401 rebuild

Discussion in ''Da Nailhead' started by woodchuck2, Nov 23, 2018.

  1. John Codman

    John Codman Platinum Level Contributor

    Tom did my 425. His pistons are great. When he was done, the engine actually had the 10.25:1 compression that was factory advertised. I also agree that you are not going to do a quality rebuild on a Nailhead for $3K.
  2. woodchuck2

    woodchuck2 Well-Known Member

    $10k for a rebuild that will probly only make 400hp???? I know im not good with math and all but damn, its a no wonder folks throw these things away for a small block chevy. $10k can get me a small block over 500hp, a rebuilt Th400 and a gear vendors overdrive unit. These Buicks are a waste of money i see. I restored mine and couldnt sell it for $6k, traded it off and bought it back for $5k with upgrades. $10k into and engine for a car worth $5k doesnt make sense to me.
  3. Bigpig455

    Bigpig455 Fastest of the slow....

    If it's all about the math, go buy a used Mustang.
  4. TrunkMonkey

    TrunkMonkey Well-Known Member

    You don't build a nailhead car for its unlimited power. You build it for the experiance.

    The nailhead is like an old school Harley. Love it or hate it.

    It's hard to explain, but it is different.

    I love my nailhead.

    And I realize I could have had a crazy strong engine for less. But you can't wipe the smile off my face with a 20 grit grinder.
  5. gs66

    gs66 Well-Known Member

    Yeah, I’ve had nailheads rebuilt too and knew in advance I would have much more power rebuilding a 455 for less money. Still, I like them.
    riv1964 likes this.
  6. woodchuck2

    woodchuck2 Well-Known Member

    I am yet to see where all this money is going i guess is the issue. OK, pistons will be a $1k, machining the block/crank shouldnt be more than $1k, cam/timing chain/gaskets around $500. Figure new rings, cam/crank bearings, oil pump at $500 so there is $3k Where is the other $7k? I dont see the point in line boring, a new crank and or rods. Decking the heads doesnt cost much. Now machining the heads and testing them yeah, but no way would i pay more then a couple grand. then if i go with roller rockers another $1300. Thats still just over $6k. Are you guys paying someone $3-$4 thousand dollars to build your engine or you doing it yourself? I plan to do it myself. I am not a pro at it but i see no reason why i cant build the engine myself. The only thing i havent done to this car myself was rebuild the tranny, but for $650 why would i take the time? I have done some reading and found cam bearings need to be matched to the cam, only use steel head gaskets and keep track of all bolt locations per size as they tend to differ with this engine.
  7. gs66

    gs66 Well-Known Member

    To clarify I have never had to spend $10k on one more like your numbers. I was just saying my return on HP/$ is less than I would have gotten with a 455. If money was the only factor considered and nothing else a crate motor or other modern motor would be the way to go.
  8. telriv

    telriv Well-Known Member

    My forged pistons include pins, pin fitting & RINGS. Moly top, cast second, quality standard tension oil ring. Depending on bore size could be Hastings, Perfect Circle, Total Seal, & other top QUALITY rings. AND, you aren't gonna get GOOD rings going with a STANDARD overbore. You need to think out of the box on this for GOOD rings via the bore size. So what I'm sayin' is your not looking at a standard overbore of lets say .030".
    Next. Most everyone at this moment in time have NO cam bearings other than those that have them in stock. I have two sets left. Next is mains. Other than standard you could spend $400.00 or more. Rod bearings in comparison are cheap. Average oil pump cost, blueprinted can be $200.00. I have standard mains & rods in stock along with new oil pumps. So right there you've got close to $800.00+.
    Machine work, depending on how deep you go, squaring block, boring, NO ALIGN BORING OR HONING, but you should use ARP rod bolts which then necessitates reconditioning rods. YOU MUST CHECK THE MAIN SADDLES FOR TRUENESS. It takes more time to set this all up & take the nec. measurements than it costs to align bore the block WHICH YOU NEVER WANT TO DO, because then you will have a forever loose timing chain. WE don't have a choice of a smaller timing chain or larger cam/crank gears. IF it needs align boring it should ONLY be done by am extremely talented machinist or else things could end up worse than you started WITH NO WAY TO CORRECT THE MISTAKES. The crank will at least need to be polished if not need to be cut undersize. . Then add in the balancing of the assembly, now you up to 2K+.
    Don't forget about the harmonic balancer. Don't forget it's over 50 yrs. old. IF it goes bad, which in most instances will, you don't just throw another balancer on it. IT NEEDS TO BE BALANCED WITH THE ASSEMBLY. Send it out to get it rebuilt & because of ALOT of reasons it only seems to last 3-6yrs. A balancer can be as little as $369.00 up to $600.00 for an SFI approved balancer. Which I also have.
    You talked about a roller cam in the beginning which will end up, after all the add-ons approx. 1.2K+.
    Right there your talking about 6.2K+.
    Maybe you should do like EVERYONE else & build an LS something or other for less $$$$ & end up with more POWER!!!!
    There's MANY other incidentals not mentioned.
    I think most will agree.

