Oil pump 430 vs Chevy 454

Discussion in 'Street/strip 400/430/455' started by 1969briviera, Apr 30, 2022.

  1. 1969briviera

    1969briviera Antique Gold Poly

    Thanks. The oiling system on the 400/430 is fine for stock applications? Or do you know of any problems despite regular oil changes are done?
     
  2. Stevem

    Stevem Well-Known Member

    I to this day do not understand why there’s is not a aftermarket meaty timing cover that makes use of a presssd in cast iron liner.
    In terms of the BBC pump it’s gears have more teeth.
    This makes for less timing chatter when a distributor is used and also more constant oil pressure.
     
  3. Bens99gtp

    Bens99gtp Well-Known Member

    There are some cast iron buick timing covers, oddly enough they are in marine applications where the water and aluminum didn't play well togethere
     
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  4. BQUICK

    BQUICK Gold Level Contributor

    The commonly used thrust plate takes care of most of the wear.

    Even without it I've gone over 200K with a stock cover and oil changes at 3 to 4,000 miles. Shamefully, I do filter every other oil change.
     
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  5. Schurkey

    Schurkey Silver Level contributor

    The main FUNCTIONAL difference between the BBC and BBB oil pumps is that the Chevy pump is SUBMERGED IN OIL. There's almost no way it can lose it's prime; and if it did, merely re-filling the pan with oil would almost immediately re-prime the pump. The suction-side plumbing is about six inches long. There's one press-fit joint, and one brazed joint, both of which are below the normal oil level and therefore if they leak, no or minimal air would enter the pump.

    The Buick (and Cadillac, and B--RB Mopar, and plenty of others) pumps are external to the pan. Getting them to work means pulling oil through two feet of gasketed passageways. IF the Buick pump should lose it's prime...it's more "fun" to re-prime it.

    The Buick oiling system has/had multiple problems. One of the biggest problems consists of two engineering mistakes.
    1. The distributor drive gear overhangs the front cam bearing. This puts extra load on that bearing. Most other engine families that have a distributor-driven oil pump have the gear that powers the oil pump straddling two cam bearings, so the load is split between them.

    2. The front cam bearing uses a groove in the bearing material as a major oil passageway. Grooved bearings have lower load-carrying limits than non-grooved bearings; and when the bearing material wears/smears, the bearing becomes a major oil leak out each side, while (partially) blocking the groove, starving one lifter gallery.

    Buick has a highly-loaded bearing known for excessive wear, that has a bigass groove cut into it making it less-tolerant of extra loading, AND that bearing becomes a major oil catastrophe starving half the lifters. The oil passageway should have been cut into the block, sealed by the non-wearing back side of the bearing--which I think they finally did on the V-6 in...'86, maybe? That could improve the load-carrying capacity of the bearing while also eliminating the oil hemorrhage when the bearing wears.
     
    Last edited: May 1, 2022
  6. 1969briviera

    1969briviera Antique Gold Poly

    Great info. Thanks.
     
  7. Mark Demko

    Mark Demko Well-Known Member

    Theres no demand for it except us Buick guys, so that would mean ,MAYBE 500 of us would be willing to swap our timing covers from a perfectly running engine.
    I remember Kenne-Bell saying in their catalog way back, "Would you run iron bearings on an iron crank?" when describing the iron gears in the aluminum pump/cover.
    How about forged or cast aluminum gears, that way the cover and gears will expand at the same rate.
    I dont think the cover expanding when hot really has a ton to do with oil pressure drop, its more to do with the oil heating up.
    When I cold start my GS, its got 70/80 lbs feathering the throttle about 1200 rpm, within a few minutes driving its down to 50/60 at 2000 rpm driving city streets.
    Water temp is still 120 degrees, if that
    You cant tell me that cover/pump assembly is so hot the clearances opened up enough to allow a 30 lb pressure drop:rolleyes:
     
    sean Buick 76 likes this.
  8. Jim Weise

    Jim Weise EFI/DIS 482

    We must realize that what some consider "mistakes" are actually only "limitations" when we expand the usage of the engine beyond it's design limits. The BMD engineers were building a lightweight large cubic inch displacement engine, to power 4000-5000 lbs highway geared cars. Most of these engines never saw the high side of 4500 rpm in their service lives.

    Ah yes, the next urban legend...
    "Front cam bearing wears a groove in the bottom of the bearing, and cuts off oil supply to the driver side galley."

    For years I accepted this as fact.. I had taken apart a performance engine in the past, that had the front cam bearing worned deeply into the groove on the front journal. I recall being surprised by that, because it was a hyd cam motor, that was dead quiet at idle. I did not dwell on it then, just noted the departure from "accepted facts", and moved forward.

