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Technical Fresh Flathead Need Help, near end of my rope!

Discussion in 'The Hokey Ass Message Board' started by anothercarguy, Apr 16, 2016.

  1. Ok...back story (it's long (sorry) but I want all the gurus on this board to have all the facts)...freshly rebuilt by previous owner 59AB, seems as though no expense was spared...had never been started.

    Combo: bored .080", new pistons, balanced (bills to prove), Isky Max-1 spec cam (copy of Isky), Harmon Collins dizzy, Eddie Meyer (original) heads and Eddie Meyer (original) dual carb intake (with rebuilt 94's), new stock fuel pump.

    First time start-up last week...primed carbs through vents...fired right up...but noticed the beehive filter was leaking (gushing actually) around the top seal (not tight enough)...shut down...tightened filter top, wiped up mess and re-started...engine noisy (similar to an sbc lifter clatter)...noticed low oil pressure (on the electric gauge looked to be around 10 lbs)...shut down. Decided to remove the beehive filter from the equation. Removed lines and installed plugs. Re-started, still low oil pressure, clatter continued and also noticed the stock (new) fuel pump did not seem to be delivering as it should...shut it down again.

    Started disassembling to look further into the various issues. I believe I've found the Fuel pump delivery issue - the fuel inlet line was too deep into fuel pump causing a near dead end of the line into the pump at the inlet. Shortened copper fuel line within inlet.

    Removed intake to check for presence of the oil pressure relief valve in lifter was there...removed plug, turned motor over on 12v without plugs. I could easily stop oil flow at the pressure relief valve with my thumb while turning over engine on starter.

    Pulled off timing cover and cam gear to check for presence of front oil gallery's there. In so doing, I notice the probable cause of the SBC lifter like clatter...the bolts holding on the dizzy were too long and were self clearancing the aluminum cam gear (problem solved- shortened bolts). I assume the rear oil gallery plug is in place as there is no sign of oil dripping down the rear of the engine.

    I then removed the oil pan, oil pump (new Mellings 19), and disassembled oil pump (inside looked good, pressure relief valve in place). Turned oil pump by hand in a container of oil, self primed and delivered lots of oil just spinning with a couple fingers.

    Thinking all looked well, I packed the oil pump with petroleum jelly, re-installed the oil pump and pan, re-filled with oil, removed the electric oil pressure gauge and replaced it with a mechanical gauge (thinking I might have had a gauge issue).

    Turned it over on the starter with 12v (no plugs, or intake...not that the intake makes any difference) with the fuel pump rod in place...and still have barely 10 lbs of oil pressure.

    What am I missing? Where do I need to look next?

    Thanks again in advance, Tim
  2. badshifter
    Joined: Apr 28, 2006
    Posts: 3,109


    Bearings. I'd start with the cam, but also time to measure crank and bearings to make sure they belong together. I've seen it first hand, .030 bearings on an .010 crank. No/low oil pressure, and not enough run time to make noise, or do real damage. Keep in mind, these engines can/do run with low oil pressure.
    Last edited: Apr 16, 2016
  3. I may start by plasti-gauging the main and con rod bearings (easy to do without much disassembly). If not that then out comes the cam, lifters etc. Is there a way to check the cam bearings without a dial bore gauge? (or is that now too on my list of must have tools?)
    Last edited: Apr 16, 2016
  4. patterg2003
    Joined: Sep 21, 2014
    Posts: 532


    That hurts. The first check before getting too deep into it may be to check the accuracy of the oil gauge with a second gauge. Then seek a few possibilities for a major pressure loss. There may be a common mistake or two in rebuilding that maybe the cause. Would start from simple to complex. The Hamb & the Fordbarn have a lot of flathead wisdom.
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  5. I have 2 electric oil pressure gauges (one in the dash and one in the firewall feeding off a dual gauge sender) plus I added a temporary mechanical gauge just in case the sender was suspect...all showed less than 10 lbs.

    I have the oil pan off again and gave the connecting rods another good wiggle and shake...they have no up and down play (and as required, they have a small amount of lateral movement). I have not taken a main cap off yet (I need to pick up some plasti-gauge tomorrow). I was really hoping to avoid taking the motor completely down...but I fear it's coming unless there are any other words of wisdom of something I might be overlooking.

    I haven't posted this on the Ford Barn site yet.
  6. Pete
    Joined: Mar 8, 2001
    Posts: 4,463


    A friend had a similar issue, turns out his cam had been turned slightly under and stock bearings installed.
  7. King ford
    Joined: Mar 18, 2013
    Posts: 1,243

    King ford
    from 08302

    Your block was not converted to full flow oil filtering was it,(actually I think it is often called 90 or 95 percent )....when this is done a much larger line in and out of the filter is used....and also I think would drop oil pressure SUBSTANTIALY if plug'ed off....
  8. Hi King Ford, No, the block has not been modified for the 95% oil filtering (it's still set up for the measly 10% filtering that Henry thought was adequate ;o)
  9. 53 ford
    Joined: Apr 8, 2012
    Posts: 136

    53 ford

    In the lifter valley at the front of the block is another pressure relief. You will see a hex at the end of the oil tube. Unscrew the hex and check the spring, sometimes it needs a shim.
  10. Thanks 53 Ford.

