Why do people only look for HP Blocks

[Cooter]

Way too many "Fo bote main, High Perf; tall deck people out there got too much Chevy thinking.

[Ghoste]

Don't forget thin wall, thick wall and high nickel blocks. 

[TUFCAT]

Don't forget thin wall, thick wall and high nickel blocks. 

as well as "HP" vs. "HP2" myth as being something special....

[ACUDANUT]

Don't forget thin wall, thick wall and high nickel blocks. 

It does not have to be a HP block to have "thicker walls", If there is such a thing.

[500Jon]

Same thing here in the UK,

Everyone carried on the myth that HP2 was a premium casting, High Nickel, better machining, heat treated blah, blah, blah.
Funny how I only heard that when I was buying a 440 block.
When you sell a block though, the buyer says that nonsense!!!

Its gotta be an HP block in a proper R/T, GTX, etc.
Folks know that and always check for the stamping!!!

I suppose HP2 just looks Coolio!

[Mike DC]

        
AFAIK the "thicker walls" thing was a myth entirely.  The Hemi blocks were thickened but I don't think there was ever much difference among the other B/RBs.  


The real story was that Mopar went to around 10% softer (cheaper) iron in 1976.  The engineers floated the thinner cylinder walls story to alert racers about the difference without openly admitting to the loss of quality.  

As a practical matter it's not worth worrying about.  The later blocks generally didn't get beat-on as much and usually have less overboring today, two factors that should count for something.  Building either block with moly piston rings should do more to help the long-term cylinder wear than harder alloy ever would.

 

[b5blue]

  So my understanding is HP stamped blocks ONLY meant the engine was built with the (what is now.) #P4452783 cam 268*/284* .450/.468 lift, # P3690933 valve springs and the thicker stamped rockers.  The HP just insured service personnel knew this.  (I'm not going into exhaust and exhaust manifolds.)
  Confusion starts with the 70 up six pack block, now the same cam profile has reduced lifter interface angle (For increased durability.) and 3 bolt mounting to the timing chain sprocket. Also the bigger connecting rods and corresponding harmonic balancer changes again with no change to the block itself.
  With early Hemi cars having the small HP-2 badge and later 440's with HP2 that indicate 2nd shift build more confusion grew into understanding as fact. I only learned this sorting out the best parts for my 440 running a 69 six pack set up. I'm not certain 69's got the thicker rockers but added them to my build as it was not costly and wanted new rockers anyway. 69-"very early 70 six packs can" A: Have aluminum intakes and B: The metering blocks and backing plates in the outboard carburetors are rectangular as apposed to later 70 on having iron intakes and the now standard 6 sided backing plate and metering block. (Like a rectangle with the corners cut off.) Were any early 70's six pack cars supplied without the big rod/balancer set up?
  To use up production of the blocks with heavy duty rods and balancer set ups I heard but never seen they could be installed in later production C Body or even Motor Home chassis 440's? If so they may not have the six pack cam set? Would they be marked HP?
  I spent more time then I care to recall just trying to sort crap from fact just to build an engine and drive line closely matched to factory to avoid the unknown consequences of changing parameters. Over 40 some odd years this information gets mixed up and mashed into a jumbled pool of facts that make the two letters stamped on a pad the holy grail of 440's! I'm fairly shocked by now someone has not made an exact reproduction "HP" stamp to sell so forgers can further swindle the misinformed out of big bucks and add to the confusion.
  Feel free to correct/modify anything in my post, as I read all the other posts many "Oh I recall learning that" moments came back to me. (I don't claim to be certain beyond dispute.) After about the first 10-12 years of owning my 70 I'd heard so much crap about 440's I didn't know what anything really meant. I had figured out that if you look up engine codes for your build using 69 Charger info on a 70.....a 318 looks like a 383 build.  Something the good friend I bought the car from believed for 17 years!   

[TUFCAT]

