2001 Jeep Cherokee 4.7L build

[Drv2e30]

Hey Guys,

I'm building what I believe is a 4.7l stroker and I just wanted to get a few thoughts on the build. This is for a 2001 Jeep Cherokee.

Here is what I've got:
-258 Crank and Rods (currently at the machine shop)
--Going with Sealed Power Bearings and ARP Studs
-1990 Wrangler 4.0l engine
--Bored out +.04 with new pistons
--High flow cylinder head from an early 4.0l engine
--Crane Cam - Not sure about the model since it came with the engine (relatively new)
-2001 Intake manifold and electronics
-24lbs Reman Ford Injectors

I've gone through the forums and I think I'll be ok, but I'm open for any comments that you might have.

A few questions:

-I've found that people have used spacers to install the 4.0l harmonic balancer on a 258 crank. Has anyone done this? Is there any problem with it?
-Will I have any problems with the 2001 Intake and electronics for this build?
-Are there there any issues with running the stock 2001 exhaust?

[Cheromaniac]

A few questions:

-I've found that people have used spacers to install the 4.0l harmonic balancer on a 258 crank. Has anyone done this? Is there any problem with it?
-Will I have any problems with the 2001 Intake and electronics for this build?
-Are there there any issues with running the stock 2001 exhaust?

1. If your 258 crank has the longer 64mm snout, you'll definitely need to place a 10mm thick spacer in front of the harmonic balancer. Just cut off the rear 10mm portion from an old harmonic balancer and use that as the spacer. It'll have the groove you'll need to slide over the Woodruff key.

2. The '01 intake manifold and electronics will do fine.

3. The '01 exhaust manifold runners won't line up properly with the exhaust ports of the early HO head. You'll need a header that'll fit on '91-'99 heads (7120 or 0630).

4. The +0.040" overbore will yield a displacement of 4610cc so your stroker will be a 4.6, not a 4.7.

[SilverXJ]

Your major problem will be the exhaust. You have a few options:


You have two options.
1) use an earlier manifold/ header and have the precat O2 bungs welded in, but the manifold has to be a tri Y style if you have the Cali emissions package with the 4 o2 sensors and precats. The bungs can be welded so the front O2 sensor monitors the front 3 cylinders and the rear O2 sensor monitors the read 3 cylinders. Then you would have to cut your stock down pipe off with the cats and have a custom down pipe bent up. Once that is done you need to do something about the after cat sensors. Sim them out in some fashion or put them after the main cat, which may not work. I have a pair of Casper's sims and they have been working great for over 5 years. Unfortanelty Casper's was forced to stop making them. You can find some other sims that replace the O2 sensor. I have also seen a sensor spacer that has a mini catalyst in it.

2) Get a 2000+ after market header and hope it covers the 0630 head ports. I have not verified this myself, but I have been told by reliable sources that the pipes are big enough to cover the 0630 head ports. You keep the precats and the O2 sensors bolt in fine.

[seanyb505]

SCAT casts a 258 crank that you can buy new and will not need a spacer

[IH 392]

You can cut the end of the crank off with a hack saw, it doesn't have to be square, just below the end of the dampner, I stuck mine in the lathe and shortened it right up!

[gradon]

Did you mean to say you have a '90 Wrangler's 4.2(they didn't come with 4.0s until 91) or did someone swap a 4.0 in there? If that is the case, you have the short-snout 4-weight crank(I prefer this one) and you will not need a spacer for the HB(buy a new one). As stated, the older head has bigger exhaust ports than the 2001 cast manifolds, so you'll want to use a different header and or downpipe. A Borla would bolt right in and you could keep your minicats and o2s, but $$$. Clifford also has a header with the o2 bungs, but would require a different downpipe section instead of the minicats.

[Drv2e30]

I have a crank from an AMC 4.2l and that's based on the crank stamp.

I'm still trying to figure out what to do with the exhaust. I've got another set of headers I'm going to try out and I may go to a junk yard this weekend.

One issue I've run into so far, I've got the bottom end assembled but the key for the harmonic balancer pulley is missing from the crank. Any ideas on where I can get one?

