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BRINGING IT ALL TOGETHER.... A's, G's & E's


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richie61
RodStRace
Scott
donivan65
Digz
econopoor
softesttouch
11 posters

    first engine rebuild

    softesttouch
    softesttouch


    Number of posts : 64
    Location : montrose,colorado
    Registration date : 2010-10-22

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    Post by softesttouch Tue Nov 30, 2010 7:41 pm

    i am tearing down a 230 straight 6 from my 66 gmc van. I AM NOT A MECHANIC (i'm a dentist) and the level of my expertise is 'oh, so that's what a pushrod/rockerarm/lifter/etc. is' , but am trying to be methodical in my mission--have been labelling everything during the tear down. using as a guide an article from chevytrucks.com--it describes a 57 chevy 6 (stovebolt?). so far i have taken the aforementioned parts plus the valves off. here are my findings and questions:

    everything looks in good shape, surfaces smooth, not worn or pitted. pushrods straight. everything this article tells me to look for regarding wear comes up a negative. maybe i'm just not looking closely enough, but it all looks pretty dang sweet!

    there is carbon buildup everywhere, like i would expect (except excessive on the larger valves of the 2nd, 3rd, and 4th cylinders from the front of the engine).

    the symptoms of this vehicle when it last ran 5 years ago were that it lost [/u]alot[u] of oil as it ran, and it never generated much power. one time my wife was following me in another vehicle on a road trip and she wondered why she was having a hard time seeing out of her windshield, only to discover later that it had a fine mist of oil on it! i used to add 1 quart oil for every 150-200 miles. top highway speed was only about 55. i am surprised the 'innards' are not worse off than they appear to be. the van has 91,000 miles on it-almost positive the odometer has not rolled over.

    -is it possible that all this engine needs is a good deaning and a 'valve job' or a 'ring job'?
    -how do i find a manual for reassembly and where?
    -is this 66 straight 6 significantly different than the 57 stovebolt whose article i have been referring to?
    -what might be the cause of an engine that looks so good internally (the head, anyway) perform as poorly as describe above?
    -what are strightforward practical economical ways to get higher performance out of this engine?
    -what do i use to clean up the parts? back on the farm, we used gasoline as a solvent, but i doubt it and a wire brush are the way to achieve the desired result.
    -why are lifters called 'hydraulic lifters' when it looks to me like they are activated by riding a cam, and have no 'hydraulic' component?
    -finally, on the subject of body work--parts on newer vehicles can just be taken off and replaced. how is it done on these old vans--to get the contour right, to get that subtle ledge right, etc. easier with putty than metal, but boy, it seems like it would be an artform. is there a trick or some information i can be referred to?

    thanks for all your help and support.
    joe
    econopoor
    econopoor
    Econoline Guru


    Number of posts : 1747
    Location : Jackson TN
    Registration date : 2010-04-18

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    Post by econopoor Tue Nov 30, 2010 8:00 pm

    Hello Joe,

    When taking apart an engine it's very important to keep everything where it belongs. The rocker arms, pushrods, lifters, all need to go back exactly where they came from. If you move them around the will wear faster. They need to stay together because of the wear patterns. When you get to the bottom end you need to number the rods, rod caps and the main caps so they go back where they came from. They are machined in place and need to stay in the same spot. Now, if you are going to replace everything it won't effect you but it should still be done just in case. A 230-250 is nothing like a Stovebolt 6. Nothing interchanges. Total redesign. Hydraulic liters are called that because they have a small piston and spring inside them. This gives it some room for error in the valve adjustment that solid lifters don't allow. The piston rides in about the center of the lifter body and maintains valve lash with oil pressure. Solids have to be right on the money. No tolerance. Hyd's can be quite a bit out of center and still work fine. If a car following is getting oil on the windsheild then it's probably from a leak. If the engine was burning oil it would just go up in smoke.

    Hope I was of some help.

    Duane in Tennessee.
    softesttouch
    softesttouch


    Number of posts : 64
    Location : montrose,colorado
    Registration date : 2010-10-22

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    Post by softesttouch Tue Nov 30, 2010 8:05 pm

    hey duane, thanks for the speedy reply. every bit of info help build my foundation- your input has been helpful. joe
    Digz
    Digz


    Number of posts : 3794
    Location : United States Six Lakes MI
    Registration date : 2008-05-17

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    Post by Digz Tue Nov 30, 2010 8:15 pm

    ST
    For me a Motors or Chiltons repair manual for the era of the van would be a good start and thing to have. If you do valves you might as well figure on rings and it sounds to me like your 230 needs attention on both fronts. One other thing you should check is cylinder taper, for this ideally you will need to drop the pistons and connecting rods out, Use and old ring and check the end gap at the top and again at the bottom of the cylinder bore, a heavy ridge at the top of the bore will probably indicate you have something like that going on anyway. It sounds like you have the cylinder head already off? if so a compression test is not do-able?
    You might find you are at a stage to find another running engine and come out cheaper than having to doa major overhaul and also you could make the jump up to a 250? If you go this route make sure you find an engine that is perhaps still in the vehichle and you can hear and maybe see run, dont take somebodys word for it !
    For tricks and tips ,, just research the forum archives on any and everything ,,there isnt much that hasnt been covered on this site.
    also ask away on anything
    another Joe,

    donivan65
    donivan65
    Governor
    Governor


    Number of posts : 12225
    Location : San Diego, California
    Registration date : 2008-05-12

