[flyin99]

What is the hardest sport on engines, between dirt track racing and truck pulling?

[SSedan64]

I'd have to say any sport where you're constantly accelerating and decelerating like Ovals or Roadcourse racing.

[flyin99]

I was thinking that, but the others were saying that because there is so much load on the truck pulling engine, it by far is harder on the engine....

[SSedan64]

Well when you're talking about tons of boost & Nitro that's a different ballgame. But add the same to the oval engine & you see what I'm talking about. Stress in both Acell & Decell. BoooM!

[flyin99]

Originally Posted by SSedan64

Well when you're talking about tons of boost & Nitro that's a different ballgame. But add the same to the oval engine & you see what I'm talking about. Stress in both Acell & Decell. BoooM!

Let's say both normally aspirated..no booost or nitro etc.....

[special-k]

Having worked on a few dirt track cars I would say they are relatively easy on the motor. Since they are constantly spinning the rear tires the shock loads are minimal. I would lean to road course cars such as "trans am" type of cars being hardest because they use the motor for braking and the races are fairly long. The pullers put tremendous loads on their engines but not for long. Also they are like dirt cars in that they are usually spinning at least a little bit to soften the shock loads. Just my thoughts.

[flyin99]

I've been building dirt car engines for a few years now and just started helping some of the local pullers. They were just telling me how hard on the engines they were, due to the load etc. and I had to open my mouth and say I thought the dirt cars were harder on them, where they are in and out of the throttle all the time........I do suppose they have a much larger load on the truck pulling engines..........

[mtnrat]

Marine I would think.

[4 Jaw Chuck]

Definetly marine off shore racing or drag.

[flyin99]

between dirt track racing and truck pulling

[OHD]

Any Marine off shore, poker runs, and racing

[flyin99]

Thanks for the replies. So between dirt track racing and truck pulling, we have decided that marine is the hardest on engines......LOL

[carsavvycook]

Truck pullers are going wide open down the track, until the weight stops them. They need to get to the end quick, and 'strong'. Which meens revving quickly, with lower "torque" Gear ratios, and higher HP loads per cubic inch displacement, in the engine. I akin these to 1/4 mile cars.

Circle track, and Formula 1 cars, need to rev High, but still have some pulling power, at lower RPM's. In other words they need less "HP" load per cubic square inch displacement, and higher "torque", per gear ratios. This can be achieved with smaller cubic inch displacement.

In answer to your debate. Truck pullers.

My theory: It's all in the gearing, and CID.

A smaller CID engine (geared right) can withstand multiple throttle changes, on and off. They can rev just as quick, and even higher, because of less mass, to push or pull. Yes they take longer to get up to speed. Less stress.

Larger CID engines could be built (geared right) to compete with smaller CID engines, but that went out in the 1960's. (What a disappointment)

There is no replacement for displacement!

Stephen

[4 Jaw Chuck]

Ok, I will quantify why marine racing is the hardest on engines.

There is no other kind of racing where the engine has to endure the kind of severe shock that a surfacing prop will put on a gear case not too mention the usual over-rev that occurs when the boat leaves the water at high rpm. The motors run at full load all the time through minimal gearing so the load is close to 1:1.

The analogy I have heard is it's the same as running your vehicle up a 100% grade (45 degrees) pulling a trailer in second gear at redline and intermittently hitting sand patches and then getting full traction again with no shock cushioning from the rubber tires. Not to mention that the water injested into the jacket is stone cold so there is also cold cycling to contend with.

Its also the most dangerous kind of racing since if you crash hitting the water is the same as hitting a solid concrete wall. The only other contender would be high performance stunt aircraft, but air is kinda cushy in comparison to water...

Until you hit the ground anyway.

[carsavvycook]

Originally Posted by 4 Jaw Chuck

Ok, I will quantify why marine racing is the hardest on engines.

There is no other kind of racing where the engine has to endure the kind of severe shock that a surfacing prop will put on a gear case not too mention the usual over-rev that occurs when the boat leaves the water at high rpm. The motors run at full load all the time through minimal gearing so the load is close to 1:1.

The analogy I have heard is it's the same as running your vehicle up a 100% grade (45 degrees) pulling a trailer in second gear at redline and intermittently hitting sand patches and then getting full traction again with no shock cushioning from the rubber tires. Not to mention that the water injested into the jacket is stone cold so there is also cold cycling to contend with.

Its also the most dangerous kind of racing since if you crash hitting the water is the same as hitting a solid concrete wall. The only other contender would be high performance stunt aircraft, but air is kinda cushy in comparison to water...

Until you hit the ground anyway.

I agree. I've lost 5 friends that were drag boat racers. It has to be one of the most dangerous sports/thrills/competitions out there.

I just do not recall 'boat' being one of the options in the OP's original post.