Bbc cn block

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by Relentless, Jun 16, 2011.

  1. Relentless

    Relentless www.bretitanium.com

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    Alright all,

    After some advice/opinions please -

    CN blocks sell a very nice splay block (standard deck) and also a cross bolt version.

    My question, any experience with either ? Were looking to go faster and want a stronger block.

    And before anyone says it - we WILL be going hemi but not yet. We want to run a faster ET with our Chevy first.

    Brief combo - 511 bbc, morgan billet heads, 14-71 kobelco with DMPE mods, byrant crank, CP pistons,

    thanks
     
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  2. NITROBANDIT1

    NITROBANDIT1 LOST IN SPACE

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    metal in the pan

    well, i am not a pro at this, but i have a cn block that broke a crank in 14 pieces. it broke every single arp bolt (27) out of the block. main, oil pan, etc. broke off the main caps and sent the crank into the pan. it broke every bolt off and didnt pull 1 stud out of the block! if that isnt a strong block, i dont know what is. just shows that the threads alone are stronger than the studs that go into them. this is a fontana style block, made by cn, but is similar to bbc made by them.
     
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  3. badbird

    badbird New Member

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    there is no doubt about the strength and quality of a CN block they are very expensive
    if you want to stay with a chevy youd be better off selling what you have and use the money you would have spent on a CN block to upgrade to a 481X, then the need to change to a hemi gets a lot further away,
     
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  4. jay70cuda

    jay70cuda Member

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    We have a billet cn block and kicked the rods out if it. Had to repair 4 windows , machinist said easiest block he's ever had to fix. Do Yourself a favor and have the lifter bores moved so you can run zero offset lifters. That will make it extremely reliable in the valve train. We had jesel .937 ran em for about 5 years before ever seen problem. Today I'd prob run 1.062. Either way you won't be sorry
     
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  5. GTPerf

    GTPerf Member

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    to answer you rquestion cross bolt version is the best. I would be looking for a KB olds block you should be able to find one less expensive then the CN and still get to race next year, CN may be the best but usually very long time to get one, what DH you need? 10.2 ???
     
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  6. Relentless

    Relentless www.bretitanium.com

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    That is definitely strong!
     
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  7. Relentless

    Relentless www.bretitanium.com

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    Splay cap is $8250
    Cross Bolt is $9000

    Cross bolt would need new pan and front cover/gears as raised cam by .250"

    Trouble is were standard deck height. This is sold as 10.4"
     
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  8. Relentless

    Relentless www.bretitanium.com

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    Thanks for advise and we did think about lifter bore move and possibly going to 1.062 (but thats only with the cross bolt version) splay cap is .904 which we run now.
     
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  9. Relentless

    Relentless www.bretitanium.com

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    We currently use a Donovan solid block, superb block we just dont want to kill it.

    Billet is stronger as we all know and easier to fix if it does pop.

    Were standard DH.
     
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  10. badbird

    badbird New Member

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    s the CN block is $9000
    iv seen 481x for sale with an M5, fuel system hat ect that run 6.0 in a pro mod for $35000
    a long block goes for around 25/28k

    that makes you about 16/18k short £10/12k english if you take off the money you diddnt spend on a block,

    the 481x is the closest chevy you will ever get to a hemi performance, it could save you an expensive change in the future and you should be able to get the ballance by selling what you have without over pricing,

    its up to you what you do but the 481x is a viable tmfc engine and are proven,
    its worth concidering befour you jump
     
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  11. jay70cuda

    jay70cuda Member

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    We have a cn legal pm motor at 2780. Went 6.0s and teens like a bracket car. I had way better luck than a 481x motor. All this was with a m4 at 20 od. Not tooo shabby for chevy guy. Oh and the heads weren't the best port job. Chevys are ultra reliable one you figure out the valve train. Our motor seen 9700 rpm all the time 30 -35 runs on rods versus 20 in hemi. Springs would past bout same versus 10 on hemi before they fell off. Dunno for easy fast power chevy seems to be better but if your trying to rotate the earth , yes hemi will be better but takes way more coin to have same amount of fun. Good luck. Rcd makes the correct gear cover for the cross caps. Make your own oil pan , you'll be much happier. Had Olson one. Not too happy with it
     
