Oil wt.

[will e]

Do you have a picture of you pick up and oil pan? I just kind of keep going back to it in my head. What oil filter are you using?

So with the engine cold using a drill you can try it a few different times, with a break inbetween, and sometimes you get oil pressure and sometimes you don't? The times you do get oil pressure it seems to 'keep working' and the times you don't get oil pressure it doesn't work from the beginning.

Is that accurate?

 

[jbojo]

Do you have a picture of you pick up and oil pan? I just kind of keep going back to it in my head. What oil filter are you using?

So with the engine cold using a drill you can try it a few different times, with a break inbetween, and sometimes you get oil pressure and sometimes you don't? The times you do get oil pressure it seems to 'keep working' and the times you don't get oil pressure it doesn't work from the beginning.

Is that accurate?

will e

Oil filter is a NAPA Gold

<> When engine is cold I get good oil pressure every time. Tried again this morning and I have over 50# pressure. I always have consistent good pressure when oil is cold.

<> No oil pressure from the beginning only when the oil is hot, then there is no pressure until the oil cools down. Even when I give it a chance for all the oil to drain back to the pan no pressure while the oil is hot however I can see some oil flow.

Unfortunately I have no picture of the oil pickup.

thx will e

-jbojo

 

[MechEng]

jbojo,

Where is your manual gauge hooked up?

 

[Don65Stang]

There is much variation on engine oil knowledge, advice, and misconceptions. I learned a lot by reading the below article. Please note that the link goes to the Bob is the Oil Guy site where he is not about selling you something; It’s about educating you so you can make informed decisions about the life blood of your engine: motor oil.

http://www.bobistheoilguy.com/motor-oil-101/

 

[jbojo]

MechEng,

The gauge is hooked up at the same location as the sending unit for the interior gauge, I use a T fitting and there is no tubes running to the mechanical gauge. Located right at the top back of the motor. Both gauges indicate pressure until oil is hot.

Don,

Thanks for the article it was a good read. So my engine at operating temp is approx. 212* so the oil should have the viscosity of 30wt oil. Do you have any thoughts why there's pressure when oil is cold and no pressure when hot?

thx

-jbojo

 

[72HCODE]

incorrect oil sender sensor maybe??? if the sender ohm range is too small it would create a high reading when cold and a low reading when hot.

 

[jbojo]

incorrect oil sender sensor maybe??? if the sender ohm range is too small it would create a high reading when cold and a low reading when hot.

72HCODE,

The mechanical gauge indicates the same as the electrical one. I originally installed both so that I have 2 different types of gauges to eliminate these kinds of issues. This problem that I am having has me completely stumped.

-jbojo

 

[Kit Sullivan]

Sounds like you may have loosely-sized main bearings. Just a WAG on my part, but I've seen it happen this way a couple times before.

 

[jbojo]

Sounds like you may have loosely-sized main bearings. Just a WAG on my part, but I've seen it happen this way a couple times before.

Kit,

Thanks for the response. I was thinking the same thing but hoping this is not the case. This is the first motor that I did not put together myself. The machine shop that did the work did the long block assembly and I would have thought all those clearances were checked. Thx again.

-jbojo

 

[mjlan]

What size drill motor are you using?

I burned up my trusty old 3/8 drill trying to prime a HV pump, and it's replacement almost broke my wrist trying to pump cold oil....

It sounds like there isn't enough resistance to the oil flow once things get warm and the pressure drops off.

I would be curious what your bearing clearances were as well...

 

[jbojo]

What size drill motor are you using?

I burned up my trusty old 3/8 drill trying to prime a HV pump, and it's replacement almost broke my wrist trying to pump cold oil....

It sounds like there isn't enough resistance to the oil flow once things get warm and the pressure drops off.

I would be curious what your bearing clearances were as well...

mjlan

Unfortunately I did not do the assembly work so I don't know what the bearing clearances are. I just checked the drill, I thought 3/8 but it's actually 1/2 inch. I can get about 55-60 # pressure when cold.

-jbojo

 

[cobra3073]

What size drill motor are you using?

I burned up my trusty old 3/8 drill trying to prime a HV pump, and it's replacement almost broke my wrist trying to pump cold oil....

It sounds like there isn't enough resistance to the oil flow once things get warm and the pressure drops off.

I would be curious what your bearing clearances were as well...

mjlan

Unfortunately I did not do the assembly work so I don't know what the bearing clearances are. I just checked the drill, I thought 3/8 but it's actually 1/2 inch. I can get about 55-60 # pressure when cold.

-jbojo

For "peace of mind", can't you check with the folks who did the assembly to see what clearances they used?

...just a thought.

BT

 

[Jeff73Mach1]

Good luck. I think you need to pull the filter and cut it open. It sounds like you may have spun a main bearing, or have improper clearances.

If you can pull the pan and check the oil pump pick up, it might be a good idea. it might be broken and not picking up oil when the crankcase isn't very full.

 

[jbojo]

What size drill motor are you using?

I burned up my trusty old 3/8 drill trying to prime a HV pump, and it's replacement almost broke my wrist trying to pump cold oil....

It sounds like there isn't enough resistance to the oil flow once things get warm and the pressure drops off.

