Are Dyno's hard on the motor
 

I have been told that the chassis dyno is hard on the crank, rods, main bearings, etc. However DynoJet claims that their free-wheeling model puts 75% less stress on components. I have a new motor with 2000 miles on it and would like to put it on the chassis dyno to get an accurate bhp, but I am a little gun shy of damaging the motor. Any thoughts-suggestions-things to avoid would be very helpful.

Well first of all you wont get bhp, you'll get rwhp, but anyways you'll be just fine. You wont put anymore stress on the engine then you would on the street :devil:

Alot less friction is present on a dyno, the rollers free spin pretty much. So that alone causes less strain then punching it on the street.

Chassis dynos save engines from being destroyed. A properly operated dyno is less harmful to an engine because many vitals can be monitored such as A/F ratio, fuel pressure, timing etc during testing. Eventually, many experimental tuners find there way to a dyno but often too late, after they have gone thru a few engines. A dyno that puts 75% less stress to an engine is not as affective at such testing as one that correctly simulates actual engine loads.

i know i guy thats making over 600 on spray on a stock bottom end thats made like 50-60 dyno pulls and hes never had one prob; youll be just fine.

Free-revving is worse on an engine than going through the rpms with load. Like revving to 6500 through 1st is not as stressful as revving it up to 6500 in N.

Bottom line strap it on the dyno and let her rip, it'll be alright.....

+1, i was looking to see if anyone posted this or not..

dyno.....dyno.....dyno.......

just do it!!!

I blew the mass air flow sensor off mine a dyno.

Were the clamps tight??

dont think that has anything to do with the dyno

A properly operated dyno is less stressful then running it on the street.

I've been told by a reputable transmission builder that the dyno is brutal on a tranny, though.

Sort of False.. While you can monitor everything easier and all, for higher hp cars the majority will be roasting the tires on the street. On the dyno when you've got a ballast on the rear tires keeping them sticking to the rollers and not spinning you are putting more load on the car than the street ever will.

Get what I'm saying?

Think of it this way... The dyno won't be any more stressful on your engine than putting it in 4th and flooring it up to redline...

Sure there's stress, and load, etc etc... but umm... thats what your engine is designed for...

Don't listen to all the fear mongering...

-Dan

:jest:

a Dyno is DEFINATELY more stressful than running it on the street. The car is trying to roll some rollers while its strapped to the ground but the suspension is pressing down, so not only does it have to fight its own weight, but the pressure applied by the suspension aswell. AND, a dyno will never have the cooling that a 4th gear pull could ever have.

You're absolutely right. You should never put your car on a dyno. The stress is just not worth it... :eyes:


As for the OP: Remember, Don't listen to all the "Fear Mongering" people babble on about stuff like it's the ultimate engine killer...

...It's a dyno pull... it's a load on an engine... Believe it or not, your engine is designed to work under loads, and a dyno pull is just another kind of load for your engine to handle.

If you don't want to put any stress on your engine. Don't EVER start your car. Because just running your engine is creating stress... :eyes:

-Dan

Apparently you have ZERO Dyno experience. You dont have the suspension "pressing down" on the rollers. You strap them around the axle tubes on solid rear cars, or the cradles on Vettes. The ONLY time you use the suspension for load is in high hp cars that want to spin the tires. and then you NEED to have the added load. And even so, how is that more stressful than hammering it on the street or track?

Well, maybe i just have crappy dyno operators, because I have hadd cars that ran well on the street and blew headgaskets on the dyno. One of which was my nitrous LS1 =[. Im going to say a dyno is harder on a car than on the street, due low airflow, even if the dyno shop has a fan. It simply cannot recreate the force of air coming through the radiator when the car is in motion.