stroker

[wheelchairman]

Ok now i have searched but please explain the parts needed to turn a 4.0 ho into a stroker for as cheap as possibly since im only 16.

I know i will need cylinders bored and 4.2L parts but which parts ans how much to bore everything? stock cam? I will be installing a knn cone and flowmaster 50 but do i also need headers or can i get away with stockers and just suffer some hp drop?

really all i want to know is what all parts i need to do this so I can keep my eyes open for good deals. Also if you know the part # please include that I will have my bro look up the #'s to find retail cost.

talk to me like an idiot i dont care


needs to offer good performance and mainly be cheap!
http://www.jeep4.0performance.4mg.com/stroker.html I'm liki the 4.5 L poor man here or 4.5L the low buck simple stroker

 

[Dr. Dyno]

Read everything about my stroker build-up at http://www.angelfire.com/my/fan/stroker.html and you'll find most of the answers to your questions there. If you still have more to ask, fire away.

 

[wheelchairman]

OK doc i read it twice to get what i missed the 1st time so here are my questions

1. I assume the factory header will work just not be optimal correct?
2. what is honing?
3. any particular cam to use for mostly street/highway driving?
4. I see you have a jet chip but is that nessessary for fine tuning it or can the stock puter do it?
5. your advertised 265hp is that with all the mods you had previously done or is that # a stroker only #(no exaust,intake,62mm tb etc.)


oh and all this is off a 91 cherokee HO but since i will be using a junkyard block I will not say the year as of now. but if nothin else my current jeep is a 91 so this stroker will have the highflow head even if i have to rob it offf my current engine!!!

this build wont happen for a while but if i can start getting parts now, it should go quick.

 

[Randy_66]

JP magazine just did a 3 part article, the first two of which are posted on their website. Go read them 2 or 3 times. Mine stay on the back of the toilet so i can re read often.They were pretty good. The third article sucked but basically said the guys at Turbo City are really nice and that the stock computer will work fine if you use the 24lb injectors.

I am still pissed that for 3300 bucks Golen didn't shorten their crank for their serpentine setup. And it's not even my motor.

 

[Dr. Dyno]

OK doc i read it twice to get what i missed the 1st time so here are my questions

1. I assume the factory header will work just not be optimal correct?
2. what is honing?
3. any particular cam to use for mostly street/highway driving?
4. I see you have a jet chip but is that nessessary for fine tuning it or can the stock puter do it?
5. your advertised 265hp is that with all the mods you had previously done or is that # a stroker only #(no exhaust,intake,62mm tb etc.)


oh and all this is off a 91 cherokee HO but since i will be using a junkyard block I will not say the year as of now. but if nothing else my current jeep is a 91 so this stroker will have the highflow head even if i have to rob it offf my current engine!!!

this build wont happen for a while but if i can start getting parts now, it should go quick.

1. Factory header will do fine but a longer tube aftermarket header would be better. Fit a 2.5" downpipe either way.
2. Honing of the cylinders is the final stage of preparation after the rebore when the surfaces are taken to a microscopically roughened, cross-hatch finish to aid cylinder wall lubrication and piston ring sealing.
3. My favorite is the one that I'm using, the Crane 753905. No other cam beats it for midrange torque in a stroker. The torque curve is virtually flat from 2000-4500rpm.
4. The JET chip isn't necessary and the stock computer works fine. All you need are Ford 24lb injectors and a MAP adjuster to fine tune the fuel curve.
5. My claimed 270hp (up from the previous 265) is with all the performance add-ons that I had earlier plus the modified Mustang 65mm TB, tapered 65mm to 62mm TB spacer, recently added custom 2.5" downpipe (old Borla downpipe was 2.25"), and Mobil 1 0W-40 synthetic oil.

 

[SCW]

1. Factory header will do fine but a longer tube aftermarket header would be better. Fit a 2.5" downpipe either way.
2. Honing of the cylinders is the final stage of preparation after the rebore when the surfaces are taken to a microscopically roughened, cross-hatch finish to aid cylinder wall lubrication and piston ring sealing.
3. My favorite is the one that I'm using, the Crane 753905. No other cam beats it for midrange torque in a stroker. The torque curve is virtually flat from 2000-4500rpm.
4. The JET chip isn't necessary and the stock computer works fine. All you need are Ford 24lb injectors and a MAP adjuster to fine tune the fuel curve.
5. My claimed 270hp (up from the previous 265) is with all the performance add-ons that I had earlier plus the modified Mustang 65mm TB, tapered 65mm to 62mm TB spacer, recently added custom 2.5" downpipe (old Borla downpipe was 2.25"), and Mobil 1 0W-40 synthetic oil.

