I had a professor that supposedly got his XJ 4.0 to run on only 4 cylinders on the highway to save gas.
The v6/v8's use a special lifter for this. My wife's Yukon has it, I tuned it out. I think I lost 0.5MPG.
Why no chatter about strokers?
- Thread starter MikekiM
- Start date
I had a professor that supposedly got his XJ 4.0 to run on only 4 cylinders on the highway to save gas.
The v6/v8's use a special lifter for this. My wife's Yukon has it, I tuned it out. I think I lost 0.5MPG.
IOwnCalculus
TJ Enthusiast
Even non-DOD LS swaps get better mileage in the TJ than the 4.0, if you keep your foot out of it. They're vastly more modern engines that had a lot of attention paid to reducing friction (less piston skirt, roller lifters, roller rocker fulcrums), with much better head designs - the 4.0 isn't even crossflow!
Really, I'm less surprised that the 4.0 gets such terrible mileage, and more surprised at the fact that it still (barely) passed emissions standards for the time while making 180hp.
Really, I'm less surprised that the 4.0 gets such terrible mileage, and more surprised at the fact that it still (barely) passed emissions standards for the time while making 180hp.
I loves me a stroker motor. Had an oddball stroker once. A 1955cc that had loads of torque. Pushed my highroof easily down the road.
I've always wondered why the Cherokee got better mileage than the wrangler too. Its not uncommon for a Cherokee to get 20+ while a wrangler is lucky to get mid to upper teens (even if its not lifted and with big tires). Probably something to do with the open wheel wells and stuff, but its always been a mystery.
Kinda like why the 4.0/AW4 combo works so well in a Cherokee, but its terrible in a wrangler.
Kinda like why the 4.0/AW4 combo works so well in a Cherokee, but its terrible in a wrangler.
Well, I was about to crash this party after my palms started itching but I see we have moved on to turning Jeeps into Priusisesis now?
Stroking a 4.0 from a strictly HP performance perspective is polishing a turd. Any HP mod to a 4.0 is really. There are too many limiting factors as mentioned above to ever make it a practical base for real performance.
That being said, the big selling point of a stroker was/kinda is the cheap cost with junkyard parts compared to a normal rebuild. Parts are becoming more scarce though, and aftermarket is expensive. You also start rapidly losing that bang for the buck when you start trying to make it actually breath with head work, a big cam, compression, fancy bolt ons, etc. Not saying it won't make more power, but your point of diminishing returns n/a starts around 300hp which isn't much.
And people bag on reliability of strokers. There is ZERO less reliable about a stroker per se. What does cause problems is higher lift cams eating lobes, high pressure oil pumps putting stress on things, and bad machining/assembly. All of these issues would be the same on a rebuilt 4.0 with the same things done. Has nothing to do with the stroke.
All that being said, what kind of crazy ass hole would dump money into one? Me
It's the motor Jeep should have installed from the factory. It's more than spunky (think Fox body Mustang fast to around 70) and will cruise up hill doing 80 on 33's with 4.10s all day long at half throttle. I love the motor. I also enjoy wrenching and have a weird obsession for more power in everything, so there it is.
Stroking a 4.0 from a strictly HP performance perspective is polishing a turd. Any HP mod to a 4.0 is really. There are too many limiting factors as mentioned above to ever make it a practical base for real performance.
That being said, the big selling point of a stroker was/kinda is the cheap cost with junkyard parts compared to a normal rebuild. Parts are becoming more scarce though, and aftermarket is expensive. You also start rapidly losing that bang for the buck when you start trying to make it actually breath with head work, a big cam, compression, fancy bolt ons, etc. Not saying it won't make more power, but your point of diminishing returns n/a starts around 300hp which isn't much.
And people bag on reliability of strokers. There is ZERO less reliable about a stroker per se. What does cause problems is higher lift cams eating lobes, high pressure oil pumps putting stress on things, and bad machining/assembly. All of these issues would be the same on a rebuilt 4.0 with the same things done. Has nothing to do with the stroke.
All that being said, what kind of crazy ass hole would dump money into one? Me
It's the motor Jeep should have installed from the factory. It's more than spunky (think Fox body Mustang fast to around 70) and will cruise up hill doing 80 on 33's with 4.10s all day long at half throttle. I love the motor. I also enjoy wrenching and have a weird obsession for more power in everything, so there it is.
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Yea I have been down the road before so I kinda know what to expect. If worse comes to worse I will make it a trail only car till I move out of state
I finished my 4.7 stroker in September 2022-I love it. With 33’s, 5 sped manual and 3.73 gears it holds fifth on hills in central Texas that used to require a downshift. I still plan a 4.56 (I think) re-gear to have even better drivability. The 4.7 stroker has about the same torque as my old 6000lb+ Tahoe 5.3L LS had and My TJ is closer to 3000 lb. TJBUD
OP
Wow.. electric, diesel, nuclear.. this thread really went sideways...
OP
7120 and the 0630 are the heads with the best performance potential.
If serious about a stroker build it’s worth checking out jeepstrokers.com
There’s a good basics section and performance/tech section as well as a calculator for displacement, dynamic & static compression, etc. It helped me a lot. Feel free to PM me on either forum if I can help. TJBUD
There’s a good basics section and performance/tech section as well as a calculator for displacement, dynamic & static compression, etc. It helped me a lot. Feel free to PM me on either forum if I can help. TJBUD
A well-built and tuned stroker should have about the same power as a 5.3 LS engine and should have similar reliability as a 4.0. Parts are the big issue. My main issue has been crankshafts. I went through 4 new ones from various sources before finding one that is in spec. One of them from a large well-known vendor had over 0.012" runout on the #4 main journal. That amount of runout would destroy the engine in a few hundred miles. These engine parts coming from overseas are extremely hit and miss. The sellers stateside are not always doing good if any inspections on the parts, and installers are not always checking them either.
There is. Go to Google and paste this - stroker site:wranglertjforum.com
Just sayin...