Jeep Strokers

Lots of arguments out there in Jeep land about the value of stroking the 4.0. Often versus swaping in a late model V8. I think the following numbers confirm what most of us know. A 4.0 stroker is a great inexpensive way to end up with a fresh engine, that puts out better than small block power and torque with the stock drive train and wiring.

For those that can't stand to wait, I'll sumerize it this way: The inline stroker has been documented putting out more HP and Torque than either Small block V8 Chevy or Ford pushrod engines in stock trim. Even the ubiquitous 350 which has 1.1 liters on a 4.6 stroker, has lower factory numbers until the LT1 in 93, and even then it's still putting down LESS torque, and with a much steeper torque curve. Out torqueing Small Blocks at peak RPM is not even that impressive; If you consider that At lower RPM's the Inline stroker will make most of these stock V8's look down right limp.

Now for the numbers; These are all flywheel numbers, meaning the output at the wheels will be considerably lower, possibly higher than 25% loss for a 4x4 Jeep with T-case and steep drive line angles, Auto transmission etc.


Stroker Numbers:
* JP Mags Golen 268 hp and 324 ft·lb
* HESCO build * 269 hp and 340 ft·lb
* CDP build ** 265 hp and 295 ft·lb

Foot notes:
*HESCO build Dyno sheet viewable here: http://home.pacbell.net/jay_w007/dyno_sheet_text.html
** http://www.cdpautomachine.com/engines/j ... block.html
I thought I had at least one more Hesco dyno sheet saved from digging around the internet but I can't find it, Dino Savva's site talks about it. If anyone wants to contribute real stroker dyno numbers and has the sheet to back it please PM me and I will give you credit. (Wheel or Flywheel).

Stock 242 (4.0L):
* 1987-1988 XJ 173 hp and 220 ft·lb*
* 1988-1990 XJ 177 hp and 224 ft·lb**
* 1991-2000 XJ 190 hp and 225 ft·lb***
* 2000-2006 XJ 193 hp and 231 ft·lb****

Foot Notes:
* Smaller injectors
** Renix fuel system, low intake port runners, smaller TB, Intake plenum, EGR
*** Very slight variations within these years coresponding to the 0650 head casting, injector changes, fuel pressure and emissions changes
**** New equal length Intake (starting in 99 for the Grand Cherokee, thus "99+ intake")

SBC/GM 305 (5.0L)
* 1982–1983: LU5 5.0L V8, 165–175 hp and 240–250 ft·lb
* 1982–1987: LG4 5.0L V8, 145–170 hp and 240–250 ft·lb
* 1983–1986: L69 5.0L V8, 190 hp and 240 ft·lb
* 1985–1992: LB9 5.0L V8, 190–230 hp and 275–300 ft·lb
* 1988–1992: L03 5.0L V8, 170 hp and 255 ft·lbff

SBC 350 (5.7L)****
* 1987–1992: L98 5.7L V8, 225–245 hp and 330–345 ft·lbff
* 1993-1995: LT1 275 hp and 325 lb·ft
* 1996-1997: LT1 285 hp and 325 lb·ft

SBF 302 (5.0L) [really 4.9]
* 1985-1992 225 hp and 300 ft·lb*
* 1993 GT at 205 hp and 275 ft·lb**

SBF Modular 4.6 ***
* 1996-1997 Ford Mustang, 215 hp and 285 lb·ft
* 1998 Ford Mustang, 225 hp and 290 lb·ft
* 1999-2004 Ford Mustang, 260 hp and 302 lb·ft

Foot Notes:
*Interesting to note that the late 5.0 was a rollerized valve train and pre 93 5.0 had Forged Pistons from the factory.
**The drop in 93 power rating is due to Ford changing how they calculated things and dressed the engine.
*** 2 valve SOHC put in for reference, even though it's not a push rod engine.
**** The LT1 was a Corvette Engine the 98 and later LS1 put out over 300hp and was also nicked from the Corvette. Both are under rated by GM

Factory Numbers will vary according to their own machines and calculations, they will also be inflated and deflated based on corporate politics (a Camaro will never be as powerful as a Corvette, even with the same Engine) Insurance and salesmanship.

Note: There's no doubt nor argument here that SB Ford and Chevy V8's have huge aftermarket support and will be both cheaper and easier to get higher power from. 275-300hp is a few bolt ons away for most any small block V8. This thread is intended to show the value of a Stroker build versus swapping in a stock small block. It is not an argument over which has the most potential for high end power! The stroker gets very expensive very quickly.

excellent post! very informative and interesting reading. i was most interested in seeing the sbc 305 numbers next the 4.0 numbers. but as you said,

1bolt wrote:This thread is intended to show the value of a Stroker build versus swapping in a stock small block.

unless im missing your point, im having a hard time agreeing with that fully. if you talking value as in money, you said it yourself,

1bolt wrote:There's no doubt nor argument here that SB Ford and Chevy V8's have huge aftermarket support and will be both cheaper and easier to get higher power from. 275-300hp is a few bolt ons away for most any small block V8.

theres is definitely more intrinsic value in that your keeping an AMC designed power plant in a jeep, but there are obviously AMC small blocks to use but they dont have the aftermarket support that the SBC and SBF have either.

the truth of the matter is that theres really only one reason to modify these engines for power. you have to love the AMC inline 6. because these things aint cheap.

btw, i plan on running a 302 in my hot rod.
sorry for the double quote.

