1981 Camaro Z28 350 SBC Engine issues.

Discussion in 'Troubleshooting & Diagnosis' started by HB_81Z28_80870, Aug 1, 2020.

  1. Jodi

    Jodi Veteran Member

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    Do you know the type of repair done to the valve guides? It looks to me that this is the source of your engine burning oil issue. The block cylinder wall also looks glazed (fuel wash from the break in period perhaps)but I can't tell for sure from the picture

    Umbrella seal or positive seal? Was a protective cap placed over the keepers groove when installing the valve seals. It doesn't take much to cut the lip of the seal when passing through the keeper grooves.
    Cast iron guide/liner or bronze liners? When liners are used, the existing guide is bored/reamed oversize and then the liner material either cast or bronze is pressed in, a steel ball which is about .001" smaller than the valve stem diameter is passed through the guides and then the guides is diamond honed to the final size which is then verified with a dial gauge.
    Most smaller engine shop do not have the proper equipment to do all the repair listed above properly.


    I've seen/repaired fresh rebuilt engine with very few miles burning oil due to improper valve guide repair. I hope you sort it out... Good luck!
     
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  2. COPO

    COPO Veteran Member Lifetime Gold Member

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    I have Manley valves that are used with no O-ring valve seal.
    D38CC383-8715-4018-9CDF-58F0405ECC86.jpeg
     
  3. rocket dawg

    rocket dawg Veteran Member

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    I had an oil consumption problem for years. SBC 400. Go thru a quart in less than 100 miles. Blue smoke on hard acceleration and when letting off. Not horrible though but still it could be seen. Engine was fresh. My problem was new World Products cylinder heads. They just werent machined right and the intake would not seal just on the bottom edge on both cylinders. The stock GM heads were fine and sealed great so I knew it wasnt a deck problem. Replaced the intake twice and still had the problem. Finally I opted for Trick Flow aluminum heads and no more oil problem.
     
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  4. G72Zed

    G72Zed Veteran Member

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    Sorry to hear about your bad luck, pulling the engine multiple times in a year trying to fix an issue gets very frustrating and expensive and takes the fun out of the "hobby" to say the least. Did the "engine builder" give you any insight on why this is happening, did he provide you with a build or spec sheet? perhaps there is info in there that may help.

    Both Jodi and rocket dawg bring up some very important points. If all is good in that dept. and the PCV system is working correctly you may have other issues.

    That being said, I have been through this scenario many times, and again this year with my own build. Not the "oiling" issue you are having, but how to properly break in a newly built/fresh engine that uses a FT cam. The cam needs to be broken in, and so does the piston rings and bores, and on a new build, this happens at the same time.

    What is critical is the oil being used, the inner/light weight valve springs, or low ratio rockers along with the timing being on the $$ right from the first fire up. The other critical part is the carb NOT being rich and over fueling the engine during break in period. Carb "size" or style is not important, it's the mixture quality in the 1,800 - 2,500 rpm's that's required.

    If the bores and finish are, or were machined and are correct for the pistons & ring pack, and the rings are correct for the piston as in tension and gaps, you might have "glazed over" the bores, and it will be tough to get it back. I would look seriously into this, and ask how it was broken in if it was not done by you.
     
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  5. HB_81Z28_80870

    HB_81Z28_80870 New Member

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    Thanks once again for all the thoughts & theories.
    Since it's Civic holiday here in Canada I have to wait a couple of days to get answers from your questions.
    rchydzik - I took a pic of my temp gauge to verify your thought on the gauge. I tried to figure out the mark from knowing the known values & calculating the 1st line as 100+ 60 = 160*.
    60 as 220-100=120/1/2 scale = 60* & add the base number of 100.
    I believe from what your telling me that I'm most likely wrong as I understand the linear factor you described. I have attached a photo of my gauge to make sure.
    COPO - I am running AC Delco R45TS straight off the timing sticker on top of the rad plate. I also checked to make sure I have 45 thou gap.

