BBC oil gallery plugs-drill holes?

Discussion in 'Oil and Lube Systems' started by Richard Tice, Mar 29, 2019.

  1. Richard Tice

    Richard Tice Member

    I see that many people advise drilling .030 holes in the front oil gallery plugs. On this site, Grumpy advises drilling only the passenger side. I drilled both of mine with a 1/16" bit since it was the smallest I could find.
    I am having a problem with oil coming up to the rockers. 1976 MK IV BBC engine with Lunati HR cam and retro fit street performance lifters (#72331-16), Harland Sharp rockers. It will take 1-1/2 minutes for oil to show up at the rear rockers, then another minute or so for some others show oil, but the #1 exhaust takes 6 minutes to get oil.
    Does anyone know if the larger holes in my oil gallery plugs could be the cause of this delay? Should I replace them with the proper size hole plugs? Or replace them with solid plugs?
    Thanks,
    Rich
     
  2. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    your oil pump should very easily provide 2 gallons or more of oil volume per minute even at lower rpm idle speeds ,
    those oil spray holes drilled in the front oil gallery, passages are not your main issue.
    the most likely problem, (but certainly not the only possibility)
    is the oil pump pick-up is being restricted by being too close to the oil pan floor
    on most engines this MUST be checked carefully, but most people fail to do so.
    they assume if the pan bolts on, its going to be fine
    your oil pump may be loose , not secure to the rear main cap,
    and certainly having two over size holes drilled in the gallery plugs is not ideal.
    the oil pump pick-up may not have the correct clearance,
    you may have the rockers adjusted too tightly,
    or the distributor lower band diameter is significantly smaller than the block,
    allowing a significant loss of oil pressure reaching the oil passages
    why not start by doing a couple quick tests,
    (1) add 1 quart of oil too the pan, and back the rockers off one full turn each,
    if the rockers are too tight oil flow volume from the push rods is greatly restricted
    http://garage.grumpysperformance.com/index.php?threads/correctly-adjusting-valves.196/

    (yeah it might be noisy but it won,t hurt anything during a quick test)
    if you see a significant improvement in oil flow the rocker adjustment was not correct
    (very COMMON)
    now spin the engine over with the starter with the coil wire removed ,
    if you don,t see oil exiting the rockers in 60 seconds ,
    you really need to check that oil pan to oil pump pick-up clearance.
    if clearance issue checked with clay and a temp re-install on the oil pan to check clearance, checks ok,
    you likely need to swap to a new oil filter , fill the new oil filter before its installed with oil and repeat, (try WIX or PUREALATOR) and if the issue does not improve you likely have an oil plug missing or incorrectly installed some place.

    http://garage.grumpysperformance.co...ilter-you-sellect-does-make-a-differance.117/

    I really wish I could stop by all of the guys who, post questions,
    about having problems, as most are simply resolved with few tests


    while your checking put some modeling clay under both pick-ups and see the effective clearance difference then see if the old pump clears the problem, in an ideal world the pick-up to pan floor clearance is a minimum of 3/8" and 1/2" is ideal
    every time the oil pump completes a revolution a predictable volume of oil is forced up the pump into the oil passages, in the block,
    even at idle or about 700-750 rpm, thats several gallons a minute.
    you can restrict the oil flow into the pump , rather easily,if the oil pump pick-up, too oil pump floor clearance, won,t allow oil to enter the pump due to very limited access,
    as its not pressurized, once its flowing thru the oil passages, pressure is a measure of the resistance to flow through the clearances in the bearings and clearances.
    If oil fails to exit the push rods its obviously either exiting else ware or not able to flow into the push rods from the lifters and lifter gallery.
    [​IMG]
    be sure not to insert oil passage plugs into oil gallery passages too deeply
    [​IMG]

    [​IMG]
    [​IMG]
    threading the oil passage plugs increases durability and I generally suggest drilling an oil pray jet hole thats .031-.035 in the pass side oil pass plug, THE ONE AS YET UN THREADED IN THE PICTURE ABOVE
    [​IMG]

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    PLEASE post the results you get during testing,
    and info you find,
    as its sure to help others in the future


    http://garage.grumpysperformance.com/index.php?threads/installing-an-oil-pump-pick-up-tube.1800/

    http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/

    http://garage.grumpysperformance.com/index.php?threads/bbc-gen-vi-no-oil-pressure.14987/#post-84634

    http://garage.grumpysperformance.com/index.php?threads/not-getting-oil-to-rockers.4537/
     
  3. Richard Tice

    Richard Tice Member

    Thanks for the information, that's very helpful.
    My pickup is just a tad under 3/8" from the bottom of the oil pan. Maybe I can coax a little more depth from the pan without removing it completely. Will another 1/8" make a difference?
    Thanks,
    Rich
     
  4. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    Your 1/16" drill bit measures .0625". The hole you were supposed to drill measures .030".
    The hole you drilled is NOT twice as big as the .030" - it's 4 TIMES BIGGER in AREA. Remember PI x R SQUARED???
    Double that because you drilled 2 of them. You are leaking an additional 7 times the oil you need to oil the chain and bleed air.

