Stroker Build.

[Sir Sam]

Building a 4.6 stroker for the MJ to move the project along.

 

Starting with a 2000 XJ engine and trans combo, I pulled this thinking it was a good to run engine since the XJ it came from was fairly clean and low mileage, and the engine its self was fairly clean. Turns out it had been replaced before and thats why it was clean, but the bottom end was fairly scored/worn, particularly the rod bearings which even had galled a bit from wear. Internally the engine was fairly dirty. Piston walls were fairly glazed but also had some significant scoring on the walls from the pistons. I debated some refresh options but ultimately decided to go with a bottom end rebuild into a stroker. I had the machine shop bore/hone the cylinder walls to .030 over for the stroker, install new cam bearings, and clean the block up. ~$360. Later I gave up pressing the piston wrist pins into the new rods and paid them $50 to do it(better than me destroying anything).

 

 

Cam lobe wear:

 

Bearing scoring, this is one of the better ones:

 

I didnt get a picture of the worst of them unfortunately. 

 

Teardown continues:

 

New Jeep 258 stroker crank arrives:

 

New forged pistons:

 

Box of parts:

 

Block back from machine shop:

 

Pulled it into the sun to try and help it warm up before painting:

 

Ended up putting a box over it with a small heater to get it good and warm overnight.

 

Painted:

 

Pressing in freeze plugs:

 

Started blasting all the aluminum stuff to make it pretty again:

 

Some RTV before oil pan goes on:

 

Pan installed, missing a few bolts:

 

Getting more builtup:

 

Painted head:

 

Ready for head:

 

Valve cover on:

 

Testing fit of header vs engine mount bracket:

 

 

[omega_rugal]

beautiful engine...

[JMO413]

That is beautiful!!

[Sir Sam]

Thanks guys. This is the first time I've built a stroker and I'm taking extra time to clean everything and make it look nice. Usually I'm just cranking to install something and get it running again. 

 

I'm taking a little extra care this time.

[Eagle]

Are you using 4.0L rods or 4.2L rods? Are the pistons custom designed to match up to the proper deck height to avoid excessively high compression ratio?

 

[ghetdjc320]

3 hours ago, Eagle said:

Are you using 4.0L rods or 4.2L rods? Are the pistons custom designed to match up to the proper deck height to avoid excessively high compression ratio?

 

The OP can correct me if I’m wrong but the icons are made with a lower compression height/deck height to accommodate the longer 4.0 rod. 

[ghetdjc320]

I’d also recommend that you add a nice flexible exhaust hanger at the down pipe to keep the weight off the header. Those atp/summit/eBay/Amazon headers are pretty notorious for cracking at the welds. Mine blew out in about 2500 miles. Perhaps they have improved the design though???

[Pete M]

no mo CRD?   

[Sir Sam]

 

11 hours ago, Eagle said:

Are you using 4.0L rods or 4.2L rods? Are the pistons custom designed to match up to the proper deck height to avoid excessively high compression ratio?

 

 

4L rods. Icon IC944 pistons with 0.030 overbore. These are custom designed for this application of 4.2 crank and 4L rods. Even though they are custom designed they are an off the shelf part. This should give me a compression ratio of 9.3. I'm not really looking to try and crank the compression and have to do extra tuning. If the stock EFI had a knock sensor I would be more inclined to crank the compression ratio higher. Really I just want an engine that runs, that doesn't need a bunch of other debugging to get it to work right.

 

8 hours ago, ghetdjc320 said:

The OP can correct me if I’m wrong but the icons are made with a lower compression height/deck height to accommodate the longer 4.0 rod. 

 

Yes correct.

 

8 hours ago, ghetdjc320 said:

I’d also recommend that you add a nice flexible exhaust hanger at the down pipe to keep the weight off the header. Those atp/summit/eBay/Amazon headers are pretty notorious for cracking at the welds. Mine blew out in about 2500 miles. Perhaps they have improved the design though???

