Buying a Magnum Core- Max Mileage?

-
B

BobK

Custom Builder
Joined
Jun 6, 2005
Messages
121
Reaction score
19
Location
Holly Springs, GA
I'm looking for a 5.9L Magnum core, and many of the ones I'm seeing are in the 150,000-200,000 mile range, which sounds excessive, but is it really? I've done several GM LS-series swaps, and 150,000 miles on one of those motors is nothing- it's considered "just broken in". Is it the same with the Magnums, or is there a certain mileage beyond which you're better to stay away?

I plan to swap the heads and likely the cam, but really don't want to get into rebuilding the bottom end if I can avoid it.
 
Personally I think any engine over 100K is shakey, ESPECIALLY if you are going to beat on it. *** opposed to "your old uncle" driving it out to fish at the lake 'er whatever
 
no personal experience but have read repeatedly these engines wear very little.
best to find one that is still running...rev to full throttle repeatedly if there is no smoke or
noises you're good to go.
 
Go here and do a search for a low mileage engine. This link lists inventory for salvage yards across north america....

www.car-parts.com

You may find a good low mileage one near you, and they may even give you a short warranty...
 
They go forever due to metric rings, fuel injection and better metallurgy. Zero bore wear at 200k is common, I couldn't hang a nail on mine that was moderately taken care of at 192k. Bearings looked OK, I tossed a re-ring kit through it just for peace of mind and to show a buddy how to shade tree re-build an engine. They die from overheating or people not keeping good oil in them before anything else.
 
Mine had around 110k and the crosshatching was very easily seen in the cylinders. Normally the transmission goes out long b4 the engine on these magnums.
 
LKQ usually sells high mileage engines like that in the 300 dollar range with a 6 month warranty. That's where I got the little 302 going in RobKat.

I don't understand you not wanting to at least freshen it up. Rings, bearings seals and gaskets are cheap. It's good to be cheap. It ain't good to be stupid.
 
I agree completely on the general opinion already mentioned.

My Brother has a 98? 360 mag with about 150 thou on it, and it runs fantastic and uses about a half a quart of oil between 6,000 mile changes.

He tried to give it to me for my Dart but I just couldn't take apart a perfectly good running and driving 4x4 with a fifth wheel setup and HD tow package to do it. :D
 
RustyRatRod said:
I don't understand you not wanting to at least freshen it up. Rings, bearings seals and gaskets are cheap. It's good to be cheap. It ain't good to be stupid.
Click to expand...

That's why I asked the question- I'm not being cheap or stupid- it's a matter of spending money where it makes sense. If the motors go for 200k miles without bore wear, and I'm only likely to put another 10k on it over the next few years, rings and bearings are a waste of money (or money I can defer until needed down the road). If the consensus is that they nee a rebuild at 100k, then it's obviously something I'd need to do now.
 
Oh and as mentioned, these newer engines (my 302 is a 99 model) do not exhibit any of the wear patterns the older engines did. My 302 was spotless on the inside. Strong cross hatch was still in all the cylinders. The striations were still strong on the piston skirts. I could have run it as is, but that's not what I wanted. I planned on better valve springs and a reground roller cam, which I did, so the engine had to come down.
 
BobK said:
That's why I asked the question- I'm not being cheap or stupid- it's a matter of spending money where it makes sense. If the motors go for 200k miles without bore wear, and I'm only likely to put another 10k on it over the next few years, rings and bearings are a waste of money (or money I can defer until needed down the road). If the consensus is that they nee a rebuild at 100k, then it's obviously something I'd need to do now.
Click to expand...

I know you're not......I wasn't implying you were. I was simply saying not to be. lol

You never know what's in an engine. I have torn some down that had a cracked skirt for instance. Things like that might not show up with granny driving to church on Sunday and to the grocery store and beauty shop during the week, but put it in a hot rod with a heavy right foot and you will find out about it the hard way.

I recommend the tear down and freshen for much more than just the new parts. It's also for inspection. approaching and over 200K is a lot of miles. That can stress even the best parts in the best of circumstances.
 
Depends on how they were taken care of. Some of the ones that've been hot- 80k's a bit much. Others that haven't, great 250k motors other than needing the belly pan in the intake, so...
 
..your approach is just such a good idea.
An adequate bottom end and carefully selected parts can produce a fun strong street engine and save thousands.
..Most of us put less than a thousand miles on a year and never race our cars.

the trick is to control your hobby and not have your hobby control you!
 
I'm glad to see some of the replies here. The 360 I have for my swap had 140K on the ticker when pulled. I'll likely re-ring and bearing before using anyhow.

My "daily driver" (quotes b/c I only drive it once a week or so) 2000 Ram w/ 318 Mag has 240K and still going. It sucks oil like no one's business. I use about a quart per fill up of fuel. I'm nearly certain that it is a leaky plenum gasket. It burns out the #8 plug about ever 10K miles or so. I just put a new one in and keep driving.

The really funny part is............I haven't changed the oil since about 2007/8 ish. Yeah it uses so much oil I just put in a quart of 3000 mile old used oil from my wife's car, and throw a oil filter on it once in a while. A great while............:D But, it's still runnin! Knock on wood......
 
BobK said:
That's why I asked the question- I'm not being cheap or stupid- it's a matter of spending money where it makes sense. If the motors go for 200k miles without bore wear, and I'm only likely to put another 10k on it over the next few years, rings and bearings are a waste of money (or money I can defer until needed down the road). If the consensus is that they nee a rebuild at 100k, then it's obviously something I'd need to do now.
Click to expand...

A quality re-ring and gasket kit is dirt cheap:

http://www.northernautoparts.com/part/ek-er0213d

$250 includes a hone rental. Just do it and get it over with. You'll pay $150 for a good set of intake and head gaskets and come out spending more if you need to dig back into it again.

At least pull the caps off and check/plasti-gauge the bearing surfaces if your not gonna do it right. My bet is the thrust bearing needing to be replaced because it's got excessive play. There's your cheap insurance.
 
The bores look great on my 94 mag, but the crank needed turned .010 / .010.
When I tore it down it was obvious the last owner did not change the oil much if ever.
And both heads were cracked.
I gave $200 for it and the guy threw in a LA style timing chain cover and oil pan.
 
ValiantOne said:
The really funny part is............I haven't changed the oil since about 2007/8 ish. Yeah it uses so much oil I just put in a quart of 3000 mile old used oil from my wife's car, and throw a oil filter on it once in a while. A great while............:D But, it's still runnin! Knock on wood......
Click to expand...

Lol! I do the same with my beater, daily driver 02 toyota CRAPolla! Drive it till the oil light comes on in a hard turn, add 1-2 qts of used oil from my dads semi and keep goin!! That engine has been rattling since b4 I got it from my bro 3 years ago! Rattles like crazy but has heat, ac, stereo and still gets 28mpg when I beat on it!! Lol
 
Picked up one,for free..175 k & a and crosshatch was gorgeous. cam lobe( yes they do go flat,with time. Pulled number one rod & main bearings,looked excellent. Crosshatch was excellent,reinstalled it with a new cam & heads. Crisp & cackles...
 
Due to the ridiculous price people are paying for LA360 cores in Australia ($2000 AUD for something that "runs" :angry7:). I recently decided to import a low mileage 5.9 for my next project.

In the end I settled on one with 109k miles on the clock. I kinda just accepted that that this is probably about as low mileage as a 15 year old truck motor probably gets and i didn't wanna spend another 4 months finding one with a few less miles. It cost me $800 USD plus shipping from a wrecking yard.

Fingers crossed. it should be here early in the new year!
 
frosty_the_punk said:
Due to the ridiculous price people are paying for LA360 cores in Australia ($2000 AUD for something that "runs" :angry7:). I recently decided to import a low mileage 5.9 for my next project.

In the end I settled on one with 109k miles on the clock. I kinda just accepted that that this is probably about as low mileage as a 15 year old truck motor probably gets and i didn't wanna spend another 4 months finding one with a few less miles. It cost me $800 USD plus shipping from a wrecking yard.

Fingers crossed. it should be here early in the new year!
Click to expand...

If you switch to Ford you would at least have the 302 Cleveland with way better heads.
 
These 360 magnum motors are extremely durable and will take lots of abuse even with 150k or more on the clock. Currently running 15 pounds of boost thru a high mile 360 magnum with a stock untouched bottom end with no issues. Now I did put a set of ARP head studs in to keep the heads from lifting lol. 450 to the wheel on 91 octane.
 
My daily driver 2000 Dakota is pushing 160,000.

It runs just like the day I bought it with 30,000 on the clock.
 
>>>>>> fordmods.com is that way if you want a conversation on smelly old clevos>>>>>>
 
You must log in or register to reply here.
-

Back
Top