Generators and Motors
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 15kw help


this thread has 50 replies and has been viewed 2053 times

Reply
 
Thread Tools Display Modes
  #21  
Old 03-10-2017, 02:09:26 AM
Motorhead's Avatar
Motorhead Motorhead is offline
Subscriber
 
Join Date: May 2007
Location: Central Coast, California
Posts: 3,818
Thanks: 1,803
Thanked 2,641 Times in 1,370 Posts
Default Re: Onan 15kw help

The ice cream trucks that used 10-15 kw generators were the ones that sold SOFT SERVE ice cream. I remember them as a kid in the early 60's
__________________
The Control panel
and gauges of my
7.5JB
Reply With Quote
The Following User Says Thank You to Motorhead For This Post:
Sponsored Links
  #22  
Old 03-10-2017, 08:20:41 AM
stretch67 stretch67 is offline
Registered-I
 
Join Date: May 2009
Location: Goderich Ontario Canada
Posts: 257
Thanks: 55
Thanked 78 Times in 42 Posts
Default Re: Onan 15kw help

Turn the VAC U Flow cooling duct down to vent out of the bottom of the truck.

The Car Audio people have some pretty good sound insulating materials.

Attention to detail on sound attenuation is key.

Even a 5 DB reduction is huge difference.

The JC is a great unit, and with proper care will last long time.
Reply With Quote
  #23  
Old 03-10-2017, 08:22:24 AM
Max Thompson Max Thompson is offline
Sponsor
 
Join Date: May 2009
Location: N.W. Missouri, USA
Posts: 5,934
Thanks: 5,239
Thanked 5,620 Times in 3,013 Posts
Default Re: Onan 15kw help

My first question is; what does it have for a muffler now?

Not relevant to the noise, but I wonder if there is a flex section in the piping to the manifold.

As was stated earlier, a JC is relatively noisy, but in your situation with proper insulation and a "good" (good can = expensive) muffler they can be quieted considerably.

Second question; how much generator do you need? What are your electrical loads?
Reply With Quote
  #24  
Old 03-10-2017, 09:31:17 AM
kosmo101 kosmo101 is offline
Registered-I
 
Join Date: Oct 2012
Location: nashville, Tennessee
Posts: 66
Thanks: 1
Thanked 1 Time in 1 Post
Default Re: Onan 15kw help

i actually thought it was overkill too. The ones up north have 18 or 22kw units. amazingly huge. For one soft serve machine 208-230v but two separate cords. The machines are basically two in one. So double the power needs. recommended on three phase to have 19amp and 17 amp . I may switch this machine to another I have which seems to need less power.

Then we have a shaved ice machine..not sure of the power needs on that. Ac unit sucks a ton of power. One light, one fridge, small freezer and shake machine.

Im going to test this weekend to see what my needs really are. More power cant hurt but there has to be a money aspect to this as im not looking to spend an unlimited amount of money.

I will trace out from the manifold to the end pipe to see what is going on. i cant tell just yet if its the engine itself being loud or the muffler/exhaust is an issue. Again it sure sounds like there is no muffler on it..that loud. it sounds like my 6500 unit with no muffler but much louder. Guess it would help if i had another one to judge against.

I assume it is the normal/stock muffler. Is there one i could swap to in order to try to get it quieter.

with the unit in the back of a truck, vents on both sides and the top on one side, how would insulating really help? we can pull the rear door down to keep the sound a bit muffled but when i tried that it sure was still amazingly loud. Maybe even worse as it echoed inside this area? Will snap photos...

thanks!
kevin

So in looking at similar units.. it appears the exhaust manifold is out of the back of the unit but shoots up...is that correct? Meaning venting vertically past the top of the unit? Wondering how mine ended up under the truck.. very tough to get in this compartment to see behind the unit.
Reply With Quote
  #25  
Old 03-10-2017, 09:41:34 AM
Wayne 440 Wayne 440 is online now
Registered-III
 
Join Date: Nov 2004
Location: Kentucky
Posts: 5,970
Thanks: 363
Thanked 5,050 Times in 2,428 Posts
Default Re: Onan 15kw help

Quote:
Originally Posted by BigBlockChev View Post
The majority of the noise is not from the muffler it is from the engine. Don't expect it to get much quieter by just changing the muffler. It is a vacuflow cooling system so you will need to properly connect the discharge on the front of the engine to the outside air and also provide some inlet airflow louvers, don't make them too small. The key to noise reduction is to seal up the generator compartment except for a baffled inlet and outlet. Lining the generator compartment with sound deadening material will help somewhat as well. It is possible to quiet down an aircooled JC but it won't be easy unless you have very good attention to detail, sound will leak out everywhere it can through little holes. Cheers Dan

The above advice is how it is done. All vents, openings, etc. must be baffled, i.e. no direct line of sight to the outside. Single layer sheet metal portions of the enclosure can "retransmit" or reverberate sound, apply sound deadening material to same. Doors and covers should seal tightly. If possible direct vents away from occupied areas, straight up is a common choice in stationary applications.

