Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-14-2012, 05:22 AM   #1 (permalink)
EcoModding Lurker
 
Join Date: Apr 2011
Location: The Netherlands
Posts: 32
Thanks: 0
Thanked 3 Times in 2 Posts
Half a diesel engine? (Mechanical cylinder deactivation - 2 of 4 cylinders?)

Yet another half-baked idea..

Could you take a 4 cylinder diesel engine, and only run it on 2 cylinders? Maybe remove 2 pistons/injectors.. would you run into trouble with th eengine management system?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-14-2012, 09:29 AM   #2 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 8,645

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 140.34 mpg (US)
Thanks: 210
Thanked 2,846 Times in 2,229 Posts
No because the engine would be out of ballance.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 03-14-2012, 09:51 AM   #3 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,225

Colorado - '04 Chevrolet Colorado
90 day: 22.98 mpg (US)
Thanks: 190
Thanked 271 Times in 165 Posts
Technically, it's possible. Removing pistons 1&2 or 3&4 would keep it the "most balanced", as they are not companion cylinders (don't rise and fall together). But you would somehow have to block the oil gallery in the crankshaft where the rods would be missing.

There is little point in attempting this on a diesel, as diesel engines are far more efficient at light loads than gas engines and there is not much efficiency to be gained through cylinder activation. If I understand correctly, cylinder deactivation adds efficiency through a reduction in pumping losses, which isn't an issue in diesel engines.
  Reply With Quote
The Following User Says Thank You to mechman600 For This Useful Post:
t vago (03-14-2012)
Old 03-14-2012, 10:02 AM   #4 (permalink)
Master EcoModder
 
Diesel_Dave's Avatar
 
Join Date: May 2011
Location: Indiana
Posts: 1,194

White Whale - '07 Dodge Ram 2500 ST Quad Cab 2wd, short bed
Team Cummins
90 day: 37.68 mpg (US)
Thanks: 112
Thanked 502 Times in 211 Posts
I believe that mechman600 is correct (at least for an inline 4). Generally 1 & 4 are positionally the same (but on different strokes--360 deg apart) as are 2 & 3 (180 deg off from 1 & 4. This is similar to an inline 6 where 1 & 6, 2 & 5, 3 &4 are together. I know an inline 6 can be run on either 1-3 or 4-6. Generally there's some additional vibration, but I believe it's tolerable.

So I believe it would technically be possible. That being said, it's going to be a ton of work, for not a huge amount of gain. To do it right, you should deactivate the valves and drill holes through the deactivated piston. And after you're done, you'll still have frictional losses pretty much the same as before, and the thing will probably take forever to warm up. Plus you'll still have all the weight of the original engine.
__________________
Diesel Dave

My version of energy storage is called "momentum".
My version of regenerative braking is called "bump starting".

1 Year Avg (Every Mile Traveled) = 47.8 mpg

BEST TANK: 2,009.6 mi on 35 gal (57.42 mpg): http://ecomodder.com/forum/showthrea...5-a-26259.html


  Reply With Quote
Old 03-14-2012, 10:17 AM   #5 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 8,645

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 140.34 mpg (US)
Thanks: 210
Thanked 2,846 Times in 2,229 Posts
Also with connecting rods removed the crankshaft would have little to no oil pressure (depending on how the oil holes are drilled), which would be bad and the crank shaft would just be dumping oil out of the oiling system through the uncoverd rod journal hole so you would have very low over all oil pressure.

There are plenty of very light weight sub 2L diesels with less than 4 cylinders why do this to a big old 4cyl?
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 03-14-2012, 04:17 PM   #6 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,732

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,571
Thanked 3,505 Times in 2,194 Posts
Quote:
To do it right... and drill holes through the deactivated piston.
Say what?!? Remove inactive pistons!
__________________


  Reply With Quote
Old 03-14-2012, 07:22 PM   #7 (permalink)
Master EcoModder
 
Diesel_Dave's Avatar
 
Join Date: May 2011
Location: Indiana
Posts: 1,194

White Whale - '07 Dodge Ram 2500 ST Quad Cab 2wd, short bed
Team Cummins
90 day: 37.68 mpg (US)
Thanks: 112
Thanked 502 Times in 211 Posts
Quote:
Originally Posted by Frank Lee View Post
Say what?!? Remove inactive pistons!
Then you end up with the oil pressure problem already brought up and, more importantly, it keeps it more balanced to keep the mass in place.
__________________
Diesel Dave

My version of energy storage is called "momentum".
My version of regenerative braking is called "bump starting".

1 Year Avg (Every Mile Traveled) = 47.8 mpg

BEST TANK: 2,009.6 mi on 35 gal (57.42 mpg): http://ecomodder.com/forum/showthrea...5-a-26259.html


  Reply With Quote
Old 03-14-2012, 09:40 PM   #8 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,732

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,571
Thanked 3,505 Times in 2,194 Posts
Wow, I can't imagine considering keeping all that useless reciprocating mass going up and down... even with the ring packs (largest single contributors to internal engine drag) removed, holey pistons will create an awful, awful internal airflow/pumping loss mess.

It would be far easier to plug up a few oil galleys than it would be to perforate pistons.
__________________


  Reply With Quote
Old 03-14-2012, 10:32 PM   #9 (permalink)
Master EcoModder
 
Diesel_Dave's Avatar
 
Join Date: May 2011
Location: Indiana
Posts: 1,194

White Whale - '07 Dodge Ram 2500 ST Quad Cab 2wd, short bed
Team Cummins
90 day: 37.68 mpg (US)
Thanks: 112
Thanked 502 Times in 211 Posts
Quote:
Originally Posted by Frank Lee View Post
Wow, I can't imagine considering keeping all that useless reciprocating mass going up and down... even with the ring packs (largest single contributors to internal engine drag) removed, holey pistons will create an awful, awful internal airflow/pumping loss mess.

It would be far easier to plug up a few oil galleys than it would be to perforate pistons.
Yes, the rings can be taken off and if the valves are closed off and the holes are large enough, there shouldn't be much added pumping loss.

I only metioned the hole drilling, because I've seen it done on research engines where somebody had a multicylinder engine and wanted to create a single-cylinder research engine. So I know it can be done. Whether there are better ways of doing it, I don't know.
__________________
Diesel Dave

My version of energy storage is called "momentum".
My version of regenerative braking is called "bump starting".

1 Year Avg (Every Mile Traveled) = 47.8 mpg

BEST TANK: 2,009.6 mi on 35 gal (57.42 mpg): http://ecomodder.com/forum/showthrea...5-a-26259.html


  Reply With Quote
Old 03-16-2012, 12:13 PM   #10 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,732

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,571
Thanked 3,505 Times in 2,194 Posts
Maybe decapitate the entire piston crown including ring lands leaving only skirt and boss for con rod. Even then it wouldn't flow air very nice. I would only do that if a con rod throw (on the crank) filler piece wasn't feasible.

__________________


  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com