No oil pressure at idle after rebuild, new block!

[turbovanman]

Ok, he just tore it down and yes, I visually inspected all 8 aluminium oil squirters and wow, they must have a 1/16" hole,

He also showed me the bearing clearance, .002" on the mains, .0025" on the rods. Spec is .0045" mains and .005" for the rods. I figure the reason for the oil squirter issue is the tighter oil clearance is letting more oil go thru the squirters, it really is the only theory I have,

So we are plugging them off, new bearings again as they are damaged from the low oil pressure and pray we got it right this time, :mad2: :iamwithstupid:

 

[nobby]

Yes, the oil cooler does have a bypass but we figure the oil pressure was so low, it couldn't make the bypass so to speak.

That does not make sense in regards to your drop in pressure when pinching the cooler line if the drop in pressure is being caused in the galleries somewhere. If the pump is OK and at spec and you block off the cooler line irrespective of what is going on in the galleries if the bypass if functioning correctly it will have to open as the pressure will now ramp up because the pump output is being physically blocked. The limiting factor here will be how much that bypass can flow. My thought would be that the cooler bypass is not full flow so to speak, it would not need to be as its job is to merely dump some pressure/oil away from the cooler when cold. This would then help explain your experience of a loss in pressure when pinching the line. If your pump were OK and you are in fact dumping pressure in the galleries somehow then when you block the cooler line the pressure goes up the bypass opens but it can not flow enough to maintain the small amount of pressure that you had with the leak in the gallery somewhere. This is why I did not like when I read of others plugging their cooler ports, my question was is this case was the bypass capable of truly flowing enough to maintain good lubrication.

Cheers
Nobby

 

[gmctd]

Each oil squirter only squirts at certain positions of the crank, when that particular piston is in positional range to be cooled - otherwise they'd just dump oil pressure, much as you're seeing, and really froth up the sump oil - also, iirc, takes a oil-squirter crank to work in a oil-squirter block????????????

 

[turbovanman]

Each oil squirter only squirts at certain positions of the crank, when that particular piston is in positional range to be cooled - otherwise they'd just dump oil pressure, much as you're seeing, and really froth up the sump oil

Well the bearings have a journal in the middle so oil is fed 100% of the time to the squirters. Hmmmmmmmmm, maybe that's something to look into? Ohhhhhhhhhhhhh, shit, I'll go check that too, I just got what you said.

We never moved the crank at all, just pressurized the oil, I should have taken a vid, the oil coming out was massive, like 8 waterfalls, :sad:

 

[nobby]

That's what I was just thinking the upper shells have an oil groove in them that feeds to the squirter hole no? Otherwise the crank would have to be drilled offset with a second hole away from the groove that is timed and talks to the squirter when the piston is down.

I dunno if it were me I'd invest in another new HO oil pump to CYA
Cheers
Nobby

 

[turbovanman]

Well that was a bunk idea, lol.

We checked the 96 crank against the 97 one and they are identical, same part number.

We dug up the 97 bearings, same as the new bearings we put in, bottom half solid, top half grooved with 3 holes.

No need to buy another $150 oil pump, nothing wrong with it.

 

[nobby]

So the question in my mind then is what is the spec hole size for the nozzles and their flow rate? Quick google on this did not find anything and my manual draws a blank on that.

Cheers
Nobby

 

[turbovanman]

So the question in my mind then is what is the spec hole size for the nozzles and their flow rate? Quick google on this did not find anything and my manual draws a blank on that.

Cheers
Nobby

I honestly don't know, I tried to contact Heath today but he wasn't answering his phone. I can't comprehend how others are not having this issue and reusing the stock squirters????????

 

[Missy Good Wench]

The cranks are definately all the same.

I have seen rebuilds that had a squirter of two not in and loose pressure.

If you plug the squirt holes you should stop the problem.

These things dump a huge amount of oil anyway.

The engine in my DaHoooley was a 97 crate motor and it has the nozzles in it.

I will go see it I can get a peek at the size of hole in them. and get back to ya asap

Missy

 

[Missy Good Wench]

OK HERE IS THE REAL DEAL

The 1997 block I ripped this nozzle out of has a .047" hole in the tip of the squirter.

With as much oil as you are losing at idle, I am suspect that you may have one or more that fell out during shipping, or ????

Be sure all nozzles are in the block and that the holes are .047" or smaller.

The large oil pump for the 97 and later is much larger and deeper ( gear segments are deeper)

A standard pump does not have the section in the middle as this one does
A standard 6.5 pump will not keep up at idle on a squirt block.
You can use the squirt pump with a non squirt block though and gett a bunch more oil is all.

Ratman did his this way to give it more oil.

A hole without a nozzle is about 1/4 inch and will dump a huge amount of oil.

Here are some pix.

