Mark IV, Gen V, Gen VI

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OC2Vegas

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« on: February 23, 2011, 10:11:48 AM »
With the different Gens of 454's out there I wanted to see what all of your opinions are on the different blocks. I know some of the difference's on them but  go ahead and list what you know about them, but most of all list what you like and dont like about them.

Lets try not to turn this into a Chevy vs Ford thread...
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« Reply #1 on: February 23, 2011, 10:59:24 AM »
With the different Gens of 454's out there I wanted to see what all of your opinions are on the different blocks. I know some of the difference's on them but  go ahead and list what you know about them, but most of all list what you like and dont like about them.

Lets try not to turn this into a Chevy vs Ford thread...

They all work fine, assuming they are assembled correctly.  Some guys are "afraid" of the newer Gen 5 and 6 blocks, but they actually have improved oiling developed by GM.  The Gen 6 was designed to work better with aftermarket and MK IV cylinder heads.  Gen 5 and Gen 6 blocks both have different style timing covers, but use the same oil pan.   The other thing is most of the Gen 5 and 6 (not all) do not have provision for a mechanical fuel pump.

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« Reply #2 on: February 23, 2011, 09:44:56 PM »
If I was starting from scratch... I would look for a deal on a decent core for either a Mark IV or a Gen 6 because....

The Mark IV because of the huge availability of good used parts and decent pricing on the required new parts

The Gen 6 because of the improved designs and bigger cubic inch cores to start with (8.1L/496ci without an aftermarket stroker crank)

I would stay away from the Gen 5 unless you already have one and don't want to use it as a planter.
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« Reply #3 on: February 23, 2011, 11:27:17 PM »
If I was starting from scratch... I would look for a deal on a decent core for either a Mark IV or a Gen 6 because....

The Mark IV because of the huge availability of good used parts and decent pricing on the required new parts

The Gen 6 because of the improved designs and bigger cubic inch cores to start with (8.1L/496ci without an aftermarket stroker crank)

I would stay away from the Gen 5 unless you already have one and don't want to use it as a planter.

Parts pricing on Gen 5 and 6 stuff is virtually the same as MK IV,,,

As I pointed out,, Gen 5 should probably be limited to GM late model heads, but 088's are ok

How do you build a 496 from a Gen 6 454 block without stroking it?  Are you saying the Gen 6 454 will bore beyond the .060" that GM recommends?

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« Reply #4 on: February 24, 2011, 06:02:56 AM »
How do you build a 496 from a Gen 6 454 block without stroking it?  Are you saying the Gen 6 454 will bore beyond the .060" that GM recommends?

What I meant was that the factory 8.1L Gen 6 is already 496ci without having to use any aftermarket parts.
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« Reply #5 on: February 24, 2011, 08:52:06 AM »
What I meant was that the factory 8.1L Gen 6 is already 496ci without having to use any aftermarket parts.

What years and models did the 8.1L, 496 BBC come in?
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« Reply #6 on: February 24, 2011, 10:45:55 AM »
496's came in 2500-3500 GM trucks 2001-2007, Avalanches (2500) and some vans
496's have a different firing order than old school SBC/BBC's.
Gen V And VI doesn't have a fuel pump boss, Gen V heads don't have an adjustable valve train.Gen V heads may not interchange with MkIV or Gen VI ( .575" lift wont work with these non adj. rockers)
They do have a 1 piece rear main seal and a 1 piece reusable pan gasket. Gen V and VI are roller cam ready. Gen VI Timing chain covers need the crank position sensor (port?) blocked off (non EFI), and needs to be clearanced for a double roller timing chain.
Mk IV or Gen VI is the way to go.
I'm Still trying to find out if a 496 crank will fit in a Gen VI 454 block (clearancing req'd?)
Thats all I got...

Daniel
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« Reply #7 on: February 24, 2011, 10:55:31 AM »
The 8.1 liter 496 was kind of a "bastard" engine,, don't bother looking for one.  They did have a stroked crank, no increased bore to make the cubic inches, and no "regular" Chevy stuff will work with it,, made from about 2001-2009 by what I have seen. 

"Important differences between the Vortec 8100 and older big blocks include a changed firing order (1-8-7-2-6-5-4-3), a new 18-bolt head bolt pattern, different symmetrical intake ports, different oil pan rails and the use of metric threads throughout the engine."