2 Questions for you Doc-
1- Are saying the 2.5" downpipe is worth 5hp? I'm getting close to upgrading the header/downpipe and I want it set up for low and miod-range power. Jury is still out as to if it will be 2.25 or 2.5, I have a 2.5" cat, muffler and tailpipe.

2- any advantage to the 24# injector before it's stroked? I have a 6mmTB and cold air intake already.

I'm trying to max out everything and get the bugs worked out, then when

 

[Dr. Dyno]

The 2.25" pipe becomes restrictive behind a 4.6 stroker from about 4300rpm upwards so that's where the 2.5" pipe really makes a difference. There's no loss of low rev torque with the 2.5" pipe. Dunno if that alone gave me another 5hp; maybe more miles on the engine also helped. Tell your jury to rule in favor of the 2.5" pipe.
If you use Ford 24lb injectors on a modified 4.0 (as I did before I built my stroker), be prepared to build a MAP adjuster and reduce the input voltage below the stock 5.0v to shorten their duty cycle. Without the MAP adjuster the engine will run too rich.
I had mine turned down to 4.15v on my old modified 4.0 (maxed out with external bolt-ons plus ported head and CR of 9.07:1). Now that I have the stroker, I'm using the same 24lb injectors but I've got the MAP adjuster set at 5.15v with excellent gas mileage and emissions.

 

[SCW]

The 2.25" pipe becomes restrictive behind a 4.6 stroker from about 4300rpm upwards so that's where the 2.5" pipe really makes a difference. There's no loss of low rev torque with the 2.5" pipe. Dunno if that alone gave me another 5hp; maybe more miles on the engine also helped. Tell your jury to rule in favor of the 2.5" pipe.
If you use Ford 24lb injectors on a modified 4.0 (as I did before I built my stroker), be prepared to build a MAP adjuster and reduce the input voltage below the stock 5.0v to shorten their duty cycle. Without the MAP adjuster the engine will run too rich.
I had mine turned down to 4.15v on my old modified 4.0 (maxed out with external bolt-ons plus ported head and CR of 9.07:1). Now that I have the stroker, I'm using the same 24lb injectors but I've got the MAP adjuster set at 5.15v with excellent gas mileage and emissions.

Yes, I've been considering going with an adjustable MAP anyway, I just moved from 7500ft elevation to 4500ft and noticed HUGE gains in performance and fuel economy. As the computer learns I seem to be losing some of those gains so rather than buy a new MAP, I think I'll just build an adjustable and see what I learn from it. Then I'll go with 24# injectors and see what happens there. At that point I'll have a pretty good reference when I start my stroker.

Thanks-
Shane

 

[bigwillxj]

How will an 87 renix computer respond to the stroker? Does anyone actually have one?

 

[old_man]

The I am running a computer from an 88 which is interchangable and it works fine. I am running larger injectors and ended up using a map adjuster, but no problems.

 

[bigjohnson69]

Dr. Dyno, what gas mileage are you getting, and what are your power numbers? also, what transmision do u have and what rear end gearing do u have?

 

[Dr. Dyno]

Gas mileage = worst 17.2mpg, best 23.8mpg, average 20.2mpg (imperial gallons) from my stroker over last ~5,000 miles. Highway cruising is usually at an indicated 85-90mph (true 80-85) where I get 20-21mpg.
Estimated power numbers = 270hp @ 4950rpm, 327lbft @ 3750rpm according to Cartest (plugged in my vehicle specs and performance numbers). Here's my plotted torque curve:

Tranny = '92 AX15
Rear end = Stock D35 with 3.07 gears
Front end = Stock D30 with 3.07 gears
Tires = 225/70R15H (130mph rated, 27.4" diameter)
Performance = 1/4 mile [email protected] in street trim ([email protected] with 142lb weight reduction)

The gearing is ideal for my engine and tranny combo. Only problem is the rev limiter cuts in at a mere 5150rpm to spoil the fun so I'm bouncing off it in 3rd gear at the end of the 1/4 mile.