3000 RPM Sustained on a 4.0L? - Pirate4x4.Com : 4x4 and Off-Road Forum

JohnC · 07-27-2006, 12:10 PM

Will a stock 4.0L handle 3K RPM sustained for hours on the freeway?

I'm regearing from 4.56 to 5.42s to handle the 40's and with no OD at 65 MPH, I should be at just under 3000 rpm. I could do 5.13s, but I'd like to go as low as possible.

DSI · 07-27-2006, 12:26 PM

our jeep speeds sit on the rev limiter for sustained periods of time, and are almost always over 3k during a race, sometimes up to 9 hours at a time... seem to be holding together great so far... now the motor mount boss's in teh block are another story...

Beat95YJ · 07-27-2006, 01:37 PM

I have driven to Moab and back (1,000 miles each way) and the Rubicon (500 miles each way) in my 98 TJ tacking over 3k there and back several times. It still makes fine power and doesn't burn oil.

jeepkevin · 07-27-2006, 01:42 PM

I run 5.13's and 37" 3000 rpm at 70. I've made 2 trips to Colorado from Dallas,Tx about 17 hours straight with no problems.

Po' riggity · 07-27-2006, 03:16 PM

Back when my YJ was a daily driver, my jeep sat at 3k and above for 120 miles round trip, every day at 65 mph, and it still runs damn good with 226k miles on it.
Scott

MellowYellow · 07-27-2006, 03:26 PM

I had 32's and 4.56 w/o OD and I drove over 3k at 55 mph. It drove me nuts, but the motor was fine.
I have since re-geared to 4.10's to drop down to 2800 with 35's.

UCTJ · 07-27-2006, 03:27 PM

I spin about 2800 RPMs while on the freeway daily...so far no problems since its pretty much within a good RPM range. If I could run 5.13s I would, but I run 4.88s right now and 35s.

CJim7 · 07-27-2006, 09:29 PM

I used to run my 4.2 between 3k and 3200 RPM on the interstate 4 hours at a time sustained, without any problems. If a 4.2 can do it, a 4.0 sure as hell can.

Csnyder · 07-27-2006, 10:58 PM

Quote:

Originally Posted by jeepkevin

I run 5.13's and 37" 3000 rpm at 70. I've made 2 trips to Colorado from Dallas,Tx about 17 hours straight with no problems.

Same here on the gearing and tires. You'll be fine John.

- Chris

ZJim · 07-28-2006, 06:27 AM

Nope, it will definitely explode.

XJ4THEKICKIN · 07-28-2006, 06:38 AM

4.0L loves to rev, i run 3k on the hwy no problem, she says she likes it even.

Dust Puppy · 07-28-2006, 07:06 AM

yeah i used to run 456's 38's 4.0 with the 3 spd auto.

used to run for 3 or 4 hours and never drop below 3-3300rpms

never hurt the motor but i did blow 3 tranny's

sawzallsammy · 08-01-2006, 10:40 PM

Quote:

Originally Posted by Dust Puppy

yeah i used to run 456's 38's 4.0 with the 3 spd auto.

used to run for 3 or 4 hours and never drop below 3-3300rpms

never hurt the motor but i did blow 3 tranny's

dude you should never blow a tranny thats gross man

forsakenfuture · 08-01-2006, 10:50 PM

Glad to know im not the only one traveling down the high way at three grand thanks to 4.56 gears and that damn three speed trans.

prostock3 · 08-14-2006, 10:54 PM

when i 4 wheel, i always hit the rev limiter..i have a heavy foot and i havent blown yet hehe

socalchef · 08-15-2006, 12:30 AM

Quote:

Originally Posted by DSI

now the motor mount boss's in teh block are another story...

funny, my buddies son is having the exact same problem with their JS XJ

CB87YJ · 08-15-2006, 06:14 AM

3000 rpm @ 70 MPH. Been there, Done that.

sustained 4 days crossing west to east thru the desert.
Plus multiple rides from LA to SanDiego 1.5 hrs 1 way
2.5 hrs to JV to wheel.
Rode up to Pismo, 4 hrs, same numbers

NP435 and 456's with 35s will do that.
Be very sure you have a powerful fan for your cooling system.
other than that, youll perk around 210-220F which isnt bad for a Jeep.

My 4.0 came from an XJ donor 3yrs ago with 65K.
now at 102K.
I still do 70 on the highway on a regular basis.

Run It.
CB

BigRedK5 · 08-15-2006, 09:12 PM

What about a 2.5L at 3000 RPM's? on the freeway for 2 hours?

