Jeep Enthusiast Forums banner

Stroker build

9K views 68 replies 16 participants last post by  Knoxes 
#1 ·
Decided my backup Jeep needed a rebuild - the 4.0L L6 just doesn't have enough power.

Started yesterday:



Some car porn:



Hood off:



End of day one:



End of day two:



Almost everything is disconnected. I was trying to avoid discharging and removing the a/c system, but I don't think it's possible to pull the engine with the ac lines crossing above and below the front of the motor. That will have to happen next. I think the intake manifold has to come off to get the exhaust pipe free from the manifold. Once those things are done, I guess it's the bellhousing next. Then it should be free to come out. The FSM says to pull the motor without the trans.

It looks like there wasn't much accomplished on day 2, but I got a lot of the little things out of the way - a ton of connectors, the radiator finally came out, fuel rail and injectors, the belt, tensioner, power steering pump, starter, etc.

Trying to figure out where the lifting points are on this engine.
 
See less See more
5
#3 ·
Wait till your at this step haha! I'm currently building a stroker as well
 

Attachments

#7 ·
Come on, who else besides BMW makes (gas) inline sixes anymore? I wish Chrysler had updated the 4.0 six to the tune of how GM created the atlas. Who wouldn't want 290hp and 270tq? Even a jeep lover has to admit that's killer compared to our 190/235.

Sent from inside my 4.0.
 
#8 ·
How big of a stroker? Poor man? Or big buck?
 
#11 ·
This is my plan, subject to change depending on what I find once I break it down:

AMC 232 3.500" stroke crank
Jeep 4.0L 6.125" rods
Silvolite UEM-2229 pistons
Increase piston dish volume to 23cc
8.8:1 CR
CompCams 68-115-4 192/200 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.040" quench height
Ford 24lb/hr injectors for '87-'95 engines, Accel 24lb/hr injectors for '96-'04 engines, '98 Chevy LS1 25.2lb/hr injectors for '05-'06 engines
241hp @ 5000rpm, 294lbft @ 3000rpm
 
#10 ·
I would have liked to see the I6 evolve with an aluminum head, maybe even go OHC but that wasn't to be with the emissions and crash protection requirements that merited the switch to V6s.

Volvo was making I6s for the XC90 up until very recently, but very few other brands have continued to use the I6. Only BMW and GM that I know of.
 
#12 ·
Knoxes said:
This is my plan, subject to change depending on what I find once I break it down:

AMC 232 3.500" stroke crank
Jeep 4.0L 6.125" rods
Silvolite UEM-2229 pistons
Increase piston dish volume to 23cc
8.8:1 CR
CompCams 68-115-4 192/200 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.040" quench height
Ford 24lb/hr injectors for '87-'95 engines, Accel 24lb/hr injectors for '96-'04 engines, '98 Chevy LS1 25.2lb/hr injectors for '05-'06 engines
241hp @ 5000rpm, 294lbft @ 3000rpm
Who is dishing your pistons? My issue right now is finding someone who will machine them.
 
#13 ·
#15 ·


Monday's progress - discharged the a/c, pulled the condenser, removed about another dozen connectors, removed the valve cover and got 3 of 4 exhaust pipe-to-manifold bolts out. Having real problems with the second bolt on the front pipe. Right now, it's soaking in a half gallon of PB Blaster. I'll take another shot at it this weekend. I think I need an offset box wrench to get under the flange. I couldn't get a good grip on it with a socket.

240 - I'm not sure, but I hope the machine shop that I'm using will do it. I'll let you know. It's about 30 minutes north of Charlotte.
 
#17 ·
Knoxes said:
Monday's progress - discharged the a/c, pulled the condenser, removed about another dozen connectors, removed the valve cover and got 3 of 4 exhaust pipe-to-manifold bolts out. Having real problems with the second bolt on the front pipe. Right now, it's soaking in a half gallon of PB Blaster. I'll take another shot at it this weekend. I think I need an offset box wrench to get under the flange. I couldn't get a good grip on it with a socket.

