350 rebuild questions.

Discussion in 'Small Block Tech' started by Juze86, Nov 9, 2015.

  1. Juze86

    Juze86 Well-Known Member

    Yes that is good point but they are 100% sure right way.

    I believe these rods have came available maybe month ago.
     
  2. sean Buick 76

    sean Buick 76 Buick Nut

    I literally just pulled the trigger on modifying some Chevy rods for a friends 350 when TA anounced they were making these rods, what the heck lol??? The cost worked out to $800 for the rods after mods to fit in a Buick 350 with Buick bearings.

    I am puzzled as to why your rods are not centred in the piston, anyone have any idea?
     
  3. Juze86

    Juze86 Well-Known Member

    Looks like stock rods has little more offset than Molnars. They dont hit to pistons so I just let them be.

    Lhetetty minun H60-L04 laitteesta Tapatalkilla
     
  4. Juze86

    Juze86 Well-Known Member

    Also cylinder 6 was too close.

    Tomorrow I'll put engine into car.
     

    Attached Files:

  5. 8ad-f85

    8ad-f85 Well-Known Member

    Were you able to keep the bob weight fairly close to the target for balancing?
    The overall formula won't be affected much by the few grams you removed...more important is that each assembly is matched to the other rod/piston sets.
     
  6. Juze86

    Juze86 Well-Known Member

    Pistons and rods were within 1 gram and crankshaft is balanced.
    I only took as little as possible, but left 3 rods untouched, should I have took from all? Damn, I should have think that earlier...

    How much oil level goes down when engine is running? Looks like I have too short dipstick, when oil is in lower level rods still barely touch to oil.
     

    Attached Files:

  7. 8ad-f85

    8ad-f85 Well-Known Member

    You should be good, it actually takes quite a bit of grinding to remove a gram.

    [The overall formula won't be affected much by the few grams you removed...more important is that each assembly is matched to the other rod/piston sets.]
     
    Last edited: Aug 16, 2016
  8. Juze86

    Juze86 Well-Known Member

    Engine is in and almost ready for break-in. Is there any difference in transmission fluid circulation in P or N in TH350? Which one is recommended for break-in. I've heard there is some differencies in some transmission but can't find any info about TH350.
     
  9. Juze86

    Juze86 Well-Known Member

    I put cooling water in and noticed rear water passages in heads are leaking from both sides, I have to take intake off and seal it again. Gladly I have extra pair of TA gaskets. Strange that both sides are leaking, I used some RTV around water passages. I also have steel valley pan cover made from old intake gasket just like TA instructions says.
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    That makes no difference at all. Leave it in Park. The last thing you want is to accidentally knock it into Drive at 2000 RPM.:Dou:

    Did you clip off the outer portion of the metal gasket? The only thing I can think of is that you have the TA gaskets overlapping the metal gasket. If you use the TA gaskets, the only portion of the metal gasket you need is the center pan.
     
  11. Juze86

    Juze86 Well-Known Member

    First time I made it like this instruction shows. http://www.taperformance.com/PDF/Intake_Instructions.pdf
    So composite gaskets and center pan were overlaying around corner bolts and Im pretty sure that was reason for leak, that overlaying area is too close to water ports so gasket wasn't sealing properly.

    Second time I cutted composite gaskets off around corner bolts so now they are not overlaying anywhere. Tomorrow I'll put water in and really hope it wont leak.
     
  12. Juze86

    Juze86 Well-Known Member

    After break-in I found aluminium flakes from oil and oil filter. What can cause these? Oil pump? Pistons skirts? Bearing failure gives goldish metal right? Oil pressure is 25psi hot idle and 50psi at 2500rpm.
     
  13. Juze86

    Juze86 Well-Known Member

    i took engine apart and found bad scratches from pistons and cylinder walls. Looks like sharp edge in bottom of the cylinder wall has caused these, piston skirt comes about .40 out in BTC and deepest scratches in pistons are that long. In friday I'll get block to machine shop to see if its honable or crap, its already in .040 over.
     
  14. 8ad-f85

    8ad-f85 Well-Known Member

    Sounds like the bottoms of the cylinders weren't deburred, oops...shame on you for missing that.
    Not the end of the world though.
    I'm more concerned with scratches in the iron bore...aluminum doesn't do that. Damaged ring from aggressive installation maybe?
    Huge scratches that can catch a nail might only be a thou or two deep. Usually easy to clean up with a hone (without going oversize).
     
  15. Juze86

    Juze86 Well-Known Member

    Yes bottoms of the cylinders were not deburred and I had no idea they should be. This is my first rebuild and again I learnt something new. Also machinery guy who honed block never mentioned about cylinder bottoms.
     
  16. 8ad-f85

    8ad-f85 Well-Known Member

    Criticism not intended :)
    If that was the only thing wrong then the worst 'should' be damage to the pistons and the cleaning you will need to do.
    Aluminum tends not to scratch iron and a drill powered hone 'should' clean up cylinders, if needed.
     
  17. Juze86

    Juze86 Well-Known Member

    At least in 2 cylinders I can feel scratches with my finger nail. I checked cylinders after piston installation, rings did not made those marks. That picture shows worst cylinder.
     

    Attached Files:

  18. Gary Farmer

    Gary Farmer "The Paradigm Shifter"


    I used to 'accidentally' knock my ST300 into drive from neutral @5000+ RPM at full throttle. I've destroyed TH400's this way after repeated abuse, but the ST300 stood up to it. Who'da thought?

    haha
     
  19. Gary Farmer

    Gary Farmer "The Paradigm Shifter"

    Looks like maybe some of the burs may have turned loose (fine particulates) and got between the piston skirt and the cylinder wall to make those scratches. You should be fine with some more cleanup to make sure it won't happen again (light honing to smooth everything out).
     
  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Never took you for a "neutral drop" kinda guy Gary:laugh: Was this in your younger misguided years?
     

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