Patrick's Twin Turbo 350 Build Thread

Discussion in 'Small Block Tech' started by patwhac, Apr 8, 2019.

  1. Mart

    Mart Gold level member

    They all should only be depressing the lifter cups abt .030 while on the base circle of cam. Double check your pushrod lengths.
     
  2. patwhac

    patwhac Well-Known Member

    I measured every single lifter with a checking pushrod and ordered new pushrods that were suppsoed to be the correct length. They measured correctly but I must have miscalculated somehow . . .
     
  3. Mart

    Mart Gold level member

    What length are they? Did you have the turbo cam you are using in, when you measured? Base circles differ.
     
  4. patwhac

    patwhac Well-Known Member

    Yup, I had the cam in, same rockers, torqued them to spec ect. Pushrods I ordered are 9.650" which I determined through math would be correct.

    Here's the sheet I used. My lifters call for .020" to .080" of preload.

    [​IMG]
     
  5. Mart

    Mart Gold level member

    Looks like adjustables would work the best to have all preloads at .035.
    Valve stem heights are quite different.
     
  6. patwhac

    patwhac Well-Known Member

    Dang and I cancelled my order of adjustables to go one piece because I was worried about durability . . .

    I measured my lowest valve tip as being .017" lower than the rest. There was only 1 low one on each side, the rest of the fluctuations are probably measurement error. Let me try and measure again today!
     
  7. Mart

    Mart Gold level member

    If you layed a metal straight edge across the stem tips and feeler gaged the gaps on the short tips and only got 2 short by .017, that would work.
    Somehow you seem to have abt .080 variation with the preload..
     
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  8. hugger

    hugger Well-Known Member

    What's the issue? Out if the four lifters pictured two look fine and the other two are just up on the lobe is all,...
     
  9. hugger

    hugger Well-Known Member

    If the stem heights are within .030 of each other you're fine
     
  10. patwhac

    patwhac Well-Known Member

    Thanks Hugger, I guess I'm just being paranoid. I took measurements again of two random lifters #1E and #3E and the math still adds up. So I'm going to run it and see how it goes!

    Right now I'm working on buttoning up the engine with the intake/carb, mounting gauges to the run stand, and trying to rig a throttle cable to it.
     
  11. patwhac

    patwhac Well-Known Member

    I made a bonehead move last night while bolting on the intake! I forgot to put RTV around the water ports between the intake gaskets (composite) and the intake. I did put it between the heads and the gasket though. Do you think it's worth redoing the intake install, and potentially buying new gaskets?
     
  12. Mart

    Mart Gold level member

    Yes, you don't want a Buick milkshake......
    Hopefully, you can pop intake off carefully and seal the water ports without having to buy new gaskets, cause it's a fresh, unstarted install.
    You hopefully didn't add water or coolant yet.....
     
  13. patwhac

    patwhac Well-Known Member

    Thanks Mart! I didn't add any fluids yet, but I did put high-tack on both sides around the water ports, hopefully it'd not going to glue to gaskets in place too well . . .
     
  14. Mart

    Mart Gold level member

    easy does it.....
     
  15. Schurkey

    Schurkey Silver Level contributor

    Leave it the fook alone. Run it. After it's warmed-up and cooled again, re-torque the manifold bolts. Why would you need silicone AND gasket adhesive?

    IF (big IF) you have a pressure tester, pump it up to 16 psi and see if it holds pressure. It will take a lot of pumping if the system is empty--a pressure tester using regulated, compressed "Shop air" will be faster and easier.

    If it DOES leak pressure, verify that the intake gasket is the source. Spray hoses at each end with soapy water, spray the manifold-to-head junction with soapy water, spray any other potential leak--thermostat housing, engine core plugs, water pump housing, radiator tanks, etc. with soapy water.
     
    Last edited: Aug 12, 2020
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  16. OZGS455

    OZGS455 Oh what a wonderful day!

    Worth doing..worth doing right.
     
  17. Schurkey

    Schurkey Silver Level contributor

    Explain to me what RTV silicone does, that some other gasket sealer doesn't.

    The issue is that you want the gasket to seal. The issue is NOT to use a specific chemical to achieve the goal.
     
    Max Damage likes this.
  18. patwhac

    patwhac Well-Known Member

    Crap well I already pulled the intake off again before I saw your post :rolleyes:

    The RTV was only for the water ports, high tack was only for the intake ports. If there's a better way of doing it then I'll try it out this time! Going to order new gaskets tomorrow as the old ones ripped into pieces when I pulled the intake.

    I'm also considering using .032" gaskets instead of .062" this time because the intake's end rails were sitting above the rubber end seals a bit (by .050" or so), so I had to use RTV on top of the end seals as well. Usually it's the opposite problem where the end seals get squished out!
     
  19. MrSony

    MrSony Well-Known Member

    I slice the rib off the end seals. Since I started doing that and using Indian head gasket shellac (lil brown bottle), no leaks. Let it tack up first. I still put rtv in the end seal corners and mush the seal into it. Sometimes I use that copper spray stuff on the valley pan sometimes I use nothing. No experience with the 2pc part gaskets tho.
     
  20. Buick#455

    Buick#455 Well-Known Member

    Update????
     

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