    This is NOT the sole cause of your delayed oil to the rockers, but if I were you, replace those plugs with solids - no holes.
    The timing set gets plenty of oil as designed.
     
  5. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    adding an additional 1/8" clearance to the oil pan to oil pump pick-up certainly will help,
    Id suggest you tig or braze a couple 7/16" nuts to the edge of the lower oil pump pick-up,
    like the clay in the picture ,
    to make sure the clearance is maintained when its re-installed.
    and the suggestion to replace the oil passage plugs with solid ones,
    has merit in this case
    drilling just the pass side plug with a 1/32" drill,
    is the recommended route,
    but not drilling either will work also

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    Attached Files:

    Last edited: Mar 30, 2019
  6. Richard Tice

    Richard Tice Member

    Reading through some of your extensive info on lifters, I'm also wondering if maybe my pre-load is too much. For a cast iron block and aluminum heads (Edelbrock Performer) Lunati recommends a pre-load of .030-,035" or about 5/8 turn on a 7/16" stud. I've done this and then added a little more because of the valve train noise, but I see you recommend less (1/4 to 1/2 turn after 0 lash). That would only be about .012-.025 on a 7/16" stud. I've been doing this cold, and you recommend adjusting while running. I'm going to try that next.

    Also, I selected my push rods by using Scott Foxwell's mid-lift method:
    This has given a narrow sweep on the valve stem nearly centered, but was nowhere near the push rod length that the pro-form checker suggested.
    Could that have an effect on oil delay to the rockers?
    Again, the oil does get there, it just takes a long time.
    Thanks,
    Rich
     
  7. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    yes the push rod length, and the lifter pre-load both has a very noticeable effect on the oil flow rates to the rockers
    the lifter seat, distance of travel from fully extended on the cams base circle to the fully depressed on the lobe nose,
    controls the volume of oil that can be forced up the push rod,
    and keep in mind the rocker oil feed hole and push rod feed holes only line up for oil flow during a few degrees of engine rotation.
    Id strongly suggest backing off each rocker until the rocker clicks rhythmically as the engine idles,
    , then slowly tighten the slack in the valve train just until the clicking stops,
    at that point add a 1/4 turn pre-load,
    do this for the whole engine then check rocker oil flow rates


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    http://garage.grumpysperformance.com/index.php?threads/not-getting-oil-to-rockers.4537/

    https://www.chevydiy.com/chevy-big-block-performance-valvetrain-optimization/

    http://www.ratwell.com/technical/HydraulicLifters.html
     
    Last edited: Mar 30, 2019
  8. Richard Tice

    Richard Tice Member

    I tried your method of backing off the rocker poly lock while idling, hearing the clicking and adding 1/4 turn. The rockers got quieter, but starting it up the next day, I still had to wait for 6 minutes for the #1 intake (that's the only rocker I can see through the valve cover oil fill hole) rocker to start showing oil. BTW, these are Harland Sharp roller rockers and there is a recess around the pushrod cup oil hole that allows oil flow at any angle.
    Could the lifters be at fault?
    Thanks,
    Rich
     
  9. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    perhaps I'm the only one here that seems to see the rather obvious route?
    why not replace the forward oil gallery plugs,
    and not have any hole in the drivers side plug ,
    and the correct 1/32 hole in the pass side plug ,
    or no hole at all.
    thats proven to work well. in most cars thats only a 1- too at most-3 hour job,
    and you've eliminated one potential issue.
    and its not expensive its a only a couple gaskets replaced
     
    Last edited: Apr 9, 2019
  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    The Supply of modern Hydraulic lifters is real Shoddy bad for Flat Tappet and Roller cams.
    China.

    Just Crower and Isky have been reliable.

    Try putting 3/4 - 7/8 turn lifter preload on.
    I set them with the engine off today.

    GM called for 3/4- 1 full turn lifter preload in vintage service manuals.

    I went 7/8 turn preload on my Olds 425 V8.
    No valve float or lifter pump up at 6000-7000 rpm.
    It has original GM Johnson made lifters.
     
  11. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    I used to go just 1/8 turn preload.
    It does not work no longer with modern lifters.

    Want Revs a Solid Flat Tappet or Solid Roller Cam is best.
    All top end oiling issues eliminated.
    China lifters not used also all made in The USA.
     
  12. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Offbrand rockers are bad too.
    Engineering faults everywhere.
    Junk.
     