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    Post by donivan65 Tue Nov 30, 2010 8:20 pm

    I think you are wasting your time and money,,,,,the engine needs to have close tolerances to perform correctly,,,,the cylinder bores are probably worn out of tolerance and are tapered,,,, the valves need to be reground and new guides installed,,,,the crankshaft probably needs to be reground,,,,bottom line,,,,this is a job for a machine shop or buying a rebuilt engine,,,,putting new parts in an old engine will just put you back where you started,,,,,an oil leaking, oil burning, gas wasting vehicle,,,,,,,,you need to do it right the 1st time and be done with it,,,,,,
    Scott
    Scott


    Number of posts : 1651
    Location : Anoka, MN
    Age : 54
    Registration date : 2008-05-20

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    Post by Scott Tue Nov 30, 2010 8:35 pm

    Hey Softesttouch,

    I'm kind of like you in that I know a little, but not everything I've needed to do everything I've done. My day job is managing computer systems, my nights and evenings are spent working on the van, and grilling people on this site for information.

    I also spent a small fortune on books, if you check out the Photobucket link at the bottom of my posts you will see what I've scanned so far. The specific link right under this paragraph will take you to the Engine Overhaul Manual. (Password: unlock)

    https://s829.photobucket.com/albums/zz213/gVanSource/68%20In-line%20Overhaul%20Manual/

    Good luck, and be sure to post some pictures, people on here are picture junkies.
    econopoor
    econopoor
    Econoline Guru


    Number of posts : 1747
    Location : Jackson TN
    Registration date : 2010-04-18

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    Post by econopoor Wed Dec 01, 2010 4:36 am

    About being down on power, That can be from so many different sources. How did the spark plugs look? Were any of them fouled? Where all the valves seating properly?
    Duane in Tennessee
    RodStRace
    RodStRace


    Number of posts : 3046
    Location : Chino Valley
    Registration date : 2010-01-21

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    Post by RodStRace Wed Dec 01, 2010 6:43 am

    A fine mist on the car behind sounds like leaks, but could also be (Exhaust) valve guides. This is usually burned due to exhaust heat, but if it's a lot, some could be passed without burning. It would smoke badly, though.
    A machinist will be able to inspect the head and components to determine what needs to be done.
    Oil leaking past the intake guides and/or rings will more likely be burned.
    Before disassembling the block components, consider what your plans are. If you want a machine shop to rebuild it, they will want to inspect some things before disassembly. If you plan on purchasing a rebuild short block, carry on disassembling for your own knowledge.
    You can buy a short block or a long block.
    http://en.wikipedia.org/wiki/Long_block
    http://www.enginefactory.com/Block_Descriptions.htm
    Both will require reusing some of your components. These should be taken to the machine shop for cleaning, unless you are enjoying the process.
    Cleaners range from Simple Green to solvents. All should be handled with care and protection.



    RodStRace
    RodStRace


    Number of posts : 3046
    Location : Chino Valley
    Registration date : 2010-01-21

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    Post by RodStRace Wed Dec 01, 2010 6:53 am

    Note that you will need the valve cover, front cover, harmonic balancer, side cover, manifolds, distributor, oil pan, and all fasteners for these items to complete the rebuilt long block. You also want to install good or new starter, water pump, fuel pump, hoses, belts, sending units and thermostat.

    To see pictures, go to the sites, the pics are too big.

    long block
    http://www.remanufactured.com/_borders/3.0%20L%20longblock%20marine%20port%20side.jpg

    short block
    http://rebuilt.net/3.0_marine_short_block1.JPG

    richie61
    richie61


    Number of posts : 445
    Location : Van Nuys, CA
    Age : 63
    Registration date : 2010-01-04

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    Post by richie61 Wed Dec 01, 2010 9:48 am

    I helped my friend... a golf pro....do his V6 in a ford exploder. After all the top end work he did and as careful as he was labeling and putting it back together, it made it from LA to Primm, NV before it blew up again and I had to tow him home. I am not a mechanic as well, just a weekend warrior. I'm about to pull my engine as well but plan to take it and let the right people do it. As much as I'd like to say I did it myself, it would be all for not if I put it back in back together wrong and I had the same thing happen to me.
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    Guest
    Guest


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    Post by Guest Wed Dec 01, 2010 1:11 pm

    One thing many don't do is to re-torque the rod bolts.

    Run a motor for about fifty miles or so, drop the oil pan and re-torque all of your rod and journal bolts.

    Then break it in.

    You might be shocked, and happy you did.

    But for now, you need to star taking measurements, to see what's usable, and what need's to be replaced.

    Of that which measures out good, send it out to have it all hot tanked and magnifluxed, to clean and check for cracks and things the eye cannot see.

