Oil Field Engines
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Antique Engine Community > Oil Field Engines & Related Equipment
Forgot Password? Join Us!

Notices

Oil Field Engines & Related Equipment OFES members otherwise known as "Oafs". If you like "BIG OLD GREASY RUSTY OIL FIELD ENGINES, you're in the right place. Founded by Russell Farmer.

Oil Field Engines & Related Equipment

F-M 346 Hp at 200 RPM


this thread has 29 replies and has been viewed 2788 times

Reply
 
Thread Tools Display Modes
  #21  
Old 03-21-2010, 11:43:07 PM
Jerry Sweet Jerry Sweet is offline
Registered
 
Join Date: Jun 2009
Location: Walnut Grove, CA USA
Posts: 607
Thanks: 0
Thanked 232 Times in 189 Posts
Default Re: F-M 346 Hp at 200 RPM

I can see where he's coming from.The spring pack in the impulse unit isn't strong enough to pull his stronger magnets out of the influx position and it causes rotor to lag behind the coupling.
Reply With Quote
Sponsored Links
  #22  
Old 03-22-2010, 08:31:50 AM
Reed Engine's Avatar
Reed Engine Reed Engine is offline
Subscriber
 
Join Date: Apr 2009
Location: Hominy, Oklahoma
Posts: 4,063
Thanks: 1,748
Thanked 4,492 Times in 1,745 Posts
Default Re: F-M 346 Hp at 200 RPM

Oh ok, thanks for the info. I'm sure this will come in handy someday.
Reply With Quote
  #23  
Old 03-22-2010, 09:56:17 AM
Alan D. Alan D. is offline
Registered
 
Join Date: Oct 2009
Location: Deseret, Utah USA
Posts: 125
Thanks: 45
Thanked 15 Times in 14 Posts
Default Re: F-M 346 Hp at 200 RPM

Hello Dirtbikepilot and Reed engine, Thanks for your comments and information on the mag. impulse lock out device, that is now on my FM 346 engine. Do either of you know at what RPM speed the impulse drops out normally? I may not need to use the lock out while running at 200 to 300 rpm. I should not need to worry about lubrication of rotating parts with the improvements that have been made by dirtbikepilot. The current issue is machining a decent flat belt pulley, I have most of the things I have determined to use. I am thinking on adding some rolled 1/4" plate to the circumference in order to have enough material that I can machine a high spot down the middle to help keep the belt on. What is the idea from you fellow that have run flat belts a lot. Is the high spot, in the middle of the pulley, real important?
Alan
Reply With Quote
  #24  
Old 03-22-2010, 10:11:59 AM
Elden DuRand's Avatar
Elden DuRand Elden DuRand is offline
In Memory Of
 
Join Date: Nov 2004
Location: Port St. Joe, Florida, USA
Posts: 7,800
Thanks: 13,041
Thanked 7,767 Times in 2,942 Posts
Default Re: F-M 346 Hp at 200 RPM

Alan:

From what I've heard told, you only need the high spot on one of the pulleys. A flat belt will try to ride to the largest diameter and, if that point is midline of the pulley, that's where it will be.

The amount of "crown" on the pulley doesn't need to be much. I've been told that a degree on either side of the center is okay. Too much crown will cause the belt to wear fast.

Hope this helps.

Take care - Elden
http://www.oldengine.org/members/durand
__________________
[SIGPIC][/SIGPIC]
Take care - Elden
http://www.eldensengines.com
Reply With Quote
  #25  
Old 03-22-2010, 11:28:56 AM
NAMPeters
Guest
 
Posts: n/a
Default Re: F-M 346 Hp at 200 RPM

Quote:
Originally Posted by Alan D. View Post
Hello Again, If the 346 will not make the advertised 18 HP even at full out RPM's. Give me you idea of what HP I should get running 1/2 speed at 200 RPM. I was hoping for 6 to 8 HP. What do you think?
Alan
My $.02 worth of knowledge:

First the slow idle crowd have no load on the engine so it is hardly working to over come friction. Marginal lubrication will most likely be enough to keep things going.