240 - I'm not sure, but I hope the machine shop that I'm using will do it. I'll let you know. It's about 30 minutes north of Charlotte.
Yeah let me know. I've got most everything just need to get my compression ratio right
 
#18 ·
Furstration setting in. I got the exhaust manifold loose from the pipe finally. Pulled the rear 02 sensor, pulled the wiring harness for the injectors, pulled the TB. Felt like I was close to hooking up the lift and jerking this thing out. The FSM isn't really clear on the bellhousing to block connection - I pulled a couple of bolts on each side and then ran into clearance issues on the driver's side - can't back the bolt out because one of the transmission cooler lines is in the way. And I think there are two more bolts on top of the bellhousing that I couldn't possibly access without removing the head (which includes both manifolds). I'm not positive about that, so if anyone can confirm, I'd appreciate it.

240 - I'm still weeks away from having the dishing conversation with the shop. Don't know if that fits your timeframe...
 
#24 ·
Ok, it's finally out!



It wasn't a piece of cake, but not impossible either. The most difficult things to remove were the exhaust flange bolt, the driver's side bellhousing bolt (you can't back this all the way out without hitting a transmission line and the transfer case shift cable) and the top two bellhousing bolts. I left the intake, exhaust manifold and alternator on. Took the a/c compressor off to access the engine mount bolts. All in, this was probably about 16-18 hours of real work. I'm slow, but methodical.

Next step is getting it on the engine stand - didn't have the right length bolts to mount it.



It was odd to find that really shiny freeze plug under the flywheel - especially with the one just below it that wasn't quite as shiny. I've had this car for 7 years, I think. Bought it with 28K on the odometer. And I know that *I* didn't put that in.

Also discovered, to no surprise at all, an oil trail from the back of the valve cover, which was probably my "rear main seal leaking".

One more, for the background, really :D

 
#25 ·
OK, after taking a 2 week break, we got back at it on Saturday. Got the motor on the stand and started to break it down. Finally pulled out the air tools, which makes things so much easier. These are the first two cylinders,

the next two,

and the last two:

So I think everything looks pretty good. The valves look ok, too, I think.



I did this with my gorilla forearms:

Drove Pop's new ride:

And then finally made a big mistake and dumped the motor on to the floor, where it stays for now:

We were lucky that neither of us were hurt when it fell over. The front leg of that stand has a caster that wasn't installed properly. So we were trying to pry the leg up enough to get the caster tightened down. It just flipped over very quickly and hit the deck. Hopefully it didn't hurt anything internal. The crank, cam and pistons are still in there. I guess I won't know for sure until it goes to the machine shop.
 
#27 ·
2 of those valves are pretty burnt...
 
#28 ·
Finally got back down there to finish up the breakdown. It's completely apart now and ready for the machine shop. As far as I can tell, everything looks like it's in good shape. The only thing I've found so far that could have caused the poor performance was the intake.

These look pretty gummed up, I think. And all six looked like that.

Anyway, got to one machine shop, which was less than impressive. The owner seemed primarily concerned with the cam lift. Not sure where he was going with that. He also couldn't understand why I'd need to dish the pistons. And he said his turn-around time was "several weeks", which in machine shop lingo probably means 2014. So, still looking for a machine shop.
Also at the point where I really need to make a commitment to a recipe and move forward with that. But I don't really have a good handle on the maths, so I can see a problem explaining to the machine shops what I have in mind. I understand the basics, but really need to better understand how to find the right CR, DCR and quench, and how those are going to affect the driveablity.
 
#29 ·
Jeepstrokers.com
You will probably find everything your looking for and more... you might have to dig for a while but, I think all the answers to your questions will be there. Even the ones you haven't asked yet.

Might even have someone on there who could direct ya to a good machine shop
 
#30 ·
You can increase the volume of the head instead of dishing. The way I'm leaning more is doing the Keith black pistons on 4.0 rods with the 258 crank.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top