WTB 4.0 head for 98 ZJ
06-08-2012, 11:13 AM
#1
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Year: 1998
Model: Grand Cherokee
Engine: 4.0
WTB 4.0 head for 98 ZJ
im starting to get some valve chatter, ima try and save myself some money and time and see if i can adjust them to get right of it, but would just like to see what people have laying around for a good head. prefer something under or close to 100k miles please. and somewhat localish to MD, NoVA, DE, NJ, PA area
Dave
443-466-6630
Dave
443-466-6630
07-05-2012, 03:59 AM
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Year: 1988
Model: Cherokee
Engine: AMC242
im starting to get some valve chatter, ima try and save myself some money and time and see if i can adjust them to get right of it, but would just like to see what people have laying around for a good head. prefer something under or close to 100k miles please. and somewhat localish to MD, NoVA, DE, NJ, PA area
Dave
443-466-6630
Dave
443-466-6630
The valves in the 6-242 are not adjustable - they're supposed to be self-adjusting. Rocker arms don't get adjusted, the screws get torqued to 19 pound-feet and adjustments take place through the hydraulic tappets.
If you have valve chatter, you may have a stuck or collapsed lifter. Try using an engine oil flush first - varnish and sludge can collect and stick the plunger in place. If the plunger can't travel up to take out lash, the pushrod will be free to move about and you'll get clatter.
Your 1998 ZJ w/6-242 should have the #0630 head, which was used 1996-1999 (XJ) or 1996-1998 (ZJ, TJ.)
The #7120 head may be adapted, but the exhaust ports are larger. You'll need to fabricate a "block-off plate" from sheet steel (go with 0.060"-0.100" or so, mild steel should do) and cut it to match the later exhaust gasket. Use the gasket for the #7120 head on the head side, and the gasket for the #0630 on the manifold side.
The #7120 was used on all 1991-1995 6-242 engines.
The #0331 may be able to be adapted, I'm not sure of the details. However, avoid #0331 heads without the TUPY foundry mark, these are the ones that tend to crack. You can source TUPY heads fairly consistently from 2002-up WJ and TJ w/6-242.
And givvus a good 24 hours to respond to posts - it's not like you're in a roomful of people talking all the time, people are in and out, and you may have to wait to find out who has your answer (I don't have all of the answers, but there's no guarantee that you're going to get your answer in the first hour or so...)
07-05-2012, 11:28 AM
#6
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Year: 1998
Model: Grand Cherokee
Engine: 4.0
Why do people insist on bumping their own posts?
The valves in the 6-242 are not adjustable - they're supposed to be self-adjusting. Rocker arms don't get adjusted, the screws get torqued to 19 pound-feet and adjustments take place through the hydraulic tappets.
If you have valve chatter, you may have a stuck or collapsed lifter. Try using an engine oil flush first - varnish and sludge can collect and stick the plunger in place. If the plunger can't travel up to take out lash, the pushrod will be free to move about and you'll get clatter.
Your 1998 ZJ w/6-242 should have the #0630 head, which was used 1996-1999 (XJ) or 1996-1998 (ZJ, TJ.)
The #7120 head may be adapted, but the exhaust ports are larger. You'll need to fabricate a "block-off plate" from sheet steel (go with 0.060"-0.100" or so, mild steel should do) and cut it to match the later exhaust gasket. Use the gasket for the #7120 head on the head side, and the gasket for the #0630 on the manifold side.
The #7120 was used on all 1991-1995 6-242 engines.
The #0331 may be able to be adapted, I'm not sure of the details. However, avoid #0331 heads without the TUPY foundry mark, these are the ones that tend to crack. You can source TUPY heads fairly consistently from 2002-up WJ and TJ w/6-242.
And givvus a good 24 hours to respond to posts - it's not like you're in a roomful of people talking all the time, people are in and out, and you may have to wait to find out who has your answer (I don't have all of the answers, but there's no guarantee that you're going to get your answer in the first hour or so...)
The valves in the 6-242 are not adjustable - they're supposed to be self-adjusting. Rocker arms don't get adjusted, the screws get torqued to 19 pound-feet and adjustments take place through the hydraulic tappets.
If you have valve chatter, you may have a stuck or collapsed lifter. Try using an engine oil flush first - varnish and sludge can collect and stick the plunger in place. If the plunger can't travel up to take out lash, the pushrod will be free to move about and you'll get clatter.
Your 1998 ZJ w/6-242 should have the #0630 head, which was used 1996-1999 (XJ) or 1996-1998 (ZJ, TJ.)
The #7120 head may be adapted, but the exhaust ports are larger. You'll need to fabricate a "block-off plate" from sheet steel (go with 0.060"-0.100" or so, mild steel should do) and cut it to match the later exhaust gasket. Use the gasket for the #7120 head on the head side, and the gasket for the #0630 on the manifold side.
The #7120 was used on all 1991-1995 6-242 engines.
The #0331 may be able to be adapted, I'm not sure of the details. However, avoid #0331 heads without the TUPY foundry mark, these are the ones that tend to crack. You can source TUPY heads fairly consistently from 2002-up WJ and TJ w/6-242.
And givvus a good 24 hours to respond to posts - it's not like you're in a roomful of people talking all the time, people are in and out, and you may have to wait to find out who has your answer (I don't have all of the answers, but there's no guarantee that you're going to get your answer in the first hour or so...)
Why do people insist on being *******s for no reason?
i appreciate the info, but if i am correct. which im pretty damn sure i am i started this thread almost a month ago and have bumped it one time. i have since then realized these can not be adjusted hence the reason i bumped it back up.
so please read the entire thread before you start bashing someone about bumping a thread when its only been bumped once over a months period..... thanks
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07-05-2012, 12:01 PM
#9
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Year: 2000
Model: Cherokee
Engine: 4.0
If you can get it to me from williamsport I am going to york jeep jamboree this month. I could meet you there in and hand delivered if you would like. Mr Matt
07-05-2012, 06:49 PM
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Year: 1988
Model: Cherokee
Engine: AMC242
Why do people insist on being *******s for no reason?
i appreciate the info, but if i am correct. which im pretty damn sure i am i started this thread almost a month ago and have bumped it one time. i have since then realized these can not be adjusted hence the reason i bumped it back up.
so please read the entire thread before you start bashing someone about bumping a thread when its only been bumped once over a months period..... thanks
i appreciate the info, but if i am correct. which im pretty damn sure i am i started this thread almost a month ago and have bumped it one time. i have since then realized these can not be adjusted hence the reason i bumped it back up.
so please read the entire thread before you start bashing someone about bumping a thread when its only been bumped once over a months period..... thanks
But, I do run across an awful lot of cases where someone will put up a thread and bump it five times in two hours - so it's a sore spot.
However, I try to not get into the situation unless I have some potentially useful information to offer as well. I try to help and correct at the same time.
It's just that when I see someone having started a thread and the first four posts are "Anyone? Anyone?" it gets a little tedious.
I generally advise people, if they're in a hurry, to put the date and time in the post so we know when you posted it - and therefore if we've gotten to it quickly or not. Information is key...