 

I agree thats a good idea, and I'm nowhere close to the point yet. I think I got one of the better headers with the thicker flange, and it appears to have proper clearance, but when I get to the exhaust shop I will have them weld in a flex pipe. I'm going to buy a new L pipe that runs from the header behind the engine, use a stock cat, and then have them build the rear section out.

 

I'm using 2000 EFI but 99 style exhaust, so I will need to do some wiring changes for the 02 sensor. 

[Sir Sam]

1 minute ago, Pete M said:

no mo CRD?   

 

Decided to get the MJ done with all the other crap I need to do with a 4L, then once it was running go back to working on the CRD swap. Turns out the 4L I grabbed I didn't want to use because of the wear, so I built the stroker. 

 

Once the MJ is running and driving, and useable again, I will go back to working on the CRD swap. Really my next step for the CRD swap is the engine bay wiring harness modifications, which are done on a table top, so when I've got all that sorted out and ready to plug in, I can switch back to the CRD plug in the wiring, and start debugging it, and building all the other custom stuff for the engine like ac lines and power steering.

 

But untill then I can do all my suspension stuff, axle work, etc to get the MJ useable.

 

Plus I got other projects that need work, so I'm scaling this one back as a way to make progress and get this one running. Right now its my only project that isnt running and street legal.

 

Also, my CRD got totalled by a little old lady leaving the nissan dealership in her new car. So I'm trying to figure out whats going on with the leftovers of that. I would like to find a good body nearby that has a bad engine and swap that in. 

 

But I might also find another Defender and swap that engine into the defender.

 

Plus everything else I have going on, it makes sense to proceed this way.

[Pete M]

gotcha    that does make sense.

[75sv1]

20 minutes ago, Sir Sam said:

I'm using 2000 EFI but 99 style exhaust, so I will need to do some wiring changes for the 02 sensor. 

The 2000 down or cross over pipe has the O2 sensor near the bell housing. That's for the Federal emissions. Don't know if that would help with your adaptation. Let us know how that wiring works out. I plan on a similar swap. There is some things I like about the 2000 Federal emissions wiring. The 2001 down pipe or cross over pipe has no bung for the O2 sensor. Just in case that helps the adaptation.

[Sir Sam]

The 2000/2001/California stuff is all pretty easy to adapt to 1999 and older setup. The main thing you need is a 2000 Federal ECU, or someone who can reflash it to that. The 2001 and California has a couple of extra channels that are used for the extra o2s upstream of the precats. These just become not used if you had them before. 

 

I helped my friend do this same conversion from 2001 to 1999, the main thing you need to do is extend some of the 02 sensor wiring to plug into the sensor further back, plus the 1999 parts and the 2000 federal ECU.

 

Since I'm going to reuse a low mileage stock 2001 Main cat I will need to weld in a sensor bung. But a 1999 or 2000 would not require this.

 

I should document this pretty well for others, really I should make a youtube video about it, would be a good traffic catcher.

[ghetdjc320]

6 hours ago, Sir Sam said:

 

 

4L rods. Icon IC944 pistons with 0.030 overbore. These are custom designed for this application of 4.2 crank and 4L rods. Even though they are custom designed they are an off the shelf part. This should give me a compression ratio of 9.3. I'm not really looking to try and crank the compression and have to do extra tuning. If the stock EFI had a knock sensor I would be more inclined to crank the compression ratio higher. Really I just want an engine that runs, that doesn't need a bunch of other debugging to get it to work right.

 

 

Yes correct.

 

 

I agree thats a good idea, and I'm nowhere close to the point yet. I think I got one of the better headers with the thicker flange, and it appears to have proper clearance, but when I get to the exhaust shop I will have them weld in a flex pipe. I'm going to buy a new L pipe that runs from the header behind the engine, use a stock cat, and then have them build the rear section out.

 

I'm using 2000 EFI but 99 style exhaust, so I will need to do some wiring changes for the 02 sensor. 

 

i used the jba TJ downpipe that wraps in front of the oil pan and it fits very nicely in there