    Last edited: Apr 9, 2019
  13. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    Change to solid plugs, as Grumpy said, to eliminate the possibility of that being your problem.
    I had this same problem, and in my case, it was the lifters!
    I'll give you the short version of the story:
    No name white box lifters bought from Skip White - Guaranteed Made in the USA - he claims.
    Actually made offshore - Mexico, China, India & Turkey. As long as the company is headquartered in the US, they can get away with saying that.

    The Delphi lifters I bought: http://www.skipwhiteperformance.com/detail.aspx?Item=J-817, and say:
    You will receive genuine Delphi / GM lifters. Use nothing but Genuine Delphi lifters. 100% made in the USA

    We have contacted the three cam companies we deal with, Crane, Lunati, and Howards, and all highly approve of this lifter. In the past we marketed these lifters under the former name, "Eaton" They are the exact same lifter.
    We purchase our Delphi lifters in bulk trays of 122 each, as all engine builders do. We use them in all of our engines running a hyd. flat tappet cam. You will receive a complete set of 16 in an unmarked well protected package. The cost difference is well worth the difference, but rest assured these are genuine Delphi lifters. We can provide proof for those that are concerned. They are genuine Delphi tappets, made in the USA.

    The lifters I bought did not pump oil to the rockers at idle. And they destroyed my new camshaft.
    Even if you buy from a known good USA company, there are unscrupulous people who buy both sets, put the junk offshore lifters back in the name-brand box, and get their money back. Then the next guy buys that box of lifters and gets screwed.

    SOME OF US HAVE BEEN THROUGH THIS BEFORE. LEARN FROM OUR MISTAKES!
     
  14. Richard Tice

    Richard Tice Member

    I have the front of the engine torn down, hope to have the timing cover and cam sprocket off tonight. Then, I will replace both of my drilled-out lifter gallery plugs with solids. I'm hoping this is the cause of the delayed oil-to-rockers issue. If it results in no change, I'll have to address the lifters.
    Thanks for all the help, I'll post back when it's running again.
    Rich
     
  15. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    from a purely pragmatic view point , you can,t help but increase the oil flow to the rockers at least marginally
    ,once the two over sized drilled plugs are replaced
    ,(with non-drilled plugs,in the oil passages),
    as you'll without doubt ,
    at least potentially have more pressurized oil flow volume reaching,
    the lifter/push rods and rockers,
    once the current over sized holes in the gallery plugs are eliminated, as a oil flow leakage point.
    as was previously mentioned drilling both plugs with a 1/16" drill provides about 8 TIMES,
    the intended oil flow, exiting the oil passages as was intended,
    with a suggested ,single 1/32" hole,
    and thats certainly far more (two 1/16" holes) than, required or ideal.

    once the two over size drilled plugs are replaced/ fixed let us know your results
    [​IMG]
    that .032--.039 hole in the pass side oil passage plug will be Just fine !
    the object off drilling the tiny hole for those that don,t know is two fold, first it prevent trapped air in the oil passage from slowing oil reaching the lifters as trapped air is bled off rapidly, secondly it provides a constant flow of extra lube flowing to the chain cam drive even at low rpms

    [​IMG]
     
    Last edited: Apr 12, 2019
  16. Richard Tice

    Richard Tice Member

    Got it back together last night, pulled the driver's side valve cover. The first rocker to get oil was #3 (intake I think) at 90 seconds, then randomly, one at a time, all the others. Last one was #1 intake at 3 minutes. So, changing to solid plugs cut the total wait from 6 minutes to 3.
    I think any further improvements are going to require a lifter change.
    Rich
     
  17. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Buy Crower or Iskenderien Lifters.
     
  18. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    well its improving, , so your making progress, have you used a gauge to watch the gauge pressure vs time ,
    if you have decent oil pressure, thats rapidly building up,
    in the engines oil passages,
    but the lifters are not passing that oil flow and are not getting that pressurized oil,
    up to the rockers, that indicates a different cause than,
    low oil pressure, in the oil passages, that builds more slowly.
     
    Last edited: Apr 16, 2019 at 2:12 PM
  19. Richard Tice

    Richard Tice Member

    I haven't kept an eye on the gauge during that first few minutes, I'll do that next time I start it up.
    Rich
     
  20. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    the secret of diagnosing most auto related problems lies in careful observation,
    and applying logic, knowing HOW the part or component or system is SUPPOSED to function,
    and then carefully observing HOW it is or is not currently functioning.
    and logically deducing, the reason for any differences,
    and potential reasons for that observed difference.
    this can and frequently will require tools like meters,
    timing lights, vacuum gauges, pressure gauges
    and measuring tools like ,dial calipers, but careful observation is critical.
    tools like drill presses, clamps, gear pullers,welders, floor jacks, mechanics hand tools,
    feeler gauges, multi-meters, etc. will all be helpful at times
     

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