    Tom T.
  9. wkillgs

    wkillgs Gold Level Contributor

    Machine shop rates vary widely depending on your location, as does labor to assemble. I'll bet most guys posting here didn't do their own prep and assembly.

    My last build in 2008 was a full rebuild, a bit over stock. I did the assembly and prep such as deburring and even mild head porting.
    Labor was about $1500... bore 0.020" over ($225), recondition rods ($190), balance ($260), plus the misc stuff they did like install cam bearings, freeze plugs, oil galley plugs (tapped). Heads cost more than expected. They were resurfaced ($110), valve guides replaced & machined for seals ($200), and 3 angle valve job ($225). Crank was fine.
    Parts I shopped around for, collected a bunch of stuff over a couple of years so I often found parts for very good prices, like the Zollner pistons for $200.
    I probably have less than $3500 in it total.... and lots and lots of my own time.
    For comparison, I rebuilt the 4.0 six in my Jeep with a stroker crank and forged pistons and total was also around $3500. Other guys doing similar builds have done it for $500 less because the shop rates in their area were much lower.
    Machining costs will be the same whether its a nh or a sbc. Parts are going to cost a lot more, especially the specialty stuff.
  10. wkillgs

    wkillgs Gold Level Contributor

    I looked up some prices....Dura Bond cam bearings are $35, avail on eBay. Rod bearings and rod bolts are same as 455. Melling oil pumps, $134. Summit carries a bunch of stuff, and Falcon on eBay is another I bought a bunch from.
    Like Tom said, the specialty stuff is going to get expensive if you want to go that route.

    Nailheads make great power, but they peak early, 4500-5000 rpm, so they don't give the big hp numbers like an engine that'll wind up to 6500.
  11. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    WOW! Sounds like grinding down the mains on a 455 crank to 2.750" and line boring the NH block for the 2.750" International main bearings would probably be the way to go if just main bearings are that much!(and if someone wanted more cubes?) Would just have to narrow the NH rods just a tad to fit the 455 crank and order pistons for the longer stroke. Could even get the 455 Molnar rods or even use factory 455 rods.

    Grind 455 crank mains down, around $200, line bore block around $175, depending on what your local machine shop charges. Not sure what the International bearings are going for these days, and plus there would be the core charge for the 455 crank, but a 401 would make 430 or more cubes and a 425 would make a 455 or more depending on over bore!;)

    As for the cam bearings, IIRC they are the same as the 215/300/340 cam bearings so they should be readily available.
  12. gsgtx

    gsgtx Silver Level contributor

    yes 400 HP but 500 TQ both coming in at a low rpm. you can use a smaller cam, less gears and keep revs below 5500 so the engine will last forever and be more street able. you will be able to smoke the tires with 3.23 gears, so you could save money not putting in a overdrive unit and 410 gears. and when you open the hood you won't have a cookie cutter chevy engine in it.
    gs66, PGSS, 322bnh and 1 other person like this.
  13. woodchuck2

    woodchuck2 Well-Known Member

    Not sure now where i am going with this. I am thinking for the engine in the car i will do the intake mod, stuff a larger carb on it and see what happens. If im not happy maybe laughing gas will be the cheap alternative to power for now. I have a couple spare engines so whats the harm in blowing one up. If i am going to spend big money maybe a 455 will be in order. Wait and see i guess, for now i am negotiating on some real estate so that is priority now. If i choose this route i will be speaking with Tom T for his advice, parts and skills. Thanks for all the advice, time to ponder.
  14. John Codman

    John Codman Platinum Level Contributor

    The only reason to overhaul a Nailhead (or almost any 50 year-old plus automobile engine) with the possible exception of an SBC or a small-block Ford, is because you want to have that particular engine . My 'Nail had been screwed up by a shop that didn't know what they were doing. Tom Telesco had to replace just about everything that moved inside the engine. The bill (which I thought was fair) was a lot closer to $10 grand then to $3 thousand. The engine turned out great and now makes the power that it should have after the first rebuild (which was about $3 grand). You get what you pay for. If what you are really interested in is maximum power, buy a high-performance crate motor and be done with it.
  15. Aussie V8

    Aussie V8 Well-Known Member

    Just for interest sake ---- my bill for hot tank, sonic test, machining and balancing was over $3000 Aussie dollars. Close to US$4000
    That doesn't include any tear down labour costs or parts.
    Woops , I got the maths wrong. :confused: That should be US$2500
    Last edited: Jan 9, 2019

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