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Discussion Starter #1
468 stroker that has about 600 miles on it, smokes intermittently, tailpipes are black, and goes through a lot of oil. Like a whole lot of oil. Like a quart in 150 miles a lot. PCV hose is dry, compression is 150-160. Engine runs good, no drivability issues. Heads are cast and were gone through when the engine was built. What am I missing here?

Thanks, Jeremy.


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468 stroker that has about 600 miles on it, smokes intermittently, tailpipes are black, and goes through a lot of oil. Like a whole lot of oil. Like a quart in 150 miles a lot. PCV hose is dry, compression is 150-160. Engine runs good, no drivability issues. Heads are cast and were gone through when the engine was built. What am I missing here?

Thanks, Jeremy.


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Who assembled it?

Who broke it in?

Type of pistons & rings?

Complete rebuild of the heads? New valve guides? New Valves? What type of oil control on the valves - O-ring, Umbrella, Viton seals?

What is your static compression ratio? 150-160 is not a lot, but could be correct depending on the cam specs.

Sounds like an oil burner which could indicate a ring issue or valve guides/seals which is my first thoughts.
 

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What type of oil; mineral or synthetic? Did you break the engine in? What type of oil for break in? If you have the ability (equipment and knowledge) do a leak down on it.
 

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Discussion Starter #4
Engine was built by a guy states away. I broke it in using royal purple, then Castrol with zinc additive, now running 15w40 rotella, no synthetic used. It’s an eagle kit I believe, should have moly rings. Heads were sent to a machine shop with the block, I can only assume guides were checked and new seals used. I can buy a leak down tester, I know how that works. I didn’t go that direction yet due to the compression numbers looking okay.


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More than likely two places the oil is going, rings or valve guides. The leak down test is the best for checking compression and where compression may be leaking from. Be advised though that if the compression is really good it may be because the oil is leaking so bad around the rings that it’s sealing it up and giving a good reading. I would recommend against the Rotella oil if you’re running a flat tappet cam as they have removed the zinc from that oil. I would check with the builder and see what was done to the heads. It’s possible the heads we’re built improperly for the cam and the valve seals are now damaged and causing them to leak?
 

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Discussion Starter #7
More than likely two places the oil is going, rings or valve guides. The leak down test is the best for checking compression and where compression may be leaking from. Be advised though that if the compression is really good it may be because the oil is leaking so bad around the rings that it’s sealing it up and giving a good reading. I would recommend against the Rotella oil if you’re running a flat tappet cam as they have removed the zinc from that oil. I would check with the builder and see what was done to the heads. It’s possible the heads we’re built improperly for the cam and the valve seals are now damaged and causing them to leak?
The zinc additive was used with the rotella. The cam isn’t very big, I don’t believe it would over actuate the valves, but I can check that too. All the plugs had an equal amount of ash also, seems to be an engine wide issue.


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Your PCV hose is dry, but maybe clogged at the valve? Are you having any oil leaks or just tailpipe smoke? If you are having both PCV and breather system should be considered in your mix of items to look at. Too much crankcase pressure forces oil out everywhere, so just make sure your breather(s) and PCV are clear adequate and working.
 

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Discussion Starter #9
Your PCV hose is dry, but maybe clogged at the valve? Are you having any oil leaks or just tailpipe smoke? If you are having both PCV and breather system should be considered in your mix of items to look at. Too much crankcase pressure forces oil out everywhere, so just make sure your breather(s) and PCV are clear adequate and working.
The PCV flows, no question. No external leaks, all out the tailpipes. All of the parts attached to the engine are new, we didn’t reuse anything with the new engine.


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Rn it the water temp and oil pressure is ok I would let it run through more of a break in period to see if it would iron itself out
 

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Discussion Starter #11
I’m still hoping that’s the case, but I’m getting nervous. I don’t want to pull the engine again for tear down.


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You sure you need 15W-40,.....I use Amsoil 10W-30 with zinc, it is synthetic and does great,..

what is the oil pressure reading?.....
 

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Discussion Starter #13
Oil pressure runs 60 above idle, hot idle about 25 I think. Can’t run synthetic until after break in, and definitely not while I have the oil consumption issue.


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Discussion Starter #15
Yes, 25 minutes between 1500-3000 rpm, then first oil change, then easy driving for 4-500 miles, then fresh oil again and let it run a little harder.


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The way I broke my rings in was on the highway. I would get the RPM down to around 2500-3000 in 3rd or 4th (depending on how much open highway you have). Then I would floor it to 500 -1000 below my desired shift point. Then back off and let the compression slow you down (no brakes). Then repeat for a total of ten times. If you have a smaller cam you can start at a lower RPM.
 

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Discussion Starter #17
Wouldn’t take much highway, this thing picks up speed nicely


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Yes, 25 minutes between 1500-3000 rpm, then first oil change, then easy driving for 4-500 miles, then fresh oil again and let it run a little harder.


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Easy driving may have not seated the rings and glazed the cylinder walls. I always thought you had to take it easy for the first 500 miles myself - which is what most owners manuals stated back in "the day" and what we were taught.

Todays' break-in procedures are different in that you want to load up the rings with pressures to seat them, both accelerating and decelerating as OMT explained. You want to do this right off the bat when you hit the road. The explanation seems to be that race engines don't get broken in gently, they go wide open from the get-go and drive the car like you plan on diving it - hard.

I did just what you did with my brother's 360CI. It used oil as well, but got way more than 150 miles a quart. He hammers on it and I think it now does better on oil consumption as compared to when it was first broken in a few years ago.
 

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Discussion Starter #19
So if I beat the hell out of it for a few tanks of gas do I have a shot at finishing the break in or am I destined to re-hone....


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I would try something similar to what OMT said then Drive it like you stole it and see what happens. Mine has been hitting the 5 grand on shifts since breakin...got 600 on it now.
 
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