Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-12-2015, 11:08   #1
Registered User
 
Wainui's Avatar

Join Date: Nov 2007
Location: Southern California
Boat: Cal 48 Wainui
Posts: 172
Liquid Piston Engine

Sounds to good to be true?
LiquidPiston unveils 40-bhp X2 rotary engine with 75 percent thermal efficiency
__________________

__________________
Wainui is offline   Reply With Quote
Old 07-12-2015, 11:20   #2
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,342
Re: Liquid Piston Engine

Well the world didn't seem to accept the rotary engine before for some reason, so I'm not holding my breath!
__________________

__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 07-12-2015, 11:49   #3
Registered User
 
Dsanduril's Avatar

Join Date: Aug 2011
Location: South Pacific
Boat: Outremer 50S
Posts: 1,451
Re: Liquid Piston Engine

Quote:
Shkolnik says that the X2 will be available for partner tests in 2013 as a new round of financing is launched and he hopes to have a preproduction prototype by 2014.
Maybe it didn't live up to original expectations?
__________________
Dsanduril is offline   Reply With Quote
Old 07-12-2015, 12:03   #4
Registered User
 
denverd0n's Avatar

Join Date: Jun 2008
Location: Tampa, FL
Posts: 3,948
Images: 6
Re: Liquid Piston Engine

Quote:
Originally Posted by Wainui View Post
Sounds to good to be true?
They're not claiming to push the limits of any of the laws of physics, so I would say, no, it doesn't sound too good to be true. It does, however, sound like a pretty radical step forward. As such, prudence dictates a certain amount of skepticism. If it is as good as it claims, then it won't be too long until it comes into common usage. At that point it will be a lot easier to judge just how good it really is. (And, of course, if it never gets to that point then we'll know that it was not nearly as good as the claims.)
__________________
denverd0n is offline   Reply With Quote
Old 07-12-2015, 12:09   #5
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,032
Re: Liquid Piston Engine

Quote:
Originally Posted by Cheechako View Post
Well the world didn't seem to accept the rotary engine before for some reason, so I'm not holding my breath!
More than anything else it was because it was a fuel hog by comparison.
Interesting to see that this design is a Wankel

Just form a quick glance at what they intend, would require a relatively low RPM and I would assume a large flywheel, think steam engine type of operation
__________________
a64pilot is offline   Reply With Quote
Old 07-12-2015, 12:43   #6
Senior Cruiser
 
newhaul's Avatar

Cruisers Forum Supporter

Join Date: Sep 2014
Location: puget sound washington
Boat: 1968 Islander bahama 24 hull 182, 1963 columbia 29 defender. hull # 60
Posts: 3,928
Re: Liquid Piston Engine

Quote:
Originally Posted by a64pilot View Post
More than anything else it was because it was a fuel hog by comparison.
Interesting to see that this design is a Wankel

Just form a quick glance at what they intend, would require a relatively low RPM and I would assume a large flywheel, think steam engine type of operation
Actually its not a wankel design I looked at his designs online about a year go and I'm watching it rather closely to just imagine an outboard with that kind of power to weight ratio. I could have a 20 HP outboard on my islander with a net weight savings over my current 8 horse.
__________________
newhaul is online now   Reply With Quote
Old 07-12-2015, 13:33   #7
Senior Cruiser
 
44'cruisingcat's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 7,452
Images: 69
Re: Liquid Piston Engine

Quote:
Originally Posted by a64pilot View Post
More than anything else it was because it was a fuel hog by comparison.
Interesting to see that this design is a Wankel
Looks a bit like one, but is really a lot different. As you say, the Wankel was pretty heavy on fuel.
__________________
"You CANNOT be serious!"


John McEnroe
44'cruisingcat is offline   Reply With Quote
Old 07-12-2015, 14:13   #8
Registered User

Join Date: Sep 2015
Location: Santander, Spain
Boat: Actively searching for one...
Posts: 66
Re: Liquid Piston Engine

Quote:
Originally Posted by 44'cruisingcat View Post
Looks a bit like one, but is really a lot different. As you say, the Wankel was pretty heavy on fuel.
Not only that, also burns plenty of oil, and the apex seals wear out quickly, requiring frequent maintenance. However, they are very reliable due to their simplicity.
__________________
Bertie68 is online now   Reply With Quote
Old 07-12-2015, 15:02   #9
Registered User

Join Date: Jan 2010
Location: Ma
Boat: Sabre 28
Posts: 190
Re: Liquid Piston Engine

Quote:
Originally Posted by Bertie68 View Post
Not only that, also burns plenty of oil, and the apex seals wear out quickly, requiring frequent maintenance. However, they are very reliable due to their simplicity.
The oil usage is what did them in due to emissions concerns. The X2 changes the position of the seals into the housing itself and claims to not need oil injection. Running it on diesel probably helps with lubrication for the seals.

For those that haven't seen it they have a video of how it operates here:

How It Works | LiquidPiston

The partial "constant volume" during the start of the power cycle would help to extract more power out of the fuel burning because cylinder pressure will stay higher longer. That is where some of the thermal efficiency comes from. The increasing volume of a typical Otto cycle drops cylinder pressure very quickly. That is why common rail diesel engines will inject fuel multiple times per power stroke to try and keep cylinder pressure higher longer.

Shawn
__________________

__________________
Shawn67 is offline   Reply With Quote
Reply

Tags
engine

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wanted: yanmar piston 129474-22000 mi amore Engines and Propulsion Systems 2 25-07-2014 07:19
Want To Buy: Yanmar Piston 4JH-DTE 129474-22000 mi amore Classifieds Archive 0 24-07-2014 18:56
Want To Buy: Looking for single piston Yanmar Sethx Classifieds Archive 7 27-02-2014 05:19
Seized Piston Mark1977 Construction, Maintenance & Refit 23 23-11-2011 05:57
Yamaha Outboard Piston Sticking mofsubic Engines and Propulsion Systems 0 28-08-2010 18:21



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 00:12.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.