best mod for my jk

[sgt rock]

a few years ago i had a 5.7 hemi installed in my jk.... i believe from day one i started the hate relationship as i was averaging 9.0 miles per gallon. my second issue was overheating and pretty mothballed my jk to the garage....
last month i contacted camp crocker from crocker offroad- he had a pretty much clean jk stock engine that he would swap with me..... i might not be fast- but who needs it! as i now have 19.8 mile per gallon on the odometer...and my temp is sitting a wee left of the middle....... my jk is happy to be on the road again....!!

:smiley_drive:

 

[BIGdaddy]

Good for you. My XJ has 185,000 on the ticker, knocks like a diesel, but I have excellent oil pressure, tons of power and get about 18-19mpg's usually.

I've heard nothing but issues from folks that put strokers in their jeeps, and most of them report that they get around 10-12mpgs.

no thanks.

When this engine finally bites the dust, I'm going to save my duckets and put the same ol' boring, reliable, pretty much perfect motor back in it. I actually asked about the cost of having my local dealer put in a factory-new long block in, and honestly wasn't too scared by the price, having shopped around a bit and seen the alternatives.

I'd love the idea of having a warranty on my almost 20 year trucks motor. haha!

 

[sgt rock]

thanks big daddy-- not knocking the hemi.... no regrets but its good to see a tank of gass last twice as long....

 

[alosix]

thanks big daddy-- not knocking the hemi.... no regrets but its good to see a tank of gass last twice as long....

Would be interesting to know why it was soo bad.

I swear I get @ least 15 out of my M725 that's running a 2005 Hemi from a durango.

Glad to see you got the mojo back with your jeep though

 

[bldeagle10]

thats interesting to know, i would like a jk in the future and i was thinking hemi or cummins upgrade. sounds like i should lean towards a cummins...

 

[JPK]

Too bad your Hemi instal didn't work out.

Mine JKU Hemi instal has worked out really, really well. No overheating, no issues at all. I've never seen the temp gauge move off dead center once its warmed up! Great performance on and off road. At ~375lb/ft torque and ~375HP my 5.7VVT Hemi provides more than enough torque and HP, and really, Jeep ought to be offerring a V8 with roughly 300lbs/ft, 300hp from the factory, and a diesel with at least that torque number too.

With the 5.7VVT Hemi, 4.88 gears, 37's, some armor, a roof rack, front and rear steel bumpers, a winch, a small Engel fridge and almost always a full load of gear I average 13mpg, which is almost exactly - actually a bit better - than what my '06 LJ with the 4.0, 33's and 4.10's, a roof rack, lots of armor, steel bumpers and a winch averages!

With a stock 20.6 gal tank range with my JKU was an issue. I fixed that with an 18 gal Long Ranger auxilliery tank. Now range, with a 50 mile reserve, is ~450miles. Since the Hemi is rarely working hard mpg/range stays fairly constant.

AEV did my Hemi conversion.

BTW, my wife has a more stock JKU with the 3.8, and there is no way in hell I would go back.

JPK

 

[sgt rock]

thanks jpk

mine was done by burnsville... i drove my jk home from MN and when i got to NM and had hills i had the temp running 3/4's ... a day later in phoenix i was calling burnsville and was told it might need a new hood and a bigger radiator...which was not the answer i needed. long story short was she only came out in the winter time.

camp crocker is a good friend and tried to remedy the issue but nothing worked. i even had luke jeep dealership tell me it was the gearing...

i know i was getting 9/10 miles per gallon as i had 2 rhinos in the jeep tracking my speeds and miles.

camp finally agreed to swap my engine as he needed a hemi.... and at this point i did not care if it was at my loss... i came across 11 other hemi swaps that had overheating issues on the jk forum side but was banned years ago when i spoke about adventure trailer and could not write to them. 5 on the jkowners side have also had heat issues.

my jk for a 2007 only has 27,000 miles on it so its time to have fun once again...

 

[sgt rock]

thats interesting to know, i would like a jk in the future and i was thinking hemi or cummins upgrade. sounds like i should lean towards a cummins...

again not ripping the hemi- was told that the 5.7 comes in a few different types and that is why i had my issue- in fact when the gauge started to show some overheating i should have did a 360 to burnsville!

 

[JPK]

thanks jpk

mine was done by burnsville... i drove my jk home from MN and when i got to NM and had hills i had the temp running 3/4's ... a day later in phoenix i was calling burnsville and was told it might need a new hood and a bigger radiator...which was not the answer i needed. long story short was she only came out in the winter time.

camp crocker is a good friend and tried to remedy the issue but nothing worked. i even had luke jeep dealership tell me it was the gearing...

i know i was getting 9/10 miles per gallon as i had 2 rhinos in the jeep tracking my speeds and miles.

camp finally agreed to swap my engine as he needed a hemi.... and at this point i did not care if it was at my loss... i came across 11 other hemi swaps that had overheating issues on the jk forum side but was banned years ago when i spoke about adventure trailer and could not write to them. 5 on the jkowners side have also had heat issues.

my jk for a 2007 only has 27,000 miles on it so its time to have fun once again...

I'm familiar with some of the reports of overheating on the JK Owners forum. Seems most are second hand and some may revolve around removal of fender liners. I also think Burnsville now adds a raditator to their swap. Maybe AEV also upped the radiator size.

With my AEV swap, the AEV heat reduction hood and a big new aluminum radiator were included.

What gears were you running and what tire size? I'm running 4.88's and 37's.

BTW, I drove an AEV 6.1L Hemi JKU and it didn't have any issues either. It was going to Bahrain after a two year stint here to overcome some Bahrainian import duty issues. I didn't drive it very long but you gotta think that if AEV's shipping them to Bahrain they have to have overcome any overheating issues, if AEV ever had them. As an aside, the 6.1 had the same 4.88's mine has but 35's instead of 37's. Damn that thing was quick.

