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Discussion Starter #1
I am interested in hearing if anyone has any views on oil consumption during the first 1000 miles a GM ZZ383's life. This was a long block assembled with all specified GM part numbers. Thus far my motor is using oil at a rate of approximately 1 quart every 325 miles. I am at about 600 miles now and wondering if this is just part of the break in. I was lead to believe that the plasma molly rings that come with this motor are supposed to seat very quickly. But I have read that in the past the big block crate motors had problems with these rings and oil consumption. I can not seem to find any informatin on this topic and would appreciate any feedback.
 

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If this is actually a GM unit..

A customer of mine bought one from local dealer. Installed it in his old pickup. Also had high oil consumption. After a lot of hassle.. It was discovered that the valve seals were ALL installed incorrectly.. Good Mexican quality! So, if one was done that way. I'll bet there a few hundred more out there causing problems..

Or the engine is sucking oil up thru the cam tunnel side of the intake manifold. Another common cause of high oil consumption.

Properly installed moly rings are usually seated soon after the engine is initially fired.
 

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Discussion Starter #3
GMPP ZZ383 Stroker made in USA. I saw the crate label. Funny enough it was next to a 350 crate that was from Mexico :) I have been concerned about the rings because of the plugs. The majority of them are dark. And I have been told by a motor builder that he thinks a stroker with low tension rings will have the potential to use oil due to the increased vacuum it draws. And he feels even plasma moly rings need time to brake in. So I am in search of input, and I thank you for yours.

BTW is there any easy way to check on the items you mentioned?
 

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The stroker in my Mustang has 1300 miles on it now. Its a 347 with probe pistons, but does not have the soft rings you have in the Chev. In the first 30 minutes of running in an engine trolley it blew clouds of oil smoke, then stopped once the rings seated. In the first 500 road miles it used about a pint.
Since the first oil change it has not used any noticeable amount up to 1300 miles so it would appear you have some serious issues there as mentioned above by other postees. Maybe a leak down test will give you a clue.
Goodluck
Al.
By the way as i have close tolerances on the crank i run 10/30 hipo Fuchs Oil.
 

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That has been the theme of my last few crate engines is either valve stem seals that "pop" off the guide and start riding on the valve or either loose valve to guide clearance. I had two motors from Blueprint engines come that way and they warranteed the engine once but the second time i just went with Trickflow 23 degree heads and can't be happier. My point is that my motor was using a quart every 400 miles and that was the culprit was 3 valves that were loose fitting in the guides. I would assume your valvesprings have dampers in them so you may use the old air compressor trick and pressurize your cylinders and pop the springs off to see if the seals are in place and there isn't excessive play in the valve to guide. >.003 will leak into the cylinders. Despite popular opinion the exhaust valves will suck oil under vacuum of the exhaust pulses. Also have a look at your plugs if only half of the plug is oil fouled it may be the corresponding intake or exhaust valve causing it so u may want to index your plugs if that is the case to see which valve is the problem one. Let us know what you find out.
 

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Discussion Starter #6
This is great information... Thank you all for the input. My goal is to gather as much information as I can before I hit the 1000 mile mark, which is when I will bring the car back to the installer for a check up. Also I made a call the GM and they told me that they will not even discuss trouble shooting until the motor has 1000 miles on it. Relative to my world going with the GMPP ZZ383 was supposed to be the safe but expensive route. :)
 

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Just out of curiosity; what does the warranty look like on this thing?
Keep notes on everything you do with this engine; what oil, how much, what filter, what plugs...everything.

Also, keep us posted. I hope its an easy fix.
 

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Discussion Starter #8
Has a good warranty. 2 Years, 24,000 Miles. Been following guidelines to the letter. Been taking lots of notes and pictures. Take a photo of the dipstick every time I take a reading. Wife thinks I am nuts!!! I know I am obsessing, but it is my nature. Still getting feedback from 1/2 the folks that say it still needs to break in, and the other 1/2 that say there is a problem. I am a bit surprised that there are not more folks out there with ZZ383's ??? But With the warranty I know I should be OK but I spent alot of $$ so I could just drive...
 

