WHAT'S LIMITING MY POWER?!?! | Page 11 | FerrariChat
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WHAT'S LIMITING MY POWER?!?!

Discussion in '308/328' started by wildcat326, May 4, 2015.

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  1. jmaienza

    jmaienza Formula Junior

    Jan 8, 2009
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    Massachusetts
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    Joe
    #251 jmaienza, Jun 5, 2015
    Good to know that ignition is functioning properly. Getting hard data from diagnostic procedures is the key. Obviously, your carbs are not tuned yet. 10kg/hr certainly is high.

    Do some diagnostics on the carbs: float level, jet sizes, and throttle shaft alignment. Certainly rebuilding the carbs is worthwhile and once done you will know hat has been done. Also with modern fuel, re-jetting is usually done.

    David Feinberg is an excellent resource and knows these cars very well. Hang in there. Every time you find a cause, you get a little bit closer.
     
  2. wildcat326

    wildcat326 Formula 3

    Dec 10, 2012
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    Justin
    #252 wildcat326, Jun 5, 2015
    Last edited: Jun 5, 2015
    Thanks, Joe, and also for your input and suggestions along the way. Part of the "joy" of Ownership to me is getting into the car and figuring out how to best restore and properly maintain it, almost equally as much as the driving itself. I wish this had happened at the end of a driving season, instead of the beginning, but look at the bright side: After exactly one month and 250 posts, the forumers waiting with bated breath got an answer to the riddle:)

    When my Porsche 928 clutch failed, I could barely get it to go into gear, and it would usually slip out after a short distance. The 308 goes solidly into gear, so I didn't even think of a clutch issue. But, on my drive home this morning, having been given the diagnosis, it's plainly clear that's the problem. I step on it, and the revs shoot right up, but the car CRAWLS achingly up to speed. I'm just relieved it doesn't appear to be an internal engine problem (valves/cams). Could always be worse.

    I babied it home from the shop this morning, had my fiancee follow me back. Still a thrill, even at 25mph on side streets. We're getting married two weeks from today, so I'm not sure I'll have the time to address this before then. But as we say in Chicago, "Wait til' next year." By next driving season, she'll be PERFECT.
     
  3. Saabguy

    Saabguy Formula 3

    Mar 28, 2012
    1,785
    Shreveport, LA
    #253 Saabguy, Jun 5, 2015
    Enough about your fiancé, what about the car? ;-)
     
  4. Jdubbya

    Jdubbya The $10 Trillion Man
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    #254 Jdubbya, Jun 5, 2015
    You going to try adjusting it first? There may be life left in it. Worth a shot. But either way hope it works and solves the issues.
     
  5. E-Dino

    E-Dino Formula Junior

    Aug 11, 2012
    378
    San Diego
    #255 E-Dino, Jun 5, 2015
    That is great that you have found a known issue to fix. That is the satisfying part when troubleshooting a myriad of symptoms. One fix at a time and you will be ripping up the roads in no time. :).
     
  6. wildcat326

    wildcat326 Formula 3

    Dec 10, 2012
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    Justin
    #256 wildcat326, Jun 5, 2015
    Last edited: Jun 5, 2015
    Thanks guys. Sorry to drag everyone through a month of agony:)

    Ultimately, the answer to the question of WHAT'S LIMITING MY POWER?: Slipping clutch and carbs that are breathing too much air.
     
  7. 308 milano

    308 milano F1 Veteran
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    #257 308 milano, Jun 6, 2015
    Persistence pays off! I for one check this thread every day to see how you're coming along, you'll get her sorted! Hats off to all the members that freely lend their time and expertise!
    One great community guys! :)
     
  8. Jdubbya

    Jdubbya The $10 Trillion Man
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    #258 Jdubbya, Jun 6, 2015
    Are you sure the tach is reading properly? Not that it would be the cause of the major issue but if it's signal is mixed up it could affect the carb reading if it's higher than showing. Like if it shows 900rpm but it's actually idling higher?