JPK

 

[Renrag]

Having had both engines on the same Jeep, do you have an opinion on the weight difference?

mikE

 

[sgt rock]

Having had both engines on the same Jeep, do you have an opinion on the weight difference?

mikE

hey mike- weight is a lot lighter - towed my trailer today and had no issue heading up the 17 that had hills.... heading to a stop light feels pretty good.

if you want a hemi- go for it- again i loved it but for me its travelling more without gas pit stops--

 

[sgt rock]

I'm familiar with some of the reports of overheating on the JK Owners forum. Seems most are second hand and some may revolve around removal of fender liners. I also think Burnsville now adds a raditator to their swap. Maybe AEV also upped the radiator size.

With my AEV swap, the AEV heat reduction hood and a big new aluminum radiator were included.

What gears were you running and what tire size? I'm running 4.88's and 37's.

BTW, I drove an AEV 6.1L Hemi JKU and it didn't have any issues either. It was going to Bahrain after a two year stint here to overcome some Bahrainian import duty issues. I didn't drive it very long but you gotta think that if AEV's shipping them to Bahrain they have to have overcome any overheating issues, if AEV ever had them. As an aside, the 6.1 had the same 4.88's mine has but 35's instead of 37's. Damn that thing was quick.

JPK

hey jpk-- the hood was replaced with an aev - did not resolve ... i have 35" tires with higher gears.... and its automatic. quite true about the hemi's going overseas but as far as 3rd partys did come across 3 direct reported issues off the jk-forum board...(i rarely in a blue moon go to some of the "other" jeep boards as this site is not as dramatic as the other ones) but being banned could not contact them. i know dan did an exchange for one person that had a aev over heating issue...
in short i had camp crocker pull it for me and sitting at a verified (GPS) mpg at 20.1 mpg (compared to 9.x ) ...

anyhoots- enjoyed the hemi but the cons outweighed pro's...and like i said b4- it was freakin' fast!!!!!

 

[JPK]

I'm assuming you are asking about the weight difference between the 5.7VVT and the 3.8L since there isn't a substantial difference bewteen the weight of a 5.7VVT and the 6.1 Hemi.

AEV installed my 5.7VVT and their 4.5" lift along with other options, including their front bumper and steel air dam/E-disco skid - a reported 115lbs, a Warn 9.5ti - about 55lbs with the rope in lieu of wire and an aluminum hawse fairlead, their rear bumper - in excess of 100lbs and with 7.5gals of water tankage, their tire carrier - hung with back up light and a BFG 37, a roof rack, five 17" Pintler wheels shod with BFG 37's (one the spare), leather seats, a rear cargo "box" from Bestop, two 9" driving lights, rear corner gaurds and a brick outhouse of a rear diff gaurd all at the same time. The tub was LineX'd as well. That has to be 400-500lbs worth of gear not including four tires on the ground or the Hemi weight gain over the 3.8, which I figure is about 110lbs more. (Found the weight of the Hemi, assumed the 3.8 weighs about 75% as much, since it is 75% the engine in cylinder count.)

Post AEV magic and the Jeep handles better, corners better, steers better, rides better, is more sure footed, has less body lean, brakes straighter and sure has PLENTY of git up and go. Its a hell of a lot more fun too.

My wife has an almost stock JKU Rubicon with the 3.8L and auto and the difference between the two is night and day in every respect. If my Jeep were stolen or totaled - God forbid! - my next one would be delivered straight to AEV for a repeat performance of their magic.

Since getting the Jeep from AEV in August I've added an 18gal auxiliary fuel tank, a snorkel and a small Engel fridge. I've towed couple of +/- 2500lbs trailers and hualed up to ~450lbs corn in an alternatively front or rear mounted hitch hauler both while the Jeep was loaded with hunting gear and had two occupant @ 350lbs combined plus two dogs @ 70lbs/ea or so. Weight hasn't been a factor, brakes are fine too, no issues, no sag with the loaded hitch hauler or trailers. Still PLENTY of go power. I'll be adding a combo trans and engine oil pan skid this spring.

Could the stock Rubicon suspension would handle all of that weight? I don't know, don't think so, I do know it would be struggling at best. The 3.8L could handle the weight and tires, etc, if the gearing was right, which I think would be the lowest available, and that is 5.13's.

JPK

 

[sgt rock]

thanks jpk for the 20/20 -- at least i can still pop in the wifes gt stang if i ever have the urge... maybe i am one of the rare ones with the heat issue but now i can continue my expedition build and close the chapter on my tj....

 

[Renrag]

Thanks to both sgt rock and JPK. I now have this '07 Rubi with 35's, 5:13's, auto, all the usual armor, etc... (Pics here: http://www.expeditionportal.com/forum/showthread.php?t=57223 ) I love those kinds of trips, but the reality is that I need to cross country(minimum of Iowa, Nebraska, and parts of Colorado) to get to where I'm going. Not many deserts in the midwest. It is these hauls down the interstate that just drive me nuts. I carry an extra 13gal of gas in a tank behind the axle, so I at least have decent range now. I only get 13-14mpg(as low as 10, high as 17) with the 3.8 as it is. I have no idea how sgt rock can get 20. Must drive slower than I do by a lot. Comes back to the need to get there in two days not three.
Anyway, I've been tossing around the decision between a RIPP or a Hemi for over a year. I just want to be able to cruise down the interstate with traffic. The 3.8 in my Jeep can't do that without a tail wind. I'm pretty sure we all know how often that happens....

mikE(thanks again for the answers)