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Dauntless For 6000 Rpm Autocross?

Discussion in 'Early CJ-5 and CJ-6 Tech' started by ChuckD, Feb 10, 2019.

  1. Feb 10, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Feb 8, 2019
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    I bought a Porsche 914 with a Dauntless conversion. Yea, I know, but this one has the GT fender flares and big tires, so not totally sisified. I like the light car with mid-engine configuration. I’d like to know if this engine is capable of spinning at 6000 rpm without more than better valve springs and bottom end in good condition. I did this with a two barrel 350 Chevy back in the day, but don’t know this engine. I’ve read many saying a Comp Cams cam and a four barrel manifold keep the great low torque but extends it, but did not elaborate on max rpm that I recall.

    Doesn’t bother me to balance the engine well and put in shot peened and maybe polished stock rods with good bolts. I am not in love with the valve train but maybe it’s fine. I’m not expecting peak hp at 6000 rpm, but want to avoid a 2-3 3-2 shift on a long stretch into a tight corner, if I only have a little farther to go.

    Anybody have experience with this? Used but good enough performance parts are of interest. Mind is open to a different engine if a decent arrangement can be made. Car has Offy intake, 390 Holley, wrapped headers, and 268H cam. Thinking this will pull pretty well to maybe 5500 rpm.

    Also, I’ve read that the Offy manifold sucks but also heard the Edelbrock manifold for the 231 leaks on the 225. Anybody know the work-around for this?

    Thanks,
    Chuck
     
  2. Feb 10, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    I would have to think twice about running an odd-fire to 6 grand. If you try, at least modify the oil pump spring to allow higher pressures to overcome the high rpm's.
    An even-fire 231 would be a little better. Better yet, a 283 or 327 Chevy.
    I helped build a 283 powered 914 a little more than 20 years ago. The 283 with a short stroke will rev high (approaching 7K) with the right cam and valve springs, and it doesn't make so much torque to kill the Porsche transaxle, if that is what you are running. If so, side shift or tail shift? By the way, first gear isn't used for anything other than loading on the trailer. You can swap gearsets around in the Porsche transaxle for a wide variety of ratios, but you need to find someone with the jigs to set them up. The gear pairs are identified by alphabet letters.
    The Chev V8 is cheap to build reletive to about any other engine, and fits fine in the 914 engine bay. That would be my choice.
    -Donny
     
  3. Feb 10, 2019
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    All the Buick V6s I raced against that pulled high revs were swapped to 231 even-fires.

    We'd love to hear you outcome if you try it though!
    :bananatool::watch:
     
  4. Feb 11, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Feb 8, 2019
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    Hmmm ... need to sleep on the 283 idea. Would love to have another SBC, but would need a different conversion kit and another engine ($). May end up making more sense. It may be that total engine weight and length is similar to the 225, the Chevy design is very efficient. Wish I hadn’t left those Powerpack heads in the bed of the Camino when I sold it 25 years ago.

    If I do convert, maybe I’ll run the current unprepared engine to 6000 and post pics of the carnage . Na, just kidding. I have too much respect for this workhorse engine. Told my wife I might want an old CJ and she rolled her eyes. Better hold that thought for a couple of years.

    Side shift. Even the wimpy 4 cyl will pop off the overhung first gear eventually. Heard the transaxle is pretty tough otherwise. Plan to go to lower final ratio some day, but many other high priority issues are taking my money and time for now.

    Thanks for your advice.
     
  5. Feb 11, 2019
    tarry99

    tarry99 Member Sponsor

    Northern California
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    I have a 231 even fired project sitting in the shop that might interest you......I sent a PM
     
  6. Feb 11, 2019
    wheelie

    wheelie beeg dummy Sponsor

    York, PA
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    :watch:
     
    ChuckD likes this.
  7. Feb 11, 2019
    homersdog

    homersdog Tulsa, Ok Sponsor 2019 Sponsor

    Tulsa, OK
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  8. Feb 11, 2019
    Twin2

    Twin2 wasn't me Sponsor 2019 Sponsor

    Virginia Beach, VA
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    not the same project but
    the pontiac fiero crowd around here like V8 power
    and they just sound mean
     
  9. Feb 11, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    What adapter do you have? Kennedy (KEP) makes a slick adapter to vw/porsche transaxles, keeping the 215mm clutch. The 914 transaxle can handle a V8 if the torque is kept resonable. A 350 Chev usually is over the limit, but the 283/327 is within reason. Aluminum heads and intake help keep the weight down for the SBC. The rear bulkhead at the trunk needs massaging for the distributor.
    A final drive change is usually not needed; just change the gear pairs around in the transaxle, after obtaining probably two more sets. You can make the transaxle into a short autocross box, or road race ratios just by swapping the gears. Read up un this.
    I have a 914 transaxle that I need to convert to a nose shift for a bug project. I'll be swapping gear sets around inside, or at least having that done for me!
    -Donny
     
  10. Feb 11, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Donny-I believe this is the Kennedy kit. I’ve studied the 901 ZF transaxle some, and definitely want to go through it in the future. I knew you could swap gears around some, but your suggestions are beyond what I was thinking... which intrigues me. Need experience with the car in autocross before I think too much on this. I bought the car in late summer and have yet to drive it successfully. It was neglected for a long time. I just want to drive to work so my homie’s don’t think I’m full of crap.

    My dad was into bugs when I was starting to drive in the early 80’s. I’m curious what you are planning with that bug. Oh, wait, am I off topic in my own post?!