Fozzy_Bear · 08-16-2006, 10:15 AM

Quote:

Originally Posted by sawzallsammy

dude you should never blow a tranny thats gross man

Well, THAT's an image i didn't need....

But for the originial question:

I also run mine pretty high. I have 4.88's turning 33 inch tires. - Great on the trails; kind of irriataing on the 3.5 hour trip to the mountains. But no problems. And my engine has a quarter Million miles on it.

jeeperak · 08-16-2006, 01:28 PM

Hell I Think It Runs Better At 3000+

Rugger99 · 08-16-2006, 02:51 PM

Like everyone else has said...it will be fine. I run mine at 3000 - 3200 rpm with the 4.0 / ax15 /5.13 gears and 37" Krawlers on beadlocks....no problems. 72k on the motor and the original clutch

05Willys · 08-18-2006, 09:31 AM

The chart i just read states that for optimal gas mileage you want to consistantly run at ~3200rpm

Fozzy_Bear · 08-18-2006, 09:57 AM

That's interesting.

I'd really like to see that chart. Is it online somewhere? If so, please post a link, or PM it to me.

- Thanks

TACH329 · 08-18-2006, 06:53 PM

Yes 3K is fine.
My 94 XJ has 4.0 HO with the AW4, 5.38's and 35's.

Even when I'm not on the freeway I drop it in 3rd to keep the RPM's up.

JeepCrawler98 · 08-18-2006, 07:11 PM

Quote:

Originally Posted by BigRedK5

What about a 2.5L at 3000 RPM's? on the freeway for 2 hours?

Also fine - I keep mine churning away at 3200-3700RPM on the freeway for hours on end all the time. 130K miles, not a SINGLE problem.

07-27-2006, 12:10 PM	#1 (permalink)
JohnC Registered User Join Date: Feb 2001 Member # 3310 Location: WA Posts: 977	3000 RPM Sustained on a 4.0L? Will a stock 4.0L handle 3K RPM sustained for hours on the freeway? I'm regearing from 4.56 to 5.42s to handle the 40's and with no OD at 65 MPH, I should be at just under 3000 rpm. I could do 5.13s, but I'd like to go as low as possible.

07-27-2006, 12:26 PM	#2 (permalink)
DSI Pirate4x4 Addict! Join Date: May 2000 Member # 920 Location: The Land of Debauchery (NV) Posts: 15,130	our jeep speeds sit on the rev limiter for sustained periods of time, and are almost always over 3k during a race, sometimes up to 9 hours at a time... seem to be holding together great so far... now the motor mount boss's in teh block are another story... __________________ Thanks to the companies that make it happen: Bilstein Shock Absorbers, Trail-Gear, Trent Fab, PRP Seats, Raceline Wheels, PSC, MJ Motorsports

07-27-2006, 01:37 PM	#3 (permalink)
Beat95YJ Registered User Join Date: Aug 2003 Member # 22176 Location: Redondo Beach Posts: 8,745	I have driven to Moab and back (1,000 miles each way) and the Rubicon (500 miles each way) in my 98 TJ tacking over 3k there and back several times. It still makes fine power and doesn't burn oil. __________________ I can break a steel ball in a rubber room!

07-27-2006, 03:26 PM	#6 (permalink)
MellowYellow Registered User Join Date: Feb 2000 Member # 20 Location: San Jose, CA Posts: 1,076	I had 32's and 4.56 w/o OD and I drove over 3k at 55 mph. It drove me nuts, but the motor was fine. I have since re-geared to 4.10's to drop down to 2800 with 35's. __________________ I've been gone a while, but I'm still hang'n in there!

07-27-2006, 09:29 PM	#8 (permalink)
CJim7 Registered User Join Date: May 2006 Member # 72257 Location: IdaHo Posts: 1,325	I used to run my 4.2 between 3k and 3200 RPM on the interstate 4 hours at a time sustained, without any problems. If a 4.2 can do it, a 4.0 sure as hell can. __________________ I drive the fastest barbecue on 4 wheels...

07-27-2006, 01:42 PM	#4 (permalink)
jeepkevin Wheeler Join Date: Sep 2005 Member # 53641 Posts: 137	I run 5.13's and 37" 3000 rpm at 70. I've made 2 trips to Colorado from Dallas,Tx about 17 hours straight with no problems.

07-27-2006, 03:27 PM	#7 (permalink)
UCTJ The Devils Trailboss Join Date: Aug 2005 Member # 51571 Location: Texas Posts: 3,893	I spin about 2800 RPMs while on the freeway daily...so far no problems since its pretty much within a good RPM range. If I could run 5.13s I would, but I run 4.88s right now and 35s.

07-28-2006, 06:27 AM	#10 (permalink)
ZJim Registered User Join Date: Nov 2003 Member # 24099 Location: Gainesville, FL Posts: 1,359	Nope, it will definitely explode.

07-28-2006, 06:38 AM	#11 (permalink)
XJ4THEKICKIN Registered User Join Date: Oct 2003 Member # 23829 Location: Alabama and Texass Posts: 728	4.0L loves to rev, i run 3k on the hwy no problem, she says she likes it even.

08-01-2006, 10:50 PM	#14 (permalink)
forsakenfuture Registered User Join Date: Dec 2004 Member # 39726 Location: Monett,Missouri Posts: 518	Glad to know im not the only one traveling down the high way at three grand thanks to 4.56 gears and that damn three speed trans.

08-14-2006, 10:54 PM	#15 (permalink)
prostock3 Registered User Join Date: Dec 2005 Member # 62903 Location: Mich Posts: 517	when i 4 wheel, i always hit the rev limiter..i have a heavy foot and i havent blown yet hehe __________________ 2009 Twisted Customs buggy (sold :C) -----2001 Donzi 38zx -----2004 Duramax 2500 CC

08-15-2006, 06:14 AM	#17 (permalink)
CB87YJ Registered User Join Date: Oct 2002 Member # 14470 Location: where ever i may roam Posts: 453	3000 rpm @ 70 MPH. Been there, Done that. sustained 4 days crossing west to east thru the desert. Plus multiple rides from LA to SanDiego 1.5 hrs 1 way 2.5 hrs to JV to wheel. Rode up to Pismo, 4 hrs, same numbers NP435 and 456's with 35s will do that. Be very sure you have a powerful fan for your cooling system. other than that, youll perk around 210-220F which isnt bad for a Jeep. My 4.0 came from an XJ donor 3yrs ago with 65K. now at 102K. I still do 70 on the highway on a regular basis. Run It. CB __________________ [COLOR="Yellow"][B]Crawl rocks instead of smokin 'em.[/B][/COLOR] Rock Rated,4.0,Gears,Lift,Tires,Armor. [COLOR="Silver"]Hardcore, Old-School and Sexy, TSL-SX[/COLOR] [QUOTE=Steve N]Thread poster may be hardcore. Post is not. So this is in wrong section.[/QUOTE]

08-15-2006, 09:12 PM	#18 (permalink)
BigRedK5 Registered User Join Date: Dec 2004 Member # 40297 Location: McKinney, Tx Posts: 159	What about a 2.5L at 3000 RPM's? on the freeway for 2 hours? __________________ 2000 Tacoma 3.4L

08-16-2006, 01:28 PM	#20 (permalink)
jeeperak Registered User Join Date: Mar 2006 Member # 69049 Location: sierra vista Az Posts: 210	Hell I Think It Runs Better At 3000+ __________________ [url]http://www.4lo.com/calc/geartable.htm[/url] STFU bitches, it's Santa". whoops.

08-16-2006, 02:51 PM	#21 (permalink)
Rugger99 Registered User Join Date: Sep 2003 Member # 22646 Location: Tallahassee,FL Posts: 1,639	Like everyone else has said...it will be fine. I run mine at 3000 - 3200 rpm with the 4.0 / ax15 /5.13 gears and 37" Krawlers on beadlocks....no problems. 72k on the motor and the original clutch __________________ " Never underestimate the power of idiots in large groups"

08-18-2006, 09:31 AM	#22 (permalink)
05Willys Registered User Join Date: Mar 2006 Member # 69994 Posts: 180	The chart i just read states that for optimal gas mileage you want to consistantly run at ~3200rpm

08-18-2006, 09:57 AM	#23 (permalink)
Fozzy_Bear Registered User Join Date: Jul 2005 Member # 50242 Location: Norfolk, Va Posts: 182	That's interesting. I'd really like to see that chart. Is it online somewhere? If so, please post a link, or PM it to me. - Thanks __________________ ... Shit happens. Carry a shovel. ...

08-18-2006, 06:53 PM	#24 (permalink)
TACH329 Registered User Join Date: Mar 2005 Member # 44579 Location: Jacksonville, FL. Posts: 15	Yes 3K is fine. My 94 XJ has 4.0 HO with the AW4, 5.38's and 35's. Even when I'm not on the freeway I drop it in 3rd to keep the RPM's up. __________________ [b][ ] [u]l l l l l l l[/u] [ ][/b]Save your money for gears and swampers then save money on your lift by cutting out your fenders.

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