the 0331 head thread (help out if you have one!)

Post by **bratcop** » December 2nd, 2008, 9:09 pm

finally got a better pic of the casting number on my 0331 head...here it is...

Jeep Laredo-01.jpg

it's a little blurry but it says "017"...also I noticed that the block is stamped somewhere with NHV which stands for Noise,Harmonics,Vibration. I was wondering if the NH* (different numbers here) could be there to indicate it is matched (Noise, Harmonics) to an NHV block. The *(seen a 2 and a 5 in this thread) could be a version number with minor refinements? Just a thought as I know it wouldn't seem like a head would have a lot to do with Noise and Harmonics...but seemed like an odd coincidence...

Bratcop

Post by **go4lo** » December 22nd, 2008, 12:01 pm

add me to the list - 2000 TJ 99K - Cracked 0331 head. Milkly coolant oil sludge mix under the valve cover between cylinder 3 and 4. Also was burning through coolant fast. Head is off now and plan to replace with a new 0331 head from Alabama Cylinder Head.

Post by **1bolt** » December 22nd, 2008, 1:00 pm

G4lo can you take some pics of the replacement? That might be the most informative 0331 pictures anyone could contribute, reportedly the Alabma 0331 head is a revised casting that doesn't have the flaws that caused early heads to crack... The markings on that head would be extremely interesting.

Also would be interested if you could contribute pics of your cracked head.

Post by **rradford9** » January 24th, 2009, 9:17 am

Just got my 0331 head back from being hot tanked & sandblasted. 145k no cracks (knock on wood!)

OOOPS that 2nd pic sucks. I'll take another one if you need me too.

Post by **1bolt** » March 6th, 2009, 8:32 pm

Bumping this thread before it falls off the main page, if we get a couple more heads in here I will sticky it. I would REALLY REALLY love to get good pics of the revised Alabama cylinder heads version of the 0331, or a very late 0331 (like from a 2005 or 2006)...

In fact the first person to post good pics of either one of those castings gets a free Jeepstrokers sticker (on me)

rradford9 thanks I must have missed it when you posted those what year did that head come off of?

Still very interested in cracked ones, or other pics of any year 0331 castings.

Post by **SilverXJ** » March 6th, 2009, 9:40 pm

I'm going to be around the machine shop tomorrow and going to see if they let me screw around with their crack detection crap on my 0331 head.

Post by **Cheromaniac** » March 7th, 2009, 8:00 am

Maybe someone can cut a cracked 0331 head down the middle with a bandsaw so we can see how much material there is, and compare it to the Alabama and stock '02+ heads.

Post by **rradford9** » March 7th, 2009, 9:21 am

1bolt wrote:rradford9 thanks I must have missed it when you posted those what year did that head come off of?

2000 WJ with 140k

Post by **SilverXJ** » March 7th, 2009, 2:38 pm

We magnafluxed the head today. No crack. I guess it was just a damaged head gasket that caused the coolant leak.

Post by **SilverXJ** » March 7th, 2009, 6:40 pm

Could the crack in the head have been too small for magnaflux to find? When I swapped the head out I didn't actually see a decrease in the engine coolant, but oil analysis showed coolant traces. After I did the head swap and gasket change the coolant traces(potassium and sodium) disappeared. I never changed the oil brand in that period, so it wasn't in the oil.

Post by **Alex22** » March 7th, 2009, 7:39 pm

If there is a crack in a cylinder head a form of MPI (magnaflux) will show it, as long as the head was clean enough. When I was checking out my 0630 head I glass beaded it to make sure it was clean, magnafluxed it then pressure tested it (30psi) just to be sure, it passed.

When you do an oil change it doesn't get all the oil out. There is still a layer of it on everything and inside the oil passages and that is probably why you saw coolant in the oil after putting the new head on.

Post by **SilverXJ** » March 7th, 2009, 7:47 pm

Alex22 wrote:that is probably why you saw coolant in the oil after putting the new head on.

I had 3 oil changes prior to the head change analyzed. They all showed similar levels of coolant. After the head swap the levels dropped significantly on the first oil change.. on the second it was gone.

Post by **Alex22** » March 13th, 2009, 4:24 pm

This came into the shop today. 0331 head off of a 1999 (unknown model)
The picture doesn't show the crack too good, but its circled there.

"NH1" "WJ" and "99" are also cast on the head.

Post by **SilverXJ** » March 13th, 2009, 7:08 pm

Its from a TJ or WJ. They got the boat anchor in 99.. the XJ in 2000

Post by **IH 392** » March 13th, 2009, 11:20 pm

If I get motivated this weekend I'll pop the rocker cover off of my '00 Cherokee core and take a look, I don't think the head is cracked? (I have a 7120 head I'm going to use) I do know that the oil was COAL black!, it's all over the bed of my pickup!

the 0331 head thread (help out if you have one!)

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