Second in your case running at 400 RPM and putting out 6-8 HP means running at part throttle with the resulting lower temperatures and combustion pressures which can be easily handled by the engine lubricating system. Remember you are lubing bearings, wrist pin, and rings. At your proposed 200 RPM you will be running at full throttle with the resulting increase in combustion temperature and pressures along with a doubling of the combustion time thus you run the risk of burning a valve and/or piston. Remember that most of the heat removal from a piston is via the top ring and if this ring fails because of poor lube it is bye bye piston. Also getting the timing right at 200 RPM is iffy at best. These engines were designed to work at the higher speed and I would honor that concept.
Reply With Quote
  #26  
Old 03-22-2010, 01:20:20 PM
Alan D. Alan D. is offline
Registered
 
Join Date: Oct 2009
Location: Deseret, Utah USA
Posts: 125
Thanks: 45
Thanked 15 Times in 14 Posts
Default Re: F-M 346 Hp at 200 RPM

I just checked on by brass MFG. tag and see that the 346 is rated to work between 225 and 450 RPM's. I deduce that the impulse will be locked out, probably below 200 RPM so I should no need to worry about that aspect. My internal lubricating should be a "non issue" also.If 200 - 250 RPM's will net 6 HP I will be OK with the results and can size my pulleys accordingly. Does anyone have a plan in mind for a belt tensioner?
Regards, Alan
Reply With Quote
  #27  
Old 03-22-2010, 10:09:32 PM
DirtbikePilot DirtbikePilot is offline
Subscriber
 
Join Date: Sep 2006
Location: Cortez, Colorado
Posts: 842
Thanks: 974
Thanked 448 Times in 204 Posts
Default Re: F-M 346 Hp at 200 RPM

Quote:
Originally Posted by Jerry Sweet View Post
I can see where he's coming from.The spring pack in the impulse unit isn't strong enough to pull his stronger magnets out of the influx position and it causes rotor to lag behind the coupling.
Exactly.
Reply With Quote
  #28  
Old 03-22-2010, 10:47:05 PM
DirtbikePilot DirtbikePilot is offline
Subscriber
 
Join Date: Sep 2006
Location: Cortez, Colorado
Posts: 842
Thanks: 974
Thanked 448 Times in 204 Posts
Default Re: F-M 346 Hp at 200 RPM

Alan- good counter with the original tag info. The impulse on this engine still clicks even at 225 rpm, but it doesn't do it consistently. NAMPeters- no disrespect, especially since your concerns are valid for a lot of engines, but I'm going to disagree. These engines are ridiculously overbuilt. The crankshaft weighs 120 pounds in this engine and everything else is proportional to that. FM originally designed this engine to run fine at 225 rpm. I'm absolutely sure that it will be fine at full throttle even down to 180 rpm with the extra splash rod. The only possible problem I can see if it is run too lean. Putting on a real carburetor (gasoline or propane) and properly adjusting it would greatly reduce the chance of this. Even then I think it would have to be run very lean for hours at full load for any damage to occur.

I've spent hours and hours and hours messing with and testing this engine. I'm pretty confident in my recommendations.
Reply With Quote
  #29  
Old 03-22-2010, 11:14:33 PM
Jerry Sweet Jerry Sweet is offline
Registered
 
Join Date: Jun 2009
Location: Walnut Grove, CA USA
Posts: 607
Thanks: 0
Thanked 232 Times in 189 Posts
Default Re: F-M 346 Hp at 200 RPM

Hi,Dirtbikepilot: Please tell us more about the " rare earth magnets".A company I worked for mined & processed "rare earth" near Las Vegas,Nv. & Questa,NM,but I never did hear much about it.That was a division by itself and I was in the oil & gas division.Thanks,Jerry
Reply With Quote
  #30  
Old 03-23-2010, 12:51:19 AM
NAMPeters
Guest
 
Posts: n/a
Default Re: F-M 346 Hp at 200 RPM

Quote:
Originally Posted by DirtbikePilot View Post
NAMPeters- no disrespect, especially since your concerns are valid for a lot of engines, but I'm going to disagree.
No problem.

I do know that the earlier engines in this series, Z & ZA, had water injection to control knock with poor quality fuel which tells me they had a tendency to run hot. I have no idea if this feature was continued in the latter variants.

I love F-M engines because the company was run by a bunch of engineers.
Reply With Quote
Reply

Bookmarks


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


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 01:11:32 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 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277