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  12. MKR-588

    MKR-588 Member

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    Just curious but can someone tell me who makes the billet morgan head ? Is it based on BBC ? How good are they & what do they cost? Who else makes a good solid BBC based head? Sonnys list a 14.5° pontiac solid head with standard bore spaceing but when I rang they said it won't be ready for another 6 months, How handy is that!! We too are looking at the cn X bolted block. Any advice will be much appreciated.
     
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  13. badbird

    badbird New Member

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    are they heads from Darin Morgan?

    i thought profiler makes a decent solid chevy head, id start looking there,

    6.0s with a cn block sure but im sure guys have run 6.0s with the kb block too
    heads compresion ratio blower and fuel system make the power not what block you have, sure when your pushing hard the more stable the block the more reliable it is,
    you dont say what the deal with the 481x was just you had more luckwith the chevy
    i dont think theres a head out there that compares with the AJ (chevy) the valve gear is bulletproof and its designed to be taken apart so you can remove 1 head without touching the blower/intake manifold, and they held the record for a few years in IHRA (roots blown)tmfc the valve gear all comes off together and can be put on without re lashing the whole lot,Its just the 9000 bucks for a block plus freight tax and vat is prety heavy Danny bellio has a complete hemi for about 15k,
    The CN block is first class no disputing that... whats its resale value? and more importantly will it sell in europe that would be my main concern........the choice is yours...:confused:
     
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    Last edited: Jun 17, 2011
  14. overkill69

    overkill69 Member

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    block

    A cast KB olds or new century with cross bolts is the way to go. You can get a used longblock for what the CN costs bare. You've got billet heads and I think the geometry is pretty good on the Morgans. With the crossbolt block and a chrysler rod journal on the crank you are about as strong as a hemi on the bottom with a better thrust bearing. It won't run like a hemi upstairs but it will haul a$$ to 8500rpm.
    The 481X doesn't pickup big power over a chevy just more durable and servicable. They are becoming just as obsolete and use hemi accessories so at that point i'd buy the real thing unless you could steal one.
    If your heads are nice and you have a good combination that works it might be worth the hassle of the billet block but since you are already talking hemi I assume it's not fast enough.
     
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  15. badbird

    badbird New Member

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    key word ...Durable.... and while it may not be a s fasionable as it once was, what motor is in the world record holder in pro mod and roger burgess's newest pro mod, thats right a 481x

    but your right putting a CN block under the existing set up is an expensive way to go for little gain if any power wise, the money could be better spent in a few different ways
     
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  16. Relentless

    Relentless www.bretitanium.com

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    New Century x bolt is the other option and at the moment looks a very nice piece too.

    We do need to think about it before we buy anything,

    but in all honesty we want the Euro record for alky altered with a chevy,

    then we will go hemi

    Will Hanna has short and long blocks for sale on eurodragster
     
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  17. Relentless

    Relentless www.bretitanium.com

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    That is about where we'd like to be, we have so far only gone 6.42 at 1000foot lift,

    valve train is our killer,

    on one of our other cars we have the T&D rockers and shafts and cant wait to use them as they look sooo much stronger/reliable,
     
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  18. Relentless

    Relentless www.bretitanium.com

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    Bob Morgan, yeah based on BBC, great head. BUT these heads I believe were out in the mid 80's so while there great and we have gone fast pretty easy so far, we have been looking at other head options or of course hemi.

    But we like Chevy's, we like beating the hemi guys with it,
     
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  19. Relentless

    Relentless www.bretitanium.com

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    Agreed, these are the head we'd buy if we stay with chevy long term, but again there are hemi's for sale at simular costs,
     
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  20. Relentless

    Relentless www.bretitanium.com

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    New Century is another option, they look a nice block.

    Thinking time!
     
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