Jeep Strokers

Howdy all, I picked up a 1986 258ci for my stroker build, I am planning to follow this plan:

4.6L "poor man's" stroker
Jeep 4.2L 3.895" stroke crank Jeep 4.2L 5.875" rods
Sealed Power 677CP +0.020" bore pistons
9.25:1 CR 0.088" quench height
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
245hp @ 4800rpm, 315lbft @ 3000rpm ('96-'06 camshaft)

What I have:
4.2 Crank (4 counterweights)
4.2 rods
0630 Head, 4.0 I6 engine block casing number 1996-98......53020569, Still in the XJ, The 4.0l has 292k and counting. I am hoping to find a 1996-1998 4.0l to build and be able to do the engine swap in a short time frame.

1. Should I consider a Aftermarket camshaft or not? (Should I keep the HO camshaft? Is a other than stock cam worth it?)
2. How much should I overbore the cylinders? I would like to keep the possibility of one additional rebuild after this one.
3. Which pistons should I get? Brand?
4. Where should I get the rebuild kit? Rock auto?
5. Is there a problem with keeping the stock fuel injectors?

Thanks!

grainofsalt wrote:Howdy all, I picked up a 1986 258ci for my stroker build, I am planning to follow this plan:

4.6L modified "poor man's" stroker
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black IC944 +0.020" bore pistons
9.25:1 CR
0.070" quench height
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
245hp @ 4800rpm, 315lbft @ 3000rpm ('96-'06 camshaft)

What I have:
4.2 Crank (4 counterweights)
4.2 rods
0630 Head, 4.0 I6 engine block casing number 1996-98......53020569, Still in the XJ, The 4.0l has 292k and counting. I am hoping to find a 1996-1998 4.0l to build and be able to do the engine swap in a short time frame.

1. Should I consider a Aftermarket camshaft or not? (Should I keep the HO camshaft? Is a other than stock cam worth it?)
2. How much should I overbore the cylinders? I would like to keep the possibility of one additional rebuild after this one.
3. Which pistons should I get? Brand?
4. Where should I get the rebuild kit? Rock auto?
5. Is there a problem with keeping the stock fuel injectors?

Thanks!

1. Keep the stock HO camshaft. That way you can keep the stock valvetrain and stock distributor gear for proven reliability.
2. Just do the minimum overbore (20, 30 or 40 thou) necessary to make the cylinders round and true for a good ring seal.
3. I suggest you use the 4.0L rods and go for the Keith Black IC944 forged pistons (modified poor man's stroker see red fonts).
4. Summit Racing have just about all the parts you'll need to rebuild the engine.
5. The stock injectors probably won't be big enough.

I think the KB's only come in 30 and 60 overbores

No, they also come in other sizes:

http://www.summitracing.com/search/?keyword=ic944&dds=1

They are available in many sizes including +0.020 and +0.040. I went with +0.020 over Keith Black 944's with my Modified "Poor Man's" STROKER.

O.K. so +0.020" Or +0.030" (as available) over on the cylinder.
Why do I want the 4.0l rods as apposed to the 258ci rods?
Why will the stock injectors not be good enough? My normal RPM range is off idle (750) to about 3000, not WOT.

This will be a build for mainly street use, on regular pump gas. manual transmission 3.07 gears and 30" BFG's.

Missourian, Are you near lees summit?
Thanks!

Grainofsalt,

YES, within 3 miles of Lee's Summit, MO.

Check out http://www.METROCRAWLERS.com, I have much of my STROKER effort documented there. Another STROKER builder on the site and he hooked me up with a GREAT machine shop here in Independence, MO. Straightline Motorsports - 816-257-5600 (ask for Doug). Doug is very knowledgeable and has really learned what it takes to build these STROKERS. His learning curve is very quick having years of experience and having built hundreds (perhaps thousands) of engines.

I didn't want to buy 4.2 rods as I struggled to find an engine at the time of sourcing everything. I ended up buying a brand new crankshaft. They say the longer rod will reduce wear on the cylinder wall, who knows?

Stock injectors will work, for additional power and to reduce the chances of running too lean the higher # injectors are recommended. I bought 24# injectors just to be on the safe side.

This build is perfect for street and off road use. There are many other things that you can do to squeeze a few more foot pounds of torque out of the engine but the biggest bang for the buck is the "Modified Poor-man's" STROKER. The rest is port /polish the head, 62mm throttle body, cold air intake, header and 2.5" exhaust.

Personally, I would regear to 3.73's - 4.11's if this is not enough performance gains for you. Honestly, a 4.0L with 3.07's on 30's is a turd. I am running 35's with 4.56's and a 4.0L = stock like performance as I started out with 3.73's and 30's. Now with a fresh 4.6L, the performance should be awesome.

Alright, I may be at step two. I found a '96 xj county (build date 8 95) for $500.

It has California emissions, Will that be a problem for my build? Or should I just tune it up and sell it for build cash?