Re: Low oil pressure in ZL-1
 

My ZL-1 set over a year after dyno time. It leaked water up thru the head bolts. Lots of water. The builder told me to go to my Gm dealer and buy tablets that go in the rad water. It took 6 times before it sealed. Runs fine now. I changed the oil 6 times before it quit. Just giving info to watch for on these motors. Kim

Re: Low oil pressure in ZL-1
 

Hey way to go.........But what are you 2 gonna do with all your spare time now......... https://www.yenko.net/ubbthreads/imag...mlins/wink.gif

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
My ZL-1 set over a year after dyno time. It leaked water up thru the head bolts. Lots of water. The builder told me to go to my Gm dealer and buy tablets that go in the rad water. It took 6 times before it sealed. Runs fine now. I changed the oil 6 times before it quit. Just giving info to watch for on these motors. Kim

[/ QUOTE ]


got back from picking up the motor..maachinist stayed on it till 2 AM to get it back together..disassambled, cleaned, new bearings. Its back in the shop awaiting new gaskets and a install on Monday..then https://www.yenko.net/ubbthreads/imag...ns/burnout.gif

had the problem with the bolts..fixed that..but when I blow air into the crossover nothing comes out the exhaust..nothing!..it all goes thru the water jackets..almost as if its set up a coolant passage under the carb..good thing??bad thing?? https://www.yenko.net/ubbthreads/imag...lins/dunno.gif.was planning on sealing the crossover area with the block off plate that comes with the intake set so it should be sealed anyway.

Albert

Re: Low oil pressure in ZL-1
 

BAD THING! The 074 heads don't use the heat crossover and it is a dead end and does not go to the water jacket. Your heads need to be pressure checked. Should have no water. The head bolts in the ZL-1 block are blind-they don't go into the water jacket and only require oil on the threads. The 4 extra head studs go into the 4 intake ports and need sealant-do not use silicone it is not gas resistant. Man, these ZL-1's are different animals.

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
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

[/ QUOTE ]or maybe a missing gally plug

Re: Low oil pressure in ZL-1
 

Glad to hear everything has been sorted out Al. Please let us know how she runs after its all put back together. https://www.yenko.net/ubbthreads/imag...iggthumpup.gif https://www.yenko.net/ubbthreads/imag...iggthumpup.gif

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
[ QUOTE ]
My ZL-1 set over a year after dyno time. It leaked water up thru the head bolts. Lots of water. The builder told me to go to my Gm dealer and buy tablets that go in the rad water. It took 6 times before it sealed. Runs fine now. I changed the oil 6 times before it quit. Just giving info to watch for on these motors. Kim

[/ QUOTE ]


got back from picking up the motor..maachinist stayed on it till 2 AM to get it back together..disassambled, cleaned, new bearings. Its back in the shop awaiting new gaskets and a install on Monday..then https://www.yenko.net/ubbthreads/imag...ns/burnout.gif

had the problem with the bolts..fixed that..but when I blow air into the crossover nothing comes out the exhaust..nothing!..it all goes thru the water jackets..almost as if its set up a coolant passage under the carb..good thing??bad thing?? https://www.yenko.net/ubbthreads/imag...lins/dunno.gif.was planning on sealing the crossover area with the block off plate that comes with the intake set so it should be sealed anyway.

Albert

[/ QUOTE ]

A 074 head unless someone has modified it has no passage, A good common practice is to pressure check a engine before installation. I highly recommend it.

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
BAD THING! The 074 heads don't use the heat crossover and it is a dead end and does not go to the water jacket. Your heads need to be pressure checked. Should have no water. The head bolts in the ZL-1 block are blind-they don't go into the water jacket and only require oil on the threads. The 4 extra head studs go into the 4 intake ports and need sealant-do not use silicone it is not gas resistant. Man, these ZL-1's are different animals.

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Greg, your NOT making my day..it seems that the flow thru the water jacket isbeing caused by a somewhat large hole..never builds pressure just blows air out...no water in the oil but then again the motor only ran to operating temp once..looks like I may pull the heads since the motor is out and look more closely at this problem..thanks for the input..anyone else care to guess comment on this..really getting frustrated now!! https://www.yenko.net/ubbthreads/imag...lins/frown.gif

Re: Low oil pressure in ZL-1
 

Ok so I just read your post about the motor is back together and everything is fine now. So what was the final problem and what about the heads?
Mark Sheppard

Re: Low oil pressure in ZL-1
 

[ QUOTE ]
Ok so I just read your post about the motor is back together and everything is fine now. So what was the final problem and what about the heads?
Mark Sheppard

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had two problems with the motor..both my/machinists fault. First was the missing oil pressure reg that presses into the block and the other was the three missing plugs that are in the lifter valley..the oil press reg is different than the kind in the older blocks..I forgot about it https://www.yenko.net/ubbthreads/imag...lins/dunno.gif you would think that at 5K or more GM could have included the oil pressure reg ( my cost 3.61 ) and the three valley plugs..all the other plugs come with the motor so why not those three..anyway a little hard work..a litle money (new bearings to be safe) and I am all good to go.

The heads..well thats another story..it seems that some one who did the machine work on these heads before I got them drilled the stud too deep and drilled right thru to the heat crossover actually drilling out the divider between the water passage and the crossover..no easy fix!!.I sealed off the crossover with a piece of stainless shim JB welded to the head followed by some good sealer and a intake gasket with no crossover hole..held pressure and should not leak..I will be keeping an eye on this but I dont think it will cause any problems..time will tell. Ran motor up tp operating temp..set timing..as soon as the roads are dry enough (we had snow this morning!!)I will begin the road tests..motor really liked 16 degrees initial advance and another 20 in the distributor..using a new MSD distributor that has a digital curve..no springs!!..so far so good..well see after the road test. Thanks everyone for their help and support. https://www.yenko.net/ubbthreads/imag...ouguysrock.gif

ALbert