    Then one day I was doing my standard HP oiling mods, and sat down and really looked at it. Ok, let's say that our high performance cam's spring pressure , easily triple what the factory intended, wears the groove in the bottom of the front cam bearing, due to the grooved front cam journal.

    So what...

    Oil flow in the main pressure galley, from the pump, is on the passenger side of the engine. It enters the front cam bearing and the passenger side main galley in a common passage. It feeds the front cam bearing at approximately the 9 o'clock position. Virtually no oil is transferred to the driver side galley feed, which is located on the cam bearing at approximately 3 o'clock, thru the bottom of the bearing, or the bottom of the groove in the front cam journal. For two reasons:

    1. The main reason is the direction of rotation of the cam. oil will not flow at any great volume against the direction of rotation. Even in the groove in the front cam journal.

    2, No oil clearance exists at the bottom of the cam journal.. only the microscopically thin layer of "boundary oil" that keeps the shaft out of physical contact with the cam bearing.

    Considering these two factors, it's easy to understand the most of the oil fed to driver side galley goes around the top of the camshaft, from 9 to 3 o'clock.

    I believe those who have experienced front cam bearing failure, in conjunction with a driver side oiling issue, simply did not notice that the oil hole in the bearing that feeds the driver side, was totally or partially restricted, by migrating bearing babbit, during the front bearing failure. Partially blocking that hole is very common when the front bearing fails, due to loads much higher than engineering specifications, that the design was built to handle.

    "Engineering Mistake".. No, those are defined when the engine, put in it's intended form, fails in service.. Say the hundreds of thousands/millions of SBC camshaft failures for instance.

    This design, while not optimal for performance type valvetrain loads, was not an in service issue for the BBB. I view this as a limitation, that is easily overcome with a back groove cam bearing, which is fact can feed the oil in the shortest path possible around the cam.. because it does not have the spinning cam to contend with. Some builders chose to groove the block behind the cam bearing, which works equally as well, as long as they use the wider front cam bearing in all positions.

    As to the position of the distributor gear:

    High distributor loads, wearing out the front bearing, are often the result of early oil mods, that thought that lengthening the gears was the answer for increased oil flow. In later years, we learned that passage sizes was the real issue, and that distributor gear/cam gear/front cam bearing eating long geared pump, has long been out of vogue, with builders "in the know".

    Again, even with performance cam loading, this gear only wears out when there is either a positioning problem due to casting/machining issues, or when inadaquate clearances in the pump cover/gear area, and/or pressure relief issues, combined with high viscosity oils, result in extremely high oil pressures when the engine is cold. That is why one rule of thumb for these motors was "never rev the engine past 2500 rpm when cold". That is largely irrelevant now, once we understood and correctly "fixed" the oiling limitations.

    And finally, going back to our "in service in intended application" definition of an "Engineering Mistake", we find no evidence of mass failures of front cam bearings, cam gears or distribuotor gears exist, when one examines the complete service bulletin catalog, for the time period that engine was in primary service. Beyond that, I have several dozen high performance engines out there, with stock cam and distributor gears, even with modified HP oil pumps, that show no wear issues at all.

    I actually believe that the distributor being installed at the front of the engine, in the timing cover is a benefit. Once one gets involved in performance evaluations and testing of intake manifolds, which you can change without touching the timing, it becomes apparent that this is a clear advantage for this engine. Anyone with extensive dyno experience will tell you that there is "one sweet spot" for timing, and once you find that, you want to lock the distributor down, and never touch it.
     
    Last edited: May 1, 2022
  9. Mark Demko

    Mark Demko Well-Known Member

    Good info! I believe there is a lot of urban legend and mis information out there on the “modern” Buick V8
     
  10. D-Con

    D-Con Kills Rats and Mice

    Your wish for a Buick platform crankshaft driven pump/cover is my command.

    [​IMG]
     
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  11. Mark Demko

    Mark Demko Well-Known Member

    That’s for the 3800 series yes?
     
  12. D-Con

    D-Con Kills Rats and Mice

    Rover 4.0 AKA updated 215.
     
  13. sean Buick 76

    sean Buick 76 Buick Nut

    I wonder if that
    could be adapted to a 350?
     
  14. lemmy-67

    lemmy-67 Platinum Level Contributor

    Excellent thread here, lots of good information. As someone who's owned both a 430 and a 454 simultaneously, both engines have their strengths and quirky designs. BBC with the oil pump in the pan was a product of the distributor being behind the carb, while the BBB had everything hanging off that timing cover in the front.

    My BBC was in a 1974 C20 pickup, dual fuel tanks, rusted to all hell but fun to drive...that is...when it didn't run out of fuel on a bridge...
     
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  15. D-Con

    D-Con Kills Rats and Mice

    I would sure be giving it a look-see if I was a 350 person. A good start may be to see if it can be retrofitted to an earlier style 215 block. My first thought would be to see if they changed the crank snout or front of block to make the change.
     
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