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« Reply #8 on: February 25, 2011, 07:33:43 PM »
Lets try not to turn this into a Chevy vs Ford thread...
Before I go on my BBF campaign....  ;D   ...let me just opoint out that I am ansewring to other posts, so don;t say that I started it!    ;D

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« Reply #9 on: February 25, 2011, 07:36:34 PM »
Some guys are "afraid" of the newer Gen 5 and 6 blocks, but they actually have improved oiling developed by GM
No, General Motors stole that basic oiling system design from Ford, who released it in 1969.  8)

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« Reply #10 on: February 25, 2011, 07:39:45 PM »
a new 18-bolt head bolt pattern,
Again, from Ford.  8)

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« Reply #11 on: February 25, 2011, 07:45:44 PM »
With the different Gens of 454's out there I wanted to see what all of your opinions are on the different blocks. I know some of the difference's on them but  go ahead and list what you know about them....
Ha! You think your confused now, wait till you read my summarization of the mess that Chevfrolet created:

  • The Gen V & VI blocks have the oil passageway alongside the cam and into the lifter valley instead of down the oil pan rail as on the Mark IV.   The oil pans do not interchange between these blocks and in fact, the Gen V & VI use a one piece rear main seal and different oil pan then the Mark IV.
  • Timing covers were changed between all three block configurations.
  • The Gen VI uses a cam thrust plate, not the Mark IV.  But the Gen V and Mark IV also have provisions to use this plate if a Gen VI cam was to be used.
  • The oil filter boss on the Mark IV uses a bolt-in adapter with an oil pressure relief inside, while the Gen V & VI filters mate straight to the block with a screw-in adapter and push-in oil pressure relief valves into the block itself.
  • Both Gen V & VI do not have a fuel pump boss, while the Mark IV does.
  • The Gen VI lifter bores are longer/higher with a machined flat surface to accept the roller lifters and their retianers; Gen V and Mark IV blocks cannot use the Gen 6 roller lifter and would need aftermarket.
  • Coolant flow on both the Gen V and VI were redesigned to increase flow...coolant passages were also made larger on the Gen V and Gen VI, therefore making it more difficult to use Mark IV heads on these newer blocks (though people have done it with some success).
  • The 10.200 "Tall Decks" are a different animal altogether.
  • Etcetera

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« Reply #12 on: February 25, 2011, 09:27:13 PM »
Ha! You think your confused now, wait till you read my summarization of the mess that Chevfrolet created:

  • The Gen V & VI blocks have the oil passageway alongside the cam and into the lifter valley instead of down the oil pan rail as on the Mark IV.   The oil pans do not interchange between these blocks and in fact, the Gen V & VI use a one piece rear main seal and different oil pan then the Mark IV.
  • Timing covers were changed between all three block configurations.
  • The Gen VI uses a cam thrust plate, not the Mark IV.  But the Gen V and Mark IV also have provisions to use this plate if a Gen VI cam was to be used.
  • The oil filter boss on the Mark IV uses a bolt-in adapter with an oil pressure relief inside, while the Gen V & VI filters mate straight to the block with a screw-in adapter and push-in oil pressure relief valves into the block itself.
  • Both Gen V & VI do not have a fuel pump boss, while the Mark IV does.
  • The Gen VI lifter bores are longer/higher with a machined flat surface to accept the roller lifters and their retianers; Gen V and Mark IV blocks cannot use the Gen 6 roller lifter and would need aftermarket.
  • Coolant flow on both the Gen V and VI were redesigned to increase flow...coolant passages were also made larger on the Gen V and Gen VI, therefore making it more difficult to use Mark IV heads on these newer blocks (though people have done it with some success).
  • The 10.200 "Tall Decks" are a different animal altogether.
  • Etcetera

LO

LO

I have a great deal of respect for your knowledge, but part of the reason for changes between Gen 5 and Gen 6 was so that the Gen 6 block is able to run MK IV style heads.

Also, at least some of the Gen 5 and/or 6 blocks do have fuel pump bosses(although most do not),, can't tell you which, maybe just tall deck truck blocks, would need to look and see what I currently have here.  Along that same subject, some Gen 5/6 cams have fuel pump lobes on them, some do not.

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« Reply #13 on: February 25, 2011, 10:45:14 PM »
No, General Motors stole that basic oiling system design from Ford, who released it in 1969.  8)

LO

Its too bad that ford oil pumps like to shear off and ruin a good weekend...gm might of borrowed the idea, but also fixed...i mean really who wants a front sump oil system anyway? Besides when is the last time you built a performance motor without advising a rear sump deal?


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« Reply #14 on: February 26, 2011, 12:11:26 AM »
what do you guys think of  a complete GEN 5 454 HO minus the mani with about 15k miles for 800 bones?
have a family member lookin for quick cash due to a divorce  :banghead: and wanting to get rid of his BBC...GOOD DEAL???

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« Reply #15 on: February 26, 2011, 02:56:15 AM »
what do you guys think of  a complete GEN 5 454 HO minus the mani with about 15k miles for 800 bones?
have a family member lookin for quick cash due to a divorce  :banghead: and wanting to get rid of his BBC...GOOD DEAL???

This was a new crate engine, or someone rebuilt it?  Which heads are on it?  As previously mentioned, the Gen 5 block limits which cylinder heads will work without water leaks, and you probably have to run an electric fuel pump.  If it has tiny peanut port heads, and cast pistons, don't know that it's worth very much as a marine engine, or rebuildable core. 


