G'day, just bought a GS455 and drove Sydney to the Gold Coast.

Discussion in 'Street/strip 400/430/455' started by OZGS455, Jul 8, 2018.

  1. OZGS455

    OZGS455 Oh what a wonderful day!

    over 2 days a bit over 500 miles, car is 1971 GS455 Stage 1, with engine rebuilt to 1970 spec evidently.
    Car ran great on the trip, was a real joy to drive and I got the hang of driving left hand drive on the left side of the road reasonably quickly.
    Just a couple of things.
    'Car has had a SAAS water temp gauge fitted under dash as well as the standard factory gauge, its rated in Celcius 80C being 180F and 100C IS 212F (boiling point of straight water) 120C being 250F (HOT!)
    Temp gauge was steadily rising and falling between 80 and 125C the whole trip.
    Factory gauge showed a 1/4 way up the scale most of the trip without much variaton (note it did go to full hot when car turned off?...I sorta thought gravity would take it down to cold)
    Checked a few times along the trip and engine didnt show any normal signs of overheating, no coolant blowoff out the pipe, no smoke from engine, could touch the radiator and engine, not for long of course but it was touchable.
    Looks like the temp senders are in the inlet manifold towards the front of the engine.
    If its not a faulty gauge I'm thinking maybe a thermostat issue.
    Engine, in fact whole car is in excellent condition, and previous owner tells me an aluminium radiator has been fitted.
    Im about to change the oil and doing a bit of research I find that these 455s dont particularly like or need thick oil, even in Aussie climate a 30 weight sounds about right, straight dino oil, with a good zinc package from what I can gather, no oint really mentioning brands as what you use in the US aint the same as what we getr here.
    I also own and ride a VICTORY motorcycle and am on a US based forum so I know what sort of debates can potentially start on the subject so lets leave brands out, I use Penrite semi-syn 15-50 diesel oil (JASO MA) in the Victory.
    Normally Id use Penrite 20-60 (30) mineral (dino) in an engine in good condition here.
    Some stuff I see on the internet suggests thinner oil, but thats in US where you get sub zero C temps.
    My other issue is auto trans related so Ill take that to the relevant section.
     
    moguy79 likes this.
  2. BYoung

    BYoung Stage me

    Welcome from GA. Post some pictures of your car.

    For oil, I run 10W 30 in mine.
     
  3. LARRY70GS

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

    1/4 up the scale on the stock gauge is 180* F. I suspect the gauge, or if the gauge was moving between extremes, a sticking thermostat.

    As far as oil weight goes, you should use the thinnest oil that gives you satisfactory oil pressure, 11-12 psi/1000 RPM. Thicker oil just wastes energy in pumping losses and on a Buick engine, puts more stress on the front of the cam, which drives the oil pump and distributor.
     
  4. OZGS455

    OZGS455 Oh what a wonderful day!

    Sounds like I need a good oil pressure as well as a good temp gauge, vacuum gauge may come in handy too.
    Right now though I need sleepo_O
     
  5. flynbuick

    flynbuick Guest

    Perhaps an air pocket could cause the gauge fluctuations.
     
  6. OZGS455

    OZGS455 Oh what a wonderful day!

    Yeah, possible, its got the sealedsystem with overflow tank and says not to remove cap.
    Ive tried removing cap when engine is cold but its stubborn.
    It turns a few degrees left then stops, this is pushing down and turning
    Ive removed thousands of rad caps in my life and never struck one like this...
    Whats the secret?
     
  7. LARRY70GS

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

    Make sure your hand is dry, then push down harder and turn:)
     
  8. OZGS455

    OZGS455 Oh what a wonderful day!

    Yeah got it open, really had to push down very hard to turn it but, was down a little on coolant so I topped it up and ran it then refitted cap.
    Ill see how the gauge behaves now before possibly canning it
     

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