Dennis Beck

Now a drink and little TV golf watching. Good to see others frustrated, I think I will take my pants off , since putting them on didn't fix my problem

Jack



You have a great sense of humor. Good Luck

Dennis

MikeM

I think if the gauge fitting or tap at the back of the block was plugged, you wouldn't show any pressure. If it was partially plugged, the gauge would only be slow to react to pressure changes but should still show the maximum pressure.

You may have had one of the oil galley plugs come out inside the engine, letting the oil pressure bypass.

Like I said, I don't see any reason for your oil pump to be any less than it was just waiting to be put back in the engine. I don't think that's your problem. If you're lucky, it'll be a plugged pump screen.

I'd get the guy that rebuilt it involved in it ASAP!. Or, are you that guy?

PS. While you have the pan off, check all the bearings for wear/scoring/scuffing.

Ron Miller

I really don't think it's your oil pump either, but if you're gonna pull the pan anyhow then I'd replace the pump. Unless the pump was relatively new when you had the engine rebuilt, I would have replaced it at that time. And, once it's replaced, assuming that doesn't cure your problem, you can proceed to determining the source of your problem. Check the pan contents well . . . .

midyearvette

i thought the original post was the car never had good pressure for 40 years......i take it the same pump was re installed?...why?? in either event the next step is to pull the pan and check the pump.....since the gauge reading was verified and jack changed the filter.......

Ron Miller

The original post was that it had never had high pressure in the past. I'm not sure what the OP considers high pressure. In any event, I'd replace the oil pump with an engine rebuild.

Jackfit

The car always had low pressure. I never knew it was low. Never remember more than 40 psi and it would always drop at idle.

I bought car in 1969 from Navy flier with 46,000 miles on it and a broken speedometer. Even after rebuilding the speedo, (it works with drill on cable from tranny end) does not work with cable in tranny. But that's another story.

I hope it is a pump. The engine was rebuild a respected builder of engines , but that was 4 years ago. Motor sat on my stand, (needed to new hips and one knee ) just got to putting car together this late fall.

I will know in a few weeks, having pan gasket replaced and will put in new pump.

Jack

1-2-b-67L89

Jack, did you receive a spec sheet with the engine rebuild showing clearances, etc.? If you have anytime on the current engine oil (to get a sample for evaluation) or the old oil still around I would suggest having a oil sample analyzed. If something is wrong or going wrong oil sampling can be a very wise thing to review. That oil filter being all gunk-ed up is, well just say strange........
And yes, if the oil filter was all gunk-ed up there is a possibility the oil screen has gunk/debris or something. Good comment about making sure the pressed in oil tube to the oil pump is tacked welded.
Chick

mechron

midyrear, good call, there is always that fitting on all SBs. i always run a mechanical OP gauge at that port, it is 1/8 th npt and so going with a 1 long inch pipe and a adapter, the gauge will clear. DOKK took pics of mine, and even though it stood out like a sore thumb (oh, by the way dokk, how is your thumb...)he didn't notice it. now he is going to put the gauge on his engine. it is trick and it looks cool. but it also gives you real readings when you are working in the engine compartmant-->the gauge is cool and reads OP in real time...later...

Jackfit

Chick, thanks for your input,

The engine was rebuilt four years ago by someone 300 miles away. I can't find the paperwork. The motor sat on my engine stand for that time as I was unable to work on car until this fall. New pistons, valves, cam, turned crank, stems, guides, rods, but I don't know about pump. New timing cover, pan, freeze plugs, engine block cleaned (cooked?) two of the cylinders are sleeved from bad rebuild 25 years ago. Engine started on first turn of key , but had low pressure from first day. I bought cheap gauge to start engine as the my oil line to cluster was too short ( original line cut to take engine out for rebuild. I assumed the cheap gauge was off , plastic line kinks etc. Restored cluster, and new copper line and same thing, low readings.


The first filter I changed after 1 hr run time was very black mud like. The oil on dip stick always seemed clear and not black. I changed the filter yesterday ( about 300 miles driven since 1 hr change) as I put back on canister and took off spin on. Same thing, oil very black. Dip stick oil seems clear. Had the oil on dip stick been dark or black, I would have been more concerned earlier.

