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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Thu Sep 13, 2018 8:24 am Post subject: Where can a 40-horse case lose OP? |
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'65 case, 1385 but otherwise stock, new .040 line bore, case savers, new bearings, cam and lifters, bigger oil pump, full-flowed, etc. Ran beautifully and strong w/ good OP, then a couple weeks later OP light begins to flicker at low idle.
Engine not unusually hot. Try a different oil filter, plumb in two different mechanical gauges to verify, note OP at cold startup no longer hitting 45 PSI then leveling out, swap in new pressure relief valve/spring [new type w/ channel] no improvement, yank motor, teardown reveals no bearing damage, oil pump gear tang properly aligned w/ cam, no chunks in screen or obvious cause.
Baffled. Only thing I can think of is lack of cam bearings so talk to machinist about boring cam saddle to retrofit cam bearings but thought I'd ask here. Case is original to vehicle so pretty keen to keep it but do not wish to flush money if the damn thing cannot be saved. Thoughts? Thank you. |
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PEPPE Samba Member
Joined: August 24, 2003 Posts: 1068 Location: Roma Italy
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Posted: Thu Sep 13, 2018 1:14 pm Post subject: Re: Where can a 40-horse case lose OP? |
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check for loose cam bearing bores. oil pump is stock? |
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Slow 1200 Samba Member
Joined: July 02, 2004 Posts: 2105
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Posted: Thu Sep 13, 2018 2:05 pm Post subject: Re: Where can a 40-horse case lose OP? |
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also sloppy lifter bores, bad line bore, overly large clearances, did the case pass the flashlight test? |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Thu Sep 13, 2018 8:00 pm Post subject: Re: Where can a 40-horse case lose OP? |
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Lifter bores are good, passes the flashlight test, bearings fit quite tightly, oil pump is lightly bigger than stock.
What else could it be but cam saddles? |
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3988 Location: Antioch, California, a block from the hood
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Fri Sep 14, 2018 8:16 am Post subject: Re: Where can a 40-horse case lose OP? |
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The pump is plugged and the fit is quite tight. Cover is a Berg cast-iron unit. Mating surfaces on pump and cover given a good surfacing with sandpaper on a slab of granite. Upon teardown inspection found no wear inside pump body nor backside of cover. Used Loctite 518 to seal pump to the case. I think if there were a problem with the pump it would have been evident from the getgo. |
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3988 Location: Antioch, California, a block from the hood
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Fri Sep 14, 2018 3:47 pm Post subject: Re: Where can a 40-horse case lose OP? |
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Tight. |
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Towel Rail Horizontally Opposed
Joined: April 15, 2005 Posts: 4622 Location: SE CR IA US NA PE
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Posted: Sat Sep 15, 2018 7:29 pm Post subject: Re: Where can a 40-horse case lose OP? |
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Any chance the oil pressure relief piston is getting stuck in the down position? I recently bought an "OEM" piston that had surprisingly square corners. _________________ 1974 Thing -- under the knife
1967 Beetle -- spring/summer/fall driver
1996 Subaru OBW (EJ22, 5-speed, AWD) -- winter car, 3-seasons "don't feel like biking today" car
049 > 070 > 053 > 009 |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Sun Sep 16, 2018 7:39 am Post subject: Re: Where can a 40-horse case lose OP? |
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No, I swapped in several plungers and springs on the off chance that was the culprit- no soap, dangit.
You are correct about the sharp corners of new plungers, though. |
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Towel Rail Horizontally Opposed
Joined: April 15, 2005 Posts: 4622 Location: SE CR IA US NA PE
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Posted: Sun Sep 16, 2018 8:22 am Post subject: Re: Where can a 40-horse case lose OP? |
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Hmm. And I assume you've changed oil a couple times, which would rule out fuel dilution. _________________ 1974 Thing -- under the knife
1967 Beetle -- spring/summer/fall driver
1996 Subaru OBW (EJ22, 5-speed, AWD) -- winter car, 3-seasons "don't feel like biking today" car
049 > 070 > 053 > 009 |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Sun Sep 16, 2018 8:44 am Post subject: Re: Where can a 40-horse case lose OP? |
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I would have asked that very question too, and yes, I sure did. 15W40 Delo/Delvac for what that is worth.
