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Thread: Engine Help!

  1. #1
    Senior Member MASTER BUILDER
    Join Date
    Oct 2003
    Posts
    144

    Engine Help!

    I have a bunch of problems on a friends 66 vette with a transplanted 502
    Keith black BBC.
    I am wondering if anybody can help.
    he had asked me to change the lifters on the engine and I found out they were roller / Hydraulic. I have done plenty roller solids, hydraulic tappet style but never done the roller / hydraulic kind.
    So I get the lifters in, degrease the packing stuff, soak them in oil for a day or so to saturate them, install them. Setting them at tdc each cylinder, I figured most accurate way. using a primer pump on each cylinder adjustment.
    Now this is where it gets weird. I called the tech at summit and he tells me to adjust the valve lash till the push rod has some drag on turning it and then tighten another 1/4 turn. So I get thru setting all of them, and guess what? engine has little or no compression.
    I decided to readjust the valves just till the push rod contacts the rocker. I start the car up cause it has compression and it runs like crap.
    I do another compression test and they are all low. I readjust the valves just till the push rod wont move up or down and it runs better and compression is back up.
    Now it seems like the car wont idle when cold, it sputters during low to mid range and sounds like crap. Since I had the manifold off. I'm figuring is a vacume leak as the car when it warms up will idle better.
    Also, the car seems like it needs alot of timing to help it accelerate.
    anybody have an easy way to check for vacume leak on these big v8's?
    P.S. we changed the lifters cause they were pretty noisy, ( even after multiple adjustments.
    anybody have a sure fire way to adjust these roller hydraulic's?
    Thanks
    Al

  2. #2
    What I do:
    Using a new set I do not soak them in oil in first. Leave the internal dry so the little pintle valve can be pushed against it's spring. Note that you can squeeze the oil out of a pumped up set to do this method if need be.

    Coat the outside of course. If the manifold is off makes it a little easier. When you tighten the rocker nut you can see/feel where the pushrod is just beginning to push the lifter slug down. (This is essentially the same thing the tech was telling you but without the lifter being pumped up you get a better feel for what's happening).
    Then do your 1/4 turn or whatever turn you like. If you have your doubts about your setting being too tight just push down on the pushrod. There should be movement left before it bottoms out. No movement means you went too far.
    Rotate and move through the firing order at each TDC accordingly.

    Then rotate and prime the engine until oil comes through all of the rockers. No oil? Keep going. This can take a while and it must be rotated for all the oil holes to line up and pass the oil through. All Done. This method rarely needs readjusting but if it does follow the deal that follows.

    Old time honored way:
    After the engine is running you can always pull the valve cover, slow the idle down and one by one go through and loosen each one at a time until it rattles, tighten until the noise goes away, then the 1/4 turn. Note that this only works on a car that is not too noisy. :lol:

    If it still runs like doo doo, then you have other problems.

    One more thing. If the owner thinks his quasi race engine should be as quiet as grandma's Buick he is going to continue to be disappointed. However, if he has sheet metal steel or aluminum valve covers they will amplify the noise. Thick cast aluminum covers will dampen the noise considerably.

    Does this thing have oil restrictors by chance? That will aggravate your noisy lifter problem most likely.

    Dave Koehler
    www.koehlerinjection.com

  3. #3
    Administrator RACING JUNKIE
    Join Date
    Mar 2004
    Location
    Maine,USA
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    1,208
    Dave

    Thanks for stopping by and helping out,we really need a good alcohol nitrous guy here

    I turely value your input on helping others along the way.

    Lets all give Dave a warm welcome here,and don't forget to check his site out
    Dave is a great guy too he has helped me tons in the past and always had the time for me in conversations.

    You got questions Dave has the answers and solutions to your problems.

    Check him out. And your welcome here Dave any time.

    www.koehlerinjection.com
    There Is 1 Thing Better Than Cubic Inches,,,More Of Them

  4. #4
    Senior Member MASTER BUILDER
    Join Date
    Oct 2003
    Posts
    144
    Thanks Dave,
    I am not sure if he has restrictors, but I can make a guess and say he does. There is not a bunch of oil coming up the push rods when the valve covers are off. ( at idle )
    I tried when the lifters just came out of the box to push them down and found no movement.
    I have them installed and am going to try your engine running adjustment.
    In the old days we would run them down til the engine started to react and just back off till the engine came back up.
    This is a hard deal do get right as the owner has no idea what cam is in it and the car at 2500-3000 rpm has a little miss it seems. I am going thru the carb and see what I can do. All plugs are good, wires new, cap and rotor. It also has a Mallory optical trigger.
    another question, What initial timing should I see on this big block ? It has vacuume advance and mechanical.
    thanks again.
    PS I run an alcohol injected SBC 436. Toilet, pretty cool stuff.
    Al


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