Jeep Strokers

I am well into my "Modified Poor Man's Stroker" having enlisted the help of a local machine shop; Straightline Motor Sports of Independence, Missouri working directly with "Doug".

I started with a 4.0L from a 2002 Jeep Grand Cherokee. This engine was said to have overheated and blew the head gasket. In tearing it down we found the pistons were ruined, cyclinder walls were needing cleaned up to +0.020", the head (0331) was cracked in two spots. The good was the crank, rods & camshaft. Everything has been hot tanked and cleaned up.

I have ordered a new SCAT 258 c.i. crankshaft from HESCO and waiting (and waiting) on new Kieth Black IKON forged pistons from Summit Racing Equipment. Once the main parts arrive Doug will be setting everything up to make final determination about decking and head gasket height for proper quinch and making for 9:1 compression ratio to ensure operation with 87 Octane fuel. Doug says he works with a custom head gasket manufacturer that will produce a head gasket to whatever thickness we need.

In time I will link photos and update on this build and the next two, provided things go well with this one.

Summit Racing Equipment has sent me in the past and just sent me another notification of delay in filling my order. This time a post card saying that it was going to be October 1st before they would have my pistons but I just checked the bank account and it appears they have taken payment already. Now, I was going to cancel my order today and find another source, but now I see they shipped FedEx 9/22/2011!

Fyi
Pick and pull are a great resource for 4.0 engines as starting platform. Cherokees are like weeds there.
a lot show up on craigslist also.
Got mine from craigslist so i was able to keep my heep running until i got one built 4.6 something poorman.
M
Stroked to 4.6? 24# injectors, 75mm mustang throtle body, borla header, aem cone 3". nsg370 6 speed, .curry Ford 9", 4 x discs, 35" meat, dana 30 allways breaking,
4:1 sye tcase, arb x2, york oba, rear bumper air tank, spring over, waggie springs,
red top battery,8500 warn winch. on board welder,
dana 60 and 14 bolt in garage for future.

I received my pistons Saturday (that was pretty quick) and taking them along with the new crankshaft to the machine shop tomorrow.

I am really starting to get excited to see this engine in my Jeep!

Dropped the parts off as planned and Doug with Straightline is eager to get started.

So, I am now looking to aquire a new head from Alabama Cylinder Head.

UPDATE

Let's see...

I went with a re-manufactured "TUPY" cylinder head from ATK as Alabama Cylinder Head was out of stock twice in two months for 4-6 weeks each time called and no definite ship date.

The short block is now assembled with high flow oil pump being the only high performance item installed. All other parts, including the cam and lifters were OEM or OEM performance aftermarket. The head will be delivered to Doug @ Straight Line Motorsports this coming week.


To recap this is a "Modified Poor Man's" 4.6L STROKER going into a daily driver 2000 Jeep Wrangler with NV3550 manual 5-speed w/overdrive (0.78:1), NP231 transfer case (1:1, 2.73:1) w/TerraFlex SS HD SYE and 4.56:1 differential gears on 35" BFG Mud Terrains. I am building to increase torque and improve the overall speed range of this configuration. When the Jeep was rolling 33's with the stock 4.0L and this configuration, I rarely had to downshift at highway speeds regardless of flat or hills. My hope is that with this STROKER I will have similar highway performance now that it is rolling on 35's (with 35's and stock 4.0L, I have to down shift on windy days and/or heavier grade hills). Offroad, my performance goal is increased torque to allow me to crawl slower.

I rarely need RPM's above 3k for typical driving. The normal sweet spot on the highway is 2100-2500 RPM. Off Road my RPM's rarely exceed 3k and for very brief periods. I am not concerned about porting the head or 2.5" exhaust and header however, I have opted for the 24# Bosch /Ford fuel injectors to ensure excessive lean conditions are not experienced as a 2000 Jeep Wrangler has limited options for adjustment. Calculations say the static compression ratio is 8.95:1 and it is hopeful to run on 87 octane crap pump gas at ~1000 feet of elevation above sea level.


The pistons are forged Keith Black 944 +0.020 pistons

The crankshaft is HESCO/SCAT 258 c.i. crankshaft

The fuel injectors are Bosch/FORD 24# fuel injectors

These pictures show the engine crankshaft side up at Straightline Motorsports. The engine is assembled short of the oil pan and valve cover. The oil pan is the delay as I have to modify the pan to fit the girdle. Once installed it will complete the assembly short of water pump, flywheel, idler bearing, clutch plate and disc, which I have ready for install.



I'm really looking forward to getting this swapped into my Copper 2000 Jeep Wrangler.


The next project is rebuilding (building another 4.6L STROKER) the engine coming out of of the Copper Jeep.

Similar build to my 2001 build..... KB944 +0.020, Scat crank, stock cam and exhaust.
Shop had to grind the small ends of the rods for piston clearance.
Hoping to have it on the road in January.

I keep reading about folks milling the rods of their balance weight and then spin balancing their crank by removal of weight from the crankshaft weights. If there is additional weight removed from the crank and rods and I have gone from an 8 weight 4.0L crank to a 4 weight 4.2L crank and the desired 4.2L crank is a 12 weight... whats the point of removing even more weight when I am taking this off road?

There has been a delay in getting my STROKER into my Jeep and this has been the oil pan. The machinist/engine builder (Doug) said that he could not get the oil pan on without adding a 0.200" to the depth of the front of the pan down it's length to the sump. During all of this I bought a new "CROWN" oil pan but I have spent a bunch of time trying to find someone to modify the pan for me. I pulled the new pan out of the box and compared it to the old pan that came off the motor. The old pan was bent throughout the area in question.

So, I took both pans back to the machine shop and showed them to Doug and wouldn't you know... a BFH will make the modifications to make everything work again.

I was going to suggest using a BFH. Mine has been thoroughly massaged.

BFH worked for me.

I got the call today at 4:00 p.m. that the engine is done and ready for install!


SO... HEY, The STROKER is complete and ready for install!

Missourian wrote:I got the call today at 4:00 p.m. that the engine is done and ready for install!


SO... HEY, The STROKER is complete and ready for install!

Mine's together with a fresh coat of paint applied yesterday. Hope to have it in this weekend.

The STROKER is in and finishing up a few odd and ends before "break in".