[Drv2e30]

Your major problem will be the exhaust. You have a few options:


You have two options.
1) use an earlier manifold/ header and have the precat O2 bungs welded in, but the manifold has to be a tri Y style if you have the Cali emissions package with the 4 o2 sensors and precats. The bungs can be welded so the front O2 sensor monitors the front 3 cylinders and the rear O2 sensor monitors the read 3 cylinders. Then you would have to cut your stock down pipe off with the cats and have a custom down pipe bent up. Once that is done you need to do something about the after cat sensors. Sim them out in some fashion or put them after the main cat, which may not work. I have a pair of Casper's sims and they have been working great for over 5 years. Unfortanelty Casper's was forced to stop making them. You can find some other sims that replace the O2 sensor. I have also seen a sensor spacer that has a mini catalyst in it.

2) Get a 2000+ after market header and hope it covers the 0630 head ports. I have not verified this myself, but I have been told by reliable sources that the pipes are big enough to cover the 0630 head ports. You keep the precats and the O2 sensors bolt in fine.

Does anyone have any idea on which brand of header will still work with the factory catalytic converters?

Also, I bought the 2001 exhaust/intake gasket and it definitely is off a bit, can I cut it at all?

I've got the 7120 stamped heads.

[SilverXJ]

Does anyone have any idea on which brand of header will still work with the factory catalytic converters?

I know rugged ridge does. I think Borla and Gibson may. Also, check with Doug Thorley. Its need a long day and I can't remember. I haven't verified it myself but I have been told the aftermarket headers will cover the earlier head's exhaust ports.

Also, I bought the 2001 exhaust/intake gasket and it definitely is off a bit, can I cut it at all?

I wouldn't. Especially if it is the stamped steel variety. I would just purchase the one for the head.

[Drv2e30]

Does anyone have any idea on which brand of header will still work with the factory catalytic converters?

I know rugged ridge does. I think Borla and Gibson may. Also, check with Doug Thorley. Its need a long day and I can't remember. I haven't verified it myself but I have been told the aftermarket headers will cover the earlier head's exhaust ports.

Also, I bought the 2001 exhaust/intake gasket and it definitely is off a bit, can I cut it at all?

I wouldn't. Especially if it is the stamped steel variety. I would just purchase the one for the head.

Ok I've come across one of the headers from rugged ridge that look like they will fit appropriately and have the correct gasket.



However, when I spoke to the manufacturer to get an idea on if this would fit appropriately they were less than helpful on specifics. The tech I talked to said it might be a custom job, but I think this may work. Thoughts?

[Drv2e30]

Ok, So I've been going through countless articles online and a lot of people are saying the rugged ridge headers tend to have weld breaks after a couple of years. So I've decided to find another header manufacturer and stay with stainless 308.

Hopefully I get lucky.

On top of that, a lot of guys are saying that the header will more than likely need adjustment on the 6th cylinder exhaust port. I'll report back on my progress.

[IH 392]

Seems all the headers crack, some just take longer to do it.

[Cheromaniac]

Seems all the headers crack, some just take longer to do it.

My Borla header has managed to survive 14 years and 165k miles so far without any problem.

[Drv2e30]

I'm anxiously waiting for the header to come in, but I wanted to post my progress so far.

I assembled the engine for the most part:

-Bottom End
-Installed my turned crankshaft [3235477] with new oversized bearings
-Seated the crank appropriately moving it front to back and then did the final torquing
-Installed Piston rings, Pistons, and Bearings; ensured proper torque
-Installed Cam and Lifters

Once that was done I checked to see if everything turned smoothly and I didn't see any problems. So on with the rest

-Top End
-Installed 7120 cylinder head with felpro head gasket and headbolts
-Installed timing gears and chain
-Installed rocker arms and pushrods

At that point I turned the engine with the oil pan off and the cam cover off to see how things were turning. I could feel compression but I did hear some air noise from the crank, should that be normal?.

Also, my new headache is the woodruff key. I can't find one that fits the crank appropriately. Does it matter if it doesn't have the absolute proper fit?

Below is a shot of the stock 4.0l key against the crank.

[IH 392]

You will hear commpression leaking from the cylinders, and that key NEEDS to fit, get the right key.