This is were most of the Stroker vs V8 dicussions go "I can get a 350 from a junk yard for $600" .... A normal (some call it budget, I call it average) Stroker build is going to run from $1500 to $2000 dollars and that's depending greatly on how much you pay for cores and parts. I can build an average 4.5L stroker this weekend for $300-400, I have a good 4.0 block and head (no decking or valve work needed), a 4.2 crank that happens to need to be turned and polished, and the rest is the cost of a rebuild kit. No overbore, stock 4.0 pistons on 4.2 rods which I can press on and off myself, no decking Quench would be high... throw some fresh tune up parts on for another $100 In other words a "Junk Yard" stroker for $400 to $500 for a range of $500 to $2000 bucks for a simple stroker depending on how you build it and what you use; from pure JY build 4.5. To a quench compliant 87 octane with some aftermarket bolt ons 4.7.

That Junk yard Stroker is completely rebuilt and will last for years as we have seen on the email group, it will bolt on to your existing 4.0 XJ YJ or TJ drive train, and wiring. There's ZERO fab work. And can be dropped in and running in an afternoon.

$600 for a JY 350 and you need to buy:
350 adaptor mounts
Bigger Radiator
trans
T-case
Custom drive shafts
Wiring Harness with ECU if it's an EFI or TBI
Hundreds of dollars worth of "run down to Autozone" bits and pieces
Tools to fabricate cross members and brackets

And either:
Buying your buddies hundreds in Beer and Pizza.
Buy yourself the free time away from the Wife (that gets expensive!) to spend days or weeks putting it in alone.
Or the down payment on some Mechanics new house.

From that you get a used possibly abused 350 and drive train that may or may not even start up, may have shot bearings the trans may be gone, the T-case may need a rebuild or any number of things.

The other argument is "I can get a crate LS1 for $2500" and you still need to buy an entire drive train and custom shafts. and pay someone or spend your hard earned TIME putting it all in, when none of it just "bolts on" you'll spend thousands on those. Going into a stroker build you KNOW the state of your existing drive train... Not so with a Junk yard trans and T-case.

good points but with a stock 4.0 block with no machine work, 4.2 crank/rods and 4.0 pistons you would get, according to the calculator, a 9.7 to 9.8 CR which it seems most people are trying to avoid. the quench can be at stock with a .045 head gasket but the CR is up at 9.85:1. the machine work is where everyone is spending the big bucks to get that CR back down to a reasonable level.

when you point out the costs of actually adapting a SB to a jeep the "value" becomes more apparent. i wasnt taking that into consideration. i was thinking of the actual engine parts cost. side by side on an engine dyno the HP/$ ratio would tell another story.

I had explain this to my son a couple of times. Finally I said, "Go check out Advanced Adapter's or Novak' s web site for a price on a transfer case adaptor, then get me a price on a used sbc and 700r4 trans from ebay or car-part.com. Add that up and we'll compare that to what we are spending on our junk yard 4.5 stroker." He hasn't mentioned V8 any more. I machined my own stock piston's to lower compression. It'll have same quench and compression ratio as stock 4.0L, if I can locate a .043 victor head gasket. Anyone know of a source, either online or major auto chain? I've heard Mopar's is discontinued. Major chains seem to only carry fel-pro. I can't wait to assembly and fire this thing up. Piston to bore clearance is a little out of tolerance, hopefully it won't slap and smoke too bad. If it does we'll just slap CRD sticker on it.

Napa had one for me about 2 months ago.

Thanks. Did they stock it or did you have to special order?

And I am still buying Mopar ones through the performance catalog.
John

oletshot wrote:Thanks. Did they stock it or did you have to special order?

It was stocked. I messed up the fel-pro one i got in the "Engine Kit" i bought when i had to pull the head to fix a broken stud. So i had my buddie take me there to pick up a replacement.

Machining for my last build was

hot tank $40
Bore $80
Freeze plugs $18
deck block $45
Shave head $40

Total = $223

Of course it'd be more if you need cam bearings and valve work.

1bolt wrote:Total = $223

what'd you do for pistons?

One other thing you forgot to mention was smoging. If you go drop in a v8 you have to go to the referee in California for it to be legal. I hear horror stories of people trying to get through the referee and some never even make it through. You can get away with a stroker since they don't know its a stroker. This is the problem we are having with my brothers truck right now. He has a 90 Dakota with the 318 v8 but its the last year they put the crap TBI, with an assortment of vacuum hoses, air pumps, and all the other pointless emissions crap. We bought a whole MPI from the junkyard to put in but its alot of work. Plus the added stress that it may have trouble getting past the referee

the last set IIRC was about 50 bucks to have the silvo's dished I think 21 cc's

1bolt wrote:If anyone wants to contribute real stroker dyno numbers and has the sheet to back it please PM me and I will give you credit. (Wheel or Flywheel).

Rear wheel dyno numbers in my sig., and torque curve as flat as a pancake:

Thanks Dino, probably most of use are familiar with that sheet already but it can't hurt for completeness sake There's aren't a lot of Chassis dyno numbers out there.

Sooner or later I will get my XJ Dyno'ed. I already am pretty sure what the numbers will be, just south of yours, possibly more torque as it was originally supposed to be a trail rig (was cammed for low torque).

BTW welcome aboard, didn't know if you would join considering how many forums you are already on