C4 rebuild

Discussion in 'Transmissions' started by jasonwthompson, Sep 19, 2016.

  1. jasonwthompson

    jasonwthompson Member

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    We are getting close to replacing the original 302 with a fresh rebuild. The C4 was working fine when last used months ago. However, since it is out I have been thinking it would be a good time for a rebuild/refresh. I do not want to do it myself. Does anyone have any recommendations for someone in the Dallas/FW area? The engine will be a basic 302 H.O., so I am fine with the stock converter. Just thought that someone may have a friend, with a cousin, who has a brother, that knows a guy.
     
  2. 71gold

    71gold Frank Cooper Supporting Member

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    most shops require a new converter with a rebuild to keep the warranty...:yup:
    may want to bump up the stall if you do...cheap performance upgrade...:thumbs2:
     
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  3. 1972Grabber

    1972Grabber Always Broke

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    And what's the stall on a stock C4 convertor??
     
  4. Krazy Comet

    Krazy Comet Tom

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    Around 1600-1800... A 2200-2400 gives a nice boost without going nuts on cruise RPM... With a AOD I'd reccomend a 3200-3500 lockup... With those, O/D RPMs are same as the stock converter...
     
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  5. MaverickEsquire

    MaverickEsquire Member

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  6. Hotrock

    Hotrock Rick, an MCCI Member Supporting Member

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    Yes camshaft profile is a factor. I'm assuming your camshaft has some level of performance profile.

    If you currently have a stock convertor, a higher stall unit will definitely wake up your engine combination, not to mention improved idle when your transmission is in gear. I've run stock and off-the-shelf 2,500 and 3,500 convertors with my engine/rear gear combination. The stall speeds on both higher stall convertors with my combination were less than the advertised stall speed. The 2,500 stall convertor performed about the same as a stock unit. I prefer the 3,500 stall unit. It's street characteristics aren't that much different than stock but my Comet's tire turning capabilities are much better and my ET improved by 0.70 over the 2,500 stall unit. I'm confident a custom built convertor for my car would be a big improvement. For now I'm staying with what I have.

    A transmission cooler should also be installed along with the higher stall convertor..
     
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  7. Craig Selvey

    Craig Selvey Indiana State Rep - MCCI

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    Everybody has opinions....right? :D

    All you do is street driving.......stick with a stock converter.
     
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  8. Krazy Comet

    Krazy Comet Tom

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    If engine idles 18-20" vac at 600 RPM, the stock converter is fine. For 15-16" step up to at least a 2400. If below 15" use 3000-3500.

    Converters are rated by flash speed, which unless engine makes huge torque will always be less than you get foot braking. A converter that stalls at 3000 behind a 400 ci in engine, may only stall at 2500 with a 300 cu in engine.
     
  9. RMiller

    RMiller My name is Rick

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    He is correct, my brother had a pretty nasty 350 in his Chevelle with a TCI 3500 converter and it started to get tight around 2800. He went for kore stall and I bought that converter from him. In my GTO with a strong 455 it would foot brake to 4200 and when matted with slicks it left at 46-4800. Man it was fun to drive!
     
  10. MaverickEsquire

    MaverickEsquire Member

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    I'm gonna try this without multi-quote - let me know if I should edit for clarity

    Only street driving for me. Imagine there is some sort of upgraded cam... bought the block already assembled - .30 over, forged internals and such, guy had the top half set up for with a high rise intake and dreams of nitrous (to give you an idea) - totally possible I inadvertently threw a "built" engine in there. I put a different intake on.

    Engine vac was around 20" at idle in park - remember being impressed with the vacuum.

    "Improving idle in gear" caught my eye as it stumbles alittle now at red lights or anytime it's just sitting in gear. Threats the stall but doesn't - perfect in park.

    3.00 gears in back - but gonna bump that up moderately when I do the rear end (last major mechanical thing left after trans - woop woop)

    Not sure how to check what cam I have - my budget likes the stock stall but not opposed to dropping a dollar

    Thanks for all the great replies!
     
  11. jasonwthompson

    jasonwthompson Member

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    I tend to agree with Craig. If it is basically street driven with only mild engine bolt-ons, there is nothing wrong with the stock converter stall speed.
     
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