All the oldtimers- folks that started with 36-horsers- I've talked to about this are somewhat dubious of the cam-saddle diagnosis but otherwise as baffled. Sure hope this can be figured out: I have a one-track mind and am not terribly good at compartmentalizing. Really chews up a guy. |
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glutamodo The Android
Joined: July 13, 2004 Posts: 26320 Location: Douglas, WY
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Posted: Sun Sep 16, 2018 11:04 pm Post subject: Re: Where can a 40-horse case lose OP? |
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Hot idle oil light flicker on such engines is so common that I ignore it if the engine passes the 2nd test - what is the oil pressure on a warm engine at higher RPM? (if it's still over 28PSI at 2500RPM I'd not be that worried)
My 62 when I first got it, had a bit lower oil pressure because some previous owner or mechanic had screwed up and put the wrong gasket between the oil pump and the cover. _________________ Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox. |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Mon Sep 17, 2018 7:52 am Post subject: Re: Where can a 40-horse case lose OP? |
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It is that, at least 28 PSI, but still...I know it can do better.
See, I'm assembling this vehicle for a friend and neighbor and I want it to be as bulletproof as can be- heck, my own '61's 40-horse [which also still has its original case] has never even flickered once at, say, 500 RPM hot idle despite temps routinely in the 100s, even following high-for-an-old-Beetle speeds through those ambient temps. Not once.
Now, Andy, in reading through the Samba on the subject I've spotted at least one reference you made in the past to 40-horsers losing OP due to lack of cam bearings. Any evidence I am on the right track here? |
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glutamodo The Android
Joined: July 13, 2004 Posts: 26320 Location: Douglas, WY
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Posted: Mon Sep 17, 2018 8:08 am Post subject: Re: Where can a 40-horse case lose OP? |
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Certainly, the lack of cam bearings can be a reason that such engines have lower oil pressure. So detailing the pump and pump cover (wet sanding them so they are both ultra flat) is one area that can help. _________________ Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox. |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Mon Sep 17, 2018 8:12 am Post subject: Re: Where can a 40-horse case lose OP? |
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Both are flat as can be given a long wet-sanding session on a dead-flat granite slab. Also running the standard paper gasket between the pump body and cover. |
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glutamodo The Android
Joined: July 13, 2004 Posts: 26320 Location: Douglas, WY
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Posted: Mon Sep 17, 2018 8:23 am Post subject: Re: Where can a 40-horse case lose OP? |
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Well, that's about as best as you can do, except changing to a higher volume pump.
What is the idle RPM? Stock spec was the horrendously low 550 RPM, but they later changed it to 700, I think 900 is better... the lower you go the more likely you get the oil light flickering.
Since I've owned an oil pressure test gauge ever since the 90s when I was a mechanic, I don't hesitate to check if I suspect it's too low. But since VW themselves said idle speed oil light flicker was acceptable, I'm fine with it if it passes the higher speed tests.
_________________ Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox. |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Mon Sep 17, 2018 8:45 am Post subject: Re: Where can a 40-horse case lose OP? |
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The oil pump is a slightly-bigger-than-stock unit since the case is full-flowed and running an external filter. Thought it wise to provide a bit more muscle to move the oil around the now-longer route.
I've spent an inordinate amount of time rereading those very paragraphs in the Bentley and trying to find comfort in them, but again I have to refer to those 40-horsers that continue to have good OP even at low RPM.
All that said, I wish this carbuncle of a Beetle had arrived with a later engine as I would not be spending so much time and effort chasing a few PSI on a dual-relief case...sheesh. |
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glutamodo The Android
Joined: July 13, 2004 Posts: 26320 Location: Douglas, WY
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Posted: Mon Sep 17, 2018 8:51 am Post subject: Re: Where can a 40-horse case lose OP? |
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Running that external filter is likely to lower things.
Now my own 40HP in my 62, despite being a 61 block, it was one that was reworked by VW with cam bearings... so I've never seen an oil light flicker at idle. (I'm sure it helps that I always detail the heck out of my oil pump, and run the idle speed at 900 as mentioned above)
Another thing about throwing an oil test gauge in place of the idiot light switch is to actually see the idle pressure and see if the switch itself was a bit sketchy. _________________ Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox.
Last edited by glutamodo on Mon Sep 17, 2018 9:08 am; edited 1 time in total |
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&Dan Samba Member
Joined: January 29, 2008 Posts: 1784
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Posted: Mon Sep 17, 2018 9:07 am Post subject: Re: Where can a 40-horse case lose OP? |
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Absolutely, which is why I confirmed the OP using two different old, good, accurate mechanical gauges- the same ones I use when building V8s- as well as two different sending units. Taking things for granted is never a sound strategy.
Off the subject, as much as I admire Electrician, Bozos, Pliers and Wrong, Dear Friends is still my life's blood. |
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