66 401 Nailhead Re-build/Re-fresh Tips

Discussion in ''Da Nailhead' started by sd-slider, May 16, 2009.

  1. sd-slider

    sd-slider Blue Skies!

    I'm getting ready to pull the nailhead out of the GS and run through the motor with fresh seals, bearings, rings, gaskets, etc. I also plan to do a valve job and hone the cylinders out as well.

    The block has ~69K on it now and I was wondering what parts I could throw back in without too much trouble to upgrade performance and longevity.

    Any advice would be appreciated.

    Thanks.
     
  2. wkillgs

    wkillgs Gold Level Contributor

    Oh boy...where do we start?
    I started a basic ring and bearing rebuild a year ago that escalated into a bit more...
    Start by measuring the bore to see if you have to go oversize.
    Cast pistons are avail for about $300, forged will cost $800+
    If you want a big cam, you will have to go with custom forged piston$$ due to valve-piston clearance issues.
    TA Performance and Poston have some decent mild cam profiles avail.
    Roller Rockers from Tom Telesco or TA will boost any camshaft profile into something that'll kick butt.
    Main bearings are tough to find.
    Rod bearings are same as 455.
    Autozone carries Melling oil pumps, timing chains, and Fel-pro gaskets at a good price.
    Maddog racing and Falcon Global are other good sources for replacement parts.
    If you want to get serious, contact Tom Telesco, Carmen Faso, or TA Performance for the performance stuff.

    Heads....check the valve guide clearance. Gesslerheadporting.com has rebuild services starting at $900.

    Good rebuild threads here:
    http://www.webrodder.com/index.php?page=showStories&pageNum=3&CID=&search=nailhead

    Eric, aka ahhh65riv has a great thread here...somewhere:confused:

    I'm sure others will chime in...
     
  3. doc

    doc Well-Known Member

    First, before you do anything, decide just what kind of performance do you want to come up with.... then build the engine accordingly,,,, for any street driven, engine you need to build it to stock specs as far as practical.... then pick the best cam combo,,, and appropriate pistons,,,, cast or forged,,, and the other embellishments that will make YOU happy....BUT, DONT OVER CAM THE ENGINE....I say go for reliability over ''wow'' and realize that you are building a torque engine not a rpm engine...put all name brand parts in,,,, trw,melling, fel pro, clevite77, ect... now days it pays to rockwell hardness test the lifters,,,, and be double sure to put zinc additive in any brand of oil that you use, every time you change the oil and filter... dont build any buick engine loose like you would a ford or chevy....build it to stock specs,,,, no loose pistons or bearings,,, then ''break it in gently'' and you will have a good reliable engine that will take a pounding.... and not come apart.... port match and just smooth the ports , in the intake, and exhaust manifolds, and heads.....it is worth the effort.... Cut the dividers out from the front and rear barrels of the intake and smooth the cuts out , LEAVING THE CENTER DIVIDER INTACT.... that keeps the torque... dont remove the exhaust heat from the intake manifold of a street driven nailhead...it helps driveability,,,, smooth the oil return areas of the heads under the rocker arm shafts.... BE SURE ON THE REBUILD, TO TAKE THE PLUGS OUT OF THE ENDS OF THE ROCKER ARM SHAFTS AND RUN A RIFLE CLEANING BRUSH THRU THEM TO CLEAN THE CRUD OUT.... IF YOU DONT WHEN YOU FIRE THE NEW FRESH ENGINE UP IT WILL PUMP THE CRUD OUT INTO YOUR NEW ENGINE.... use valve stem seals on the intake side of the valves and run the exhausts ''wet''... gap your new rings.....always replace the cam bearings.... they are your oil pressure insurance.... prime the oil pump before starting up the first time, with a drill motor.... recurve the dist. for a performance boost....lube the cam and lifters with moly grease , not the liquid stuff that runs off in a few hours,,, the grease will stay on there for months and not drain off...arp makes good moly grease.... unless it is a absolute have to, do not align bore the mains on any engine,,,, doing that puts the crank closer to the cam and creates slack in the timing chain that you cannot get out.... use only all steel timing chain and gears ,,, no plastic coated gears....remember, an ''ole Doc'' saying ''If it aint clean enough to eat out of , an engine aint clean enough to put together''.....engine parts soaked in pure simple green for 24 hrs will come perfectly clean in most cases...:Smarty: nuff said.....
     
  4. sd-slider

    sd-slider Blue Skies!