    Thanks,
    Chuck
     
    47v6 likes this.
  11. Feb 11, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Ahhh, site doesn’t like big pics
     
  12. Feb 13, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    Chuck, I played with bugs for about 20 years, mostly building Baja bugs for beach, but still streetable. I sold off almost all of my air-cooled stuff when I move to Florida over 20 years ago, though I still drive a Vanagon syncro with a Subaru 2.7 H6 (Kennedy adapter/flywheel). I missed the air-cooled stuff, and found a solid '69 convertible bug that had the front chopped for a baja nose. I put the front sheetmetal back to stock, and have wide 'glass full fenders, so it will be sort of a Class 11 lifted offroad look. I'm building a 2.0 914 engine for it, maybe stroking/overbore to a 2.3. I want to use the 914 trans in there with regearing (not ring and pinion) for about 30" rear tires. I have talked to a guy in central FL that has the jigs and skill to rework the 901 series transaxles, but I still need at least one set of gears, and the nose adapter for converting to the central shift rod. I think this shows where my comments are coming from.
    I have been watching for a cheap 914 for a while, but they are either rusted away of too expensive. I always wanted to build a Chevy-powered mid engine 914 after the one I helped build before the move to FL. That thing was awsome to drive!
    -Donny
     
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  13. Feb 14, 2019
    jeep2003

    jeep2003 Active Member

    Vestal NY
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    Heres my 72 its begging for a conversion. still got the 1.7 in it i converted it to sideshift but it needs a rebuild so it shifts worse than the tailshift did. the car was in 3 floods and folding in half when i got it
     

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  14. Feb 14, 2019
    nickmil

    nickmil In mothballs. Sponsor

    Happy Valley, OR
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    A Dauntless can be built to handle 6000 rpm but it isn't cheap and requires a lot of work. Easier and better results to use a 231 with high port heads that flow better.
     
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  15. Feb 17, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Your 914 turned out well, but you are a glutton for punishment. I have a 2006 Mazda 3 that will probably start folding in half in 5 years, but at that point I’ll just harvest parts and scrap it.
     
  16. Feb 17, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Nickmil-could you elaborate a little more on the key things that would be required? I’m starting move in the EF direction but want to justify it more clearly. Part of me wants to show I can do it without high cost, but the reasonable part of me says I’m going to get bit and waste money and time. My biggest concern is bearing loads in the crank, and more oil pressure would not do much to prevent edge loading of a main journal from crank bending. I’m not sure internal balancing would be enough, or if it would, it might cost $1000 for machine work. That would be beyond what I’d want to do. So, please expand on your concerns.

    Thanks, Chuck
     
  17. Feb 17, 2019
    chrisg

    chrisg My Flatty Sponsor

    94555
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    Nice... Right outta high school I worked in a VW shop, brings back alot of memories. I knew a guy who had a 914 with the 6cylinder, and man, that thing would fly
     
  18. Feb 17, 2019
    wheelie

    wheelie beeg dummy Sponsor

    York, PA
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    :watch::watch:
     
  19. Feb 18, 2019
    tarry99

    tarry99 Member Sponsor

    Northern California
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    Not sure about your concerns for bearing loads?..........If it was turbo charged Maybe? And any use of a stock crankshaft would be a NO-No........ Balancing would be mandatory and I think your a little short thinking you could get it done for a $1000 or less.

    Want a 231 that will see 6000 rpms easily and make 300 HP all day?..........Here is where I started on a similar project for a naturally aspirated 231 using a 550 cfm carb or FI 4-barrel throttle body on top.
    • 231 Turbo Block and all the additional machine work.
    • 8445 Turbo cast iron cylinder heads.....these have been fully machined and surface ground on two sides......valve pockets have been ported for flow.....3-angle valve job using Ferrea Stainless valves, hardened seats, valve guides have been machined and cut for seals. All smog ports were filled with aluminum and the combustion chambers reground after the pouring. The rocker stands have not yet been modified to accept roller rockers...These heads will flow about 185 cfm..........if you want to flow upwards of 220 you have to go aftermarket aluminum heads with bigger valves.
    • Scat connecting rods.
    • Aftermarket Steel 231 Crankshaft.........these steel cranks are next to impossible to find anymore, there was only a few hundred made and went fast........all the turbo guys have now gone to custom crankshafts that cost about $3000 per copy.
    • TA Perf. aftermarket timing cover and close tolerance oil pump.
    • I never bought pistons yet but Diamond has what I need at 10.5 to 1 compression. Camshafts are easy to get., roller rockers, build a new oil pan, Ignition...........Your Looking at about $4000 k in parts and machine work in the pictures and were only about 55% Along the way.
    • [​IMG]
    [​IMG]
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    I have plenty of manifolds to test with.............Weiand Air Gap , Kenny Bell , Even a rare Smokey Yunick Manifold
    [​IMG]
     
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  20. Feb 21, 2019
    ChuckD

    ChuckD New Member

    Illinois
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    Tarry99 - that’s some nice stuff you’ve got there. Over the top for what I’m trying to do. Now, if I had a money tree out back, I would be all over that. That Smokey Yunick manifold is coool. I would pick some leaves from the money tree to get my hands on that. I’d be interested to hear about any naturally aspirated 79-83 231’s for sale. My buddies keep pushing me to get newer years with all the modern ignition and fuel systems, but I just don’t find that stuff sexy. I like my carbs and distributors, fancy stuff is for the car that takes me to work.
     

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