:18AM (7/25/2006)
I tune cars and build engines for a living. If you have money, I'll tell you where it all comes from. Then build it for you. That's parts and a 90th percentile engine. If you wanna race in the top 5 slots, it'll cost (way) more for tuning.
If you were in the business, you'd see all the vendors of that stuff at PRI every year. It's hardly magic, it just seems that way until you get behind the curtain.
Don't get me wrong, pushrods can work. But anything that works well with pushrods will work better with (properly designed) OHC. Pushrods are horribly inaccurate, impossible to get consistent cylinder-to-cylinder, and add pointless complication to the engine.
The only reason they still get used is the cheapo factor.
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