    Indeed, I was there before I removed the cam gear and cover to check for the front gallery plug. The spring and small ball/mushroom type valve were clean and had tension on it (though no shims). I'm currently planning on pulling the motor out of the car tomorrow, will put it on a stand and tear into it the rest of the way to check and measure all bearing clearances etc.

    I appreciate all the suggestions.
    slack likes this.
  11. alchemy
    Joined: Sep 27, 2002
    Posts: 14,391


    Stretch the spring on the valley pressure relief a bit.

    Also, you said up above "stock oil pump" then later said the pump had a relief valve as well. Sure the pump isn't an 8ba? So you have two relief valves in the engine. Only one needs to work. Maybe stretch the relief valve spring in the valley even more.
  12. You are correct, the oil pump is the Mellings M-19 with helical gears and the pressure relief valve from an 8BA. I was referring to the stock "fuel" pump above as I understand there may be oil pressure related issues caused by the fuel pump rod not being properly blocked off.

    Based on a few suggestions on the FordBarn site, I'm thinking of making an oil pressure pre-lube tank to pressurize the block with the oil pan off to see where oil pressure might be bleeding off. I'm also thinking I might try and do some measuring to determine the lifter valley pressure relief valve blow off pressure (to see if the spring needs more tension and/or shimming.

    Thanks for the reply/suggestion...I'll be heading down to the shop this afternoon to continue the quest for answers
  13. lowsquire
    Joined: Feb 21, 2002
    Posts: 2,564

    from Austin, TX

    Im guessing your cam bearing journals have been turned down 0.010" to clean up scores whilst being reground, and the builder installed standard shells. hard to check without full disassembly as the spring pressure on the cam makes it feel fine when turning by hand..
  14. choppedtudor
    Joined: Nov 28, 2009
    Posts: 650


    I'd put money on that motor having the wrong bearings in the cam. Crank bearings can be easy to check with plastigage, but without the proper cam bearing clearance you'd have little or no oil pressure.
  15. winduptoy
    Joined: Feb 19, 2013
    Posts: 1,602


    Stretching the spring will not change the k factor of the spring so all will remain the same

    The k factor is the pounds of load per inch of deflection. If you stretch the spring and re-install it you have not changed anything. If you shim it, you have started to compress, deflect, the spring and you increase the pressure required to deflect it more
    I don't know if the relief valve spring pressure is your low pressure problem or for that sake what might be the root of it
    Good luck in your quest to find out and solve your problem
  16. alchemy
    Joined: Sep 27, 2002
    Posts: 14,391


    Ok maybe stretching won't fix it, that's just what I've read before, and did in my situation. I have a pre-48 block with a later oil pump as well, so I stretched the spring in the valley so it would not open before the one in the pump. Mine usually runs about 40 lbs.

    I was thinking that if the OPs relief springs were opening at 10 lbs, that would explain why he can only get 10 lbs. I like to do the easy fixes first. I would have hoped that the engine builder would have assembled the proper bearings, and he would find his problem before he got that far.
  17. 20160417_121945_resized.jpg 20160417_122055_resized.jpg 20160417_122302_resized.jpg Ok...findings so far...using some fittings, a valve and my brake bleeder, I was able to apply a constant supply of 30 lbs of air (cleaner than what I expected oil might be, picture #3). Carefully listening with a piece of hose, I determined the most amount of air was coming from: the front oil pressure relief bleed off hole (behind cam timing gear) and at the front and center cam bearings.

    I took apart the oil pressure relief valve and looking more closely, looked at the flat spot (see pictures 1 and 2...I had assumed previously that this was supposed to be there). Can anyone confirm whether it is supposed to be there or not? If not, can I turn it down in my lathe to create a smooth surface and then shim it back? for the air leaking at the cam bearings, I think it takes me back to full disassemble for proper measurements and to confirm what a number of you have suggested might be the cause (wrongly sized cam bearings and cam journals.
  18. Andy
    Joined: Nov 17, 2002
    Posts: 4,472


    Flat on plunger is stock. Good luck with it!
  19. H380
    Joined: Sep 20, 2015
    Posts: 411

    from Louisiana

    falcongeorge likes this.
  20. So far, the engine is out of the car, and the valve train and cam have been removed (crank and rods still in place). Tomorrow, I'll mount the block on a stand and remove the crank and rods and put the micrometer to them.

