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Technical Help with 59 Bonneville 389 ..

Discussion in 'The Hokey Ass Message Board' started by Sparkyman, May 26, 2017.

  1. Sparkyman
    Joined: May 25, 2017
    Posts: 7


    Hi all,

    Not sure if I'm in the right place to start with, but I guess I'll soon find out ...

    Have just acquired a 59 Bonneville in need of a full restoration, not least the 389 2bbl which is missing parts, crucially the cylinder heads. Car is in transit, so thought I'd try and find some qualified information on this engine while awaiting delivery.

    Getting up to speed on this model year, I note that 59 was last year of reverse flow cooling, heads having end ports ....which I guess restricts alternative year head fitments ?

    Can anybody help shed some light on my options here ?
  2. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,110

    from Kansas

    Looking at some of the later heads, it looks like there is a freeze plug where the old water inlets were. It may be possible to remove freeze plugs and install inlets.
  3. Bird man
    Joined: Dec 28, 2009
    Posts: 594

    Bird man
    from Milwaukee

    stillrunners likes this.
  4. 30panel
    Joined: Sep 12, 2007
    Posts: 129


    I've been running a 389 dual afb's, 59 block with a 57 gusher pump and 61 heads, no tubes stays at 180 all the time. I have a article on Pontiac gusher water pumps, I'll look for the link send it to you.
    As you get in to it, Pontiac's have some of common components, just take's some research.
    Try the Wallace web site for some info.

  5. I'm running an early Pontiac motor with later heads and the "gusher" reverse cooling setup. There are several considerations to look at before doing this head swap. The easiest way to go about it is to simply use 1959 heads on your engine with the tubes in the ends of the heads and the water elbows hooked up as original.
    However, I and 30panel don't do "easy". I used heads from the 70s with bigger valves, screw-in rocker studs and push rod guide plates. I needed to get the compression down a little with the Jahns pop-up pistons so I use late heads with 96 ccs. Now, the rocker oiling is different from 65-later and 55-64 engines. The later engines oiled the rockers with hollow pushrods and the earlier engines also had hollow pushrods but had an oil galley running all the way down the length of the head. The rocker studs extended down into the heads into this galley. The studs are hollow and have a little hole drilled into their sides to help oil the rockers. The oil gets into that galley from a passage in the block that corresponds to a hole in the head that feeds into that galley.
    I just tapped the oil feed hole in the block with an 1/8th inch pipe tap and screwed a n 1/8th inch pipe plug into the hole. I'm relying on the hollow pushrods to do the rocker oiling....that's how the later Pontiac engines oiled and I dont' see why it won't work for my early engine.
    Now, there's the issue of the cooling holes in the fronts of the heads. It gets a little tricky here. The bolt holes for the elbows are the same for early and late heads BUT!.....the cooling passage hole is offset to one side on the late heads. I made up a pair of 1/4 inch thick "adapters" with the hole offset about 1/2 way between the old and the new patterns. They allow me to use the coolant elbows on the late heads and the gaskets will cover [barely] the sealing surfaces. I'm making it sound a lot more complicated than it is. If you use a gasket and an elbow from a 59 and earlier motor and hold it up against the later head, you'll see what I'm talking about.
    This brings up the issue of the cooling tubes in the heads...forgetaboutit. The late heads will not accept those tubes for the early heads period. They're made different so you'll have to leave them out and I say so what? The 60 and later Pontiac V/8s not only didn't use them. the coolant came from the water pump, down through the block and only then did the coolant come up to the heads, to the front of the heads and into the intake where the thermostat is. The coolant was already heated by the block before it gets to the heads and those engines cool just fine. I wouldn't sweat the cooling...I'm not.
    So, late heads will work on early engines but there's a little screwing around to make 'em fit.
    BTW, using those 1/4" spacers or adapters on the fronts of the heads helps the coolant elbows line up with the water pump housing. Yeah, it seems the late heads are about 1/4 inch shorter than the early heads so the 1/4 inch spacers line everything back up. Maybe you can see it in the photo .
    All this diatribe is strictly theoretical because I have yet to put coolant in my engine...haven't gotten that far yet. 370altbrackets.jpg
    62hotcat and clunker like this.
  6. 30panel
    Joined: Sep 12, 2007
    Posts: 129


    Rocky Excellent step by step instructions just follow the dots, good to go.
    Fire it up!
    The real trick was put all this inside my closed hood, the old 10 lbs in a 5 lb box, and Hydro too ?

    Attached Files:

    62hotcat, 31 B'ville and pigfluxer like this.
  7. Sparkyman
    Joined: May 25, 2017
    Posts: 7


    Hi guys, thanks for the initial replies, links and insights - seems I've come to the right place after all !
    We had originally hoped to restore to original, but we may ultimately decide to customise slightly...early days yet.

    Rocky - so the oil gallery in the block, which feeds the rocker stud gallery in the 59 heads, needs to be blanked off in order to use later heads ? This is simple enough. Regarding hose elbows and fabricating adaptors, I guess it would be just as feasible to fab some custom elbows, with the correct flange to suit a later head& gasket, and get the pipe alignment right to suit the pump ?.... or have I missed something critical here ?

    I'm not sure how easy it's going to be to find any Pontiac heads in the UK - the predominant US Engine parts specialist have odd stock of things, but if later heads can be used after all, then there are a few Trans-Am/Firebird guys over here that should be able to help. I'll start getting in touch with them, previously passed them over as nothing for 59 on their inventories.

    Appreciate continued support on this and other aspects of this 59 Bonny - will be needing lots of help along the way....with everything !
  8. manyolcars
    Joined: Mar 30, 2001
    Posts: 8,378


    Lets see a picture of your Widetrack
  9. Sparkyman
    Joined: May 25, 2017
    Posts: 7


    Photo attached
    Body restoration started last week, lots of perforated panels !
    Need guidance on how to tackle the trunk gutter and rear deck/pinch weld area ..... WP_20180324_033.jpg WP_20180324_013.jpg Bonny.JPG
    Texas Webb and 62hotcat like this.

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