so how much power does your stroker have?

[philip_g]

my block is still in the machine shop.... But I've been wondering how much difference it really makes.
My 89 has 195k on it and barely has enough power to get out of it's own way. Going up a hill on the freeway? 4th gear for sure :scared:

Convince me it'll be worth my time and money

 

[stever6kid]

It depends on the stroker. I'll tell you go to thess web addresses they have loads of good info. http://www.angelfire.com/my/fan/stroker.html
http://www.jeep4.0performance.4mg.com/stroker.html
What engine do you have any ways the 4.0L, 242 or the 4.2L 258?

 

[Beej]

Depending on how you build it, you're gonna be looking at somewhere between 250 and 275ish...

 

[ZomBrady]

I don't have a super fancy stroker, but I could smoke my tires for 50+ft at 2800 rpm. That was on 28" tires with stock gearing, and now I'm running 31's with 4.56s and it's even better!

Trust me, you couldn't be happier with a good stroker!

 

[philip_g]

It depends on the stroker. I'll tell you go to thess web addresses they have loads of good info. http://www.angelfire.com/my/fan/stroker.html
http://www.jeep4.0performance.4mg.com/stroker.html
What engine do you have any ways the 4.0L, 242 or the 4.2L 258?

I'm doing a budget job, I'm basically copying dinos.
4.0 renix I'll put a HO head and manifolds on.
258 4 weight crank I got for 50 bucks and having reground, bore the block .030 and deck it, new cam bearing and freeze plugs, nothing crazy. I'll have delta cams custom grind me a knockoff of the compcam since it's like 1/3rd the price and use their lifters.

Actually having a hard time finding a deal on pistons and rods.


I'm just having a hard time believing an extra half liter will make that much difference unless my engine is really, really tired.

 

[ZomBrady]

. . .I'm just having a hard time believing an extra half liter will make that much difference unless my engine is really, really tired.

That .5 Liters equals 25% more displacement than a stock engine. . .conservatively that means that you should pump out ~210(more like 230+)Hp and the same goes for your torque. It's very noticable, well worth it.

 

[Dr. Dyno]

That .5 Liters equals 25% more displacement than a stock engine..

Not quite. If you go from 4.0 to 4.6 liters, that's a 15% gain in displacement. To gain anywhere near 15% more HP and 15% more torque, that extra displacement has to breathe in and out though a bigger straw i.e. free-flowing intake, bored TB, ported head, performance cam, header & 2.5" exhaust.

 

[ZomBrady]

Not quite. If you go from 4.0 to 4.6 liters, that's a 15% gain in displacement. To gain anywhere near 15% more HP and 15% more torque, that extra displacement has to breathe in and out though a bigger straw i.e. free-flowing intake, bored TB, ported head, performance cam, header & 2.5" exhaust.

You're right, I'm off by a factor of two. . .I'm embarrassed.

 

[Quacked]

I am gathering parts to put together a 4.7 myself.

I do not know if this question has been answered before, but I know that the HO harness and computer are more aftermarket supported, tuneable and make more power. Does anyone make an engine harness to swap the engine management system from Renix to the HO set up?

If I do this will I have to swap Transmission as well?

Brad

 

[87manche]

I am gathering parts to put together a 4.7 myself.

I do not know if this question has been answered before, but I know that the HO harness and computer are more aftermarket supported, tuneable and make more power. Does anyone make an engine harness to swap the engine management system from Renix to the HO set up?

If I do this will I have to swap Transmission as well?

Brad

the renix system is quite adept at adapting itself.
My stroker plan involves simply upgrading the injectors and a better flowing manifold. I did not plan on touching the Renix system, with the exception of a MAP adjuster if I need to fine tune the mixture.
Because the renix system has a knock sensor it's very well suited to engine modifications, as it can retard the timing if the motor starts to ping.

 

[j99xj]

I've been thinking about a stroker and wondering the same things about the performance of them.

But no matter how built my stroker would be I would still be 15% lower horsepower and torque than the rest of you guys. (My elevation.)

Do you guys think I would be better off with a supercharged 4.0 as opposed to a n/a stroker?

 

[Dr. Dyno]

Do you guys think I would be better off with a supercharged 4.0 as opposed to a n/a stroker?

How about a supercharged stroker?
To answer your question, it all depends on the stroker build spec and all the external bolt-on performance parts that you add. I managed to eke out about 273hp/328lbft from my 4.6 stroker and although I didn't put anything exotic inside the engine, I'd maxed out on all the external bolt-ons.
A 6psi supercharged XJ 4.0 puts out about 255hp/305lbft.

