Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

402 with a 454 crank

Discussion in 'The Garage' started by shaun, Jun 29, 2004.

  1. shaun

    shaun 1/2 ton status

    Joined:
    Apr 22, 2003
    Posts:
    745
    Likes Received:
    0
    What would a 402 (or 396 bored 30 over) be with a 454 crank. Can you do it? Will it work like a 383 (350 with a 400 crank?) Just curious. Trying to decide the best way to build my 402 for the most torque. Any suggestions (dont say 454 or 500) I am building this motor. What is the best build to get torque
     
  2. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    it would be a 427. It would not be a factory 427, that has the same crank stroke as a 402. They both have a 3.76" stroke, while a 454 has a 4" stroke. Never heard of this and I'm sure the crank journals are different sizes but I bet it can be done.
     
  3. mudjunkie 82

    mudjunkie 82 1 ton status GMOTM Winner

    Joined:
    Dec 27, 2002
    Posts:
    11,449
    Likes Received:
    0
    Location:
    Cleveland Ohio
    Do you have the crankshaft? If so I would buy an aftermarket Crank like an 4340 eagle with internal balance.(Stock 454 is external balance)If you have the oval port heads those would be fine. A nice set of pistons and good cam would give you a nice strong motor..............
     
  4. ben427

    ben427 1/2 ton status

    Joined:
    Mar 10, 2002
    Posts:
    1,123
    Likes Received:
    0
    Location:
    Waverley, Nova Scotia
    [ QUOTE ]
    it would be a 427. It would not be a factory 427, that has the same crank stroke as a 402. They both have a 3.76" stroke, while a 454 has a 4" stroke. Never heard of this and I'm sure the crank journals are different sizes but I bet it can be done.

    [/ QUOTE ]
    Actually with a good balance job, all the 3.76" stroke and 4.00" stroke cranks are interchangeable. I would think it would be a good torquey engine to say the least.
     
  5. shaun

    shaun 1/2 ton status

    Joined:
    Apr 22, 2003
    Posts:
    745
    Likes Received:
    0
    Just what I wanted to hear. Is it neccessary to use a 4340 crank or can I use a standard 454 srank? Will squareport heads work or are they just not as performance oriented? What size cam should I buy? And would this be a destroked 427?
     
  6. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    a destroked 427 would be a 454 block with a 427 crank, and in all reality its just a 427 not even a destroker. What you are talking about would be a stroker motor. A 427 stroker motor. Sounds interesting, if its successful it gives me something to think about since I've found lots of 402s and 396s but 454s are like gold around here.
     
  7. shaun

    shaun 1/2 ton status

    Joined:
    Apr 22, 2003
    Posts:
    745
    Likes Received:
    0
    So what block machining do I need. Will the machine shop no what to do.
     
  8. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    I don't know, the machining I can think of you need is, the crank will likely need to be turned down. I am not certain and can't locate the journal size charts for a BBC. I think the 402 block probably has a smaller journal setup than a 454. Besides that a good performance machine shop would be able to do block clearance work for a stroker. I have never heard of anyone doing this setup before, makes me wonder if there is a reason. I know a small block you can only clearance for the stroker setup so much before you hit water passages.
     
  9. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,548
    Likes Received:
    937
    Location:
    Massachussetts
    I think you have to grind clearance in the block to miss the counterweights when putting a 454 crank in any of the other big blocks.I have the book"How To Hotrod Your Big Block Chevy" out in the shop--it advises against putting the 454 crank in a different block because of the machine work and rebalancing--If you need more details I can look it up for you. /forums/images/graemlins/grin.gif
     
  10. shaun

    shaun 1/2 ton status

    Joined:
    Apr 22, 2003
    Posts:
    745
    Likes Received:
    0
    If you would I would greatly appreciate it. I am being told on another board that I wont be able to find pistons of the right deck heigth. Is this true? Is there something smarter I should do with this engine. Should I just build it stock with an upgraded cam and call it good. What is the difference between oval and square port heads?/?
     
  11. nvrenuf

    nvrenuf NONE shall pass! Premium Member

    Joined:
    Jan 7, 2002
    Posts:
    13,076
    Likes Received:
    246
    Location:
    Mobile, Al.
    Don't use rectangular port heads unless your building something like a high rpm mud bogger. The rect heads don't flow good for our application on the bottom end, find a good set of oval ports (casting #'s 781 and 049 are really good).

    Personally, I'd keep it as a 402. Maybe up the compression slightly (+/- 9.5:1) and find a nice camshaft for it, it will be dependable and make all the power you'll want.
     
