Jeep Strokers

Phase I - Planning and Parts Collection
Phase II - Disassembly, Cleaning, and Machining of the Block
Phase III - Assembly of the Stroker
Phase IV - Break-in and Tuning

Phase I
(26 July 2009)
I have wanted to stroke my TJ for longer than I can remember. I purchased the TJ in January 2004 with 56k miles. It currently has about 80k miles and has been sitting in the Ft. Lewis POV storage yard for the past 15+ months. A couple years ago it started sounding really rough after one off-road trip the The Mounds Off Road Park in Flint, Michigan. At the airport a European man asked me if it was petrol or diesel, that's how rough it sounds! I never had the time or resources to tear apart the engine in college, than after that I spent six month in Army training. I got to Ft. Lewis in July of 2007 but I lived in an apartment, very inconvenient to do a build there; although SilverXJ did his in a storage unit, that's just not how I want to do mine. I have been deployed since April 2008 which brings me to now. Since March I have been serious in getting ready to stroke my TJ. All this time over here has given me the opportunity to do a lot of research.

Why E85? Why the hell not! I want a unique stroker with gobs of torque. I use my Jeep primarily off-road. I want to get the most bang for my buck. E85 is a viable fuel option. This stroker build will not be a flex-fuel vehicle. It will run high-compression that would be self-destructive on gasoline. To take full advantage of E85 it needs to be run on a high-compression engine. E85 availability is not much of a concern. it's not widely-available for me, but it's still present. A future mod will be a tire carrier with jerrycan holder to sustain myself on longer trips. Down the road I may still my own ethanol.

To my knowledge nobody has successfully completed an E85-only stroker. There have been attempts to run E85 on Jeeps and strokers, with mixed results. Running lean is the greatest threat so that is what I will watch for the most. I will mitigate that threat by monitoring my AFR and delivering the proper amount of fuel with larger fuel injectors and laptop-based tuning with a piggyback computer.

There are still some variables for me to decide. I will update my parts list as I get them or as I decide on something else. There are some items not on the planned list but that's either because they are not significant to the build, I haven't decided on what to get, or I just plain forgot. I have all the basics planned out as of now.

The acquired parts list:
Crankshaft - 12CW 3214723
Pistons - KB945 0.060" overbore, 11.38cc dish
Head Gasket - Mopar 4529242 MLS

The planned parts list:
Donor Block - 96-98 XJ or TJ
Crankshaft Position Sensor - modify existing for adjustable timing
Connecting Rods - 4.0 shot-peened
Camshaft - P4529228AB Mopar
Valve Springs - P5249464 Mopar
Retainers - P4529218 Mopar
Keepers - P4452032 Mopar
Roller Rockers - Yella Terra 1.7 Ratio YT6628
Intake Manifold - 99+
Throttle Body - 5.0 Mustang 86-93 as per Dino
Injectors - Ford Motorsport D-302 36# "White Top"
Piggyback Computer - Split Second PSC1

The parts list that is not stroker-specific:
Ford 8.8 Rear Axle - purchased and already setup for a TJ - 4.88 with Auburn ECTED
Super30 Front Axle - partially purchased, need a donor XJ HP D30 and 4.88 gears - with ARB air locker
Superlift 4" lift - purchased and will replace my Skyjacker 2.5" lift, also have longer control arms
MORE bombproof 1" MML - JM600L - got a hell of a deal for it on eBay
Slip Yoke Eliminator - haven't decided on which one
Rear Driveshaft - I'll either shorten a Ford Explorer or get a Tom Woods
Tummy Tuck - I'm waiting for Savvy to release theirs

The results from the compression ratio calculator: As time passes I will edit this thread and post pics along the way. Your comments and suggestions are always welcome. This will be my first time working on the internals of an engine, and I'm diving into it for sure!

A video that has really eased my worries about taking on the project is Basic Engine Building by Boxwrench Media. It is a professionally produced step-by-step guide covering the removal, rebuild process, installation, and break-in of an engine. I'll let you now how it works out for me when I'm all done.

Can i borrow that video? I can convert it to be web friendly and make it available to all.

