The 24 Hours of Lemons Forums → Lemons Newcomers → What fails?
As I work on my hypothetical build, I'm trying to learn from the mistakes of others. Which components fail most frequently?
I recall a certain number of thrown rods - the engine I hope to use includes an oil pan baffle in most iterations, which is a bit of a comfort.
I don't recall any other items that fail at high frequency, so please, remind me, which parts have the highest failure rate in these races. Other than the drivers, I mean.
What kind of car are you building? Different cars have different soft points.
Engine's of course are the most catastrophic, and there are far too many things to kill on a car to name them all, knowing what you are building will make it easier to point out the areas that need more attention.
Everything fails.
Although, I have seen more brake failures (mostly pad failure) than anything else. Which is stupid because it's the one place you can spend money to make it right. Then engine, tranny, clutch failures. People always seem to lose a wheels lug, wheel, hub failures.
Everything fails.
Although, I have seen more brake failures (mostly pad failure) than anything else. Which is stupid because it's the one place you can spend money to make it right. Then engine, tranny, clutch failures. People always seem to lose a wheels lug, wheel, hub failures.
We cooked our breaks our first race. My recommendations:
-expensive break pads aren't worth it. They wear our faster that cheap pads. Just buy two or three sets of the entry level pads, or at most the second cheapest pads from AutoZone.
-change your pads (or at least check them) between race days #1 and 2.
-bring a spare clutch cable. Check this between race days as well.
-make sure your temperature gauge works.
-oil. LOTS of oil.
Head gaskets. There are probably a thousand other catastrophic failures, but blown head gaskets seem very common, most especially during the hot summer races.
RobL wrote:Everything fails.
Although, I have seen more brake failures (mostly pad failure) than anything else.
We cooked our breaks our first race. My recommendations:
-expensive break pads aren't worth it. They wear our faster that cheap pads. Just buy two or three sets of the entry level pads, or at most the second cheapest pads from AutoZone.
It depends on the pad and the temperature range it's meant to operate in. You really need to look at track pads, not high performance street pads.
Anything that's rubber fails. Primarily, coolant hoses and belts. Also fuel hoses and hydraulic hoses.
Cooling problems are probably the #1 failure.
If you're running a high-mileage engine, it's probably wise to put a new set of bearings in it, even if you don't do any machine work or replace anything else, at least you'll have fresh bearings. Cheap insurance, plus it gets you inside the engine where you'll spot other potential problems. Ditto with head gaskets if it's a really old engine or an engine prone to head gasket failure.
Brakes, as Rob mentioned. Just put a set of race pads on the car with high temp fluid. Don't ask questions, don't wonder if generic parts store pads will do. Just do it. Add some brake ducting, too. Why not? Just do it.
Electrical systems fail. The more complex they are, the harder they fail. Unless you're working with something older than mid-80's, you're going to have to keep the ECU and a lot of the factory engine harness. That's fine. But, don't rely on factory wiring for anything else. When it comes time to troubleshoot electrical problems, your simplified "wire from the kill switch through a fuse to a switch that goes directly to the fuel pump" is gonna be a helluva lot easier to figure out than whatever convoluted ECU-controlled, safety-interrupted, relay-switched system the factory gave you! Same goes for lights, brake lights, etc.
Gauges are not considered in the budget. Install some in a visible location and be sure your drivers know how to read them. A giant "low oil pressure" light could save your engine.
Exhaust system. Another "safety" item. Spend the $200 and do it up right. This can save you black flags and hours of off-track repair time.
Replace the clutch. Find room for an eBay clutch kit in your budget. Just do it. Like so many other Lemons teams before you, you'll kick yourself for the clutch that failed during the race. Just do it.
A lot of the wheel/lug failures that Rob mentions are mechanic error problems. Invest in a torque wrench. Use it. Undertorqueing lugs will result in failure, as will overtorquing. Use the torque wrench on wheel lugs, major suspension components, brake caliper mounting bolts, etc.
Whatever you overlook will fail. Whatever you knew was "iffy" and didn't replace or repair will fail. Take the hit at BS judging if you have to. The 10 lap penalty they'll give you for the obvious new radiator will be better than 2 hours of down time scrounging a new one, or an hour replacing with the spare you brought... or the trashed engine due to allowing it to overheat.
What kind of car are you building? Different cars have different soft points.
Engine's of course are the most catastrophic, and there are far too many things to kill on a car to name them all, knowing what you are building will make it easier to point out the areas that need more attention.
I'm leaning very heavily toward a second generation GM U-Body minivan. The ones I've seen available around here tend to have bad head gaskets, so that's a logical start. One idea I'm toying with is installing some auxiliary radiators for the oil and transmission in the back and running cooling ducts down through the roof to give them air - the tailgate would, of course, be removed.
the gen 3 3.1L have some weird gasket problem so its not a surprise. I think it was linked to the material they were using so hopefully a replacement one will last.
the gen 3 3.1L have some weird gasket problem so its not a surprise. I think it was linked to the material they were using so hopefully a replacement one will last.
Hopefully. After all, 140K on the road equals what, five Lemons races?
The very act of applying to this race, is the biggest fail.
My recommendations:
-expensive break pads aren't worth it. They wear our faster that cheap pads. Just buy two or three sets of the entry level pads, or at most the second cheapest pads from AutoZone.
-change your pads (or at least check them) between race days #1 and 2.
Sorry but the great looking brake pads on our car and the car exactly like ours that came in with Autozone pads on fire disagree.
