Topic: What to do with this engine

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  • str8racn’s Profile Photo
    str8racn
    #1
    Jan 18, 2009 at 7:30 pm
    I bought a 1970 Camaro Z28 with the original engine and the guy did not take care of it at all. I think the carburetor he has on it was too big. Engine is a small block 350 with stock heads. Carburetor is a Holley 4150 750 CFM. I really need some direction. I want a strong day to day drive and goo times at the track.

     


  • revhard’s Profile Photo
    revhard
    #2
    Jan 18, 2009 at 8:03 pm
    For the first thing I would do would be run the casting number to find out if it is a 4 bolt main block if it is, then I'd tear it out rebuild it & maybe even have it Boared 30 or 40 over depending on how much HP you want Rebuild the Stock heads as well because those are some good heads for that year, Then clean the engine bay & block Throw alittle paint on it & stick it back in. applause image woot2 image
    ONE OF many Question left un answered what type tranny does it have? dizzy image
    Keep the Carb that's $300.00 you don't have to spend just go to your local parts store & get a complete rebuild kit for the Carb tired image
    also If you are going to race you may want to invest in a set of frame ties, To much HP will cause you to twist the Rear End out or through a drive shaft through the floor board melodramatic image
    For a Daily driver you will also want to think about what kind of gears you are going to run because if you want to have it as a daily driver & drive it on the track you are going to loose some bottom end torque because you can't put large gear in the rear end if you want it as a daily driver you will wind the motor out so go w/ @ most a set of 373 that way you'll be in the middle raspberry image
    also go with a Miladon oil pan & a One piece rubber oil pan gasket by Mr.gasket
    I also prefer the Flex Fan over the standard clutch fan or maybe even An electric fan instead reading image then throw you a good Intake on it w/ the Carb you already should have rebuilt by now & a nice free flow Air Cleaner checkeredflag image
    I hope This info has been of some help to you,if you have any other Question feel free to hit me up or there are some guy's here that build racing engines Like Monzter Racing for one example steeringwheel image
    Rev Hard /RPM BURNERS CAR CLUB & TEAM RACING

     

    Race The Strip not the Streets - REV HARD

  • str8racn’s Profile Photo
    str8racn
    #3
    Jan 18, 2009 at 8:52 pm
    It has a turbo 350 auto transmission with a shift kit. The carb is dumping way too much fuel. Bought the power valve 5.5 off of the vacuum reading, but now runs worse than before.

    I really appreciate the help. Not too many old school builders I know.

     


  • MonzterRacing’s Profile Photo
    MonzterRacing
    #4
    Jan 18, 2009 at 8:54 pm
    One question I have for you is this carb a vacuum secondary or a double pumper? Also is there a P/N: on the air horn or choke tower? That could be looked up to see what model it is. For a street and once in a while weekend warrior I would recommend a 750 normally if built a little above stock. Otherwise I would go with a 650 or even a 725 Road Demon carb. I really like the Demon line as my carb picked up some HP on Steve's motor at the dyno on Friday. If the engine looks like it had been ran for years I would definitely spend the money and rebuild it. More so if it is a numbers matching motor. The heads on these motors were definitely pretty good but one thing to think about is cost effectivity on having them overhauled. What I would recommend there is buying an inexpensive street head like AFR, Brodix, Dart, Edelbrock, World Products, etc... as Steve had a set done at another facitlity closer to him and it cost only a few dollars short of the brand new Brodix Aluminum ones on his 355 now. Then put the cast iron units on a shelf and save them just in case you ever sell the car as those will help keep teh value of the car up. If nothing is the original stuff then say the heck with it and do it all and don't worry about saving the heads just well them on line or something. If you haev any questions as to what options you have or would like some help desigining an inexpenive motor that is pretty respectful just send me a message. I would be glad to help you out !!

     

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    Mark Francis @ Monzter Racing Happiness is the smell of 116 octane race fuel with raspberry additive.

