Interesting head modification

Discussion in ''Da Nailhead' started by wkillgs, Sep 6, 2008.

  1. 1bolt

    1bolt Active Member

    You know looking at those numbers again, I'm gonna guess that the numbers just got input one column off OR maybe the flow bench operator had the dial indicator zeroed on .50 or .100 actual lift... Which means when he opened it to what he thought would be .100 lift he was really at .150 or .200. This is easy to do if you're chatting, or just not paying enough attention..

    So the real flow numbers for Rotten honda's head would more look like this:

    Code:
    Stock---ported---rotten honda heads
    100- 60-  68-N/A
    200-110-127-112
    300-158-187-166
    400-179-214-217
    500-181-219-224
    600-183-222-231
    700-N/A-223-237
    800*N/A-N/A-239 
    
    Now this makes more sense, the sawed off port might have some problems slamming air across the back of the valve, which could account for the poor low lift numbers.

    One overall impression, Buick had some serious "voodoo" going on to make 450 foot lbs of torque out of 400 cubes with that little air.... I have a stock untouched Jeep 4 liter straight six head that out flows all three of those heads.

    [Edit opps I only just stumbled on 56familykar's post suggesting the same thing I am, okay so I'm a little slow]
     
    Last edited: Dec 22, 2008
  2. wkillgs

    wkillgs Gold Level Contributor

    Definitely. But at present there is no intake made for the modified heads.
    How would one even start to design a new intake manifold? Build one out of clay and flow test it?
    I wonder if there are computer programs to model how a port will flow?
     
  3. gsjohnny1

    gsjohnny1 Well-Known Member


    send me a block, the heads and an aluminum intake and i'll see what i can come up with :laugh:
     
  4. 1bolt

    1bolt Active Member

    I don't know if you really intended that how is came across but It only just caught my attention while I was looking back through this thread for those SAE paper references.

    I think it's unfair to characterize there achievements or the nailheads design with 40 years of hindsight as laughable in any context. Let alone from the performance enthusiast/hot rodder single minded perspective.

    A late 80's early 90's modern fuel injected Mustang 302 (rollerized, forged pistons from the factory in some years) makes 270lb foot pounds and 220 hp thats .9 pound feet per cube and .7 hp / cube

    A Jeep 4.0 (241ci) makes 225 lbs and 191hp (incidentally with factory heads that flow significantly more CFM than a Nailhead) that's .9 pound feet per cube
    and .8 hp per cube.

    401 Nailhead at 425 and 325 (factory gross rating) would be 1.05 lbs torque per cube and around .8 hp / cube.

    Even if the factory numbers are puffed up it seems that "reasonable job" is still putting out more torque per cube and similar hp per cube than two modern and highly popular engines with 30 or 40 years of development.
     
  5. doc

    doc Well-Known Member

    I have shown my tail lights to a bunch of those so called more modern, efficent engines and cars, with the old bad breathing nailhead,,,, those that have raced me have learned the hard way.... One nailhead that I had lasted 2 years racing on the street, in Houston tx. before it was beaten the first time... and that was by a car that was several classes above it at the strip...I would pounce on a corvette like a duck on a bug.... and I lost count of how many of the street hemis that it bested....
     
  6. 66gsconv

    66gsconv nailhead apprentice

    HA HA,Doc I hope you might be at Bowling Green this spring. I just got to say high and meet ya..... Well here is to all you nailheaders that like it stock and are trying to make more go.:beers2:
     
  7. 66gsconv

    66gsconv nailhead apprentice

    Oh And since I am here, Thanks to everyone for figureing out the flow # for the rotten heads,,,:TU:
     
  8. wkillgs

    wkillgs Gold Level Contributor

    HaHa!
    Well, there are a few of us that know the real numbers, right Bob?:Brow:

    So if Edelbrock does pursue a new head for the Nailhead, I wonder if they will take this idea into consideration???
     
  9. doc

    doc Well-Known Member

    I plan on being at B/G again this year.... any body know the dates???????
     
  10. D-Con

    D-Con Kills Rats and Mice

    Unless someone knows someone at edelbrock, I doubt it.