Brakes don't stop the car, tires do. Everyone is limited to 190+ treadwear tires, so full on race brakes quickly turn tires into squares.
Hawk HP+ pads did us well for both days at CMP on a 2700 lbs Prelude. Probably still have another day left in them. Pretty reasonably priced too!
Chris is hoping to run the Ohio race, which is a full 24-hour race. You don't get down time between the days to change pads. I strongly recommend race pads - especially on a relatively heavy car you'll want their heat resistance. We ran Porterfield / Raybestos pads - R41's, I think, but I'll check to be sure. Only 2H 49M on track, but they did great and showed no weaknesses in that time period. That's on a light car, 1800 pounds, but only 9.x" rotors.
Loren is right in that whatever you overlook will fail. What did us in was something I knew was a problem and I should have taken care of. Sleep deprivation makes me do funny things.
FWIW, Nelsons is really easy on brakes.
For our 93 Civic (#571) and 93 Civic Si (#39)
In Toledo:
-Our brake fluid wasn't good enough. The high-temp (600F) stuff isn't really that expensive, and will help you feel confident in your brakes. Confidence in brakes = higher speeds in straights and generally higher performance. And you're safer, too.
-Add some brake ducts. They help keep temperatures down, and take close to zero time and money to install.
-We were involved in a collision that broke our timing belt (we had a spare engine, so that wasn't a deal-killer) but also broke suspension parts. Non-oval races are far less collision-prone, but bringing some spare parts for collision-vulnerable areas is a very good idea
Stuff that would have been big problems at the race that happened during testing:
-Alternator seized when we started #571 after this last winter.
-A fuel line corroded through and started leaking (same line on both #39 and #571)
-Something clutch-related died on #39 (fixed by welding clutch springs)
-Burnt a valve on #39
At Nelson
-Some brake problems again, mainly because we were braking heavily for most of the corners on the circuit rather than driving smoothly.
-Wheel fell off. As said above, if you over or under-tighten your lugs, you can lose a wheel. Invest in a torque wrench. Also, bring at least one spare wheel with a nice tire mounted in case you do lose your tire.
-A nearby team had a big fuel leak that resulted in fuel sloshing around the driver's feet. Since fuel fixes are free, make sure it is in perfect condition. Finding parts in the middle of Ohio at midnight is hard, and can end your race or at least take big chunks out of it.
-#571 was sending prodigious amounts of unburnt fuel out the exhaust. We had Canadian hockey flags on the back that started white, and ended dark gray. We calculated we were burning twice as much fuel as #39 was, which was getting sucked into the cockpit and causing stinging eyes for the drivers. If you can't fix the engine, at least rig fresh air for the driver.
I think the head gasket and bearing failures would be cut way down if more teams improved their cooling systems. Junkyards are full of big radiators and nice oil coolers.
By the way, excellent question. If there's any subject this bunch knows inside and out, it's broken parts.
I think our Caddy's head gaskets failed due to a wonky water pump, personally... I mean, did you see the size of the radiator on that thing? It's almost as big as the rad in my friggin' Cummins Ram!
What a fantasic question. First and foremost we need to know what car you are running because each car breaks in different ways. Honda's blow head gaskets, BMW's loose wheels, Yugo's roll over, Corvair's overheat, Porsches break pretty much everything, etc, etc.
More helpful is a way to prevent failures. Two things we have found helpful in our racing (1967 Plymouth Fury):
- Spend money on brakes, no limit on spending so go nuts. We run Porterfield race pads which are really expensive but we get 3-4 races out of them. We have stock front rotors (excellent design) with Viper four piston front calipers using a bracket we engineered to mount it. We also have almost no front end on the car aiding in brake cooling.
- Put as much cooling into the car as you can. We raided an 80's Dodge Diplomat cop car of every cooler it had, oil, power steering, etc. We have a friend who works at a Ford Dealer who gave us a tranny cooler out of an F-350 pickup out of the scrap pile. We also use an accusump that a team member got from a wrecked SCCA car. It was full of metal but we sent it out to get rebuilt and it only cost us $40. We have a 10 quart oil system on our car plus an oil cooler. The more oil you have the cooler it's going to run. Cooler is always better. Preventative maintenance is the key word.
Hmm, ya'll are correct. I was talking about 'high performance' brake pads and not race pads. Honestly, tho, we've had much more luck with cheapie break pads than expensive stuff. Maybe we're just easy on brakes?
Who knows! Just think (a lot) about your braking system. 'Cause fire is bad, yo.
Hood latch. There's nothing more frustrating than having the rusty old hood latch cable break and having to pry open the hood with a crowbar. Fortunately this happened to me before the race, and I removed the latch and installed a set of pins.
Flex disk/guibo/rubber donut/whatever it's called. This and the center driveshaft bearing are pretty important.
Rubber brake lines, replace them.
Seizing e-brake cables will cause you grief.
I think the head gasket and bearing failures would be cut way down if more teams improved their cooling systems. Junkyards are full of big radiators and nice oil coolers.
$7 of AC vents at Lowes helped us out at CMP. Temp never moved all weekend
What a fantasic question. First and foremost we need to know what car you are running because each car breaks in different ways. Honda's blow head gaskets, BMW's loose wheels, Yugo's roll over, Corvair's overheat, Porsches break pretty much everything, etc, etc.
It's most likely a second generation (1997-2005) GM U-Body minivan.
I know, not the quickest around the track, but I have my reasons.
suspension links and a-arms fail alot... you should remove the bushings and weld the a-arms directly to their mounts. if the suspension doesnt move it should fail, right?
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