Quote:
Originally Posted by kosmo101 View Post
...So in looking at similar units.. it appears the exhaust manifold is out of the back of the unit but shoots up...is that correct? Meaning venting vertically past the top of the unit? Wondering how mine ended up under the truck.. very tough to get in this compartment to see behind the unit.
I covered that possibility earlier--

Quote:
Originally Posted by Wayne 440 View Post
The exhaust manifold can be turned to point the outlet down, and then all that is needed is a hole in the air shroud for the pipe exit. I have seen some that looked like they beat the hole out with a hammer and cold chisel.
Reply With Quote
  #26  
Old 03-10-2017, 11:32:00 AM
Max Thompson Max Thompson is offline
Sponsor
 
Join Date: May 2009
Location: N.W. Missouri, USA
Posts: 5,934
Thanks: 5,239
Thanked 5,620 Times in 3,013 Posts
Default Re: Onan 15kw help

From the equipment you listed, the starting power requirements could be quite high.

There was not a "stock" muffler per sae. Mufflers were an option and different ones available for different requirements. Most anything of the proper inlet & outlet size (1 1/2" ips inlet on most), that you can fit under the truck will work.

You may as well start devising a plan to remove the set from the truck. Sooner or later it will have to come out. With all lines and exhaust disconnected (the exhaust will likely have to be sawn off where it goes through the floor) it can likely be slid out onto a platform of concrete blocks & a piece of plywood. A sheet of 1/8" steel sheet on top of the plywood would make it slide much easier. You could possibly raise it up and get some 3/8" rod or 1/2" pipe under the mounting rails and roll it out. Probably in the #700 neighborhood. If you have access to a "lift table" or motor cycle lift it could be pretty easy to remove.
Reply With Quote
  #27  
Old 03-10-2017, 11:38:31 AM
kosmo101 kosmo101 is offline
Registered-I
 
Join Date: Oct 2012
Location: nashville, Tennessee
Posts: 66
Thanks: 1
Thanked 1 Time in 1 Post
Default Re: Onan 15kw help

Why do you say to start thinking of it coming out? Maintenance? just curious your thoughts.
Reply With Quote
  #28  
Old 03-10-2017, 12:16:09 PM
Max Thompson Max Thompson is offline
Sponsor
 
Join Date: May 2009
Location: N.W. Missouri, USA
Posts: 5,934
Thanks: 5,239
Thanked 5,620 Times in 3,013 Posts
Default Re: Onan 15kw help

Quote:
Originally Posted by kosmo101 View Post
Why do you say to start thinking of it coming out? Maintenance? just curious your thoughts.
Maintenance yes.

The starter is mounted on the back side. It will be very difficult to adjust the rocker arms or get inside the control box with the limited space over the unit.

If you do any insulating (sound deadening) to the compartment, you will have to get to the back side.

If I were going to rely on this set to run my business and keep several $ worth of product from being lost, I would pull it out and give it a through going through Before I put the truck into service.

Removing it (with the right equipment) would not be a big job. Though I may not be a very good judge of the degree of difficulty. Having 9 JCs floating around the place, I am pretty adapt at moving them around and up & down.
Reply With Quote
The Following 2 Users Say Thank You to Max Thompson For This Post:
  #29  
Old 03-10-2017, 12:20:10 PM
kosmo101 kosmo101 is offline
Registered-I
 
Join Date: Oct 2012
Location: nashville, Tennessee
Posts: 66
Thanks: 1
Thanked 1 Time in 1 Post
Default Re: Onan 15kw help

understood. as you mention, that is why i am considering maybe pulling it out as well. if it doesnt work when we get to an event, im dead. im used to smaller honda units so no idea how reliable these are. checking out the quiet diesels and also a yanmar unit. A bit out of my element on the reliability of such makes.

I was going to ask to borrow a neighboring shops forklift to remove or maybe use a engine hoist. I also need to possibly remove the soft serve machine from inside.. that should be fun.

happen to have a good unit for sale ? figured since you had nine units.. it may be worthwhile to ask!
Reply With Quote
  #30  
Old 03-10-2017, 12:54:47 PM
Max Thompson Max Thompson is offline
Sponsor
 
Join Date: May 2009
Location: N.W. Missouri, USA
Posts: 5,934
Thanks: 5,239
Thanked 5,620 Times in 3,013 Posts
Default Re: Onan 15kw help

Quote:
Originally Posted by kosmo101 View Post

how reliable these are.

I was going to ask to borrow a neighboring shops forklift to remove or maybe use a engine hoist. .

happen to have a good unit for sale ? figured since you had nine units.. it may be worthwhile to ask!
When properly maintained, the J series are very reliable and will outlast most of us here.

A fork lift should make short work of removing the set from the truck.

Not saying they could not be bought, but none advertised for sale (we do not buy and sell on this board).

You may have a great generator right now, give it a chance. If I did not think they were great sets, I would not bother accumulating them.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Onan 15kw jzbseattle Onan Generators 6 10-19-2012 06:35:05 AM
Onan 15KW JC on LP Cruiser Onan Generators 14 07-01-2012 04:14:43 PM
Onan 15KW Cruiser Onan Generators 8 06-27-2012 04:26:01 PM
Onan 15kw Ed Dina Onan Generators 3 04-23-2003 05:16:00 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 05:48:12 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277