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Technical 392 build ideas for 600HP for mild drag racing FED 8.60ET

Discussion in 'The Hokey Ass Message Board' started by ChevJerico, Feb 11, 2019.

  1. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    Hey guys new member. Always loved Hemi's and Nostalgia drag racing, but never thought about racing one. Always been a Chevy door car guy. Just trying to get a handle and learn my Hemi's. Wanting something vintage looking. Maybe blown with Hilborn four port mechanical injection, or just injected. Thinking solid cam flat tappet.

    I guess my first question is. Will I need to go over .5" lift, and purchase taller rocker stands? Kind of wondering what cams you guys are running for performance applications?
     
    chryslerfan55 likes this.
  2. BadgeZ28
    Joined: Oct 28, 2009
    Posts: 1,165

    BadgeZ28
    Member
    from Oregon

    600 hp? I hope you have deep pockets?
     
    RDR and XXL__ like this.
  3. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    Not something one builds if they are on a budget
     
    loudbang likes this.
  4. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    Can't be that hard! I'm sure someone on the board knows.
     

  5. The build would start with hot heads cylinder heads. Check out their web site.
     
    Bandit Billy likes this.
  6. And that most important tool.....Your checkbook!
     
  7. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    I think it can be done with factory iron. Especially with a 6-71 if I go that route.
     
  8. buffaloracer
    Joined: Aug 22, 2004
    Posts: 816

    buffaloracer
    Member
    from kansas

    Looked for your introduction and couldn't find it. Sure it can be done with mostly factory parts. I watched Bennie Osborn do it all the time. Not trying to be an ass, but with the questions you have asked I think you should start with something simpler than a blown injected hemi.
    Pete
     
  9. Other than the weight, what do you have against a pair of ported iron heads at a fraction of the cost?
     
    402BOSSMAN likes this.
  10. Listen to the guy that races nitro hemis.
     
  11. 150J/F
    Joined: Jan 2, 2010
    Posts: 239

    150J/F
    Member

    Car in my avatar was .060 over 354 (365"), injected on alcohol in 200" FED. Iron heads flowed 340 @ .700", stock crank, 14:1 CR, Crane roller cam (270°@.050, .670 lift), good
    valve train, MSD 20 mag. This combination was good for 7.80s @ 170. More expensive than a Chevy but great fun. Get a Hot Heads catalog to see whats available.
     
  12. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    150J/F thanks for chiming in. Yea I just bought a Callies Compstar crank and rods for 800 brand new in the box. Plus a set of AFR CNC heads for 2300 for my BBC, so yea I been looking at Hemi prices and it can get crazy fast. I think it can be done smartly without wasting money though.

    What's a typical 8.60 Hemi build look like. I know most guys are doing it with methanol injected, but what cam, rockers, and level of head porting. I'm guessing mild head work? Are you running high end rockers like Missile?
     
  13. Mike VV
    Joined: Sep 28, 2010
    Posts: 3,029

    Mike VV
    Member
    from SoCal

    It takes a bit on the heads (if you don't go aluminum). Remove the bolt bosses in the intake ports (straight walls), shape the short turn carefully in both the intake and exhaust.
    .500" lift is about it for most early 392 cams. Or go custom ground, that can be done.
    Methanol = at least 11 to 1, (with blower).
    Gasoline(/Nitro) = about 6.5 to 1 (with blower).

    Mike
     
  14. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    I would farm out the head porting. Here's a blown build with a not so needed expensive small hydro roller and stock heads. Nothing exotic here. The numbers are probably real.
    https://www.enginelabs.com/engine-tech/engine/engine-build-blown-early-hemi-makes-670-horsepower/
     
  15. People and cams are kind of strange relationship.
    Could be he simply wanted to not be worried about oil additives and cam wear so a roller cam.
    Those numbers are what I'd expect from a street duty pump gas 392 on 10 psi boost.
    He had 400 cubic inches all in and 1.68xatmospherivc pressure. 400x1.68 672
    I didn't see any mention of a bottom end girdle but I'd have one and it should live a nice long productive and fun filled life.
    Cranking up the boost by turning the 671 faster gets into diminishing returns, a 871 and more boost gets into expensive parts and fitment issues. Race fuel and aggressive tuning could get more out of it I'd imagine.

    Check this out if you haven't yet
    https://www.jalopyjournal.com/forum/threads/heinz-57-street-hemi-heads.984943/
     
    stillrunners likes this.
  16. grdra1
    Joined: May 20, 2013
    Posts: 526

    grdra1
    Member

    I pieced together an iron block / alloy head, blown, injected 392 for my (unfinished)Topolino altered - quickly became very expensive here in Australia due to lack of parts and having to purchase from USA. If I was to do it again I would go for a later Hemi KB, BAE etc. Same look but an abundance of parts new and used. I found it hard to source parts and was limited to a couple of suppliers. If you must have a 392 go for a Donavan alloy block - cheaper in the long run. Also check out Front Engine Dragsters and Herbert Racing Engines websites - they are full of 392 builds / advice. Glen
     
    stillrunners likes this.
  17. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    Think I just saw some ARP main studs in one of the pics. Good to know dyno numbers look good to you. That's a bitchin heald build up. Pure gold!:D
     
    Last edited: Feb 12, 2019
  18. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico


    I read your thread, that was one cool build! I'm not trying to go that fast. I should be fine with mostly stock parts. I'll check out Herbert website.
     