    I've measured the front cam the front half (forward of the cut around the circumference) there is .0039" clearance, and the rear half of the bearing has .0042" clearance. I can't measure the mid bearing until the crank is out (no bore gauge...have the telescopic gauges so need room to be able to get in there).

    Also good to know the flat spot on the pressure relief valve is supposed to be there.

    The quest in the shop will continue tomorrow. Again, Thanks to all for your help, suggestions and knowledge. Tim
  21. The 39 guy
    Joined: Nov 5, 2010
    Posts: 2,666

    The 39 guy

    I think that flat spot allows some oil to flow through to the front cover area to supply oil to the timing gear.
  22. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,683

    Bruce Lancaster
    Member Emeritus

    Flatspot indeed stock. You mentioned front plug. There is also a rear plug at other end of tube on pre-49!
    Next would be old-fashioned pressure tank oil into engine with pan off, see if any of the bearings seem to be gushers.
  23. Gene Boul
    Joined: Feb 9, 2006
    Posts: 807

    Gene Boul

    The way you are going about it is most excellent. You will find "it" and be much better for it.
    Note: cam bearing clearance should be about .002!
  24. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,798

    Atwater Mike

    My neighbor has an O/T BBC with no oil pressure. (5 psi max) He and his son 'checked everything', so I went over and with pan and intake already removed suggested we blow 45 psi compressed air into the oil port, watching the lower and uppers. "NO AIR in MY oil ports!"
    I laughed, as they pulled the engine to take it to the machine $$hop. Geniuses.
  25. Today started with a couple hour project of building a sidemount flathead adaptor for my engine stand...then on with the teardown. This is what I measured. Not sure I've had the aha moment that said this is it!

    I measured the cam journals at both the front and rear of the groove cut into each journal. The cam journals mic'd at:
    1.7994" (front side of front journal), 1.7991" (rear side of front journal)
    1.7997" (front side of mid journal), 1.7993" (rear side of mid journal), 1.7996" (front side of rear journal), 1.7992" (rear side of rear journal)

    Cam bearing clearances measured at:
    .0038" (front side of front journal), .0042" (rear side of front journal)
    .0047" (front side of mid journal), .0045" (rear side of mid journal), .0039" (front side of rear journal), .0035" (rear side of rear journal)

    (higher than the .002" limit)

    Main bearing clearances measured at:
    .0021" front cap
    .0015" mid cap
    .0019" rear cap

    (within spec of .000-.003")

    Con rod clearance measured at:
    #1 .0013"
    #2 .0001"
    #3 .0017"
    #4 .0034"
    #5 .0015"
    #6 .0011"
    #7 .0015"
    #8 .0018

    #'s 1,2, 5, 6, & 7 (especially #2!) have clearances tighter than the acceptable range of .0017"-.0036"

    With the engine out and the flywheel removed, I can confirm that the rear oil gallery plug is also in place. It seems to me that low oil pressure is still quite drastic relative to the oversize of .002"-.003" of the cam bearings...and the too tight con rods which would cause heat but not necessarily oil pressure loss (or am I missing something?).

    I'm taking my pile of parts to a machine shop that does a lot of flathead work tomorrow.
  26. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,683

    Bruce Lancaster
    Member Emeritus

    Another leakage spot peculiar to some recent replacement pumps is right near the source...some have too small a shank where pump goes into block, leaking right there, and some have been spotted with bad machining where the valve on pump seats causing pump to operate in bypass all the time. You have to be suspicious of everything...
    v-v and patterg2003 like this.
  27. Mystery solved!!!

    I was so focussed on clearances, I didn't catch this (and must admit my unfamiliarity with flatheads didn't realize they had floating and non-floating con rod bearings depending on the year).

    The motor has 49-53 rods with non-floating bearings. The crank however is a 59AB and is drilled for floating bearings with the single hole in the centre of the journal to oil the floating bearings. With regular bearings however, the oil is directed right at the parting line between each pair of rods.

    The fix will be...another crank (8BA...already sourced), re-balancing, put new cam bearings in while we're at and try again.

    Again, thanks to all of you that made very helpful suggestions (or just watched along with I usually do ;o).

    benke likes this.
  28. The 39 guy
    Joined: Nov 5, 2010
    Posts: 2,666

    The 39 guy

    I have been one of those watching with interest with nothing to contribute until now. I found that when I switched to the 8BA crank that I had to use some different main bearing pieces. The link below will take you to the page of my build that covers this. There is also a link to a HAMB thread that helped me figure the difference between the mains and where to get the right parts at the end that page 4 segment on bearings. I'll keep watching and I hope this new crank is the answer to your problem.
  29. choppedtudor
    Joined: Nov 28, 2009
    Posts: 650


    Glad you found the issue and gave us all a little to think about along the way....
  30. alchemy
    Joined: Sep 27, 2002
    Posts: 14,391


    Huh. Never woulda guessed that one.

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