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Trusted Contributor
Trusted Contributor

Re: Help getting legacy D399 engine information

You are correct that the D399 dimensions will be different from the Waukesha.  It will be Thursday before I can get back to my office.  I will send you what dimensional information that I have, which should help with the physical installation.  I am not sure about the torsional information that I can get.  But you should have a torsional analysis performed.  For Cat to do this, you will have to visit your local Cat dealer and make arrangements to order this.  There are independent firms that perform TAs as well.

 

Best Regards,

Al Hunt

Visitor

Re: Help getting legacy D399 engine information

[ Edited ]

Al,

 

Thank you so much for a prompt response. I'm sorry if I did not make it clear but the gas engine that is being replaced is not a CAT, it is a Waukesha 7042GSI engine. The client wants a replacement because his natural gas wellhead pressure is going down and he wants another prime mover solution to run his compressor. I don't have any nameplate info right now, since that engine was already pulled out and a tarp has been put on it, its in storage. But I believe we already confirmed that the footprints are not the same which is why we have to do some modification work with the engine pedestal.

 

Yes, please do have a look at your files. We're also interested in the flywheel OD and bolt hole pitch diameter circle. I feel like a set of outline drawings can give us what we need. Meanwhile, we'll be taking some raw measurements using a tape but those will be approximations. 

 

Should we get the mass and stiffness parameters we're looking for, do you think we should approach Caterpillar to perform a torsional study of this setup? And what channel do we go through to get that done?

Trusted Contributor
Trusted Contributor

Re: Help getting legacy D399 engine information

I do not have access to all of this data right now but probably can provide it later this week.  Here are some comments that I am fairly sure are correct.  The 36Z D399 should work as a replacement engine for the G399 with minimal issues.  I would call it a "drop in" replacement with more horsepower than the G399.  The cooler used by the G399 will not cool the higher horsepower rated D399; it will have to be replaced and be sized for the higher heat rejection to the coolant.  Also the D399 does not use a separate core for  the aftercooler; the D399 is usually using jacket water for the aftercooler.

 

1. Weight (dry and wet) The weight of the G399 engine is almost the same as the D399 engine with the G399 being slightly less.

2. Operating characteristics  The operating characteristics are entirely different with the D399 being rated at approximately 40% more horsepower.  The diesel D399 is also much more positive in load response and engine speed stability because the fuel injection system is much more positive than the G399 fuel delivery system and governor control.  If the G399 engine is using a 2301 governor, then it will have to be replaced in the system with a similar 2301 designed for use with a D399.

3. Engine footprint  The D399 engine footprint is exactly the same as the G399 engine. 

4. Critical dimensions :  All of the critical dimensions listed here are the same for both the G399 and the D399 engine.

  • Vertical dimension from crankshaft centerline to mounting plate bottom surface
  • Crankshaft end to first hold down bolt
  • First hold down bolt to 2nd hold down bolt
  • Diameter of crankshaft
  • Location and diameter of stubshaft

5. Crankshaft torsional inertias and stifnesses This data is different for the D399 engine.  I don't know if I have this data or not until I take a look at my files.

 

Best Regards,

Al Hunt

Visitor

Help getting legacy D399 engine information

[ Edited ]

Hello everyone,

 

This is my first message in the board, I figured I'll start here for suggestions before trying to contact Cat directly by phone.  

 

I work for a gas compression packager in the U.A.E. We have a job where the client wants us to switch out  an existing gas engine driver from his compressor package and replace it with a D399 diesel engine driver (for various reasons). The diesel engine he has provided is an old D399. it looks like a legacy product that is not produced anymore. The nameplate of this engine is shown in the attached image. 

 

D399 nameplate.jpg

 

 

In order to carry on with this job, we need some key information , some as listed below :

 

1. Weight (dry and wet)

2. Operating characteristics

3. Engine footprint

4. Critical dimensions :

  • Vertical dimension from crankshaft centerline to mounting plate bottom surface
  • Crankshaft end to first hold down bolt
  • First hold down bolt to 2nd hold down bolt
  • Diameter of crankshaft
  • Location and diameter of stubshaft

5. Crankshaft torsional inertias and stifnesses

 

Some of this info will also be input to a torsional study that we hope to have either Cat or someone else perform for us to make sure this setup is safe. 

 

Question : How can I get outline drawings of the engine to get the above info? Plus technical parameters such as those in Pt# 5?  I'm afraid the local dealer hasn't really been of help so looking for best advice. Thank you!