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SBC engine build rant

Any chance it sucked the bottom of the intake gasket in the port and is now pulling in oil from the lifter valley? Would be easy enough to check if everything else checks out. only cost ya a set of gaskets and a tube of silicone.
 
jhama78 said:
Any chance it sucked the bottom of the intake gasket in the port and is now pulling in oil from the lifter valley? Would be easy enough to check if everything else checks out. only cost ya a set of gaskets and a tube of silicone.
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I wouldn't think so, the intake was put on a couple weeks before we got the engine in the car but it would be an easy thing to check. Thanks.
 
You are burning 3 quarts in 20 miles, almost as much oil as gasoline. I've had engines with shot rings and huge blow-by or non existent valve seals and while I drove around in a blue cloud, I never came close to burning that much oil.

Let us know what you find when you start checking things.
 
Mikel said:
You are burning 3 quarts in 20 miles, almost as much oil as gasoline. I've had engines with shot rings and huge blow-by or non existent valve seals and while I drove around in a blue cloud, I never came close to burning that much oil.

Let us know what you find when you start checking things.
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Same here. Hopefully we'll have time to check it out one evening this week. I'll report back when we find something.
 
pull plugs, inspect and see if one( or more) looks oil soaked or anyway different from the others. Do a compression test and report back
 
Chevy_man said:
Sure sounds like it's vacuuming it out the PCV.

To consume so much and still run is pretty impressive.:laughing:
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Thing is, it runs great. Pulls good, and will spin tires in second gear effortlessly.
spareparts said:
pull plugs, inspect and see if one( or more) looks oil soaked or anyway different from the others. Do a compression test and report back
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He said he pulled plugs on passenger side today. All are oil fouled, with #8 being the worst.

[486] said:
intake gaskets sucking it outta the valley?
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Maybe. I guess that's on the list when we have a free evening.
 
Jblack6527 said:
Thing is, it runs great. Pulls good, and will spin tires in second gear effortlessly.

He said he pulled plugs on passenger side today. All are oil fouled, with #8 being the worst.


Maybe. I guess that's on the list when we have a free evening.
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If it's pulling it out of the PCV it will oil everything. I'd at least unplug it and toss a little breather filter on for a few days and see if it clears up.

If it's sucking oil down the intake, the cylinder to cylinder dispersion is going too have more to do with airflow and carrying the oil into individual cylinders than it is anything wrong with any one cylinder.
 
It doesn't really matter why....if it's going through that much oil, it needs to come out and get torn down again. Someone fucked up something in a pretty spectacular fashion.
 
Lbhsbz said:
It doesn't really matter why....if it's going through that much oil, it needs to come out and get torn down again. Someone fucked up something in a pretty spectacular fashion.
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That's what we're assuming, but I was hoping for ideas that didn't involve that. If it has to come back out it's probably gonna get sold.

Stuff has changed since we started this project and neither of us have time to pull, tear down and rebuild another motor. Not to mention there's very little in the way of shops that do this kind of work in our area so every one is backed up 8-10 months.
 
Jblack6527 said:
That's what we're assuming, but I was hoping for ideas that didn't involve that. If it has to come back out it's probably gonna get sold.

Stuff has changed since we started this project and neither of us have time to pull, tear down and rebuild another motor. Not to mention there's very little in the way of shops that do this kind of work in our area so every one is backed up 8-10 months.
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Its a SBC....not a rocket ship. Take an afternoon and tear it down to find the smoking gun.
 
Put the PCV hose in a coffee can and cap off the vacuum side of it. Take it out and run it another 10 hard miles, and see if the smoke diminishes.

I don't know why people put moly rings in street builds. I bet they haven't seated yet, you're pushing major blow by, and that is carrying all the oil right back up in through the intake to burn out.
 
rugger said:
Fuck a 400 sbc. I almost built one for the Miata. Glad I went the 327 route and should have done an LS from the start.
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I've heard lots of horror stories about them, but the guy at the machine shop convinced us they were mostly old wives tales or from people that didn't put steam holes in the heads and talked us into it.

[486] said:
this

just dump a fucking 4.8 in it
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I tried to talk him into a 6.0 3 years ago but he wouldn't do it for some reason.
Lbhsbz said:
Its a SBC....not a rocket ship. Take an afternoon and tear it down to find the smoking gun.
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Yeah, they're not rocket ships, but it's finding the time when both of us have time to do it.
He owns a small business and works lots of hours in the summer, neither one of us have a garage big enough to put it in.

DRTDEVL said:
Put the PCV hose in a coffee can and cap off the vacuum side of it. Take it out and run it another 10 hard miles, and see if the smoke diminishes.

I don't know why people put moly rings in street builds. I bet they haven't seated yet, you're pushing major blow by, and that is carrying all the oil right back up in through the intake to burn out.
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We talked a little last night, I think this is basically the plan. Unhook the PCV, replace the oil fouled plugs and see what happens.

The machine shop guys talked us into the moly rings. 🤷🏻
 
Nothing wrong with moly rings, you just need a straight bore and a good cross hatch. Cast rings are more forgiving, but don’t last as long. I will only use moly rings on a fresh bore. In fact I wouldn’t use cast rings on a fresh bore, but on a cheap garage rebuild with a drill hone job and an old bore they are the best choice.
 
Norm said:
Nothing wrong with moly rings, you just need a straight bore and a good cross hatch. Cast rings are more forgiving, but don’t last as long. I will only use moly rings on a fresh bore. In fact I wouldn’t use cast rings on a fresh bore, but on a cheap garage rebuild with a drill hone job and an old bore they are the best choice.
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Its a SBC, not an LS, its not going to last long enough for the ring material to matter.
 
DRTDEVL said:
Its a SBC, not an LS, its not going to last long enough for the ring material to matter.
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Iron rings are going to be fine for several hundred thousand miles if everything else is generally in order.
 
KungFooMASTA said:
Throw a handful of sand down the intake while it’s running about 2000 rpm. That will seat the rings. :flipoff2:
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It's not far from being an actual option. Old school dudes used to dump in something that was like comet or bar keepers friend to get rings to seat back in the old days. I forget the actual name of what they all used.
 
Ummduh said:
It's not far from being an actual option. Old school dudes used to dump in something that was like comet or bar keepers friend to get rings to seat back in the old days. I forget the actual name of what they all used.
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Does it lap the valves too? :laughing:
 
I'm going intake to cylinder head angle mis-match...

Or PCV, not sure you could have a worn ass out cylinder to piston ring situation from the jump.
 
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