Magnum Heads Durability, Opinions

1970FuryConv

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My question is on durability of 1992-2003 Magnum Heads

In an article on building magnum V8 engines, Mopar Action, Feb 2014, Rick Ehrenberg tech editor says:

“Most, if not all, of the magnum V8 Heads castings, with anything over 50-75K miles, will have cracks in the exhaust seat. True, the magnum typically don’t go to water (leak coolant into the chambers) until 150K plus and a high percentage never do.”

In the magnum V8 build, Ehrenberg junked original magnum V8 heads without checking them, and ordered new heads

Are the original magnum V8 heads that bad?

What is your experience with the durability of these magnum V8 engines 1992-2003?




Thanks, Ben
 
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Find a mechanic at a Police Garage. I was delivering some snowplow lights yesterday to our Local "County" garage. There were three HEMI engine's and transmissions sitting on pallets inside the door. Sure they will often times see heavier use than normal. But, they don't have the high mileage some salvage units will either. Alot of the newer hemi's and pentastar v6 engines have converter that bolts directly to the head. That's ALOT of heat contained up against the valve train. A high school friend of mine traded his Jeep in before the warranty ran out because of the issue your asking about. Twice, he had the passenger side head replaced under warranty.
 
Magnum heads are prone to cracking between the seats and like the article states the cracks "usually" aren't a issue. What are you thinking? Do you have a Magnum that needs heads or are you thinking of a retrofit on a LA engine?
My question is on durability of 1992-2002 Magnum Heads

In an article on building magnum V8 engines, Mopar Action, Feb 2014, Rick Ehrenberg tech editor says:

“Most, if not all, of the magnum V8 Heads castings, with anything over 50-75K miles, will have cracks in the exhaust seat. True, the magnum typically don’t go to water (leak coolant into the chambers) until 150K plus and a high percentage never do.”

In the magnum V8 build, Ehrenberg junked original magnum V8 heads without checking them, and ordered new heads

Are the original magnum V8 heads that bad?

What is your experience with the durability of these magnum V8 engines 1992-2002?




Thanks, Ben
 
I had a Magnum 5.2 in a 97 Dakota. It went to 240k+ before there were frame rust issues that did it in. Engine/drive train was never apart, even had the original clutch. I never noticed any issues.
 
I had a Magnum 5.2 in a 97 Dakota. It went to 240k+ before there were frame rust issues that did it in. Engine/drive train was never apart, even had the original clutch. I never noticed any issues.
I have 2 97's both with 3.9 v6 Magnums. Like yours, the frame is getting soft. Too bad too, the engines are still running like a top with 175,000 rounds on each truck.
 
Magnum heads are prone to cracking between the seats and like the article states the cracks "usually" aren't a issue. What are you thinking? Do you have a Magnum that needs heads or are you thinking of a retrofit on a LA engine?
Hi Mike
I was thinking of replacing my pickup truck.
Evaluating options. Sounds like the magnum engines are a gamble. I have seen lots of magnum engine trucks for sale with over 200000 miles. Then I hear these stories of cracked heads doing the vehicle in. Ben
 
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Find a mechanic at a Police Garage. I was delivering some snowplow lights yesterday to our Local "County" garage. There were three HEMI engine's and transmissions sitting on pallets inside the door. Sure they will often times see heavier use than normal. But, they don't have the high mileage some salvage units will either. Alot of the newer hemi's and pentastar v6 engines have converter that bolts directly to the head. That's ALOT of heat contained up against the valve train. A high school friend of mine traded his Jeep in before the warranty ran out because of the issue your asking about. Twice, he had the passenger side head replaced under warranty.
Hi Justin,
Are you recommending the 3rd gen hemi engines?
What does converter that bolts directly to the head mean? I guess we are not talking about torque converter.
Thanks! Ben
 
Hi Justin,
Are you recommending the 3rd gen hemi engines?
What does converter that bolts directly to the head mean? I guess we are not talking about torque converter.
Thanks! Ben
They removed the exhaust manifolds. There is a small 4 bolt flange that bolts directly to the head.
 
And that is the 6 post tour of Mopar late model stuff. Don't forget to tip your guides on your way out, hehehe.
 
Mnay used heads will have small cracks between the intake and exhaust valve seats, when magnafluxed, but will not leak water or generall cause problems. Usually, such heads get scrapped, although they can work a good while longer. BTAIM Perhaps the message might be to not remove the heads unless there is a definite issue with them?

The car converter is bolted to the head in order to get the car fired-off quicker to get the engine through "cold start emissions" sooner and cleaner. No more, no less. Chry is not the only OEM that does that, either.

The various generations of Gen III Hemi have their own issues, by observation. Many of which are documented on YouTube videos. Most were fixed in the later generations of Gen III. Related to valve train issues, those issues usually happen with "fleet" engines which spend more than 30 minutes at a time idling, so the videos mention.

Just some observations,
CBODY67
 
My 92 Dakota has the 318 magnum and I have had no issues with it in this regard.I tested the coolant for contamination last fall because I thought I might have lost a head gasket but it tested clean.The motor couldn't run any better than it does at 210,000 miles but it is a pig on gas.
 
My dad told that the mind is the second thing to go. When I asked him what the first was, he couldn't remember.
 
Old thread, but wanted to add another opinion that the heads are generally not an issue - meaning that, there were logically LOTS of engines running around A-OK with cracks in the heads. The stories you hear (lots of them) is that they pulled the heads off an engine they were going to rebuild and the heads were cracked. I've never seen a story where someone pulled the heads (or engine) *because* the heads were cracked (because you cannot know they are cracked until inspecting them).

Pull a set of heads off a *wrecked* ragged-out truck in the junkyard, and the heads will be cracked.
The heads will look like they've been on there forever - and unless it got hit while parked on teh street, the truck had to be driving around to get that ragged, and to get wrecked.

There used to be a company called Engine Quest that made upgraded heads for a replacement.
 
There used to be a company called Engine Quest that made upgraded heads for a replacement
Sadly out of business. Their replacement heads outflowed stock heads, and later they made them with the option to have LA bolt pattern which opened up a crapload of cheap used manifolds for a carburetor.
 
Sadly out of business. Their replacement heads outflowed stock heads, and later they made them with the option to have LA bolt pattern which opened up a crapload of cheap used manifolds for a carburetor.
I thought I read there was a different company that took that over?
IIRC Engine Quest was from Australia?
Of course the replacement company could've been gone by now, too.

They were a great ticket to soupin' up a 5.2 or 5.9, that's for sure.
 
Looks like they are still in business.
Home - EQ Cores & Recycling

Looks like all sales are thru ebay.
Some of their listings show China as country of origin.

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