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Technical Early 331 Hemi Oil Pump Options

Discussion in 'Traditional Hot Rods' started by ace high, Jan 9, 2018.

  1. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high
    Member

    Need opinion about choice of Early Hemi oil pump for 1953 Chrysler 331.
    Choice #1 -- Rebuild original pump assuming housing is in good shape.
    Choice #2 -- 340 oil pump with adapter from Hot Heads
    Choice #3 -- 392 oil pump with modified rear main bearing cap
     
  2. Contact Gary=73RR
     
  3. i have used the hh pump the titan and missile pumps with good results. it depends on what you want to do with this engine.
     
  4. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high
    Member

    Old school Street hot rod
     

  5. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

    Nothing at all wrong with the 340 pump from Hot Heads. This is a simple swap and works very well.
     
    foolthrottle likes this.
  6. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high
    Member

    Does it use the stock intermediate drive shaft ?
     
  7. Hombre
    Joined: Aug 22, 2008
    Posts: 1,030

    Hombre
    ALLIANCE MEMBER

  8. Lucky667
    Joined: Dec 3, 2008
    Posts: 2,233

    Lucky667
    ALLIANCE MEMBER
    from TX

    I realize this thread is over 10 months old. Before you make any decision, You really need to read the oil section in Hemi Tech here on the HAMB. There are some different opinions about Hemi oil pumps that have NOT been covered on this page.
     
  9. zeph4057k
    Joined: Nov 28, 2011
    Posts: 476

    zeph4057k
    Member

    we put a 340 small blk Chrysler pump in our engine masters engine. it revved to 7000 rpms (required) and put out 660 h.p. with a 1050 cfm holley. it's a bored and stroked 1956 354 to a 396 cubic inch. the pump works great ! we made our own adapter, but hot heads is good, just a little pricey. make sure you disassemble the entire rocker shafts and CLEAN them super good if using the originals.
     
    oj likes this.
  10. zeph4057k
    Joined: Nov 28, 2011
    Posts: 476

    zeph4057k
    Member

    you can use the stock shaft that goes to the distributor, the after market ones are a little short and can lift up off the male end of the cam gear and you will lose oil pressure. it happened to us.
     
  11. Lucky667
    Joined: Dec 3, 2008
    Posts: 2,233

    Lucky667
    ALLIANCE MEMBER
    from TX

    First, I don't want to say anything negative about anyone. If you are in the market to buy an oil pump for a Hemi read, "HEMI Tech: Oil systems- filters, pumps, pans." It is here on the HAMB. I've read all of it several times, Page #4, Post #99 really got my attention. Decide for yourself, . . . My choice, original pump, if it's useable or a new M50 with the rear main cap modified. There are two members here on the HAMB that do the main cap modification, they are 73RR and TR Waters.
     
  12. AndersF
    Joined: Feb 16, 2013
    Posts: 705

    AndersF
    Member

    I did not had any luck with my aftermarket oilpump in my dodge 53.
    Allmost cost me my new restored engine.
    Put back the stock one and never looked back.
     
  13. oj
    Joined: Jul 27, 2008
    Posts: 6,247

    oj
    Member

    I just ordered the M50 for my 354, Gary said he had posted how to modify the rear cap so we'll see how difficult it is.
     
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  14. zeph4057k
    Joined: Nov 28, 2011
    Posts: 476

    zeph4057k
    Member

    ive been running the 340 small block pump in all my hemis (4), drag racing, street, haven't had one problem. good luck out there hemi guys !
     
  15. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    Hey Zeph!

    I'm coming to the end of building a 1965 Dodge D100 with a 331 hemi in it. I fired it up for the first time
    - I have a temporary mechanical oil pressure gauge installed under the hood so I can monitor during tuning etc.
    - All of a sudden the oil pressure dropped to 0 psi ... (not a slow decline)
    - Obviously I turned it off immediately and went into research mode

    The engine has the 340 pump but I dont know about the shaft. (I took this build over from my father when he got sick to finish it for him .... and he passed away recently)

    I have the distributor a LITTLE bit loose to set the timing. Is it possible it has raised up just enough to disconnect from the drive gear?