  • MonzterRacing’s Profile Photo
    MonzterRacing
    #5
    Jan 18, 2009 at 9:16 pm
    Most street engines use about a minimal 6.5 or usual 7.5 power valve. Especially with a turbo transmission. I would check to see if your vacuum advance is hooked up properly or even working. This all depends on whether or not there is aftermarket cam in the motor that has too much duration. If this is the original
    L-79 cam that came in some of those Camaro's of that era is would have a lot of duration with about .447/.447 lift. Duration at .050 is like 284. I use one of these camshafts in my Green Monza that runs 10's in the 1/4 mile. The other thing is that those motors also came factory with solid cams once in a while and 11 to 1 compression. I would recommend checking out the vacuum advance, then rebuilding the carb as a lot of the old Holleys get problems like dead spots, leaks, float issues, etc.. If it is dumping way to much fuel down the carb somebody could have changed the squirters, accelerator pump, jetting, or even the pump cam could have been changed. It is hard to say what could be wrong without being there to see what is actually going on and how the motor is running. Sounds like it could also have a bad needle and seat.

    I would check the float level too. Check out on line the Popular Hot Rodding 600 CFM to 750 CFM Carbs Holley Carburetor. It is a Step-By-Step Rebuilding Guide, Troubleshooting Tips, and Identification Guide. That may help you out !!

     

    Monzter was here!! Click on this photo to go directly to my challenges and vote on them Please.



    Mark Francis @ Monzter Racing Happiness is the smell of 116 octane race fuel with raspberry additive.

  • revhard’s Profile Photo
    revhard
    #6
    Jan 19, 2009 at 7:01 am
    Quote:
    Originally posted by str8racn  It has a turbo 350 auto transmission with a shift kit. The carb is dumping way too much fuel. Bought the power valve 5.5 off of the vacuum reading, but now runs worse than before.

    I really appreciate the help. Not too many old school builders I know.


    The T350 is a good one if it's built right, I would still take it in for an overhaul get some new bands & Etc...you can take the 750 eldenbrock & change the jets on it to match what you want it to do, does it have an electric choke or manual, also on the front there should be to nozels the left one is for your distributor if it is a vacume advance, the other one has a higher vacume force, Most guys plug it off unless they have huge cams like mine except I am not running a vacume advance
    distributor I'm running a Protronic Flake thrower HEI distributor with 8.5mm MSD wires! woot2 image idea image flamed image eye-popping image crazy image

     

    Race The Strip not the Streets - REV HARD

  • str8racn’s Profile Photo
    str8racn
    #7
    Jan 19, 2009 at 8:50 am
    Vacuum secondary and no choke that I can tell. After taking this off again and a closer look. He has run some sealer along the bottom of the house for some reason. I think I am going to buy another Holley 650 instead for now. I will keep this one and tear is down to see what the situation is on it. Also had to unplug the hose to the constant. Carburetor is toast I think LOL. mad image

     

    Edited Jan 19, 2009 at 9:01 am


  • BRS’s Profile Photo
    BRS
    #8
    Jan 19, 2009 at 9:27 am
    That Edelbrock is a great carb, and easy to work on. If you think your getting too much fuel I would meter it down a bit. What you need to work on is the air flow. Get the motor to breath right and that will cure most of you troubles. No one has said what type of cam your working with. The engine / trans combo is a good one and you can build it for the daily drive as well as some performance. With all the Chevy guys out there I'm sure they can tell you the right combo to go with. Best of luck!

     

    Yesterday is gone and tomorrow ain't here yet!

  • MonzterRacing’s Profile Photo
    MonzterRacing
    #9
    Jan 22, 2009 at 3:54 am
    Yes, cam can matter but if it is a stock motor it could/should be a hydraulic cam. I did mention something about the cam in my last post that could be in that motor. Like I said the Demon carbs are awesome and they run great right out of the box. I personally do not care for the std Holleys and Edelbrock carbs. We have tried a few different ones on my daughters boyfriends truck and now he is convinced that I am right about the Demon line. Just ask him !! He is 69c_10sbc335. He is a member of this group.

    Get with me on some combos if interested and I can help you out a lot more than people think. I do have a state of the art program that should get you hooked up better than just some guess work.

     

    Monzter was here!! Click on this photo to go directly to my challenges and vote on them Please.



    Mark Francis @ Monzter Racing Happiness is the smell of 116 octane race fuel with raspberry additive.

    Edited Jan 22, 2009 at 3:59 am


  • BRS’s Profile Photo
    BRS
    #10
    Jan 23, 2009 at 6:53 pm
    From everything I've heard about them, the Demon is a great carb.....but being an old Mopar guy the Edelbrocks are very similar to the old Carters. I've never ran a Demon but I plan on setting one up on a 360 that I'm putting in a '69 Dart. I've had trouble with Holleys in the past but my son loves them. I guess it's what you are comfortable with.

     

    Yesterday is gone and tomorrow ain't here yet!