Help me! New rebuild. Low oil pressure. SOLVED!!!

[modok]

Your going to hate me saying this..... I don't see any oil starvation.


Contact on rod bearings looks like they were too tight.
Contact on piston skirts looks too tight.

I was wondering if it was machined for oversize cam bearings...oversize oil valves, or something... and you didn't notice?? Soon you can have another look at that, and the see if the oil pump lines up correct.

[VW_Jimbo]

[modok]

Hmm, well maybe. I just figured if the piston scuffed and took all the coating off it must be too tight, OR, some other reason. Maybe that coating wasn't put on right or the skirt got some dirt stuck in it some way and caused it.

I don't think you damaged the rods, I don't see any real HEAT thankfully.

The assembly torque on the rod bolts should be the same as when they were finish machined. It is customary to put this value ON THE BOX.
If you use a higher torque value, they will squeeze smaller, and sometimes not evenly.


I know some of the china rods are sold without bolts. How does that even work then? it's just not right.

[VW_Jimbo]

The rods are from CB Performance. Their H beam 5.4 rods with ARP bolts. I believe they are stretch bolts and will need to get new ones. But how can one over torque a stretch bolt. I guess I may have found a way! My eyes are not as good as they once were. Maybe I missed my number?!?! Damn, I hate that!

I think you answered your own statement with itself, in that last sentence. Let me pull out the key word, China.
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[modok]

CB's rods are VERy good.
the bolts can be re-used many times, usually.
28-29 ft-lb sound familiar?

[VW_Jimbo]

Sounds too low. I was thinking 38. That’s why I write stuff down. I will check it tomorrow, and let you know for sure. Believe me my memory is not worth too much lately. I need to write everything down!

So, no new bolts? I was taught to always change stretch bolts. Maybe I am remembering the Cb bolts wrong. I need to double check it tomorrow.

Thanks for your experience!
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[modok]

Same here. People fail to understand how poor my memory is.
But after torquing, you know.... 100,000 bolts or so, I started kinda seeing a pattern, so I can guess pretty close now. Assuming that's a 5/16 arp-200 bolts

Sometimes strange stuff just happens.
4 cyl jeep, did all the machine work on it. My co-worker assembled the shortblock. The owner did all the correct pre-lube and break-in procedures. Somehow it scuffed one side of one piston. I can't find a reason. Checking everything again, it all checks perfect. Maybe there was sand cast in to the piston. Just have to try it again.

[VW_Jimbo]

That’s me as well. I rebuilt was too many engines, all sorts of manufactures. I often mix up the values between them. That’s why I write them all down before building. Research first, action afterwards!

Sounds like a tapered cylinder. Do you have a bore meter?
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[modok]

Yes. By day I am an automotive machinist. By night, spiderman.
<.00025" taper, bottom edge nicely chafered too.

[Greg Ward]

When you get around to putting it back together, I noticed something in your pics, we never use a grooved oil relief piston in a dual relief case. I know they were used in some Type3's with dual carbs but never in a Beetle or Bus engine.

Was that a kit? I really wish the aftermarket wouldn't sell rubbish like that, even trying to use the non grooved plug from the aftermarket kit wouldn't work the one time I tried it, the piston itself was not machined properly, some of them fall in and some of them aren't even smooth on the outside, also made of rubbish material....unfortunately.

Always used OEM non-grooved pistons with a light polish with some 1000grit paper in the lathe and never had a problem.

[esde]

If the rod is slightly tight on the crank, wouldn't it cause excessive piston rocking? That would explain the worn piston skirts
Seems it would be a fine line between stiff and seized, but maybe it did happen..
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[VW_Jimbo]

[VW_Jimbo]

[williamM]

I agree with Modoc- I only see some contamination and an even sweep on those rod bearings. The deeper lines indicate debris running thru the bearings, but if run with 5w30 oil that set up looks like it had a lot of miles left in those bearings- and if the oil pressure problem could have been solved-- no telling-

The scuffed pistons on the other hand-- maybe an over heat problem-- or again debris from the re-hone. With out putting a micrometer on the skirts, and comparing them all-

You should check out the flow thru your oil cooler I have an oil cooler that ran with HIGH oil pressure and actually ballooned up to close the air flow.- and make sure all your under tins to the cylinder are in place.