    Probably not, just a thought that popped into my head
     
  9. kiwiokie

    kiwiokie Formula 3

    Aug 19, 2013
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    John McDermott
    #259 kiwiokie, Jun 6, 2015
    Would a slipping clutch prevent the engine revving past 5,500rpm that was mentioned in the first post?
     
  10. Saabguy

    Saabguy Formula 3

    Mar 28, 2012
    1,785
    Shreveport, LA
    #260 Saabguy, Jun 6, 2015
    Right! It could certainly keep the car from accelerating but the engine would rev right up.

    Something still doesn't seem right, pulling "too much air" can't happen. I mean one side pulling too little air is possible but air flow is dependent on valve timing, bore, stroke, RPM, and venturi size. I mean the venturi can be changed on Webers but it takes a lot of work, i.e. it's not accidental.

    It's good that you have a known problem to fix but I don't think you are even close yet but I am pessimistic. ;-)
     
  11. Dancia

    Dancia Rookie

    May 15, 2015
    35
    #261 Dancia, Mar 14, 2016
    I'm a fellow pessimist.

    Has your problem been solved?

    Richard
     
  12. wildcat326

    wildcat326 Formula 3

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    Justin
    #262 wildcat326, Mar 16, 2016
    Last edited: Mar 16, 2016
    We discovered at least four problems working in tandem:

    1) Electromotive control was set at a timing advance not optimal for a carb car.
    2) There was a muffler obstruction and a bad leak in the front header; had basically lost scavenging pressure.
    3) Clutch was slipping badly.
    4) Something else wonky and not yet fully accounted for: The carbs are breathing waayyy too heavily at idle. Still don't know if it's leaking throttle shaft bearings, bad floats, misadjustment, or (my personal theory) a bad tachometer relaying the wrong data for idle adjustment at the carbs and ignition control. In other words, could be revving at 3k when I'm adjusting for idle, or redlining when I think it's stuck at 5,000 RPM. etc.

    Ultimately I stopped chasing down the "power loss" issue and moved forward with all my intended rehab work anyway:

    - New clutch and housing seals
    - Alternator rebuild
    - Gear reduction start motor
    - New electronic ignition
    - New exhaust, with ceramic coating for headers
    - New wheels and tires
    - Complete suspension, brake, and steering rack rebuild (with new shocks, rotors, bushings, lines, pads, etc)
    - All new fuel and coolant lines
    - Birdman fusebox
    - Engine and fuel tank cleaning
    - Some light rust prevention on rear chassis members
    - CV boot rebuild and differential seal replacement

    At any rate, I began a mechanical restoration in earnest in the fall, but we've had nothing but family crises since then. Five family members have been in the hospital this winter, and my wife has been in with an illness for almost a month. Things have been pretty much at a standstill. My goal was to have it perfect for FCA nationals in Columbus, but at the moment I'm just praying for everyone's good health. The car will always be there.
     
  13. jmaienza

    jmaienza Formula Junior

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    Joe
    #263 jmaienza, Mar 16, 2016
    Sorry to hear about your family's health problems. i hope things do get better for you and everyone.

    It sounds like you are making progress in rehabbing all the major systems. Smart move. It will pay off in the long run and make the car more dependable, plus many of those things won't have to be done again for a very long time, if at all. It took me three and a half years to get my car in order and I essentially did everything you are doing, plus a motor rebuild and re-dying the interior.

    As I was working on my car I tried to keep to a schedule dictated by the car, almost drove me crazy. Eventually, I decided to work on the car on my terms and when I could. Things were slower, but certainly less stressful. You are right to look after everyone's health because the car will always be there. Hang in there.

    Rebuilding the carbs is actually not as bad as you would imagine. And after you do one, the other three are easier. The throttle shaft bearings and plates are not that bad to remove. There are specific procedures that work well. Plenty of posts on the rebuild. Also, Pierce Manifolds in California is a great source for parts and Mike is very helpful.
     
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