    I was told that upon 1st turn over of breaking the motor in to be careful with fuel wash when breaking in cam & piston rings. Flat tappet cam,lifters & piston rings broke in real nice np.
    Motor builders were constantly on me about glazing cylinder walls with fuel wash, So I went with fuel regulator at 5psi & went with complete stock carb set up on my Eddy.
    Most likely will get into deeper discussion later this week with engine builders on valve seals, guides, etc.....
    I did however after the 2nd check & reassembly have someone help me set time on my motor with the ping method, advance till ping then back a hair & tighten down distributor.
    In the winter I ordered top of the line Eqqus timing light & when I brought the car out of storage in the spring I rechecked & found static at 21*, too much..
    I pulled distributor & set up # 1 cylinder tdc & went from there, but the small amount of driving last year collapsed all journal bearings on all 8 cylinders.
    Might have been a good thing it came apart again as the engine builders told me it might have self destructed in time.
    Feel sometimes I can't win. I thought a SBC engine should not be that finicky & easy to set up. Seems not. I have however learned a hell of a lot going through this.
    When I figure this out & make it right I will believe my 30 years of studying Hot Rodding will pay off.
     

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  6. G72Zed

    G72Zed Veteran Member

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    Did the engine builders get on you about using a proper break in oil right from the get go?

    1 year old "mild" (non race) engine build out 3 times for issues and the "engine builders" said it might have self destructed, perhaps due to collapsed journals.

    I don't want to be a Debbie Downer here, but If these words are from them, I would look for a new "engine builder" cause your gonna take it out a 4th time.
     
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  7. 73 Z

    73 Z Veteran Member Gold Member

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    What do the plugs look like, got pics?
    The engine pics definitely look like oil contamination, use Viton seals.
    Nocking and pinging long enough to kill rod bearings, Was the music up loud or is the exhaust that loud?
    What G72Zed said.
    Is this warranty work, wallet work, buddy work?
     
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  8. HB_81Z28_80870

    HB_81Z28_80870 New Member

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    G72Zed - Yes I was given comp cams break in oil for cam, lifters & pistons rings which I used from 1st fire & followed instructions the builders gave me to a "T".
    To be totally honest the timing for the break in was not on the $$ as I had a scat balancer put on at my request & didn't realize I needed a 2 o'clock timing tab, so timing was out,
    but break in was unaffected for cam ,lifters & piston rings. With this issue on the 2nd pull the engine was disassembled & checked by builders & timing tab was discovered & rectified.
    Builders gave me a clean bill of health on motor & I reinstalled, but had same issues with oil burn & loss, which is where I am right now.

    73Z - I looked & I can not find a pic of the plugs & the builders have them, but they were grayish tan coloured.
    Will take a pic when I get them back, but to me they looked OK, except the oil burn around the outside of the bottom of the plug.
    No, knocking or pinging as you asked, unless roller rockers noise was misdiagnosed by me & I was using 93 octane fuel last year before the re time. Now I use 87 pump gas.
    This is a combo of warranty & wallet work, by a reputable shop??? I am at the point of if it's there fault then I'm not paying a cent,but I'm seeing it as 50/50.
    Thanks for the continued support of what could be wrong.
     
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  9. Robert stuart Bell

    Robert stuart Bell Rsb78LT

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    Not sure if that block is cursed or if the shop building it has been letting the new kid do all the work but this definitely does not seem right.
    I completely rebuilt my small block 3 years ago in the back off a dead and gutted caravan, I've put 80,000 on it and beat the hell out of it but it's never had any of these problems.
    If they installed the balancer should they not have known it needed a different timing tab? And all 8 journals collapsing? There's not a chance in hell that's just a coincidence
     
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  10. manicmechanic

    manicmechanic Veteran Member Lifetime Gold Member

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    The big question is how many miles are on the rebuild?
     

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