4.6 I-6 stroker motor

[94Dodge Truggy]

Anybody build one of these or know of someone who has? I am trying to figure out what all is needed. Here are a few items I know that I need.

4.2 crank
new rods
new pistons
bore out of 4.0 block
20% larger injectors
head work
computer upgrades?

I have a 1995 wrangler 6 cyl. with low oil pressure and need to do a repair and figured to maybe build another motor while I nurse the one currently in the jeep through winter. I need to find a similar motor to build from 1993 to 1995 I think? Some companies want no less than 1350.00 for the crank, pistons, rods and gaskets! Gotta be a cheaper route. I plan on porting the head at work and need to find out about building it also. Thanks for any input!

[95blackyj]

that oil pressure has read the same for 2 or 3 years....

[94Dodge Truggy]

that oil pressure has read the same for 2 or 3 years....

Had it making some rattles recently and put a mechanical guage on it and get not so good readings when warmed up also. No rush to replace it until further signs but want a backup ready! Can't handle downtime from wheelin! :D

[Hope Springs Hauler]

I want to keep appraised of this situation and help you if I can.

I have a spare motor but it is a '92. I have searched this before and the most info has been on a page from the middle east sandbox.

EDIT: Just found this http://www.ajeepthing.com/stroker-motor.html

[94Dodge Truggy]

Titan engines makes a stroker kit complete with block and head for $2,200.00. Some kits that include rotating assy. want 1400.00 for just that! Can't see putting alot of $ in this. Checking on supercharging a stock 4.0 also.

[DinkDavis]

I have a 89 or 90 mdel XJ 4.o 4speed if it will help runs good 157000 miels just rotted body.

[Rubi06]

what happened to the 360 swap?

[MrShoeBoy]

I have built more than a few motors, and several of them have been strokers. STUPID EASY they are to build :D

Theres lots of shiny bling parts out there and you can dump as much money into this thing as you want. Best way I think to get a crank is to order a "crank kit" from your friendly machine shop. Its nothing more than a factory crank with matched bearings, the trick is order a crank for a 4.2L motor, use a good set of 4.2L rods, and order the correct size 4.0L pistons for the bore you are running (.030 bore you need .030 pistons).

Now this combo is ALL stock parts and has some issues, first being they are all stock so forced induction isnt THAT good of an idea since the stock rods arent up to much boost past 8psi and the replacement pistons are cast aluminum. You can upgrade the rods and pistons to forged units that will take a beating AND fix the other problem with the stock setup.

Second issue you will have is Quench. This is pretty much a fancy word for the distance from piston to cylinder head. The quench for the stock stroker crank, rods, and pistons is something like .063 and it needs to be in the .035ish range. You can mill the block and gain some of that back, but you will really bump up the compression. I did the cheap way out and got a super thin head gasket and dont have any HUGE issues. I did have to adjust the crap out of my MAP sensor and do get a ping here and there when under heavy load and long steep hills. Do a little research and you can have a pretty peppy motor with better quench than if you just slapped it all together.

As for injectors, if this is going into a 93, toss in some #24lb Ford Motorsports injectors along with an adjustable MAP sensor and call the fuel done.

CAM!!! Most important thing here. It makes your motor do what it does. DONT SKIP ON THIS!!! If you are going to blow some money, do it here! You WANT roller rockers, you WANT a double roller timing chain, and I HIGHLY RECOMEND a cam from HESCO. Hesco is expensive as hell but they have high quality parts and know what they are doing. Also get the oil pump from Hesco.

Headwork is simple, portmatch the intake and head to the gasket and smooth out all the bumps in the head, radius the corners, and polish the crap out of the exhaust ports. Leave the intake ports slightly rough, not polished. Has something to do with air and fuel atomization....

I would recomend a MSD ignition box and good set of wires. The factory coil is big enough to handle the MDS box and run Champion Copper truck plugs at a gap of .045. I have YET to have a problem in 3 years with this ignition setup and wouldnt change it if I had to do it again.

Get a good intake, and nice header, manderal bent 2.5" downpipe and exhaust out with your choice of muffler.

AARON

[MrShoeBoy]

I currently have a factory 4.2L crank and rods with Sealed Power H802 pistons. A cam, lifters, oil pump, double roller timing chain from Hesco. I have yella terra roller rockers. I did the head porting and polishing, a custom S&B reusable cone filter, Banks header and custom exhaust through a Spintech muffler. It sounds BAD, and people will often ask what motor is in it and dont believe its an inline 6. Also they wont step out in front of me when I am driving along, and even hesatate when they have the walk sign in the crosswalk :D

I have built 3 motors for my truck, first motor blowing up to parts failing from Crane Cams. Second motor same thing, distributer gear in the cam went soft and shavings ruined all the bearings. I am still on my 3rd motor built from Hesco parts. I would not built a Jeep motor with out the cam, lifters, valve springs, oil pump, and timing chain from them. Oil these days is not as it was a few years ago and the lack of additives makes inferior parts fail super fast.

So my advice for building your motor is to:
*balance the rotating assembly including flywheel/flexplate
*buy all valvetrain components and oil pump from Hesco
*injectors from FMS and adj MAP sensor

That will get you a very good motor for not that much money. If I had to do it over again I would get custom pistons and use 4.0L rods for a better rod angle and a stand along ECU like Accel DFI or Megasquirt.

Good luck, cause any combo of above parts will blow up axle parts, ask me how I know :D