I would be curious what your bearing clearances were as well...

mjlan

Unfortunately I did not do the assembly work so I don't know what the bearing clearances are. I just checked the drill, I thought 3/8 but it's actually 1/2 inch. I can get about 55-60 # pressure when cold.

-jbojo

For "peace of mind", can't you check with the folks who did the assembly to see what clearances they used?

...just a thought.

BT

This was built a while back and this info isn't available anymore. Actually had it build at a performance shop in FL. I am going to have to suck it up here.

Jeff73Mach1

Yeah, I was thinking of getting one of those snake cameras and try to see where the pic up is.

One last question. What are the thoughts about replacing the filter and oil and trying it again. I was thinking of using Valvoline 10-30 VR1 oil. If that doesn't solve the problem the motor will be coming out again. Thx all for the help and suggestions you all have provided. If the motor comes out I am considering a stroker 393 mod.

thx

-jbojo

 

[TommyK]

mjlan

Unfortunately I did not do the assembly work so I don't know what the bearing clearances are. I just checked the drill, I thought 3/8 but it's actually 1/2 inch. I can get about 55-60 # pressure when cold.

-jbojo

For "peace of mind", can't you check with the folks who did the assembly to see what clearances they used?

...just a thought.

BT

This was built a while back and this info isn't available anymore. Actually had it build at a performance shop in FL. I am going to have to suck it up here.

Jeff73Mach1

Yeah, I was thinking of getting one of those snake cameras and try to see where the pic up is.

One last question. What are the thoughts about replacing the filter and oil and trying it again. I was thinking of using Valvoline 10-30 VR1 oil. If that doesn't solve the problem the motor will be coming out again. Thx all for the help and suggestions you all have provided. If the motor comes out I am considering a stroker 393 mod.

thx

-jbojo

Try 20W-50. If the hot oil pressure picks up and there are no funny noises you may be able to write it off to bearing clearances being on the loose side. If it doesn't improve then I would pull it and find out why.

 

[jbojo]

For "peace of mind", can't you check with the folks who did the assembly to see what clearances they used?

...just a thought.

BT

This was built a while back and this info isn't available anymore. Actually had it build at a performance shop in FL. I am going to have to suck it up here.

Jeff73Mach1

Yeah, I was thinking of getting one of those snake cameras and try to see where the pic up is.

One last question. What are the thoughts about replacing the filter and oil and trying it again. I was thinking of using Valvoline 10-30 VR1 oil. If that doesn't solve the problem the motor will be coming out again. Thx all for the help and suggestions you all have provided. If the motor comes out I am considering a stroker 393 mod.

thx

-jbojo

Try 20W-50. If the hot oil pressure picks up and there are no funny noises you may be able to write it off to bearing clearances being on the loose side. If it doesn't improve then I would pull it and find out why.

TommyK,

Yeah I'll give that a try, nothing to lose at this point. When I drain the oil I'll filter it to see if there are any metal shavings in it.

thx

-jbojo

 

[Qcode351mach]

You have a definite problem you should see around 40-50 psi HOT especially on a new build..If your not, than the question is where are you losing pressure from ? The hot oil is flowing past a clearance that when the motor gets hot & it expands it's pissing past it..Changing the oil weight isn't the answer..As others have said the first logical place to start is the mains. It actually could be an easy fix..I would pull the pan (if possible while still in the car) Plastigauge one bearing & see what you get..It will tell you whats going on..If it's excessive than you need to pull the motor..They make over size & under size bearings so you can dial in you clearance..

 

[jbojo]

You have a definite problem you should see around 40-50 psi HOT especially on a new build..If your not, than the question is where are you losing pressure from ? The hot oil is flowing past a clearance that when the motor gets hot & it expands it's pissing past it..Changing the oil weight isn't the answer..As others have said the first logical place to start is the mains. It actually could be an easy fix..I would pull the pan (if possible while still in the car) Plastigauge one bearing & see what you get..It will tell you whats going on..If it's excessive than you need to pull the motor..They make over size & under size bearings so you can dial in you clearance..

Thx Q, I have a feeling that I'll be pulling the motor. I posted this in my build thread earlier today and I figure I'll try out one more thing.

-jbojo

===========================================

I drained the oil today and filtered it to see if there were any metal particles in it and I came up with nothing. Still have the problem though its changed a little now. When I primed the motor with a drill I got good back pressure and about 60lbs of pressure on both mechanical and electrical gage. As the motor warmed up the pressure began to drop on both gages and at the end the mechanical gage had zero however the electrical showed about 25 lbs at idle. There are no unusual noises coming from the motor and no lifter noise so I believe that the motor is being oiled properly.

Tomorrow I am going to remove the tee that I am using for the electrical oil sensor and mechanical gage to see it that makes any difference. One question that was asked was whether I was sure that the oil pickup was the right one for the deep sump oil pan. I couldn't verify it visually however when I filled the oil again I put 5 qts in and tried to prime the motor. It immediately primed and filled up the oil filter and kept up good pressure the whole time I was priming. I then added an additional 4 qts so there should be plenty of oil.

Depending on the outcome tomorrow I'll decide whether to go ahead and pull the motor which I really don't want to do.