Low oil pressure in ZL-1
 

I am in the middle of taking the ZL-1 out of the Malibu. Really PO'd but at least its not blown up. OIl pressure is very low..29 lbs cold and less than 5 hot...not good!!..been that way since we started it up fresh machinist will take care of it whatever it is....were thinking bad oil pump or pick up as the oil is foaming..or maybe a missing gally plug..oil filter is good also..first time this has happened with a new motor..dont know who is worse..me or the machinist..he keeps calling to check on my progress..we shall see what the problem is..thanks for hearing my vent

Albert

Re: Low oil pressure in ZL-1
 

Better to catch it now when it's still fresh versus later when the low pressure has taken its toll.

Was the pickup welded to the pump?

Re: Low oil pressure in ZL-1
 

Good thing your machinist is that concerned about it.
Hope it turns out to be a simple fix.

Re: Low oil pressure in ZL-1
 

that happened to me too with one of the motors for the 57. only ran it for a few hours and took it to the track. staged the car and noticed i had only 5 lbs of pressure....spun a bearing some how. at least it was caught before anything too bad happened....i feel your misery !!

Re: Low oil pressure in ZL-1
 

The pickup is most likely not your problem ,but add 3 Qts of oil above full ,if it doesnt change the pressure its not the pickup. Drain oil and stick a wire in the pan to feel around for the pickup. Foaming is most likely due to moisture [water] or contaminate in oil. And of course check the gauge to see if its working right.

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
The pickup is most likely not your problem ,but add 3 Qts of oil above full ,if it doesnt change the pressure its not the pickup. Drain oil and stick a wire in the pan to feel around for the pickup. Foaming is most likely due to moisture [water] or contaminate in oil. And of course check the gauge to see if its working right.

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This motor has had poor pressure since I started it for the first time..I have changed the filter..added extra oil, checked both the eletic factory gauge and the mechanical guage with no changes.pipck up is welded...motor is quiet and has oil on the top end..just looses most of its presure when hot..crank is new..rods are new..machinist is very qualified..we have recently fired 4 of his motors..2 L-78's 1 454 and my 427..the other three are perfect 60 psi cold 30-60 hot with good response to the throttle..it has to be the pump is no good..cant be anything else?? https://www.yenko.net/ubbthreads/imag...lins/dunno.gif

Re: Low oil pressure in ZL-1
 

Have you replaced the pressure relief valve?

Re: Low oil pressure in ZL-1
 

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Have you replaced the pressure relief valve?

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this block does not use one.....bowtie design thanks for the good ideas..keep them coming..gotta be a simple answer

Re: Low oil pressure in ZL-1
 

Pull motor,drop pan,change pump.Dyno. Lastly, dont assume you cant have crud [or a blocked screen] in a brand new motor. Have seen many silicone/gasket material blocked motors too.

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
Pull motor,drop pan,change pump.Dyno. Lastly, dont assume you cant have crud [or a blocked screen] in a brand new motor. Have seen many silicone/gasket material blocked motors too.

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I agree..motor is coming out tomrrow and will be inspected thoroughly..Ill post the findings

Re: Low oil pressure in ZL-1
 

Triple check the bearings.

Re: Low oil pressure in ZL-1
 

Is this a new ZL-1 Chevy block 053 casting? it does use a relief valve under the oil filter. Make sure is was installed and staked in the correct hole as there are 2 holes it fits in. If not there, could be your problem.

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
Is this a new ZL-1 Chevy block 053 casting? it does use a relief valve under the oil filter. Make sure is was installed and staked in the correct hole as there are 2 holes it fits in. If not there, could be your problem.

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I dont remember puttng that in..do you have more info that I can use??

Re: Low oil pressure in ZL-1
 

Remove your oil filter and look at the block. There are 2 large (3/4"?) holes. 1 large hole should have a check valve in it or you will bleed pressure like crazy. The valve is availible thru Chevy Performance Parts-Scoggin Dickey knows what it is if you tell them its for ZL-1 block.

Re: Low oil pressure in ZL-1
 

thats got to be it!!..never put one in!!!

Re: Low oil pressure in ZL-1
 

The relief valve part number is 25013759. This is the set-up on all ZL-1's. I would have to remove my oil filter to see which hole I put it in as I don't remember.

Re: Low oil pressure in ZL-1
 

Check it, and if you don't have one in the block let us know.

Re: Low oil pressure in ZL-1
 

I know I did not put one in..Ill verify it in the AM and order that piece..many thanks!!

ALbert

Re: Low oil pressure in ZL-1
 

Wow, this is better than any soap opera or game show. It actually has a happy ending (crossing my fingers at the moment). Alss, update us as soon as you know.
https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Low oil pressure in ZL-1
 

Sounds Like sound advise to me from 69ss ZL1... Lets check it out tomorrow.. Sounds like what is going on!!!! All the problems indicate the facts at hand... And lets go from there....

Re: Low oil pressure in ZL-1
 

69SSZL1 is correct. If this is an 053 block. The relief valve and the filter nipple have to be purchased separately and installed by the user. For some reason they don't come with the block. I left it out of the first ZL-1 I built and had about the same numbers as you're seeing. Easy Fix

Relief Valve

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
Sounds Like sound advise to me from 69ss ZL1... Lets check it out tomorrow.. Sounds like what is going on!!!! All the problems indicate the facts at hand... And lets go from there....

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Man! I guess they'll let anyone join this site https://www.yenko.net/ubbthreads/imag...ns/naughty.gif
Just kiddin Joe. Welcome to SYC..

Joe was nice enough to stop in a few weeks ago and help out with the firing of my ElCamino..... and it's a good thing Joe was there. It needed some more valve adjusting, before it lit https://www.yenko.net/ubbthreads/imag...ns/worship.gif

Re: Low oil pressure in ZL-1
 

Sounds hopeful! I hope you didn't get too far in the removal ALbert!

