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Reverse flow blown nailheads?

Discussion in 'The Hokey Ass Message Board' started by Traditions Racing, Aug 26, 2011.

  1. I'm reading through Wikipedia for some very general info on the Nailhead, dates of manufacture stuff like that. When I got to the sectionon of the 401 nailer I read this paragraph. " In an effort to overcome the " restrictive " exhaust port design, Buick drag racers in the 60's adapted superchargers with custom camshafts to feed in through the exhaust ports and used the larger intake ports for exhaust outlets ". Well nothing here lately has raised my eyebrows as much as this statement has. Who has some pictures and honest difinitive info on this. Dig deep guy's this is important. Thank you in advance. TR
  2. LeadSledMerc
    Joined: Nov 29, 2003
    Posts: 4,106


  3. burnin53
    Joined: Mar 22, 2009
    Posts: 596

    from cuba,n.y.

    How do you know he didn't do a search? I just did a search with his key words also.
    Got three threads and only one about reverse flow blown nailheads,which contained very little info.
    Maybe that's why he started a new thread?
    Last edited: Aug 26, 2011
  4. Thank you !!! :D

  5. I think it depends on the search key words. For me it is always a crap shoot sometimes I find what I want and others I don't.

    Anyway I don't have any first hand knowlege of blown reverse flow nailheads. But the concept is good. This is from my experience for what it is worth. Most of the engines that I have fooled with over the years the battle isn't necessarily getting mix into the cylinders it is getting spent gasses out.

    Taking that thought with the Nail having small restrictive exhaust port it makes sense to take advantage of the bigger intake ports for exhaust duty. You then can overcome the now smaller intake ports by forcing fuel through them.

    You could keep it real clean by using a potvin style setup or even twin turbos set up to draw though. In a drag vehicle you overcome the turbo lag from being a draw through by launching at a higher rpm when your turbos are already starting to spool up.

    Just conjecture here.

    OK just checked out the other thread and shazaam there is a potvin setup, that was just a guess on my part fellas.
  6. flyin-t
    Joined: Dec 29, 2004
    Posts: 1,361


    I use to work with the guy that built this reverse flow nailhead for his 1963 Stevens. I don't see him any longer but he hangs out on a few boat forums that I know of. If you want i can track him down and put you in touch with him. He's here in so cal.

  7. Thanks Benno, I'm leaning toward the possibility's of a centrifugal supercharger used for the reverse flow set up. I have some ideas for the cylinder head also. I was once told by a Engineer from GMPP, that you couldn't do such an such a modificationto the Pontiac Big Chief head for the BBC. 2 weeks later, the first set of heads were on the dyno. :D
  8. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,070


    Interesting........Just wondering if the reversal affects the combustion chamber flame travel? As in the spark plug and chamber shape might be positioned wrong for reversed flow. So you might get a bit better flow for more risk of detonation........
  9. Thanks flyin-T, I appreciate that offer, and actually might know some of the same guy's from the boat forums :D. If you happen to speak with him, please just ask if that has been dynoed and what kind of numbers did he get. Torque and H.P. and at thier respective RPM's. What fuel was used for testing, if he wants to divulge that info. I'm really trying to gather some information for comparison data right now, thank you, great picture by the way! TR
  10. Stevie Nash
    Joined: Oct 24, 2007
    Posts: 2,999

    Stevie Nash

    Hey, this has turned into another search thread!!! I can't wait to hear more...
  11. snaptwo
    Joined: Apr 25, 2011
    Posts: 696


    I seem to recall Bruce Crower messin' with a deal like that for a stock block indy project. Sounds good at first but what about valve sizes ?
  12. Thank you snaptwo for the reminder, and yes I have considered the valve size differences and are well into procurring a couple of "shop" heads to begin preliminary design work and testing. TR
  13. Benno, after seeing the cut through of this head design, there is no doubt this is for me. Sorry, I know you wanted to get onto that smokin Olds you have waiting in the wings, but these Buicks are calling me. I love a challenge and this is it, :D TR
  14. TomWar
    Joined: Jun 11, 2006
    Posts: 727


