Cylinder head question - JeepForum.com
 
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post #1 of 10 Old 02-24-2018, 02:19 PM Thread Starter
devildawgg42
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Cylinder head question

So,

I have my heads out and in one of them there is a Hairline crack (it seems).. So, my question is; Do I get an all new head? Or do I attempt to put it back? Also, If I decide to get a new head, should I replace in pairs? Or will I be fine milling the good one and replacing the old one?

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post #2 of 10 Old 02-24-2018, 02:31 PM
paulsheer2
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Quote:
Originally Posted by devildawgg42 View Post
So,

I have my heads out and in one of them there is a Hairline crack (it seems).. So, my question is; Do I get an all new head? Or do I attempt to put it back? Also, If I decide to get a new head, should I replace in pairs? Or will I be fine milling the good one and replacing the old one?

I highly recommend hughes engines performance iron heads with larger stainless valves.

I have a pair.

I use stock springs.

BTW do NOT get the crack welded -- mine cracked again :-(

Paul

93 ZJ 5.2, 3.58 stroked. 242 swap. 2.5" lift. dozens of mods.
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post #3 of 10 Old 02-24-2018, 02:31 PM
jtec
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nice to know which engine...5.2? maybe

Is there a crack or not machine shop can tell AND advise if the remaining head is worth reusing and if necessary matched to replacement.

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
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post #4 of 10 Old 02-24-2018, 02:44 PM
PolkaPower
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Ratmonkey used to say that he never saw V8 magnum heads that weren't cracked. RIP.

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post #5 of 10 Old 02-24-2018, 02:47 PM
Timo_90xj
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I'm suspecting a V8 since OP is talking about cylinder heads, not one cylinder head.
A lot of 5.2/ 5.9 heads have hairline cracks, and most people ditch them at that point and get something that flow better. The stock heads restrict airflow a lot, so a set of EQ/ Indy cast iron large valve heads is a good option. Or if there are no plans for any upgrades, just get stock replacements for dirt-cheap.

That being said, if they really are hairline cracks and you haven't had any coolant loss issues, you could just clean 'em, check 'em, and simply run them as is. There are probably about a couple million 5.2/ 5.9 engines on the streets running fine that have stock hairline-cracked heads

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post #6 of 10 Old 02-24-2018, 03:18 PM Thread Starter
devildawgg42
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It's a 5.2L And I have been looking at aftermarket heads.. I am just not sure I want to pay the money right now, I also don't want to break them out again haha... Anyhow, Thank you for the input! And it looks like there is a crack between the Valves.. That's the issue..
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post #7 of 10 Old 02-24-2018, 03:44 PM
GOLDWING
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RA has new bare heads for $213 each.

ENGINETECH EHCR3181 Bare Head Info
New bare head without valves or springs. 62cc Casting # 466,671.3126" guide ID. Valve head diameter 1.920 / 1.624".
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$213.79 $0.00 $213.79

GW

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post #8 of 10 Old 02-24-2018, 04:03 PM Thread Starter
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Looking at the JEGS bare head... Good price, what yall think?
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post #9 of 10 Old 02-24-2018, 04:40 PM
kg6mov
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A new head is gonna be better than a cracked head. Not by much if the rest of the engine is the same, kinda comes down to what the piece of mind is worth to you.


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post #10 of 10 Old 02-27-2018, 11:45 PM
CatSplat
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The Magnum head cracks between the valve seats are pretty much a non-issue unless they get so bad they start seeping coolant. Probably 99% of 5.2/5.9s on the road have cracked heads. You can always reinstall them and save for better ones to install later.

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