    Do you have more information?

    Thanks so much!!!

    Luke
     
  16. Beanscoot
    Joined: May 14, 2008
    Posts: 1,555

    Beanscoot
    Member

    I would think the stock one would be fine for a rebuilt engine without large, sloppy bearing clearances.
     
  17. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    upload_2019-9-19_9-39-51.png

    So heres a sketch of my set up .... I have contacted HotHeads and this is the reply:

    Luke,
    I don't have a 331 or 354 block here to I can measure but I measured the lengths of the int. shaft and the oil pump shaft and distributor shafts and they all show to be correct. I have a longer shaft that we use for our chevy distributor adaptor that I can send you that is longer than stock( 7.060 length) and you can use it to make a custom length shaft and cut it down to match your engine and re pin it. Like we discussed before factory engagement was around .120-.130 on either side but you can go deeper if you want. We have seen some industrial versions that needed this done before but not car engines.
    Thanks,
    Eric
    Can anyone confirm the dimensions?

    Also does this plan make sense:
    1) Press the intermediate shaft up slightly to fully engage the distributor (redrill the set pin) (I think this is going to be easier than cutting and extending the distributor shaft
    2) Press the oil pump shaft to fully engage the intermediate shaft (This means the end of the shaft will NOT be flush with the bottom of the oil pump drive gear .... but I dont see that being a problem.

    I'm scratching my head why I have to do this though!!!! I measured up the old oil pump and it would have the same problem ....

    And I dont agree with what Eric said about the 0.100 engagement being enough .... that seems like a recipe for disaster
     
  18. Luke; Did you find the actual cause for your Oil Pressure to drop to zero before deciding to dive into pump drive and sub pieces?
     
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  19. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 13,024

    Jeff Norwell
    MODERATOR
    Staff Member

    I run HH hi volume pumps in my dodge and Chrysler... pan mods are needed.. will not fit as stock pan.
    As for the pumps.. they really deliver...solid.
     
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  20. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    Yes, Check out the pics attached here ... you can see up into the hole where the oil pump and intermediate shaft "tore up" (sorry about how grainy they are ... snap shot of a video)

    Also had a lot of metal in the oil pan (I think from the bottom of the intermediate shaft) .... could also be the engine breaking in.

    Even the pics of the top of the int shaft (gear side) I can see some wear .... looks like its going to skip or let go ...

    When it was running (before i lost oil pressure) I was having a VERY hard time keeping it running and doing the initial tune ... so its possible the distributor was skipping already?

    It just seems like 0.050" to 0.100" is not enough to drive an oil pump. it takes a lot of force to develop 60-80psi vlcsnap-2019-09-19-12h53m40s101.png vlcsnap-2019-09-19-12h54m15s605.png vlcsnap-2019-09-19-12h55m22s789.png vlcsnap-2019-09-19-12h55m35s429.png IMG_0886.JPG IMG_1033.JPG IMG_1041.JPG IMG_1042.JPG

    Yes - I have the Steph's rear sump oil pan and the right pump arm (see pics)



    ALSO! THANK YOU GUYS FOR THE HELP
     
  21. I have to agree with .050-.100 is questionable engagement. Seeing your photos is pretty convincing. With metal frag in the pan did you open up your Pump to make sure a frag didn't get in and jamb the gears?
     
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  22. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    I did open the oil pump. everything seems ok (no scoring etc)

    and I will be replacing the bolts (grade 8) and using red locktite when i re-install ... (I know some had issues with bolts on this form)
     
  23. Shouldn’t the male tang on the pump engage the female end on the intermediate shaft.
    Looks like the oil pump spacer may be too thick and not letting the tang engage deep enough?
    I can’t tell very well from the pics,,,sorry.
    Just an idea.

