Volvo D13 Dyno Results

[Av8r3400]

I got the results for the Dyno test on my prospective HDT.

The HP numbers look good at 356/425 = 83.8%

I can not find any spec for blow-by however.  The test showed a peak number of "7", average of "5.5" across the 10 data points..  I think this is inches of water.

 

Does anyone know the blow-by spec for a 2012 D13 Volvo engine?

[VegasFlyer]

You won't be able to get a blow by measurement because it is a closed system on the D13.

The main point of a Dyno on the D13 is what the truck produces compared to where the horsepower is set at.  Secondarily some folks feel if you have a marginal truck, any weak points will be pushed to the breaking point under the strain of a Dyno

IMHO the second part is more urban legend or Anecdotle, at best.

Did you get the oil analysis back yet?

[Av8r3400]

Thanks for the quick response.

The oil labs were to be back Thursday or Friday.  They were sent out Tuesday.  I was hoping for today, but the mail is already in with no report.  So they should hopefully be in tomorrow's mail.

The Dyno report does mention that they used the "Cummins Method" with a .302 orifice to collect blow by data.

 

(Edit)  From what I've found the Cummins ISX spec is 12" new and 18" used is considered acceptable.  SO...  This means that the Volvo D13 is a lot tighter engine than a Cummins ISX.

[Biker56]

Does the Dyno give HP & torque at the drive wheels?

[cwr]

Apologies in advance, but I am not well versed in automotive mechanics. I'm in the market for an HDT, and just curious what the lowest acceptable dyno result would be, percentage-wise. I know its a good idea to get a dyno done, but I would need some guidance on interpreting the results. Thanks!

[Ronbo]

You will have lower hp at the rear wheels than at the engine. I am not sure what is acceptable. Mine was over 400 on my cummins N14. Also my blowby was 5 in hg where 18 is allowed. They said I would no have any problems. I also have no oil leaks from the engine. 

[VegasFlyer]

I would say that 83 percent is great.  As Ron said above, there is an inherent  loss between engine output and rear wheel output.  The exact amount depends on drivetrain ratios.  A general rule of thumb is 20 to 30 percent loss.

so again, 83 percent looks pretty good.

[Av8r3400]

Biker56 - A chassis dyno measures the HP and torque at the drive wheels.  

crw - From what I was told 75-80% of engine rated HP at the wheel or better is what you are looking for on a dyno test.  You are probably going to loose at least 15% from driveline drag.

Ronbo - On a dyno test the blow by is usually measured in inches of water, not mercury.  5" of hg (mercury) converted to water would be 5 * 13.514 = 67.57, so I hope the number they gave you was inches of water...  

[VegasFlyer]

Along with showing developed horsepower, the Dyno can be very useful as a diagnostic tool.  We had a Kenworth K100 that had a Detroit Silver 92 engine that developed a serious case of semi truck anemia (STA).  We had chased our tail trying to find out why the power seriously dropped off on a truck that for all practical purposes, should be very healthy.  We had replaced all fuel filters, ran the rack, inspected injectors and still nothing.  When we put the truck on the Dyno and they ran it, the truck would only develop about 45 percent of the set horsepower.  The Dyno showed a restricted fuel flow.  As we investigated that, we found a plain old no2 pencil lodged in the fuel intake at the primary fuel tank.....

That became a very expensive pencil, but sure showed the value of the Dyno, especially for older trucks that don't have all the onboard sensors that our modern chariots possess....

[Ronbo]

Thanks av8r. I stand corrected.