4.7 HO go BOOM!!!!

[HammerZ71]

Update:

Got a good bit done so far, this was my engine last week:



and this is it as of today, got all 8 pistons in and I'm about ready to tackle the heads:

[HammerZ71]

Got that summbiotch rebuilt - low and behold it fired right up!!!

Sounds good too, ran it on and off for about an hour, rev'd it a couple of times up to about 3000 rpm.

I have some more work to do to button it up, have to figure out how to mount the two small pusher fans. Right now the upper radiator support and hood latch is just sitting on top as I lack about 1/4" of clearance from the fans and there are two upright supports I'm gonna have to refab. Some wiring to re-do. But at least the bitch runs!!!

[AWE Daniel]

Congrats Hammer that looks like quite the job!

[BAD HABIT]

Hell yeah, we got another 287cc guru now...

BAD HABITS BADASS EVO ON TAPATALK TRANSPARENT...

[HammerZ71]

I have a bad feeling we all are going to be before long, Jay. The Jeep forums are filling up with guys with 4.7s getting up in miles that are dropping valve seats (3.7s too). Remember they started putting 4.7s in Grand Cherokees in 1999, three years before Rams and it's mainly the 99s-02s that I'm seeing. Most have over-heated at some point, but some, like mine have not.

DF has had a few '02 & '03 Rams recently. One guy had his '02 Ram done at the dealer who only bought a re-manned head on the one side that failed and only rebuilt the one cylinder that failed - didn't rebuild the entire engine like I did - and soaked the guy for $4400!!! I got a feeling it's a matter of time before one of the seats on the other side drops as he had an overheat 4 months prior to his seat drop.

I hope I'm wrong - but I got a feeling we are going to start seeing this more and more.
BTW - the HEMI is not immune either as I've seen a couple do it - but the Hemi just seems to be more resistant due to it's pushrod design. The OHC engines are really suffering after what I would consider just mild overheats!
I've got it from a mod on DF who is a full time Chrysler tech in CA. (who helped me quite a bit with questions I had during my rebuild) who is seeing it almost daily and also tells me the new Pentastar V6 has the problem as well. He says EVERY aluminum head engine developed during Daimler (Mercedes) ownership suffers from the problem...

[Fla 66 cuda]

My hats off to ya rebuilding it in the vehicle thats gotta be a b---h i would never do that. Good job!

[AWE Daniel]

Originally Posted by BAD HABIT Hell yeah, we got another 287cc guru now... BAD HABITS BADASS EVO ON TAPATALK TRANSPARENT...

Dirt bike guru? Lol jmwy I know you meant ci

[garner]

Glad it's fixed!

When I was at my sister's house on the 4th I told her about this(she has a 04 gc with 102,000 miles but has the 4.0 as does her husband with his 03) and she said she's glad my aunt didn't order her one with the 4.7 as she just had her fuel pump go out but the shop mistested it so they replaced a bunch of unneeded stuff

[BAD HABIT]

yall know what i meant, yeah i hope this doesnt happen to me, HEMI here i come if it does, lord let me pay it off first...

[HammerZ71]

UPDATE:

Sorry it's been so long since I posted. Jeep ran like a champ for a week then one of the rebuilt heads failed! Shop thinks the guy pulled specs for regular 4.7 heads and not HO. Luckily it stalled as soon as the head failed, so damage was minimal. Rocker arm snapped and took the valve clean off at the stem. Free floating valve just barely nicked the new piston.
Shop took full responsibiltiy and re-re-manned the head, including paying another shop to remove it and re-install it. HOWEVER, they refused to pay for removal or even look at the other head because it hadn't failed - YET!

So anyway when I got it back it wasn't running the same as after my rebuild. RPMs at idle were down and it wanted to stall at lights UNLESS the AC was on to keep idle up a hair. PLUS I just didn't trust the other head, feeling if they spec'd one head wrong - they surely spec'd them both wrong.

Put it up for sale for $7500 and took the first guy's offer of $6500. Told him up-front about the total rebuild but I didn't volunteer that one of the rebuilt heads had to be re-rebuilt. Let him test it to his hearts content before buying it though.

Used $2500 of the $6500 to pay off my rebuild costs and put the other $4000 down on a new Hyundai 4 banger to be my new daily driver. Obviously isn't as fun to drive as a lifted, V8, 4x4 Grand Cherokee, but my gas credit card bill for the first month was $80 lighter than normal.

This is what I found when I towed the thing back home and removed the valve cover: At least proving my low end rebuild was solid and the head was indeed what failed. As you remember cylinder 2 was the one that originally failed, this valve is on cylinder 7.






The new daily driver, after two full tanks of gas is averaging just shy of 40 mpg: