LA / Magnum blocks

[rumblefish360]

Oh, thanks for passing it on. I don't know why the automotive industry wants to build lighter engines, the little weight that they save with doing so will never be noticed. I would put quality, durability in engines if I was in charge of that department

It all comes down to the almighty dollar.
Also, the less an engine and the rest of everything else weighs, the more mileage you get, the quicker you are with the otherwise same exact build and parts over the heavier engine.

A light weight engine has nothing to do with its quality, power it can make or potential longevity.

 

[YY1]

Oh, thanks for passing it on. I don't know why the automotive industry wants to build lighter engines, the little weight that they save with doing so will never be noticed. I would put quality, durability in engines if I was in charge of that department

That's just it.

Because of the hi-tech rings and pistons, plus the EFI, a mag block can be usable without new rings at over 100,000 miles.
Bearings may not last that long if abused, from what I understand.

My 5.9 has 167,000 of borderline abuse on it and runs as strong today as it did at 30,000 when I bought it.

I wouldn't hesitate to drop that engine in a car and run the hell out of it as is.

 

[Dan the man]

It all comes down to the almighty dollar.
Also, the less an engine and the rest of everything else weighs, the more mileage you get, the quicker you are with the otherwise same exact build and parts over the heavier engine.

A light weight engine has nothing to do with its quality, power it can make or potential longevity.

Thin wall casting as well as thinner deck surface, thinner deck surface of cylinder heads very much affects quality. The small amount of weight that is saved by making the block lighter would never be noticed. Look at fords 4.6 block's, they over heat with a 0.030" over bore. Why do you think that the magnum heads crack so easily, it's not a matter of if it's a matter of when they will crack.

 

['68cuda416]

That's just it.

Because of the hi-tech rings and pistons, plus the EFI, a mag block can be usable without new rings at over 100,000 miles.
Bearings may not last that long if abused, from what I understand.

My 5.9 has 167,000 of borderline abuse on it and runs as strong today as it did at 30,000 when I bought it.

I wouldn't hesitate to drop that engine in a car and run the hell out of it as is.

Yup that would be a boring *** turd and the laughing stock of most towns

 

[MopaR&D]

Yup that would be a boring *** turd and the laughing stock of most towns

Oh great here we go

 

[mopowers]

Oh great here we go

I bet he has lots of friends too.

 

[YY1]

Whut?

That 5.9 runs like a scalded dog in a 4200 pound extended cab truck.

I can only imagine that engine in a 3100 pound A body.

...and it's bone stock, and has an exhaust restriction.

 

[rumblefish360]

Thin wall casting as well as thinner deck surface, thinner deck surface of cylinder heads very much affects quality. The small amount of weight that is saved by making the block lighter would never be noticed.

Consider the weight savings 1 cent towards a dollar. Now do that all over the car. It adds up. It gets noticed. Once you start adding it all up.
But not that you actually point out something as if it were a fact, let’s dive into that aspect.

Thin walls. Can you personally prove. A nuke have thinner walls over a 340 or 360?
Can you personally prove that the decks of a Magnum have thinner decks over a 340 or 360?

How much deck thickness is needed for longevity, what ever longevity is in your head which you’ll kindly respond with an actual mileage minimum before failure.

Now the same with cylinder wall thickness.

Look at fords 4.6 block's, they over heat with a 0.030" over bore.

**** Ford examples on a MoPar board.
But then again, I have had 340 tank with only a .030 overbore done. Glad I didn’t have to put any more money into that block besides the sonic check!
So much for “That’s one of the good year blocks, that’ll take a .090 overbore for sure!”

Wrong! I was left with a cylinder as thin as .030.
(OH! I just found another one of my sonic check papers. See below! Oooooooo, sooooo thick!!!!)

Why do you think that the magnum heads crack so easily,

That is a very good question that an engineer should answer. Here on the I-net, I’m hard pressed to believe anyones word on why it exactly happens as a fact.

it's not a matter of if it's a matter of when they will crack.

That maybe so, but can you prove it will happen for certain?

Look at this. 340’s can take a massive overbore?

 

[rumblefish360]

That 5.9 runs like a scalded dog in a 4200 pound extended cab truck.

I can only imagine that engine in a 3100 pound A body.

...and it's bone stock, and has an exhaust restriction.

I like my 5.9 in my ‘79 Magnum. Backed with a 2500 stall/727 & 3.55’s on 26-1/2 tires. It weighs under 3600lbs. I just added a 750 (removed the 600) AFB, RPM intake, 1-3/4 headers into an2-1/2 exhaust. Chrome box fired on a JY distributor.
Now I need a camshaft for it. Something small. I like to drive it everywhere.

 

['68cuda416]

Whut?

That 5.9 runs like a scalded dog in a 4200 pound extended cab truck.

I can only imagine that engine in a 3100 pound A body.

...and it's bone stock, and has an exhaust restriction.

I will correct you.......they are the loudest sounding exhaust of any truck so to people that don't know what fast is the 5.9 in the trucks runs like a scalded dog....

 

[YY1]

Whut?

 

[AJ/FormS]

Whut?

My 367LA now has over 100,000 on it and it also runs like a scalded dog. But if I was to pull it out of the car, there is notachance it would go into another without a freshening.
In 2004 it went 93 in the Eighth. What will it do with 100,000 miles on it?
Don't now/don't care;
it runs like a scalded dog.

 

[YY1]

Stroker is automatically disqualified from OP's backyard criteria.

My OEM untouched non-build automatically qualifies.

(right?)

 

[DC Dart]

I've pulled apart a few older LA 318s with over a 100k and minimal bore wear. The biggest weak link was the nylon geared timing sets giving up at over 100k.
If they had EFI and overdrive wear would be less. Most had 2:76 gears though.
Would not run an OEM head on a magnum or LA.
Like the roller lifters on the Magnum block.

 

[Rat Bastid]

Oh, thanks for passing it on. I don't know why the automotive industry wants to build lighter engines, the little weight that they save with doing so will never be noticed. I would put quality, durability in engines if I was in charge of that department

CAFE. It’s as simple as that.

 

[Tbro]

A cam like Trailbeast runs would be great. Especially in a heavy car.

 

[Dan the man]

Consider the weight savings 1 cent towards a dollar. Now do that all over the car. It adds up. It gets noticed. Once you start adding it all up.
But not that you actually point out something as if it were a fact, let’s dive into that aspect.

Thin walls. Can you personally prove. A nuke have thinner walls over a 340 or 360?
Can you personally prove that the decks of a Magnum have thinner decks over a 340 or 360?

How much deck thickness is needed for longevity, what ever longevity is in your head which you’ll kindly respond with an actual mileage minimum before failure.

Now the same with cylinder wall thickness.


**** Ford examples on a MoPar board.
But then again, I have had 340 tank with only a .030 overbore done. Glad I didn’t have to put any more money into that block besides the sonic check!
So much for “That’s one of the good year blocks, that’ll take a .090 overbore for sure!”

Wrong! I was left with a cylinder as thin as .030.
(OH! I just found another one of my sonic check papers. See below! Oooooooo, sooooo thick!!!!)


That is a very good question that an engineer should answer. Here on the I-net, I’m hard pressed to believe anyones word on why it exactly happens as a fact.

That maybe so, but can you prove it will happen for certain?

Look at this. 340’s can take a massive overbore?

View attachment 1715906363

Don't have to prove if they will crack, it's a known fact that magnum heads crack

 

[Dan the man]

Consider the weight savings 1 cent towards a dollar. Now do that all over the car. It adds up. It gets noticed. Once you start adding it all up.
But not that you actually point out something as if it were a fact, let’s dive into that aspect.

Thin walls. Can you personally prove. A nuke have thinner walls over a 340 or 360?
Can you personally prove that the decks of a Magnum have thinner decks over a 340 or 360?

How much deck thickness is needed for longevity, what ever longevity is in your head which you’ll kindly respond with an actual mileage minimum before failure.

Now the same with cylinder wall thickness.


**** Ford examples on a MoPar board.
But then again, I have had 340 tank with only a .030 overbore done. Glad I didn’t have to put any more money into that block besides the sonic check!
So much for “That’s one of the good year blocks, that’ll take a .090 overbore for sure!”

Wrong! I was left with a cylinder as thin as .030.
(OH! I just found another one of my sonic check papers. See below! Oooooooo, sooooo thick!!!!)


That is a very good question that an engineer should answer. Here on the I-net, I’m hard pressed to believe anyones word on why it exactly happens as a fact.

That maybe so, but can you prove it will happen for certain?

Look at this. 340’s can take a massive overbore?

View attachment 1715906363

Thin wall castings, machine shops know this

 

[Dan the man]

Consider the weight savings 1 cent towards a dollar. Now do that all over the car. It adds up. It gets noticed. Once you start adding it all up.
But not that you actually point out something as if it were a fact, let’s dive into that aspect.

Thin walls. Can you personally prove. A nuke have thinner walls over a 340 or 360?
Can you personally prove that the decks of a Magnum have thinner decks over a 340 or 360?

How much deck thickness is needed for longevity, what ever longevity is in your head which you’ll kindly respond with an actual mileage minimum before failure.

Now the same with cylinder wall thickness.


**** Ford examples on a MoPar board.
But then again, I have had 340 tank with only a .030 overbore done. Glad I didn’t have to put any more money into that block besides the sonic check!
So much for “That’s one of the good year blocks, that’ll take a .090 overbore for sure!”

Wrong! I was left with a cylinder as thin as .030.
(OH! I just found another one of my sonic check papers. See below! Oooooooo, sooooo thick!!!!)


That is a very good question that an engineer should answer. Here on the I-net, I’m hard pressed to believe anyones word on why it exactly happens as a fact.

That maybe so, but can you prove it will happen for certain?

Look at this. 340’s can take a massive overbore?

View attachment 1715906363

I've never heard of anyone boring a magnum block 0.060", this is due to the cylinder walls being of a thin wall casting. Machine shops don't recommend boring more than 0.030". It's even been in several car magazines. I talked to a lot of guys who build their own engines and I've talked to the machine shops as well. I don't know of anyone that owns his own sonic testing equipment or a xray machine. The magnum blocks may have some improvements over the LA block's, but they still use the restrictive oil pump pick up tube opening in the oil pump body. Cheap cylinder head design. I'm not trying to argue over it just stating what's known and been said about the magnum blocks. I believe that they still use a 2 piece rear main oil seal.

 

[Ottmundr]

Magnum. Easy call over the LA



Joking aside, I'd go with the LA. It's an older and proven technology. Points WORK.

 

[Ironracer]

Not fishing for controvery, I question everything., accept very little at face value.

Man, I don't question too many Mopars, most were BadAss! BUT, in all other aspects, I'm right where Yer at! Now I had a 6000# '02 Ram 4 Dr w/ a 300k 5.9 that Mother was Brutal! Just lots of balls.... thank Chinese Junk parts (hub bearing) from Advance for killing that truck. Thank God I didn't get on the expressway as planned that day. Would have killed people...not only did the wheel/ tire come off, but the brake caliper, caliper mount, but part of the steering too...

 

[YY1]

Gee, I wonder if no one bores Magnum blocks because.....they never need it.

 

[66fs]

I never do anything that is not needed.

 

[66fs]

A lot of heads develop cracks. At least MOPAR heads don't fail catastrophically and dump antifreeze in your cylinder. No facts, just thinking out loud, but I think the factors for cracking are casting core shift, thermal cycling, frozen shut heat valve in the exhaust manifold, induction hardened valve seats, thin sections. You started to see cracked heads about 1973, I used to buy 2 sets since it seemed every other head would be cracked. Then in the 90's I tried to get a good set of "308" heads, but finally gave up since I never found one that was not cracked. "302" heads were hard to find good heads, pulled and scrapped quite a few after paying to have them cleaned and maged. I finally ended up with 3 good sets, only to decide the "920" 273 heads flowed better with what I could do. I do believe once I mill the good heads, They will be fine for what I use them for, a quick A Body, usually 4 speed, with free flowing exhaust and 3 row radiator.

 

[Professor Fate]

I've never heard of anyone boring a magnum block 0.060", this is due to the cylinder walls being of a thin wall casting. Machine shops don't recommend boring more than 0.030". It's even been in several car magazines. I talked to a lot of guys who build their own engines and I've talked to the machine shops as well. I don't know of anyone that owns his own sonic testing equipment or a xray machine. The magnum blocks may have some improvements over the LA block's, but they still use the restrictive oil pump pick up tube opening in the oil pump body. Cheap cylinder head design. I'm not trying to argue over it just stating what's known and been said about the magnum blocks. I believe that they still use a 2 piece rear main oil seal.

Oil pump flow restriction? Thought the original question was for a "simple performance upgrade"? Been in "several car magazines"? I can point out all kinds of BS that's been printed in magazines- they're only slightly more reliable than crap you read on the internet. Basic sonic testers are under $150- lotsa guys have them in their toolboxes (Amazon.com: LotFancy Digital Ultrasonic Thickness Gauge Tester Meter, Range 1.2-220mm, with Hard Storage Box : Industrial & Scientific for example, if you don't believe me), myself included. So whether anything you're saying is true or not, it appears you already have your mind made up- so why did you even bother asking the original question and wasting everybody's time in the first place?