I've been back in the States for 32 days after spending 506 days deployed. I haven't been on Jeepforum.com or JeepStrokers.com very much, but I finally cleared out the garage in my new house and today pulled the TJ into it. I set up the chock blocks and tomorrow I'll be pulling the transfer case and transmission. Then I'll be cleaning up and disconnecting the engine bay. It's been difficult finding time since I bought my brand new (zero on the odometer) 2008 Suzuki Boulevard C90. I PCS next June so that is my ultimate deadline to have this project 100% complete; and it's more than just stroking, there's also a lift and two axle swaps involved. There's more to a stroker than just the motor...

Change of plans. I'm not using a donor. The TJ is not roadworthy, there are no brake lights and the cat is clogged so I had to remove it to make it run properly. Suprisingly I only get a check gauges light and no check engine light (the oil pressure has read zero for more days than I can count, it wants me to notice that I have "zero" oil pressure). The enigne will be coming out this week and I'll clean and paint the engine bay (per the Cheep Cherokee).

I'm now in Phase II. I've pulled the motor out of the TJ and am now disassembling, cleaning, and will so be sending it to be machined. I will not be using a donor block, the TJ is not road-worthy as-is. This also gives me a chance to find out why it sounds like a diesel.

On another note, when I picked up a couple people walking along the freeway with a gas can last weekend (their car was a mile behind them, I saw it) I dropped them off at the first gas station that I came to. It turns out that it's the only gas station in town that sells E85, and it's only two miles from home. Last I was tracking the nearest gas station with E85 was 30 miles away. I like when events turn-out good like that.

Anyone tell you that you look like Josh Homme?

gradon wrote:Anyone tell you that you look like Josh Homme?

Nope, and I had to Wikipedia him. Queens of the Stone Age kicks ass!

Check out the wear of the connecting rod bearings: Check out the wear of the crank bearings:
The bearings are in a random order, I just let them fall and lined them up for the photo.

The rod bearings are copper throughout, and bright shiny copper on half of them, a dull/black-striped copper on the other half. The crank bearings are all silver-colored. The thrust bearing shows no copper on it.


The only other thing internally that I found was that the timing chain had 3/4" of play, the FSM recommends 1/2" or less.

What could have been making this thing sound so rough?

Measure the bores and the pistons. I bet you'll be amazed at what you find.

It looks like it could have been an oil pressure problem.

Plechtan wrote:It looks like it could have been an oil pressure problem.

Agree. The oil pressure must have been low for a while and since the rod bearings are under much greater load than the mains, they're the ones that wear out first. The dieseling sound was probably caused by the worn rod bearings but I wouldn't be surprised if there was advanced bore/ring wear.

Well after finally getting off my ass the block is back from the machine shop ($1,231.12, detailed bill to come) and I'm painting it as I type, I'm just between coats.

I never did get any measurements for the pistons or bores so I don't know about that wear, but I did for a long time have low oil-pressure problems. My gauge would drop to zero, I just chalked it up to a faulty gauge but I guess it wasn't. Can I add an oil pressure gauge to one of the galley plugs and run that into the cab? I want to have a better idea of what is going on as opposed to what the ECM tells me on the dash.

It's assembled and running. I broke in the cam, which I had to switch to a COMP 68-231-4 because I couldn't find the Mopar 28AB in stock. I also went with 1.6 Yella Terra roller rockers, which I got a bit of a deal because they couldn't get me 1.7 ($409 shipped). I had a hell of a time starting it, my distributor was 180* off. I just switched the wires around, it can stay misaligned for now.

I started backing out of my driveway to test it out but I had to stop because my brake line rusted through. It's the hard line that runs from the proportioning valve to the rear axle so I'm waiting for a new set of stainless steel lines to come in. The TJ is from Michigan where there is a lot of salt on the road in the winter.

My combustion chamber volume is 55.5cc so my SCR works out to be 11.25 and DCR is 9.79. One of my next mods will be a bumper/tire carrier that holds four jerry cans so that I always have plenty of E85 on-hand. This thing would ping itself to death on any gasoline.

Been a while--glad to see it back up running.

gradon wrote:Been a while--glad to see it back up running.

You're telling me! I got it running about 1pm on Monday and the movers came Tuesday at 9am to pack up my household goods, including my garage (minus a few hand tools).

So what all is needed to run E85? Is it just bigger injectors and a high comp. ratio?
I might be intrested in giving it a try.