0331 head change results

[cherokeemi]

how do you make the coil pack ground correctley with the head change

 

[5-90]

how do you make the coil pack ground correctley with the head change

By making sure your fabricated bracketry has a solid mechanical connection to ground (solid mechanical connection generally equals a solid electrical connection.)

If that makes you uncomfortable, run a secondary ground lead from under one of the mounting screw heads to the engine block or cylinder head - it will double up on the grounding from the mounting screws. Use something like a 10 or 8AWG wire for that one, for added assurance.

 

[Talyn]

An infrared thermometer could prove if there's a serious hotspot at 3 and 4.

The so called "debris shield" recall for 00-01 was fishy. The "shield" is really an insulator. this thing is aluminized glass cloth. It probably prevents the vapor lock on injector 3, but likely makes the hot spot even worse.

A real debris shield would be a sheet of aluminum or something, like on the renix engines.

That debris shield does not prevent vapor lock on the injector, there is a separate heat shield for that injector and a different TSB. I doubt that debris shield has anything to do with the head cracking.

 

[Talyn]

If that makes you uncomfortable, run a secondary ground lead from under one of the mounting screw heads to the engine block or cylinder head

That is what I did.

 

[Talyn]

Is the 0630, the best head to get for replacement? I've seen heads for as low as $50 around here on Craigslist. What years had the 0630?

A 0630-07120 head casting will work for you. 1991-1999 are the years. If you are concerned about coolant in your engine and you can't find any external leaks get a used oil analysis done. I use blackstone. Also, if you think your head is cracked and going into the engine take action now as coolant will damage other parts of your engine such as the bearings.

As far as that aftermarket aluminum head goes, I would never put an aluminum head on a cast iron block.

I under stand your concern, but I haven't heard of any issues of that sort with the Hesco Aluminum head. Hesco also has plans for an aluminum block, but if their head costs $2000, I would hate to see the price tag for a aluminum block.

 

[Talyn]

If you did port a 0331, you'll have coil rail bosses, and 91-99 exhaust manifolds would fit...but that's a ton of grinding through nickel steel.

That is a ton of work to do on a head that might crack. Unless you get a 03+ head, which I have heard have fixed the crack problem.

Also, those with cracked 0331 heads may want to look into Alabama Cylinder's 0331 modified head. They said they fixed the cracking issue.

 

[Root Moose]

I under stand your concern, but I haven't heard of any issues of that sort with the Hesco Aluminum head. Hesco also has plans for an aluminum block, but if their head costs $2000, I would hate to see the price tag for a aluminum block.

Just to counterpoint, there really are not enough of the Hesco heads out there to get any kind of data regarding cylinder head gasket issues. Even of those that are out there, how many would we know about by just hanging out in Internet forums.

I'm a fan of reducing weight where possible but with our old battle tank engines I don't think it is worth the effort vs the cost. Additionally, for a Jeep you tend to want a robust setup that can deal with over heating as best as it can. That makes a case for keeping like materials for the block and head in my mind.

I "lightly" over heated my stock engine this past fall. If it were another setup I likely would have had a head gasket problem and warpage issues. At least, if my experience with other engines with dis-similar head and block materials are any indicator. Or maybe I just got lucky.

Don't get me wrong, if I were building a race Jeep and the aluminum head were allowed by the rules I'd have one in a second.

 

[beakie]

bumping this instead of starting a new thread

I just picked up an '05 short block and have plans of stroking it over the next year or so.
it had 1400kms on it (reaplced after owner repeatedly bitched about lifter knock)

but it has the 0331 head and I am somewhat hesitant of doing any work on this head unless I can confirm the cracking issue was corrected '03 and later.
not to mention, on a stroker would this head really be worth it since it has the smaller exhaust ports trying to get rid of more gases than stock?

it's going into a '97, so its gonna get the dizzy, so I can get rid of this head and go with a 0630 if need be.

 

[winterbeater]

Why go with the small exhaust ports? Your probably going to do a valve job on it anyway for a stroker.

 

[beakie]

well I am looking this info up on jeepstrokers aswell. the feedback there is to ditch the head and look for a 0630 instead because of the exhaust ports like you say.
but from reading, those smaller ports are also designed better, flow pretty well, and should be good for torque as such, which is what I am after anyway.

I could also do some porting to the ports to enlarge them a bit, I would think my Banks header (designed for the 97) would match up somewhat, enough that they would take advantage of any port work done... I would think.

but I will be on the look out for an 0630 head anyway.

 

[Root Moose]

I say run the 0331 until it becomes an issue. Lots of other things to do instead of getting more parts to cleanup and R&R. If/when it cracks deal with it then.

 

[winterbeater]

Yeah, seems like you could grind the 0331 to match the bigger header. The cracking issue is supposedly fixed by '03, but this has not been confirmed.

 

[beakie]

I think I will take the 0331 head into the machine shop and see if he can open up the ports to match the gasket... just a bit (say 50thou something shallow but significant), then I can port n polish from there using that bit as a guideline.
I have read lots of info on the cracking issue being resolved post '03, whether it be the engines are too new to have any problems, or whether they were actually fixed, who knows. But since I'll have another head after I swap this one in I can switch back, worst case scenario.

thanks for the advice, much appreciated.

 

[GTABurnout]

The more I read about this the more I think I may have a cracked head.

I will need to pay mor attention but I have added coolent. I have a light to moderate coolent smell in the vents when using the vent in both hot or cold but no smell when using AC.

When I bough the jeep the kid who owned it before ran it out of coolent but it was not over heating. I flusehed the system to remove tons of mud type stuff from the coolent system.

No milky residue on the oild cap or in the oil.

Damn it I hope this isn't the problem but I fear it is...

 

[winterbeater]

My oil still looks clean, but the milky residue on the cap and steady use of coolant are the giveaways. Your head might still be good. I would have to think that no milky residue = good head. (Sorry, I phrased it that way accidentally.) Maybe you have a head gasket issue or a leak you haven't found yet.

 

[GTABurnout]

I pray its a leak. I hate to think I bought a cherokee with low miles for a reliable DD only to have a cracked head.

I will look more in to this as time passes.

Hell I just drove the thing to Sedona and back 8+ hours of driving and it didn't skip a beat. who knows...

 

[Root Moose]

Don't get too excited about scum on the oil cap. The newer coolants can do that as they break down.

Depends on what you are seeing of course.

 

[Talyn]

I have a light to moderate coolent smell in the vents when using the vent in both hot or cold but no smell when using AC.

That is no indication of a internal engine coolant leak. If you smell coolant with the heat on you probably have a bad heater core.

 

[GTABurnout]

Ok so both Tranny and oil look good but there is missing coolent I am sure of it and it seems like the jeep just after turning it off the coolent boils you can hear it in the coolent lines boiling. That tells me the system is not seeling all the way right?

Well added more coolent and looked thru the oil fil cap but can't see a crack. I can tell I need to replace my valve cover gasket but so far thats it.

Any advice on where to look for lost coolent?

 

[lifted00]

I had the head swap done on mine. I used the original 2000 exahaust manifold. I just had to get a custom adapter plate.