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Are you certain that the dipstick is reading correctly and that your not putting too much oil in it?
Might try draining the oil, all of it. May need to remove the filter if it dosen't have an anti-drainback valve. Re-install the drain plug. Fill it with 4 quarts of oil and wait an hour and check the dipstick a couple of times. If you have a 4 quart pan the stick should read full or close to it.
Good luck,
ssmonty
 

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Discussion Starter #11
Interesting thought on the dipstick. The spec is a 5 Quart oil pan with filter. Hard to think the installer would have added more than 5. I will be talking with him tomorrow. As far as smoke... I set the idle mixture screws last week and got 17" at 750 RPM's. The motor running smooth as can be. I have a vacuum gauge temp mounted and have been monitoring it. The motor draws 21" criusing down the hiway at 70 MPH. 27"+ on deceleration. With that said when I rev it up in the driveway no smoke! BUT.. Last night it was cold up here in MA and I drove down to CT in the dark. I was keeping up with the traffic 70 - 75 (~3500 RPM) and noticed looking in my rearview mirror that when I hit the gas I saw smoke?? Could not tell what color it was??? That was a 50 mile criuse. On the way home at midnight I decided to back it down. Cruised at 65 for about 15 min, then 57 for about 35 min, and 50 for the final 10 min. When I got home and pulled into the garage I noticed that my idle was down to 650 form 750 and I was only drawing 14.5" down from 17", and it smelled rich. Hmm. I have more but I think I am getting a bit wordy....
 

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Installer decided to change the oil and filter and switched to synthetic, MOBIL1 . Took a liitle over 4.5 Quarts. Dipstick at Full. Told me to keep monitoring the consumption and if it continues at the same rate we will contact GM at 1000 miles and open a case under the warranty.
 

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Installer decided to change the oil and filter and switched to synthetic, MOBIL1 . Took a liitle over 4.5 Quarts. Dipstick at Full. Told me to keep monitoring the consumption and if it continues at the same rate we will contact GM at 1000 miles and open a case under the warranty.
As a point of reference for you, my 350 after being rebuilt used less than a quart for the entire first 1000 miles even with an oil plan leak.
I say you have a problem somewhere. Maybe some rings installed upside down? :smash:
 

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Discussion Starter #14
Well everything is documented, so I will see where the oil is when the motor hits the 1000 mile mark. If needed I will open a case with GM under the warranty. I guess the question I would LOVE to have answered is: "How much oil should I expected a GMPP crate ZZ383 Stroker to use?" Simple... Seems like someone would know what the average oil use is. I can not find this number anywhere...
 

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Well everything is documented, so I will see where the oil is when the motor hits the 1000 mile mark. If needed I will open a case with GM under the warranty. I guess the question I would LOVE to have answered is: "How much oil should I expected a GMPP crate ZZ383 Stroker to use?" Simple... Seems like someone would know what the average oil use is. I can not find this number anywhere...
Well it's going to be different for every engine. After break in you're supposed to change the oil. For the next 1000 miles after the break-in i would say a quart is average. After that it shouldn't use any.
 

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Discussion Starter #16
What is you definition of a break in period and reasonable oil use during that time? And so I understand your feedback... Example: If break in was 1000 miles, you are saying that on average a motor should taper down to a quart for the 1000 miles after break in, then settle down at the 2000 mile mark?
 

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What is you definition of a break in period and reasonable oil use during that time? And so I understand your feedback... Example: If break in was 1000 miles, you are saying that on average a motor should taper down to a quart for the 1000 miles after break in, then settle down at the 2000 mile mark?
I break in the engine as if i were running a flat tappet cam. 30 minutes running 2500rpm plus. Do a few hard pulls, let it rev a little. Then change the oil and filter and check the filter for excessive metal particles. From that point til 1000 miles it shouldn't use more than a quart. At 1000 I'd change it again then go to your normal oil change intervals.
 

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My 454HO was an oil sucking pig.
Engine was out of warranty before I even started it up.

When I took this $5000 dollar engine out of the car and took it
to a performance engine builder to look into, he found this:

All piston rings in upside down.
(******* GM monkees)

GM performance parts just pretty much told me "Tough Friggen Bunnies"

There was oil pooled up on top of the pistons when the engine builder took it apart.:rolleyes:
There was oil dripping from my mufflers while the engine was out of the car and sitting in the garage.:pain:

Did a plate hone, new rings and he machined the heads for different seals.
6000 miles later----oil still on the full mark
 

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Yep, I wouldn't buy any gm crate engine.. I'll just build em myself that way if there is any problems, I only have me to blame. Me personally I would have waited on the syntetic until at at least 1500 miles min, if it made it that long.
 

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I am back. Been running the motor with Mobil 1 and tracking eveything I do... Motor has about 1700 miles on it now. I have been averaging 390 miles per quart... Put in a claim with GM last week. Been waiting on the garage to get in the loop, which they did this week. Apparently GM engineering is scutinizing the case. Well I got a call a short time ago and here is what they want to try: Apparently in the Fast Burn Heads the hole for the intake valve rocker stud is drilled through. And the stud is threaded in. So GM wants the garage to remove all the intake studs and seal them. So obviously they suspect that as a possible path for oil to get into the intake. More so due to the high vacuum that the stroker pulls on decel will a stardard tranny. Hope to get this done this weekend. HERES HOPING...
 
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