Who would I send oil to sample? I live in Maine just outside of Portland. I have the dark oil from both changes.

I am having a respected garage change the pan (oil leak, front bolt on pan) ( the oil leak is what got me thinking about the pressure as I have stated, the car always had lower oil pressure than what forum members have stated in this thread)

I will get a new pump for him to put in. We will inspect screen and bottom of pan for debris. What could cause oil to be so dark? I am not burning oil, no smoke. Took out plugs and they are dry and look very good.

Jack

MikeM

That black, mud stuff is assembly lube and/or breakin oil. Keep your fingers crossed you have a stopped up pump screen.

MikeM

That 1/8" plug is not there on a Tonawanda SBC.

Jackfit

I ran out to garage , no pants to take pictures of oil

#1 first oil filter change 1 hour run
#2 second filter change 300 miles

red bucket #1
black bucket #2

jim lockwood

I use Staveley Services for oil analysis. For accurate results, they will need an oil sample collected in a clean, non-contaminated container. I save empty quart oil bottles for this purpose.

Jim

Jackfit

I will send them a sample. what are we looking for? Metal in oil,

Jack

1-2-b-67L89

Jack, if you check the web you will find many places that you can send a oil sample to but would not do so until the preliminary things your doing, i.e. new pump, screen, etc., are completed. Many commercial businesses do oil sampling including mfg. oil sampling on machines. If you have any Portland friends that are into the trucking end of business you might want to ask them. I assume the person who built the engine knew it was going to sit awhile and might have had it protected internally for you, hence maybe some of the oil filter findings which alarmed us initially. Hope it is the screen or something simple
Chick
http://www.blackstone-labs.com/all_a...le_counts.html

1-2-b-67L89

Opps, your post was not there when I started to respond Jim! Good information to have
Chick

66BlkBB

This thing sat for (4) four years. Is it possible that the assembly lube used coagulated and has now blocked some of passages? Oil should never be that black, even with the assembly lube it after the initial break in. Is it also possible that the rebuilder did not cook the engine out, or cooked it out and never got all of the residual passages clean causing this problem? New bearings and pump should give close to 60 #'s at RPM if the clearances were correct. My 68 327 carries 45 #'s at RPM and 20 to 25 #'s at idle with no rebuild and I can only guess at the mileage on the engine.

StickShiftCorvette

I like many, like to run plenty of oil pressure.

However, when these cars were new most had "Readings of 30 to 40 psi may be considered normal during moderate road speeds of 35 to 40 mph at proper operating temperature."

Oil pressure and 15 psi at idle is normal and if very if the oil is very hot, 10 psi might be seen.

The quotes above are from the owner's manual of my 1969 (Page 15)!

I run high volume, high pressure pumps in my Corvettes, although I am aware as there is little benefit from higher pressures and that it does consume added power.

I utilize a pressure reducing valve to protect the gage from damage. It makes the gage read accurately below the set point and limits the gage reading to the setting. On my '61 I set it to 50 psi and on my '69 to 60 psi.....

BLOCKMAN

Where do you live in Maine as I am from there too not far from Portland either.

Dark oil fast sounds like poor ring seal do a leak down test not a compression test to see if you have good ring seal as Putting sleeves in all 8 cylinders causes a lot of unwanted stress in the block.

You can give me a call at 207-892-7215

We have never used any High Volume pumps on any of our builds but all our blocks are line honed bearings are sized and fit and we measure the cam tunnels and if they are over the high side we line bore them to .010 or .020 so far in 36 years we have had zero problems.

And with a small journal crank a high volume pump may to much if every thing is fitted right!!!!!!

We have seen guys that have had a spun cam bearing cause a low oil pressure problem but make no noise either.

Jackfit

I was a little concerned with first dump of oil and filter change. The engine did sit in unheated area during winters in Maine.

We will know shortly when pan comes off. As stated in above thread, those readings where consistant (30 to 40 psi ) in 1969 when I bought car. Sometimes it would drop pretty low at idle. The black oil ....

Jack