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« Reply #16 on: February 26, 2011, 07:18:56 AM »
Also, at least some of the Gen 5 and/or 6 blocks do have fuel pump bosses(although most do not),, can't tell you which, maybe just tall deck truck blocks, would need to look and see what I currently have here.  Along that same subject, some Gen 5/6 cams have fuel pump lobes on them, some do not.
Yes, I mentioned that the Tall Deck blocks are a different animal. In regards to some Gen V & VI cams having fuel pump lobes and some not having them, that's simply a matter of the factory using whichever cam cores they have available at the time of manufacture.

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« Reply #17 on: February 26, 2011, 07:40:07 AM »
Its too bad that ford oil pumps like to shear off and ruin a good weekend...gm might of borrowed the idea, but also fixed...i mean really who wants a front sump oil system anyway? Besides when is the last time you built a performance motor without advising a rear sump deal?
Nordie,

1) Any engine on the planet may be set up as either front sump or rear sump, regardles of manufacturer. No-one should have to spell that out for you. (But as far as your pointless issue goes: what if the engine is flipped around as in a v-drive???)

2) Ford oil pumps do not "shear off" by design. A few (perhaps 15 out of 3 million M84 pumps) failed as a result of the hot rod artist's ignorance to proper setup and installation (as Ford recommends but many dismiss). And that is the fault of the hot rod artist, not the engineering design. A good BBC analogy might be some ignoramous complaining about losing camshafts and lifters because he didn't understand the cam button dealio in his particular BBC engine combination.

3) The Ford oil pump and distributor drive are in the front of the engine because that's were the timing chain is tugging on the camshaft. Putting those components at the rear of the engine (as in a BBC) is cause for increased torsional loads (read: twisting) of the camshaft as an engine's performance level (stiffer valve springs, etc) is increased.

4) The BBC is notorious for having the lousy spur gear oil pump, not the Ford. Fords have the superior gerotor mechanism, which allows the oil to be bypassed back to the inlet side of the oil pump which--in effect--"supercharges" the pump (figuratively speaking) and thereby minimizes the pump loading caused by 100% of the oil always being drawn from the sump.  The BBC's lousy spur gear oil pump beats up the oil so badly that chevy is FORCED to bypass it back to the pan and allow the air bubbles to rise to the top of the sump before the oil is routed back to the oil pump. If chevy did not do this, your BBC would last about 5 minutes in your jet boat before chewing up every last bearing in the engine.  And so Titan comes out with an aftermarket BBC oil pump to address this issue and all the BBC hot rod artists hail it...but guess what? It has a Ford gerotor mechanism. Once again, Ford parts in a chevy.  ::)

Know what you're talking about before shooting your mouth off.    ;D

LO
« Last Edit: February 26, 2011, 07:52:14 AM by LakesOnly »

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« Reply #18 on: February 26, 2011, 12:24:53 PM »
Maybe I am wrong, I am pretty sure I have a standard deck Gen 6 with fuel pump boss stashed in my garage, but the description of the GM Gen 6 454 HO crate engine seems to confirm what I was saying: http://sdparts.com/details/gm-performance-parts/12568774

« Last Edit: February 26, 2011, 01:39:50 PM by obnoxious001 »

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« Reply #19 on: February 26, 2011, 12:46:56 PM »
It's days like this that make me wonder why people spend time fighting over who is second best.  Why don't you all just run Mopars?   Put a factory 440 crank in a bored 383 block, bolt on the small valve heads, add a nasty mechanical cam, and you get 550 hp 550 ft. lbs. of torque from 3700 to over 5K rpms.   Oh yeah cuz nobody can find logs for one.   :banghead:
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« Reply #20 on: February 26, 2011, 09:17:08 PM »
Why on Earth  :mad:
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« Reply #21 on: February 26, 2011, 09:29:57 PM »
Ya know...I dont know how many times I had to read this to figure out wtf is goin on!

Pretty sure I got it....Jus  putt'n in my 1 cnt.!.... In my opinion & humble at that, I found this to be one of the most disturbing , misguiding, and most of all  detouring threads  to earn a customer's faith.
I can't add more at this time....except for very user unfriendly.

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« Reply #22 on: February 27, 2011, 08:37:11 AM »
It's winter and all us boat bitches tend to get a bit strange.  Plus everyone's opinion seems to be a bit more strongly held when it comes over the internet.  I don't really think anybody has really gotten their feelings hurt.  Although I admit the answers have probably gotten a bit confusing for the OP.   I'm going dirtbiking with the grommets to dispel the cabin fever.  The dirt should be EPIC!  :thumbup:
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« Reply #23 on: February 27, 2011, 07:09:18 PM »
With the different Gens of 454's out there I wanted to see what all of your opinions are on the different blocks. I know some of the difference's on them but  go ahead and list what you know about them, but most of all list what you like and dont like about them.

Lets try not to turn this into a Chevy vs Ford thread...

And everyone thinks the Ferds are complicated............................ :screwy:

Ray
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« Reply #24 on: February 27, 2011, 09:32:41 PM »
Glasscutter, have fun...Ray you too...see you all at Puddingstone ;D!
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