    From what I remember, they seemed little interested in working with anyone that does Buick heads, or even getting a fully-ported iron head to base their patterns on. The 455 head is little more than a copy of the factory casting and it really baffles me why people buy those things unless bragging-rights about aluminum are worth that much coin to them. :confused: There is also that chevy rocker thing that baffles me when chevy guys are paying huge dollars to convert to full-shaft rocker systems. again, :confused:
     
  11. wkillgs

    wkillgs Gold Level Contributor

    I see your point. An aluminum clone of the cast iron head would be cheaper for Edelbrock to manufacture. Would they go to the extra effort and R&D $$ to extensively redesign the ports for an extra 25 hp? Unfortunately, that's not likely.
    They would be just as likely to sell x number of alum clones as they would a modified version....that would cost them much more R&D $$ to develop.

    New heads would open their gates to other potential Nailhead products...intakes and valve covers.

    A full rebuild on iron heads can run $900 with all new parts. So a set of Alum heads for $2000-2600 isn't a stretch for fresh engine.

    The bottom line is...if Edelbrock could make a profit on bringing new heads to market, I think they would do it. Plain business.
     
  12. D-Con

    D-Con Kills Rats and Mice

    I read your other post, and think that if someone with connections could convince them to at least copy a Gessler head or those Max B heads you would be onto something spectacular for the nailhead engine. I think Gessler works with E-brock now and may be able to get a word or head into them?

    While I am sure Max was "the guy" at the time, Who knows how his heads would stack-up to even a iron Gessler head today. Knowledge, theory, and results have changed so greatly with time. It would sure be neat to see Max's heads and the flow numbers.

    Just look at the improvements in the standard configuration 23* SB chevy head in the last 8 years! The parallel says there is tons to be had with what has been done with the best nailhead ports you have available today.
     
  13. 1bolt

    1bolt Active Member

    Okay I agree with the sentiments on Edelbrock but...

    They tend to improve the chamber designs... their 409 head has a modern heart shaped "compact wedge" chamber design. The Nail's chamber is shaped by machine work... leaving a less than ideal chamber.

    That said yeah they are shooting for the shade tree guy who's hopping up his street car... Guys who are paying big money for shaft rockers are also buying Brodix and World and CHI... AFR etc. They aren't buying Edelbrock heads unless that's their only choice of course.

    An Edelbrock Aluminum head can be welded.. ported welded ported and so for until you have the head you want... within the confines of the valve train... So if you wanted to trade torque for horsepower you could open up the ports.

    Mostly though it would be nice to see some aftermarket support from a big company... and the intake manifolds that follow the head would be nice... And the dress up stuff too if that's your thing.
     
  14. wkillgs

    wkillgs Gold Level Contributor

    I hope Edelbrock would make some performance improvements! I can only speculate..
    The word is that Russ knows who has the old Max B..(ICan'tSpellIt!)Aluminum heads....are they better than the stockers?...I don't know.

    I would think a machined combustion chamber would be better than a cast one...better control. But I'd bet the 50 year-old design could be improved??

    The 'S' shaped intake port design may have been a compromise to the old shorter-deck 322's, or a cost-cutting machining operation ....I don't know.

    I just hope that if E-Brock does pursue an Alum head, they take the time and $$ to make it worthwhile.

    Do you think a new (milled flange)intake design would be worth the change???...it would add a few hundred to the cost of the head swap, would E-Brock go for the change for a few more HP?
     
  15. D-Con

    D-Con Kills Rats and Mice

    My guess, again based on what they have done with other jobs (AMC, Buick 455) is that they will keep a bolt-on head so people can run the conventional manifolds at both ends. Same for the comb chamber, they aren't going to do anything that costs too much in machine work, or requires different pistons. It alienates too many "easy" sales to people that want to bolt them on their currently running engine that might have an old-school hot rod intake, or factory 2x4.

    I hate to believe it but I think more people buy aluminum heads because they think the aluminum is the difference and not what's in them. The good news I have heard and that Simon also alluded to is that they are known to have lots of meat in the ports for custom work.

    If I were someone really trying to get them to do a real-good stock-type smaller-port head, I would get a group to collectively have one ported and wet-flowed for the best flow quality. Then send it to E-brock with a red bow tied around it. with those little ports, I think you are best to look for optimizing flow-quality as the big numbers are just not going to present themselves. Maybe finding them some better valves to use if you have come up with anything in that arena. I guess my take is that if you do all of their homework for them, they might just turn something in!
     