  12. XtrmChevy

    XtrmChevy 1/2 ton status

    Joined:
    Jul 14, 2001
    Posts:
    148
    Likes Received:
    0
    Location:
    Finland, Europe
  13. mcinfantry

    mcinfantry 1/2 ton status

    Joined:
    Dec 2, 2003
    Posts:
    308
    Likes Received:
    0
    IDEAL FOR A CORVETTE BUT NOT EVER ON A TRUCK.

    above taken from above site
     
  14. mudjunkie 82

    mudjunkie 82 1 ton status GMOTM Winner

    Joined:
    Dec 27, 2002
    Posts:
    11,449
    Likes Received:
    0
    Location:
    Cleveland Ohio
    [ QUOTE ]
    Just what I wanted to hear. Is it neccessary to use a 4340 crank or can I use a standard 454 srank? Will squareport heads work or are they just not as performance oriented? What size cam should I buy? And would this be a destroked 427?

    [/ QUOTE ]I guess the biggest question is what kind of budget are you working with?
     
  15. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    like said above me, rectangular ports are higher rpm ones. The large oval ports 789 and 049 are idle to upper rpm power, but they cost almost as much as the rectangle port heads (atleast around here rectangles are gold). If you are just doing rockcrawling you could always put a set of peanut port (small ovals) on it but they run out of breath at like 4500. But because of small ports, they have high velocity which makes torque. Thats what my 88 454 had on it, but i switched to 049's it all hit the fan, and i built what i got now hahaha.
     
  16. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,548
    Likes Received:
    937
    Location:
    Massachussetts
    Here's what it says in the book "How to rebuild your big block chevy" on swapping a 454 crank into the other big blocks-"Another consideration is fitting a 454 crank in a 366,396/402,or 427 block--the crank will bolt in,BUT the rods will interfere with the block at the bottom of some cylinders.You'll have to do some checking and grinding to make this combination work.An exception is the late 427 block,this block uses the same casting as early 454's,so there's no clearance problem.If you'd like the 4 inch stroke 454 crank in your block,dont forget to consider the cost of time of grinding clearences.There is also the cost of the crank,damper and flywheel.With theese points in mind,leave a 454 crank in a 454 block."
    "Swapping big block crankshafts is simple.With the exception of the 454,all big block cranks will interchange.For starters,they are all the same diameter journals.Connecting rod journals are 2.200 in.:mains are a hefty 2.7495 in.-except #5 rear journal is slightly smaller at 2.7488 in."
    396/402,427--as similar as they is a difference in counterweighting between 396/402 and 427 crankshafts,the 427 has heavier counterweights than the 396 to compensate for the heavier 427 pistons.You can tell a 396/402 crank from a 427 by the width of the third counterweight.Count from the front of the crank to the third counterweight,the 396 crank is 7/16 wide,the 427 measures 7/8.The two cranks are interchangeable,but you will have to rebalance the enginge."
    There is much more in this book about pistons,heads,ect,its author is Tom Wilson,and its published by HPBooks.
    I also have the "How to Hotrod the Big Block Chevy" companion to this book in the clutter of my room somewhere.Hope that helps you some,I dont want to bore everyone by reprinting the whole book,but if you need any more info,I'll gladly look it up for you. /forums/images/graemlins/grin.gif
     
  17. shaun

    shaun 1/2 ton status

    Joined:
    Apr 22, 2003
    Posts:
    745
    Likes Received:
    0
    Where did you get these books. So I cant take my 402 block have it clearenced for a 454 crank using a stock 454 crank with dampner and flexplate? And If I can will regular 402 pistons not work?
     
  18. 84gmcjimmy

    84gmcjimmy 1 ton status

    Joined:
    Dec 3, 2003
    Posts:
    12,838
    Likes Received:
    0
    Location:
    B.C. CANADA
    You can get the books on amazon.com, or summitracing.com should have 'em /forums/images/graemlins/waytogo.gif Those books are next in line for me. /forums/images/graemlins/woot.gif
     
  19. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,548
    Likes Received:
    937
    Location:
    Massachussetts
    I've had theese books so long I cant remember where I got them--probably at a swap meet--I think I've seen them in the library too.
    The "How To Rebuild Your Big Block Chevy"book deals mostly with stock rebuilds,but there are many tips on what heads are best,what to AVOID doing,like the crank swap we are discussing,it also tells how you can internally balance a 454 with"heavy metal"in the counterweights,but its a costly procedure.There is at least a whole page on pistons,the size differences,pin heights,compression ratio's,forged vs cast--it doesnt say which pistons would work with the 454 crank swap into the 402--just says that it gets very complex as soon as you start talking high performance,meaning you may have to have custom pistons made--very expensive.There may be more on this in the"How To Hotrod The Big Block Chevy"book--I'll have to dig it up later and see. Also theese books are copywritten in 1983,so they only deal with the motors of that vintage and down,they may have more pistons,etc,available now than they had back then. /forums/images/graemlins/crazy.gif
     
  20. ben427

    ben427 1/2 ton status

    Joined:
    Mar 10, 2002
    Posts:
    1,123
    Likes Received:
    0
    Location:
    Waverley, Nova Scotia
    You can put the crank in easily, but you need to find proper pistons, stock 402 pistons dont work. gimme a little bit and ill see if i can find any.
     

Share This Page