    This all sounds very interesting to me.
  15. Thanks Tom I feel like a kid again. I remember my first reverse cooling, and my first reverse oil flow, but this will take some real engineering to be a success. It might take a few years but I'm stoked. No I just need someone to tell the wife, sorry babe, but I'll be in the shop a few years :eek:
  16. I am looking for at least {2} 401 or 425 Nailheads, just the cylinder heads, that are well junk, and within driving distance in South East Florida. Yes for free, I'm just slicing them into pieces and do NOT want to use a good set of heads for this purpose, thank you very much anyone who can help, TR
  17. TomWar
    Joined: Jun 11, 2006
    Posts: 727


    You Keep saying that you are going to show up at our Breakfast, But now you make me want to see your shop!
  18. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,906

    need louvers ?

    This is a bit of a reach, but I was reading an old Hot Rod, Car Craft, or Popular Hot Rodding from the '62 or '63 era the other day on who's building what for Indy that year. The one that stands out was Mickey Thompson who was working on a couple of mid engined cars with 215 aluminum Buicks. This was when mid engined cars were brand new, but what made me think was they mentioned something about one of the cars being supercharged and reverse flow. Might be something to search from if nothing else. If things let up around here over the weekend, I'll try to dig it up.
  19. cavemag
    Joined: Jan 8, 2011
    Posts: 210


  20. Candy-Man
    Joined: Mar 21, 2006
    Posts: 1,713


    Great thread, thanks for starting another thread.....

    PM me if you wish, as a good friend of mine has the worlds fastest nailhead in a roadster which he runs at Bonneville. I can give you his phone number, as he may or may not have some good info...
  21. drag_punk
    Joined: Mar 6, 2001
    Posts: 99


    I too saw a picture of Crower's reverse flow small block chevy but I've got no further info.
  22. slickhale
    Joined: Dec 19, 2010
    Posts: 770

    from Phoenix

    there is nothing cooler than zoomies where the intake should be. Traditions Racing keep us posted on the progress, i'm interested to see what kind of improvement it actually makes...and it looks so damn cool.

    too bad you had to start yet another reverse blown nailhead thread tho, these things are really clogging up the board:rolleyes:
  23. Thanks slickhale, Ryan has made me turn in my copy of American Graffiti until I uh " stop clogging up the board " :eek::rolleyes::D
  24. Thanks Chip and Candy-Man, I very much appreciate the help and information and the offer, you guys are awesome! :DTR
  25. Thanks to everyone who has contributed to the thread!!
  26. Dale Fairfax
    Joined: Jan 10, 2006
    Posts: 2,585

    Dale Fairfax
    Member Emeritus

    Several years back a guy named Merle Bryan in Flint, MI ran a nailhead powered digger. Merle was a general foreman (maintenance?) in the Buick foundry and had some heads cast with either modified or no cores around the exhaust ports-meaning no water jackets. He then machined the heads to create extra exhaust ports above the originals. Result was 8 ports and 8 header branches. Maybe there's an oldtimer from up there that was closer to the racing scene( than I was) who will remember how well it worked.

  27. Thats a great story Dale, Ive seen the cut away pictures, and yes that exhaust port has to curve up and then around the water jacket on the exhaust side. No water on the hot side could spell disaster though on anything less than a drag race engine. I have a few other ideas brewing, and need to open a few heads to clarify what can and cannot be done here. The intake port has a great straight shot into the chamber, but the exhaust is a nightmare, like Dead Mans Curve I'm beggining to call it. Yes HAMBers, I have officially named the exhaust port on the Nailhead- Dead Mans Curve!! TR
  28. Here are some head casting numbers that I am looking for. 1172889, 1185485, 1190415, 1196914, 1374603, 1376912, these are the number of 364/401/425 Nailers from 59-66. I can extent my travel from Daytona to West Palm. Junk heads only please, for free, thank you :D TR
  29. BTTT, anyone with some junk heads? Thank you, TR
  30. TomWar
    Joined: Jun 11, 2006
    Posts: 727


    You're probably about 25 years late on that request!

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