Missy

 

[bison]

I still would check that cooler supply line,never mind a cooler bypass valve,(must be internal cause i've never seen one on the outside between the connections),if not enough oil cant get to the cooler, the buck stops right there.

 

[nobby]

I still would check that cooler supply line,never mind a cooler bypass valve,(must be internal cause i've never seen one on the outside between the connections),if not enough oil cant get to the cooler, the buck stops right there.

Yes it's internal.

Cheers
Nobby

 

[turbovanman]

OK HERE IS THE REAL DEAL

The 1997 block I ripped this nozzle out of has a .047" hole in the tip of the squirter.

With as much oil as you are losing at idle, I am suspect that you may have one or more that fell out during shipping, or ????

Be sure all nozzles are in the block and that the holes are .047" or smaller.

The large oil pump for the 97 and later is much larger and deeper ( gear segments are deeper)

A standard pump does not have the section in the middle as this one does
A standard 6.5 pump will not keep up at idle on a squirt block.
You can use the squirt pump with a non squirt block though and gett a bunch more oil is all.

Ratman did his this way to give it more oil.

A hole without a nozzle is about 1/4 inch and will dump a huge amount of oil.

Here are some pix.

Missy

Thanks, all nozzles were counted, I personally did it myself on the tear down and were not loose. I would estimate the size at 1/16 or slightly smaller. I honestly don't care as they are history. I should have taken vid as the amount of oil these bled off was insane.

We had the wrong pump in the first build then have the pump now your picture shows, made a bit of a difference but not enough to overcome the 8 gaping bleeds.

 

[turbovanman]

I still would check that cooler supply line,never mind a cooler bypass valve,(must be internal cause i've never seen one on the outside between the connections),if not enough oil cant get to the cooler, the buck stops right there.

Yep, checked, its there and fully functional. I am guessing there just wasn't enough oil flow at idle.

I bypassed the cooler with some 1/2 line, when revved and held at 1500, the line was very hard, at idle, I could almost pinch it closed with my fingers and you could feel a pulsation.

 

[bison]

Yep, checked, its there and fully functional. I am guessing there just wasn't enough oil flow at idle.

I bypassed the cooler with some 1/2 line, when revved and held at 1500, the line was very hard, at idle, I could almost pinch it closed with my fingers and you could feel a pulsation.

Hope the pumpshaft aint spinning in the gear? I dont think the press should pulsate,cause that should be visable on the gauge as well.
Did you try running the pump up to press with the drill trough the pump drive bore? You will have to rig up a sleeve with an 0 ring to block of the lifter oil gallery.

what was the reason the original engine blew? Did it share the pump?

 

[turbovanman]

Hope the pumpshaft aint spinning in the gear? I dont think the press should pulsate,cause that should be visable on the gauge as well.
Did you try running the pump up to press with the drill trough the pump drive bore? You will have to rig up a sleeve with an 0 ring to block of the lifter oil gallery.

what was the reason the original engine blew? Did it share the pump?

New pump and after I put another HO pump in, we checked the new old HO pump and nothing wrong with it.

I am assuming the pulsating is because the pressure was so low, as soon as it got throttle, the pressure shot up and the line got hard, no more pulsing. It did this on both HO pumps.

We check the pumps on the bench, they flow, wow.

 

[turbovanman]

Got the longblock back at 3:30 pm, would have been 11 if my f(&()&* stupid suppliers hadn't messed up and forgot to order the bearings, luckily they had someone at the warehouse.

Put all the tin back on, timing covers, IP etc, and its halfway back in, I am thrashing to get this done as I need to drive it home and deliver it tomorrow.

I'll post up my results in a few hours, :rolleyes5:

 

[turbovanman]

Fixed and gone, phew.

Got it finished just after 10pm, would have been faster but took a UFC break and
had to put the oil cooer and grill etc back in.

Cold oil pressure was 75 psi, then dropped to 50 warm, after a hard run, its
steady at 20-25 psi or a 1/4 on the gauge, at idle, phew.

We have alot of machinists and engine builders stumped so I guess we had one of
those jobs that you just can't explain. The squirters in this case were worth 25
psi of oil pressure,

EGT's went to around 1200 up hills not towing, I had my foot into it, lol. Temp went up to 3/4 on the gauge then the fan would kick in, so a Dmax fan upgrade is next.

Anyhow, its done and I drove the truck 2 hours thru mountains to the owner on holidays, the oil pressure was perfect. Just wish we knew why this happened?

 

[NVW]

Glad to hear that

Leo

 

[Brooklyn Tow]

Isn't that oil pressure still a little low (20-25 psi) when hot......You would think around 40psi (about 1/2 way on the gauge) for a fresh rebuild/refresh?

Not trying to throw any fuel on the fire,.....just asking.

Anyway I know your glad to have that job out of your shop.......Good follow thru, alot of guys would of gave up or subbed it out or whatever.