Re: Low oil pressure in ZL-1
 

[b]The knowledge on this board never ceases to amaze me!! https://www.yenko.net/ubbthreads/imag...iggthumpup.gif https://www.yenko.net/ubbthreads/imag...ouguysrock.gif

Re: Low oil pressure in ZL-1
 

There is a lesson here. When you build an engine, always pre-lube it on the stand with a priming shaft. May not be able to catch a mechanical problem or assembly error, but a problem like this, or a missing galley plug would have easily been found.

MB

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
[b]The knowledge on this board never ceases to amaze me!! https://www.yenko.net/ubbthreads/imag...iggthumpup.gif https://www.yenko.net/ubbthreads/imag...ouguysrock.gif

[/ QUOTE ]

aint that the truth..thanks everyone https://www.yenko.net/ubbthreads/imag...ouguysrock.gif

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
There is a lesson here. When you build an engine, always pre-lube it on the stand with a priming shaft. May not be able to catch a mechanical problem or assembly error, but a problem like this, or a missing galley plug would have easily been found.

MB

[/ QUOTE ]

Did prelube the motor..had 30 psi cold with a drill tought it was good..different story when hot!!!

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
[ QUOTE ]
There is a lesson here. When you build an engine, always pre-lube it on the stand with a priming shaft. May not be able to catch a mechanical problem or assembly error, but a problem like this, or a missing galley plug would have easily been found.

MB

[/ QUOTE ]

Did prelube the motor..had 30 psi cold with a drill tought it was good..different story when hot!!!

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Not trying to beat you up, but I would have stopped right there. 30 psi cold and you will have practically nothing hot as you found. In any engine, the cold oil pressure will be significantly higher than when hot. You should have seen somewhere between 60-80 psi cold, depending on the internal clearancing. Then the motor would make around 20-40(sometimes higher-alot of variables here), once it warmed up.

Point is if you know that the oil pressure was 30 cold and it will drop sgnificantly when hot, then the 30psi reading was enough cause for concern. When you spin the drill up on the stand, the drill should "kick back" significantly. 30 psi will barely affect a quality 1/2" drill. Hopefully the engine was assembled with a high quality assembly lube. You would be surprised at how well that stuff will lubricate in the event of an issue such as this.

The motor is proabaly fine, especially if you didn't load it down. Glad the you found the source of the problem early. Keep us posted.

MB

Re: Low oil pressure in ZL-1
 

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Check it, and if you don't have one in the block let us know.

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Thats what we love about this site. It's people like this who come forward with a little help and knowledge and potentially save someone a little money and LOTS of time!! https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
There is a lesson here. When you build an engine, always pre-lube it on the stand with a priming shaft. May not be able to catch a mechanical problem or assembly error, but a problem like this, or a missing galley plug would have easily been found. MB

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Don't feel bad, Al, I learned a similar lesson years ago...early block, new cam/lifters [most of you probably already know where this is going!], had the thing ready to drop in minus the carb, was priming it on the stand, and noticed it never would oil the top end...naturally, the early block required the grooved cam, which I had neglected to purchase! So, apart she came, Mo put the cam on a lathe, and then we were back in business...just glad we found it before we wasted a day on the dyno! https://www.yenko.net/ubbthreads/imag...emlins/eek.gif

Re: Low oil pressure in ZL-1
 

Just verified the pressure reg is NOT in the block....its ordered and on its way..glad I didnt get the motor ALL the way out. Thanks SYC

Re: Low oil pressure in ZL-1
 

That is *great* news, Al! https://www.yenko.net/ubbthreads/imag...iggthumpup.gif

Big props to 69SSZL1 for the catch! https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Low oil pressure in ZL-1
 

Aw shucks. Just glad Alss can get that ZL-1 running and really hammer on it. These motors are monsters and run real well when dialed in. Hey don't forget 427king mentioned the relief valve early on.
https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Low oil pressure in ZL-1
 

Probably not the problem, but I bought an all rebuilt ZL1 motor and when dynod it had problems similar...The builder forgot to put in the 2 extra studs in each head that are only on a ZL1 motor...water was mixing with the oil and we had poor oil pressure when warmed up...after fixing problem, the motor dynod at 603 HP with LOTSSS of oil pressure!!! Bolts can be used if you cannot find the correct studs....but they need to be drilled and wiretied after torquing....hope that helps...good luck!!

Re: Low oil pressure in ZL-1
 

Thanks Bill For your recognition... I really am proud that you let me work with your BABY... She is stunning. But soon needs to be spanked like mine...LOL.. Let me know if I can ever help you!!! I am There

Re: Low oil pressure in ZL-1
 

WOW... Can some people not read ???? AIR IN OIL...NOT WATER
BB head problems with studs and bolts are common.... This is NOT

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
WOW... Can some people not read ???? AIR IN OIL...NOT WATER
BB head problems with studs and bolts are common.... This is NOT

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Welcome Joe. Just an FYI, Everyone here is just trying to help out. No need to jump down anyone's throat.

Re: Low oil pressure in ZL-1
 

Sorry, Just frustrated on this one... Really did not mean to be disrespectful to any one !!!!!

Re: Low oil pressure in ZL-1
 

Im sure there is someone out there that read iluv69s post and learned something that may help them down the road and thats the important thing. Both air and water in oil can cause low pressure readings and foaming in case anyone encounters that again.

Re: Low oil pressure in ZL-1
 

Both air and water in oil can cause low pressure readings and foaming in case anyone encounters that again.

REALLY???? Please foward me your expertise on this topic I am truely interested on your facts.