  19. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    You are asking a lot out of 60+ year old iron, good A1 blocks are highly sought after and priced accordingly and then you have to locate a expirenced engine machine shop to do the 4 bolt conversion and prep work. There was guy here in CA that was making an aftermarket 392 block-- real nice piece- but haven't heard much lately, around $4000 which seems like a bunch, buts its just a few hundred short of doing a used 60year old block
     
  20. 73RR
    Joined: Jan 29, 2007
    Posts: 7,174

    73RR
    Member

    Some years back we built a blown 392 for a customer in England, intended to be a daily driver; basic details are carbs on a 6:71, solid cam at .525 lift, stock heads with slightly larger valves, stock crank and stock 2-bolt mains with studs. Dyno said 675 hp. YRMV.
    Yes, all of the small details add up, dollar wise, and this was well North of $18k fifteen years ago.
    There are are couple of block projects out there but none with inventory afaik. A stock block will doo everything that you need and the HH block is every bit as good as the A1.
    If you want to get a good port job check with Bruce Toth, Toth Performance.

    .
     
  21. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    I found an A1 block local I believe is standard bore for $800.00, I'll bore gauge before I pick it up. We have Hutchinson racing here in Sacramento. He also has .060 over complete, but apart that I'm going to pass on. Yea I seen articles about that block. Guess it never materialized.
     
  22. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    I'll keep an eye out for both blocks!
     
  23. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    Very good place to have the work done correctly
     
    loudbang likes this.
  24. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    Good to know. Thanks for all the info
     
  25. nitroholic were do i begin. yes there is the weight issue. you may think the iron is the cheap way out but it isnt. by the time a iron set is race prepped its still not as good as the hot head. the cost will be the same after the iron head is modified and all the new parts are bought. the hot heads come assembled ready to go. now price out disassemble; hot tank; deck; guides; valve job; port; valves; locks; retainers; keepers; springs; setup and re assemble. the hot head is easier to modify than iron. race engines being race engines things will eventually go wrong. things like dropped valves; pistons hitting the chamber; burned valves etc. with the hot head they can be welded up and repaired over and over again. the iron gets thrown is the trash and you start all over. now you are really out money having to buy it all over again. the guy wants to run a blower as stated. the hot heads can be modified to run their 10 bolt blower intake. this design vastly improves the time it takes to work on the engine when service is needed. the blower and manifold can now come off in one piece. looking at it over the long term the hot head is the better investment. chev.jerico as far as the expensive missile rockers there is a reason why they are used. the stock valve train parts severely limits lift and spring selection. .550 is about the max lift before the springs bottom out. installing .100 long valves opens up alot of possibilities both in cam and spring selection. the missile stands lift and seperate the shafts .100 to correct the geometry. they are worth every penny. modifying 70 year old rockers is a waist of time because in the end they are still not as strong as the missiles. if you plan on using mostly stock parts go for it just understand you wont be going that fast or for very long. simple economics show you cant get something for nothing.
     
    loudbang, Dick Stevens and ottoman like this.
  26. Or for "Mild Drag Racing."
     
    loudbang likes this.
  27. ChevJerico
    Joined: Feb 10, 2019
    Posts: 20

    ChevJerico

    I'm going to look at those Hot Heads again. Was drooling over them this morning.

    I talked to Stanke and he gave me a number to a J/F guy that runs his economy rockers. I haven't called him yet, but will soon. I'll be at a fraction of his power and RPM. A mild blown engine with 6k RPM I think would last. Otherwise a big solid and some compression, but then longevity will be compromised.

    https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/253825975397

    Still looking for 600HP combo ideas
     
  28. We tried a pair of those Hotheads cast heads a few years ago and we soon learned that they didn't play well together with 85% like in torching a trough in the cc between the spark plug and the exhaust valve seat. Never saw that happen with iron heads or billit aluminum heads on a 392.
     
    Last edited: Feb 12, 2019
    ChevJerico likes this.
  29. again you get what you pay for. keep reading this over and over again until it sinks in. the stanke rockers are cheaper for a reason. besides the material used they are not bushed. the shafts on the missiles are far superior. stanke rockers can be bushed at a extra charge. steve at missile only does things one way and that's the best. call steve to get the facts before you buy. unbushed rockers are a poor way to go about things. they have no business in a blown engine. no one has the money to buy the correct part the first time but they always some how find it the second time. words from herb mcandles.
     
    loudbang and ChevJerico like this.
  30. Maybe the old adage "Speed costs money how fast do you want to go" will sink in better. ;)
     
    loudbang likes this.

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