  16. 87GN@Tahoe

    87GN@Tahoe Well-Known Member

    They will have to make all new patterns for the castings anyway.. it would be silly for them to not take, say, a street-ported (or max ported) head as an example to base their design on... of course, one for max wet-flow performance would be best..I don't know if anyone has done any wet-flow research on the nail'..

    with Tom's and TA's roller rockers.. frankly, going to chevy rollers would turn me off to the edelbrock heads.

    Oh, and BTY... Ford 2.3 litre valves are the EXACT same length as the Nail's, they're 11/32" stems and can be had in performance designs (i.e. undercut, etc.) and materials.. Only issue is valve lock grooves need to be cut higher up on the stem by a competent machinist.

    wes
     
  17. bob k. mando

    bob k. mando Guest

    Even if the factory numbers are puffed up it seems that "reasonablejob" is still putting out more torque per cube and similar hp per cubethan two modern and highly popular engines with 30 or 40 years ofdevelopment.

    problem is, you're comparing Gross ratings to Net ratings. you want to compare apples to apples, you'll need to penalize the Nail ~25%.

    note that i'm not saying that the Nail engineering is bad, especially for the time. but if you're thrashing a lot of people with a 425 you're beating them on cubes and torque, not efficiency.

    how much does an engine typically gain just in EFI?
     
  18. Schurkey

    Schurkey Silver Level contributor

    My apologies for taking so long to respond.

    Granted, hindsight is 20/20, and when I said "laughable" that IS with fifty-five years of hindsight. When introduced, Buick claimed the Nailhead was the "lightest and most compact automobile engine for it's power output now in quantity production in America". And that may be true, but it's still ~180 horsepower/260 ft/lbs out of 322 cubic inches, and with NO MUFFLER and 100 degree air coming down the carb air horn--it would have been even less power "as installed". Yup, looking back on it from the vantage point of the current-production LS-series or modern Hemi--that 180 hp does make me giggle. And even by '66, there were many other engines that exceeded what was then the current-production Nailhead's capabilities; part of the Nailhead's problem was directly related to valve area--in '53, Buick knew that they had to have more exhaust cam lobe than the competition (and as displacement increased the issue got progressively worse.) That was a design choice; and the engine stayed in production long enough for that choice to bite them in the butt. Buick decided it was more effective to discard the Nailhead design and go with an "ordinary" wedge-head engine using significantly larger valves. Again, I have to grant that some of that decision may have been that the Nailhead was at the limit of economical cubic-inch increases; and there's some marketing benefit to having an "all-new" engine even if there ISN'T a problem with the old one. (In other words, bigger is better; newer is better--from an ad-copy point of view.)

    None of this should be taken to mean that the Nailhead wasn't/isn't a viable engine design; or that it can't be improved on using some amount of "modern" techniques which are readily available to a dedicated hobbyist today, but completely unavailable to even the Industrial Giant that GM used to be when the engine was being designed and produced "way back when".

    And how much power is tuned out of more modern engines because the vehicles they came in are forced to meet emissions requirements AND fuel-economy requirements that didn't exist--or were so lenient as to not make a horsepower difference--for the entire production life of the Nailhead design?

    In other words, that Mustang, or that Jeep, may have put down even better numbers if the engineers weren't required to control emissions while also making the thing pass the CAFE standards.
     
  19. D-Con

    D-Con Kills Rats and Mice

    Wes,
    All excellent points. Is there any room left for a larger valve or un-shrouding? Could a spring/retainer package be assembled without the re-grooving? The simpler/cheaper you make it for those guys the more favorable I think they will look at it. If they can do the hardware with common off-the-shelf stuff that is a plus! I am pretty sure because of the unique valve to lifter angle of the nailhead that retro-fitting any other rocker will be a tough job.

    Adam
     
  20. D-Con

    D-Con Kills Rats and Mice

    I would sure like someone to ask Dennis Manner the story on how and when the decision was made to come up with a replacement for the nailhead. I believe he was a jr. engineer during nailhead development and sr engineer with the 400-430 development. This would include why they didn't just upgrade the heads/intake and keep an updated shortblock sort of like Olds did. I will bet there are clear-cut answers for each of those questions.
     

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