    Thanks for the tips.

    My primary goal is to shoot for a "stock" refresh.

    The only reason I'm even tearing it apart is to re-seal everything. Currently the oil filter mount leaks, the freeze plugs are pissin' on the exhaust manifold, the rear main leaks, and the oil pan gasket leaks. I originally just planned to pull it and replace all of the gaskets and seals.

    I'd be more than happy to just seal it up and not worry about any major performance mods....but, if there are any bolt on or bolt in upgrades that won't violate or stress the motor, I'm willing to add them. I've been through a handful of maintenance and upgrades on my "bone stock" GN just to make it street worthy without tearing anything up. Maybe that mentality is spilling over into the Nailhead project...

    I have a shop that owes me money but I'm not getting a warm fuzzy regarding them doing the work on my Nail...:(

    Any Nailhead guys in San Diego LA area?

    Thanks again. :)
     
  5. doc

    doc Well-Known Member

    OK, you definitly need to take care of the leaking freeze plugs they will cause overheating......and the leaking seals are mainly just annoying, unless they are just pouring....normally an engine is good for about 85000 miles before it starts losing ring seal and pumping oil.... also the timing chain and gears are definitly gone by that time.... a auto engine of the 50s,60s,70s, era was designed to be ''overhauled'' at 50,000 miles and trashed at 100,000 miles...but the heat of 195 deg. thermostats takes a toll on the seals and gaskets.... when those engines were designed the norm was 160 to 180 deg. thermostats and 220 deg was the shut off point....back then when we installed a a/c unit in a car, part of the kit was a new temp sending unit that registered lower temps when the car was near the boiling point.....:Brow:
     
  6. wkillgs

    wkillgs Gold Level Contributor

    Since you are in California, contact Russ Martin. He's the west-coast Nailhead guru.
    He's north of you....he relocated to Grass Valley from Fremont.
    http://www.nailheadbuick.com/

    Before you go too far....make sure the water leaks are from a freeze plug, and not a cracked block. The blocks often crack on the side when they freeze. Hard to see until you take off the exhaust manifolds.
     
    Last edited: May 19, 2009
  7. 66electrafied

    66electrafied Just tossing in my nickel's worth

    I would also add that it would be a good idea to recheck all of your machine shop's measurements when re-assembling the motor, - just to be on the safe side. These engines like to run tight, no slop, and no sloppy "it works for a small-block" machining. If you're going to re-use your old intake, make sure to get a new "plug" installed in the bottom; - they work loose with old age, and doing this solves a lot of untraceable vacuum leaks that might crop up.

    Get the block professionally cleaned, it's worth the money. Same goes for the heads.

    Double check your frost plugs, get the block and heads magna-fluxed. Besides the foot long crack that was obvious in my old block, there were a number of smaller cracks emminating from the frost plugs. Always put new frost plugs in!

    Install new guides and new valves; - avoid the hardened seats unless you really trust your machinist. There's a good chance he'll hit water or crack those heads if he isn't good enough or experienced enough to put in new seats.

    Line up your lifters before installing them; - I had a set that came from a large national vintage parts supplier that were mismatched right out of the box. Beware of any foreign made parts, they're generally not good enough.

    New cam bearings are a must when loading in a new cam. The old one is probably shot, so bank on throwing a new one in. Like Doc says, decide how driveable you want to make the car; - and use lots of zinc in the oil on startup, and there ever after on oil changes.

    Try and replace the rope seals with neoprene on the crank; if you decide to go purist and use them, it's about 50-50 that they'll leak. Doing them right is all about experience, and if you choose to use them remember that the initial run-up speed can't be more than 1000 rpm; - otherwise they could burn. I'm sure the guys that have built thousands of nails like Doc have a better way to do them - I opted for modern neoprene replacements, and they don't leak.

    I'm not sure what the rule of thumb for sleeving a block is with a nail, but usually if the block is worn over 40 thou, consider sleeving the cylinders.

    A good machinist is the difference between a crappy engine overhaul and a good one. Anyone can throw expensive parts at a warmed over and slightly honed block and then wonder why it's still a pile of junk; - but a well machined crank and straight block makes all the difference in the world.

    And last but not least, - take your time enjoy what you're doing! If you rush it, or find it a stressful chore, pay someone to do it!
     
  8. sd-slider

    sd-slider Blue Skies!

    Don't think thats an issue..at least I hope. The car has never left SoCal according to the history of it.
     

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