Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Alpine Coach Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 09-18-2014, 07:50 AM   #15
Senior Member
 
dennismhamm's Avatar
 
Alpine Owners Club
Join Date: Sep 2014
Location: FLORAL CITY,FL
Posts: 669
Blog Entries: 1
my overflow tank radiator cap is a 16lb vented cap? is this correct for the cummins 400 hp isl? don't think we have ever replaced the radiator cap and should we?
__________________
Dennis & Brenda
2017 Tiffin Phaeton 40 qbh
2022 Ford F350 Super Duty 6.7 PowerStroke
dennismhamm is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 09-18-2014, 09:33 AM   #16
Registered User
 
Newmar Owners Club
Join Date: Nov 2008
Posts: 2,899
Take the cap to almost any auto parts store, NAPA is a good choice, they can match it. I believe it is 17psi rated.
Renipladlo is offline   Reply With Quote
Old 11-19-2014, 11:02 PM   #17
Senior Member
 
Stretch's Avatar
 
Join Date: May 2004
Location: cayucos, ca
Posts: 1,299
Old r ver
Regarding Jake (engine) brake. The jake actually works by holding the exhaust valve slightly off the seat. That way when the piston comes up on the compression stroke sit is forced out of the cylinder making a compressor out of the engine. Forcing air thru the partially open valve takes energy or horsepower. That is what slows the coach. If the exhaust valve was allowed to close the compression would force the piston back down. That would NOT make a compressor out of the engine
__________________
Ross Starkenburg
2017 Newmar Dutch Star 4369. Spartan chassis w/full disc brakes. 2015 Jeep Grand Cherokee toad
Stretch is offline   Reply With Quote
Old 11-20-2014, 10:59 PM   #18
Senior Member
 
Mule Skinner's Avatar
 
Join Date: Jul 2006
Location: Newcastle, CA
Posts: 307
Quote:
Originally Posted by Stretch View Post
Old r ver
Regarding Jake (engine) brake. The jake actually works by holding the exhaust valve slightly off the seat. That way when the piston comes up on the compression stroke sit is forced out of the cylinder making a compressor out of the engine. Forcing air thru the partially open valve takes energy or horsepower. That is what slows the coach. If the exhaust valve was allowed to close the compression would force the piston back down. That would NOT make a compressor out of the engine
I believe I saw in the manual that the Jake brake randomly drops cylinders by cutting the fuel. On the low setting it drops 3 cylinders randomly, on the high setting it cuts the fuel to all 6 cylinders.
On the ISC ?, 350 hp the exhaust is blocked by a butterfly valve in the exhaust pipe.
As for using the up and down arrows to manually shift your transmission, remember that you will need to press D or arrow back up to 6th gear once you are back on level ground.
__________________
Dan and Patty
"04" Alpine 34' FDDS 2018 Jeep Grand Cherokee
Newcastle, CA
Mule Skinner is offline   Reply With Quote
Old 11-21-2014, 02:42 AM   #19
Senior Member
 
Stretch's Avatar
 
Join Date: May 2004
Location: cayucos, ca
Posts: 1,299
Old rver
Not sure about the jake randomly dropping 3 cylinders on low setting. I guess with the electronic controls it would be possible. However with the non electronic engines it is the same three cylinders that the fuel is turned off and the exhaust valve is held open. The other braking method, the exhaust brake is just a butterfly valve that closes off the exhaust pipe entirely causing pressure to build like a compressor. Again that takes energy holding the coach back.
The engine or Jake Brake is far the better braking method.
__________________
Ross Starkenburg
2017 Newmar Dutch Star 4369. Spartan chassis w/full disc brakes. 2015 Jeep Grand Cherokee toad
Stretch is offline   Reply With Quote
Old 11-21-2014, 07:37 AM   #20
Senior Member
 
Join Date: Oct 2014
Posts: 7,867
On any modern electronically controlled diesel, whether Cummins, Cat, etc when the throttle is closed, there is ZERO fueling.

With a two speed engine compression brake (aka Jake brake), low activates three cylinders, high activates all six cylinders.

It requires a LOT of work to push a piston up-- compressing roughly 17 volumes into one. In coast mode (engine brake off) most of that work is returned after the piston passes TDC (Top Dead Center).

Lifting the exhaust valve at the end of the compression stroke releases all the energy used to compress that 17 or so volumes into one (out the exhaust).

Brett
2003 Alpine 38'
wolfe10 is offline   Reply With Quote
Old 11-22-2014, 06:25 PM   #21
Registered User
 
Newmar Owners Club
Join Date: Nov 2008
Posts: 2,899
FWIW - Alpine owners only, with ISL engine, other brands don't reply.


1. Never go down a hill faster than you go up it. Leaned that in CDL school, don't follow what the other guy is doing, be safe, if you went up at 40, go down at 40 till you get to the bottom.
2. Regardless of others, in my Alpine, when I push the engine brake, it does couple of things, first shifts transmission into 4th gear (50 MPH or below)(over 50, you could OVER-REV the engine and blow it up-Cummins told me specifically when I asked, never over rev the engine in any situation, acceleration or deceleration period, he was fixing a Monaco Coach whose owner had used the engine brake and over revved the engine, to the tune of a rebuild, lots of dough for that. The ISL redlines around 2300-2400 RPM's, the Allison will shift it correctly when accelerating. It also closes or almost closes the intake/exhaust valves, and shut off fuel delivery to the cylinders. Making the engine a braking compressor if I understand the principle correctly.
3. I switch between high and low engine brake going down a hill, as high will slow me down real good, below 40mph, so then I switch to low, which allows the coach to build up speed, prior to 50, I switch back to high. This works for me, but, I never go down faster than 50, unless I know the road, and it is not a long downhill stretch.
4. Once I am near the bottom, I turn off EB and accelerate a little to get the transmission to shift into it's correct gear. Normally I never need to touch the transmission going downhill.
5. Going uphill, since I want max RPM's turning my Hydraulic pump so I get max RPM's out of the cooling fan assembly for the radiator, I keep my engine RPM's in the 1900-2000 range, using whatever gear is required to keep it at that RPM. I don't worry about MPH going up a hill. We don't carry more than 33K in weight, (max GVWR for the coach) so we can normally pass most trucks, they will also normally stay in the right lane or the shoulder so traffic can pass. I use the arrow keys on the keypad to downshift as needed, remembering to use the up arrow to get it back into 6th, then I use the EB to go down.


Other drivers have their own system, and the recommendation of their MH builder. If you don't have an owners manual, believe it can be downloaded from the ACA tech library, or an owner can make a copy and get you one.
Renipladlo is offline   Reply With Quote
Reply

Tags
cummins, water



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
MaxxForce 10 350hp vs 400hp Cummins Dennis_K Navistar MaxxForce Engine Forum 11 12-29-2015 11:47 PM
Cummins Water temperature Rudyard1 Class A Motorhome Discussions 33 11-16-2014 07:59 AM
Retractable Water Hose 2006 Ambassador dangme55 Monaco Owner's Forum 2 08-15-2014 10:59 AM
Cummins Supports Gvnmt Efforts to Develop GHG Standards for Medium and HD Vehicles DriVer RV Industry Press 0 02-18-2014 11:40 AM
Cummins 2.8L TD Engine Powers Concept Vehicle DriVer RV Industry Press 1 02-06-2014 09:55 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 10:21 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.