 

[jeepinwi]

While I don't have any hard numbers, here's a real world experience comparing the 4.0 to a 4.6 stroker: My daily commute has a hill about 2 miles long which the 4.0 could keep my XJ steady at 65 mph in 5th gear and VERY slightly accelerate up the hill if I floored it. The 4.6 stroker keeps my XJ at 65 mph at roughly half throttle, and accelerating up the hill is now effortless in 5th gear.

Another example: passing on the highway required me to downshift to 4th gear for a swift pass. The stroker seems to accelerate at the same rate when in 5th gear. 4th gear acceleration is now quite fun! It pulls up to 80 mph very nicely. I have not had a chance to go more than 80 mph, but 5th gear pulls much easier at high speeds than the 4.0

Also, I only have about 500 miles on the stroker, but my 2nd tank of gas got me 19.75 mpg. I am VERY pleased with that. The 4.0 usually got me about 21 mpg, so I can live with the small increase in fuel consumption.

 

[philip_g]

While I don't have any hard numbers, here's a real world experience comparing the 4.0 to a 4.6 stroker: My daily commute has a hill about 2 miles long which the 4.0 could keep my XJ steady at 65 mph in 5th gear and VERY slightly accelerate up the hill if I floored it. The 4.6 stroker keeps my XJ at 65 mph at roughly half throttle, and accelerating up the hill is now effortless in 5th gear.

Another example: passing on the highway required me to downshift to 4th gear for a swift pass. The stroker seems to accelerate at the same rate when in 5th gear. 4th gear acceleration is now quite fun! It pulls up to 80 mph very nicely. I have not had a chance to go more than 80 mph, but 5th gear pulls much easier at high speeds than the 4.0

Also, I only have about 500 miles on the stroker, but my 2nd tank of gas got me 19.75 mpg. I am VERY pleased with that. The 4.0 usually got me about 21 mpg, so I can live with the small increase in fuel consumption.

thanks, that's exactly what I wanted to hear

 

[philip_g]

How about a supercharged stroker?
To answer your question, it all depends on the stroker build spec and all the external bolt-on performance parts that you add. I managed to eke out about 273hp/328lbft from my 4.6 stroker and although I didn't put anything exotic inside the engine, I'd maxed out on all the external bolt-ons.
A 6psi supercharged XJ 4.0 puts out about 255hp/305lbft.

my machinist mentioned something about setting up the block to accept some forged chevy piston and rods or other, I wasn't really paying attention since I'm focused on the budget stroker build and don't have intentions of going FI

 

[Pharaoh XJ]

I am thinking of a stroker too but i was told that it improves milage cause i m getting 15mpg mixed HO AW4 stock tyres so i need someone to tell if my mpg is going to get any better than 15 mpg

 

[Quacked]

I am surprised you are only getting 15 MPG on stock tires. I am getting that on my non-regeared 33 inch tired truck.

I wounder if you might have an O2 sensor out?

Brad

 

[old_man]

I might get better mileage if I could drive it like a normal adult. I get in it and I'm 16 again.

 

[RockMobster]

Hey guys,
New to the board. After a long string of bad luck with my 00 xj resulting in a new front end and about 5k in body and frame and paint repair, I got my baby back from the body shop put about 30 miles on it then it threw a rod. I was about ready to crush the thing i love so much, when i began to read these forums about the stroker motor. This has seemed to re kindle my love for my jeep so i have decided to put a 4.7 in. Terry at Western Engine in Denver Colorado is doing my build since I currently dont have a garage. He tells me with intake down pipe header and exhaust I can expect anywhere from 275-305 hp and more tork than necessary for any rock crawler. I'm super excited and plan to drop it in on the first of the new year. I'll post to let you know the specs.

 

[2drezq]

Consider doing what I did with mine:

The 17.5cc dish in the piston is 3.362" diameter (radiused at the bottom) and 0.116-0.117" deep. Since the dish is "D" shaped, if you mill it circular and increase the depth to 0.160, then the volume will be 22.6cc (23.28 minus 0.725cc for the radius). This lowers the compression back down to 9.0:1 Since the piston is 0.328" thick at the thinnest point, and we're removing 0.044", the thinnest point (dead center) will still be 0.284"

This is with the Sealed Power 677P piston. we actually went to 0.170, for a cr of 8.87:1 10K miles so far, burns 87 octane with no issues whatsoever.

I'm guessing hp is 235-245.