    Tommy
     
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  24. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 13,024

    Jeff Norwell
    MODERATOR
    Staff Member

    The pump I used wrecked a fresh done pan... Hemi pans in good shape are worth gold....Dodge ones are worth even more.... after all the hard work of metal finishing a decent one and the expense of plating.... the 340 pump pressed right through the pan upon assembly....... this was 2 nights before Detroit(mad thrash as per usual).... Luckily .... I had a somewhat decent pan and used a stock pan.
    When i bought the 340 oiler...I was told it was a direct fit.... nothing needed ....

    I was pissed.

    IMG_0124.JPG
     
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  25. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 13,024

    Jeff Norwell
    MODERATOR
    Staff Member

    Btw.... I used a stock rebuilt Dodge Oil pump...I whipped that 340 across the shop.....Hard.
     
    LukesMotorShop and Desoto291Hemi like this.
  26. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    Yes sir.. EXACTLY ... based on my measuring the male oil pump only engages the female intermediate shaft by 0.100" ....... I might investigate grinding down the 340 oil pump spacer ... but i dont have a surface grinder and i think it would be easier to push the intermediate shaft down .... instead of "moving the oil pump up by grinding the HotHeads provided spacer.
    Its killing me .... i REALLY hope the bit of time it was runnin with out oil pressure didnt screw this engine. things ain't cheap to rebuild!!!!

    Heard that bruh .... I have measured where the pick up sits in the pan ... and made sure it wasnt dead locked in the bottom.....

    I will be "drill spinnin' the pump" with oil in the pan to see if it makes pressure once i finish all the mods I'm planning on....

    BUT again ... I dont know why i need to do it.
    1) push the intermediate shaft UP to engage the distributor fully
    2) push the oil pump drive shaft UP to fully engage the intermediate shaft
     
    Jeff Norwell likes this.
  27. Do you still have the original pump to measure how far down the pump extends into the main cap?
    Or at least to compare it to the 340 pump?
    There must be more tang engagement than what you currently have,,,it will never stay together with what it is now.

    As far as any damage might be,,,,for my peace of mind,,,,I would remove each rod cap one at a time,,,and give the bearing an inspection look.
    Then ,,,do the same to the mains.
    If it only ran a few seconds,,you should be fine.
    I am assuming you used good assembly lube?
    Hope it works out for you!

    Tommy
     
    LukesMotorShop likes this.
  28. Hey Luke,
    You do have the correct distributor in there,,,,,did you check clearance between the distributor shaft and the intermediate gear top?
    Just a thought,,,,I know the cam gear drives the intermediate down,,,but the pump will also try to screw it back out of the top,,,too much clearance and the tang will disengage.

    Tommy
     
    LukesMotorShop likes this.
  29. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    I did measure the original Oil Pump:

    from pump base (mounting point) to tip of pump = 2.910"
    soooo since the spacer = 0.500"
    2.910" + 0.500" = 3.410"

    The measurement on the 340 conversion = 3.375" (see the drawing i did above)

    3.410" - 3.375" = 0.035"

    which is basically Sweet F*ck All ... and might as well be an error in measurement on my part being under the truck trying to measure with a caliper and a straight edge etc.

    the way i see it is the original pump and the 340 pump have the same dimensions.

    Again: THANK YOU GUYS .... for questioning my thought process and bringing these things up ... its helping me work though it!!!
     
  30. LukesMotorShop
    Joined: Jul 31, 2019
    Posts: 10

    LukesMotorShop
    Member

    Correct Distributor: TECHNICALLY ... no .... i have a 318 distributor. BUT according to HotHeads it should be "ok with 0.100" to 0.150" of engagement"
    but it just doesnt seem like its enough

    And the second part of your statement:

    "Just a thought,,,,I know the cam gear drives the intermediate down,,,but the pump will also try to screw it back out of the top,,,too much clearance and the tang will disengage."

    thats my thought also ..... sh*t just has too much variable clearance.
     

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