GunBroker.com Message Forums
Review our Posting Guidelines
GunBroker.com Message Forums
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
Forgot your Password?   Trouble / Can't log in?

 All Forums
 GunBroker.com Message Forums
 General Discussion
 Cummins with Achates Builds Military Diesel Engine
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

serf
Anti Gun Lib

6194 Posts

Posted - 11/14/2017 :  1:26:21 PM  Show Profile  Reply with Quote


Interesting 2 stroke diesel up to 1500 BHP with vastly increase efficiently with no valve train! I doubt there will be a civilian model anytime soon.

serf

https://www.trucks.com/2017/10/03/cummins-achates-advanced-tech-military-diesel-engine/

Specifications call for the production engine to reduce waste heat by 21 percent, improve power density by 50 percent and cut fuel use by 13 percent compared with current “typical combat vehicle engines,” the companies said.

Wild Turkey
Senior Member

1149 Posts

Posted - 11/14/2017 :  5:36:45 PM  Show Profile  Reply with Quote
4 cylinders means about 216 cid each -- 6" stroke and 6.75" bore?

pretty serious machine!

Wild Turkey
We may see the writing on the wall, but all we do is criticize the handwriting.
Go to Top of Page

dav1965
Advanced Member

USA
10501 Posts

Posted - 11/14/2017 :  5:42:52 PM  Show Profile  Reply with Quote
My wife is an engineer at Cummings.
Go to Top of Page

Don McManus
Advanced Member

USA
25007 Posts

Posted - 11/14/2017 :  6:03:18 PM  Show Profile  Reply with Quote
quote:
Originally posted by Wild Turkey

4 cylinders means about 216 cid each -- 6" stroke and 6.75" bore?

pretty serious machine!



4 cylinders with 8 pistons = 109 cid per piston.

5" diameter by 5.5" stoke would be close.

The opposed piston design used to be fairly common among marine diesels, but the I believe the monsters of today are single crank machines.

Edit; A link:

https://en.wikipedia.org/wiki/Fairbanks_Morse_38_8-1/8_diesel_engine

Everything old is new again....

'Freedom and a submissive populace cannot co-exist.'
Brad Steele.


'The Constitution that was actually enacted and formally amended creates islands of government powers in a sea of liberty. The judicially redacted constitution creates islands of liberty rights in a sea of governmental powers.'
Randy E. Barnett


CA #3


Edited by - Don McManus on 11/14/2017 6:05:16 PM
Go to Top of Page

iceracerx
Advanced Member

USA
8005 Posts

Posted - 11/14/2017 :  6:10:53 PM  Show Profile  Reply with Quote
quote:
Originally posted by Wild Turkey

4 cylinders means about 216 cid each -- 6" stroke and 6.75" bore?

pretty serious machine!



Two crankshafts (CS on both ends of the 'cylinders' and pistons meet in the middle forming the combustion chamber) and opposed pistons = 8 cylinders.

Helped develop one of these for a Tank 5 years ago. The design is rather old and requires forced air induction. It's an interesting design but HEAVY.

EDIT: I've been corrected and sent on the correct path. 1,312 lbs, The weight of the early Junker engine) is NOT heavy according to the experts on GBGD.

Considering the weight of an additional crankshaft and ensuring the crankcases/cylinders don't come apart at diesel combustion pressures, I'm sure the experts are correct.

Edited by - iceracerx on 11/15/2017 4:55:54 PM
Go to Top of Page

spasmcreek
Advanced Member

31686 Posts

Posted - 11/14/2017 :  7:35:33 PM  Show Profile  Reply with Quote
like to see that down to our pickup/suv/car size
Go to Top of Page

SCOUT5
Advanced Member

11301 Posts

Posted - 11/14/2017 :  9:37:15 PM  Show Profile  Reply with Quote
With new materials and other improvement in valves, crank design etc. Some of these old designs can really do what was only envisioned when they were first developed. Some designs are just ahead of the technology needed to build them.

Go to Top of Page

Flying Clay Disk
Advanced Member

USA
30967 Posts

Posted - 11/15/2017 :  08:31:33 AM  Show Profile  Reply with Quote
"Aim for the timing belt, boys!"


FCD

"Fortes et liber"

Go to Top of Page

serf
Anti Gun Lib

6194 Posts

Posted - 11/15/2017 :  1:36:22 PM  Show Profile  Reply with Quote
quote:
Originally posted by iceracerx

quote:
Originally posted by Wild Turkey

4 cylinders means about 216 cid each -- 6" stroke and 6.75" bore?

pretty serious machine!



Two crankshafts (CS on both ends of the 'cylinders' and pistons meet in the middle forming the combustion chamber) and opposed pistons = 8 cylinders.

Helped develop one of these for a Tank 5 years ago. The design is rather old and requires forced air induction. It's an interesting design but HEAVY.



Most engines are turbo charged or super charged anyway now days and they have these on Prop planes now so how is it they are heavy?

http://www.geminidiesel.aero/aviation

Although the Gemini is a totally new engine, its two-opposing-pistons-per-cylinder design is actually based on the six-cylinder, 12-piston Junkers Jumo 205 engine. This was a well-established engine design that has been well proven through tens-of-thousands of hours aboard WWII era multi-engine German bombers and commercial aircraft.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
GunBroker.com Message Forums © 1999-2017 GB Investments, Inc. All Rights Reserved Go To Top Of Page
Powered By: Snitz Forums 2000 Version 3.4.06


Visit GunBroker.com at: www.gunbroker.com
Use of this Web site constitutes acceptance of the site's User Agreement
Site Map