Went back and ran the OP videos again and did seem to hear a sticking valve or ignition problem on rev up- and- that clean exhaust valve might be leaking- either thru the seat, or the valve face,-- had that in a dodge- where all the seats were loose and it ran like a major vacuum leak.



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_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[jason]

The pistons look flaky to me. My cam did that when I got crazy with brake clean. Make sure all your crank plugs are in.

[Danwvw]

Yeah, something not right with the piston fit there (VW Jimbo's bottom photo). Maybe the engine was just running so hot from that it wouldn't hold oil pressure? Just a thought? What stroke is this engine? Are those A offset pistons? (Looks like they come out of the cylinder too far to work!) But probably there is just a fit problem with the case to oil pump or a restriction in the oil system somewhere.
I don't think the rods or the bearings are damaged except for the debris damage showing here:

Mine 150 miles:(Disregard the mess it was from a fail sparkplug hole repair and why the engine had to come apart at 150 miles.)

VW Jimbo's

Mine 150 miles:

VW Jimbo's

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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[VW_Jimbo]

Hey guys, got home at 5:30 tonight after chasing a water leak on a thrid story hose, misplaced nail 4 rows down from the ridge, rotted all kinds of stuff!!! I am no stranger to chasing oddities!

After saying hi to my girls, there are no other males in my home, (even the dog is female!), I went out to the garage and did a four wheel brake job on the oldest kids Jeep Liberty! Fun stuff. Wrapped that up in just over an hour, thankfully the rotors were all bigger than minimum and looked to be in good shape. However, I now own 4 rotors. Next brake job on it I wont have to buy rotors! And lord knows I store ALOT of parts!

After the brakes, I jumped into tearing down the short block.

Stripped and split the case. Pulled the cam, looked it over, it looks good, no grooves in the camshaft itself, but the bearing look a little worn, for less than 5 miles.

Then onto looking at the crank

Finally the oil pump alignment

So then I put my thumb over the on the oil suction hole at the case, in the oil
pump, and blew into the pick up tube. Air came out at the top of the oil pick up shield, cover metal, where it is connected to the oil pump feed tube. My gut says this is not right, but is it? Where the yellow arrow is.

_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[Danwvw]

That's your problem probably will braze or perhaps silver solder.
_________________
1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[Busstom]

Woah, yeah, that's not normal. That needs to be brazed shut, or replaced.

Unrelated, but the edges of your cam lobes need some bevel grinding to relieve stress and prevent the lobes from cutting into the lifter faces over time.

[Greg Ward]

Sorry Jimbo, and I'm prepared to get flamed, but you're using "Lose a Lobe" lifters....

Never had one of them work in my life, your's look like a 100,000 mile engine after what 5 miles? they are a product I would never have in any of my engines. Humour me and take 2 and see if you can rock them together or if they stay flat against each other.

Also please measure the cam lift now, I would hazzard a guess they wiped out against each other and caused bits to go through all your bearings like the sand and grit that others have noticed.

I've always used lifters with no holes, my current engine has them just like stock and they are heavy, the rest of my valvetrain is very light, good enough for 69 x 94 and 9500rpm...

I also use the stock cooling system with no modifications, and have 85PSI cold idle pressure (for a serious RPM engine) I see no reason to modify something that works perfectly, I worry about things like oil galley plugs that are added that plug what they shouldn't and oil lines that route to horrible areas such as next to the exhaust or can get split by some road debris hitting them.

And one more thing, apart from all the bearings copping a sanding from debris, the oil pump case looks like it has a thread machined into it from the same stuff... my guess is cam and lifters... lovely bits of metal throughout the engine.

Do the oil relief pistons fall out? Let me guess...