    What comes back good from that is where the fun begins.

    Want a really nice running motor?

    Send the moving parts, the harmonic-balancer, the crankshaft, rods, pistons & pins, flywheel, along with a new clutch and pressure-plate, everything that rotates on the crankshaft, send it all to a reputable machine shop and have it balanced as one unit.

    Your reward will be significant in both performance and longevity, not to mention smoothness of operation.

    mo_1040
    mo_1040


    Number of posts : 645
    Location : Hibbing, Minnesota...The land of 10,000 rednecks
    Age : 53
    Registration date : 2008-07-04

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    Post by mo_1040 Wed Dec 01, 2010 4:52 pm

    I agree with Don... It needs to be done right or your wasting money building a motor that you'll get very few miles out of. Have it done right the first time with the help of a machine shop. There is alot of stuff that can be done by a novice mechanic but with the experience that you describe...I would leave the rotating assembly and head/valve job to the machine shop.
    econopoor
    econopoor
    Econoline Guru


    Number of posts : 1747
    Location : Jackson TN
    Registration date : 2010-04-18

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    Post by econopoor Wed Dec 01, 2010 6:10 pm

    I agree with everybody else. This is a job better left to the pros. I built a 250 Chevy back in 84. Spent a ton on it. New valves, guides, springs, seats, in the head. I polished the crank, bored the block, new pistons, resized and trued the rods, all new pumps, It was a nice engine, When I built it I had a choice of six machine shops to do the work. Today there is only one left in town. It's hard to find a good shop. Ask around before you trust a stranger.

    You can get a rebuilt engine from any of the chain parts stores but keep in mind. They are out to build them as cheap as possible. Parts are mixed matched, All the rods go in one bin and everything gets worked to get it back to spec. Not to match. You lose the blueprint factor when you get a assembly line rebuild. It cost more for a pro shop to build you an engine but I think it's money well spent. Attention to detail. Quality parts, The best gaskets money can buy. That's the key ingredients to a quality engine. I also think having it built by a person that has something to lose if it comes back is better than some flunky making minimun wage and doesn't care if it gets returned is better.

    Duane.
    BILLS66
    BILLS66


    Number of posts : 1383
    Location : Salem Or.
    Age : 64
    Registration date : 2008-05-17

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    Post by BILLS66 Wed Dec 01, 2010 6:38 pm

    I would say unless you really want to do it yourself( and thats ok just ask lots of questions and have the machine work done by a pro) have a reputable shop rebuild yours and yes have it balanced and bored with new pistons if nessesary .I wanted to do as much as i could myself when doing the V8 conversion on my van but a pro did the short block. Bill
    donivan65
    donivan65
    Governor
    Governor


    Number of posts : 12225
    Location : San Diego, California
    Registration date : 2008-05-12

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    Post by donivan65 Wed Dec 01, 2010 7:19 pm

    ,,,,,,as for your other questions,,,,,,,I use paint thinner to clean the grease off everything,,,,,,,,let the rag set outside and the thinner evaporates, you throw the dirty rag away,,,,,,,,Oven cleaner works the same way,,,,,,,and they make some replacement parts for our vans,,,,,,the whole van is just pieces of metal spot welded together,,,,,,I have bought metal filing cabinets from Goodwill for a few dollars and cut metal patches out of it to weld into rusted out areas,,,,,,,van is real user friendly,,,,,a blacksmith could do the bodywork,,,,,,


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    Vanadian
    Vanadian


    Number of posts : 187
    Location : Bragg Creek, Alberta, CANADA
    Registration date : 2010-11-17

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    Post by Vanadian Sat Nov 12, 2011 6:03 pm

    Anybody know if I can easily stuff this in my 65G?

    Vortec 4.2L DOHC I-6
    Engine type 4.2L DOHC I-6
    Displacement (cc) 4,160
    Block/head material aluminum/aluminum
    Bore x stroke (mm) 93 x 102
    Horsepower (SAE net) 275 @ 6,000 rpm
    Torque 275 lb.-ft. (373 Nm) @ 3,600 rpm
    Specific output 65 hp/L
    Compression ratio 10:1
    out of a Chevrolet TrailBlazer
    Fuel economy for tested vehicle (EPA city/highway mpg) 15/21
    Twinpilot001
    Twinpilot001


    Number of posts : 6186
    Location : spokane ,Wa.
    Registration date : 2009-09-28

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    Post by Twinpilot001 Sat Nov 12, 2011 6:32 pm

    Y=??
    Vanadian
    Vanadian


    Number of posts : 187
    Location : Bragg Creek, Alberta, CANADA
    Registration date : 2010-11-17

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    Post by Vanadian Sat Nov 12, 2011 8:24 pm

    hmmm? What I am wondering is...I currently have the same issues. I have a 230 that is spaying oil out the back. It is very under powered for what I would like. (I just need to be able to accelerate up hills and reach the speed limit without putting it to the floor) I am considering a rebuild of a 250. But while researching I-6's, I came across this modern Vortec 4.2L DOHC I-6. I'm just wondering if anybody has tried to swap a newer I-6 in an early?

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