 So my understanding is HP stamped blocks ONLY meant the engine was built with the (what is now.) #P4452783 cam 268*/284* .450/.468 lift, # P3690933 valve springs and the thicker stamped rockers.  The HP just insured service personnel knew this.   (I'm not going into exhaust and exhaust manifolds.)
 Confusion starts with the 70 up six pack block, now the same cam profile has reduced lifter interface angle (For increased durability.) and 3 bolt mounting to the timing chain sprocket. Also the bigger connecting rods and corresponding harmonic balancer changes again with no change to the block itself.
 With early Hemi cars having the small HP-2 badge and later 440's with HP2 that indicate 2nd shift build more confusion grew into understanding as fact. I only learned this sorting out the best parts for my 440 running a 69 six pack set up. I'm not certain 69's got the thicker rockers but added them to my build as it was not costly and wanted new rockers anyway. 69-"very early 70 six packs can" A: Have aluminum intakes and B: The metering blocks and backing plates in the outboard carburetors are rectangular as apposed to later 70 on having iron intakes and the now standard 6 sided backing plate and metering block. (Like a rectangle with the corners cut off.) Were any early 70's six pack cars supplied without the big rod/balancer set up?
 To use up production of the blocks with heavy duty rods and balancer set ups I heard but never seen they could be installed in later production C Body or even Motor Home chassis 440's? If so they may not have the six pack cam set? Would they be marked HP?
 I spent more time then I care to recall just trying to sort crap from fact just to build an engine and drive line closely matched to factory to avoid the unknown consequences of changing parameters. Over 40 some odd years this information gets mixed up and mashed into a jumbled pool of facts that make the two letters stamped on a pad the holy grail of 440's! I'm fairly shocked by now someone has not made an exact reproduction "HP" stamp to sell so forgers can further swindle the misinformed out of big bucks and add to the confusion.
 Feel free to correct/modify anything in my post, as I read all the other posts many "Oh I recall learning that" moments came back to me. (I don't claim to be certain beyond dispute.) After about the first 10-12 years of owning my 70 I'd heard so much crap about 440's I didn't know what anything really meant. I had figured out that if you look up engine codes for your build using 69 Charger info on a 70.....a 318 looks like a 383 build.   Something the good friend I bought the car from believed for 17 years!  

Yup. Another significant change making later 440 blocks better (in my opinion) were changes to the blocks coolant passage design. Instead of a round hole, they were enlarged into a figure eight - which doubles volume in theory.  

Also should be considered if numbers mean nothing, would be the strength of the later blocks due to stronger (thicker) engine mount ears.    

[Ghoste]

Mike where did that info come from about cheaper iron?  Is that part of the high and low nickel thing because I thought that was a myth as well?

[ACUDANUT]

       
AFAIK the "thicker walls" thing was a myth entirely.  The Hemi blocks were thickened but I don't think there was ever much difference among the other B/RBs.  


The real story was that Mopar went to around 10% softer (cheaper) iron in 1976.  The engineers floated the thinner cylinder walls story to alert racers about the difference without openly admitting to the loss of quality.  

As a practical matter it's not worth worrying about.  The later blocks generally didn't get beat-on as much and usually have less overboring today, two factors that should count for something.  Building either block with moly piston rings should do more to help the long-term cylinder wear than harder alloy ever would.

TRUE AND THE WATER PASSAGES ARE THE SAME AS NON HP ENGINES.

 

[TUFCAT]

TRUE AND THE WATER PASSAGES ARE THE SAME AS NON HP ENGINES.

 

You are correct. Enlarged coolant passages relates to the later engine block design not HP.  I think my '72 had them.

[hemi-hampton]

Is the title of this post talking about blocks only because I thought we were talking about complete motors with there internal parts. LEON.

[Mike DC]

     

Mike where did that info come from about cheaper iron?  Is that part of the high and low nickel thing because I thought that was a myth as well?

Years ago, Ehrenberg (I think) did a little article about this issue.  They took a batch of blocks from various years, sonic-checked the walls, and pressure tested the hardness of the iron.  The results were consistent.   

It also bears out what I've personally noticed when guys are getting blocks sonic-checked.  I have never found the later blocks to have thinner walls in real world experience. 

   

[Ghoste]

I remember the article but I also seem to recall reading somehwere that the bit about high nickel and low nickel blocks was bs too.  Thats why I'm curious about the cheap metal thing.

[TUFCAT]

I remember the article but I also seem to recall reading somehwere that the bit about high nickel and low nickel blocks was bs too.  Thats why I'm curious about the cheap metal thing.

Here's a good read about Chrysler big block casting material, weight, thickness....and sonic checking.  This article actually concluded the last generation 440 (1976-78) blocks used a slightly inferior (softer) metal in the casting.  It was also determined that the later blocks were cast just as thick or thicker, than the earlier ones.

http://arengineering.com/tech/sonic-checking-the-mopar-big-block/

[500Jon]

Recycled iron is another factor I believe!

Mopar and others were encouraged to use 'recycled iron' in their foundries.
This had a marked effect on the quality of bodywork sheet-metal and casting material.(IRON)

When it comes to the 'HP' stamping, this denotes the type of engine build, not its qualities LOL!

On a different note, no two engines are really the same, even HiPo engines were 'THROWN' together with inferior machined parts.
Some of the crank/rod forgings (I have found) have been borderline unusable in a rebuild.
Indifferent balancing and sometimes badly scuffed pistons from over-tight bores from factory!

[Stegs]

Uncle Rico

https://www.youtube.com/watch?v=BxN9Mw6iQUs

[ACUDANUT]

 I should have mentioned this.  I was talking about the steel Crank 440's.  (66-71) or maybe later ?