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This won't be the 1st one, but it's my first old school engine.
I bought a project car (1968 c3) about 9 mths ago and finally got around to engine work. It was an original BBC car but at some point got a 396 swapped into it. I decided to paint the heads, spruce everything up, install a new water pump, etc... I finally drain the oil and -- milk (see pics).
I'm not sure how long the car ran like this or how it happened, but I started to tear it down today. So far I only got the intake manifold off, tomorrow I'll drop the pan. I didn't see an sparkles in the drained oil, and cutting the oil filter open revealed 0 metallic flakes. ** WHEN I DRAINED THE COOLANT, THERE WAS NO OIL IN IT. ** I'm not sure if the previous owner just put new coolant in it, but the car ran in my presence for roughly 5+ min, which should have been enough to contaminate it (I'd assume... But again, maybe the thermostat never opened?)
Like I said, this isn't my 1st rodeo. I've saved maybe 3 other engines before (usually blown head gaskets on imports, never a Chevy big block) -- so I'm trying to learn all of the weak points. So far:
The intake manifold gasket was soaked, so I'm assuming this could be a point of failure. The bolts weren't too tight, maybe hand tight, so from what I read there are a few bolts that go into water jackets... Couldn't tell if there was sealer on the bolts either.
I was planning on taking the heads off either tomorrow or the weekend. I had bought a full felpro gasket replacement set so I was going to do head gaskets as well. I'm going to check for cracks during that time.
With the heads off I was going to look for marks/cracks in the cylinders as well. I have a leak down tester, should I even bother before taking the heads off?
When I drop the pan I'll take a peak in the bottom of the pan for flakes again, and maybe take a few piston caps off to check the bearings. Anything else I'm missing that could have caused this? I planned on replacing the engine with a crate, but not for another year or so... So it'd be nice to be able to save this for atleast 1-2000 miles max.
You'll want to check the heads for straightness, an overheated engine is a common cause of head gasket failure and that often warps the head so a new head gasket alone won't fix the problem.
It has to have had a rectangle port intake manifold over the top of your oval port heads because it has rectangle port intake gaskets still stuck to the heads. Has water in oil circulated everywhere including in the valley area. If you don't find something obvious caused that make sure you have the heads and block checked for cracks before you start putting any money into it.
Last edited by Little Mouse; Jun 2, 2021 at 08:38 PM.
You'll want to check the heads for straightness, an overheated engine is a common cause of head gasket failure and that often warps the head so a new head gasket alone won't fix the problem.
Correct -- I'll be checking for that as well! These still have the iron heads.
It has to have had a rectangle port intake manifold over the top of your oval port heads because it has rectangle port intake gaskets still stuck to the heads. Has water in oil circulated everywhere including in the valley area. If you don't find something obvious caused that male sure you have the heads and block checked for cracks before you start putting any money into it.
Wow good eye, I didn't even bother to look at the IM after I pulled it.
Does the water pump/radiator/water jacket have any milky liquid in it?
That's the cleanest nasty internals I have ever seen considering you witnessed the engine running.
IF it is water/coolant...shouldn't it have separated in 9 months?
Some type of strange additive previously added in the oil before you saw it running (rookie guess)? I'm !
Last edited by doorgunner; Jun 2, 2021 at 09:58 PM.
Does the water pump/radiator/water jacket have any milky liquid in it?
That's the cleanest nasty internals I have ever seen considering you witnessed the engine running.
Some type of strange additive previously added in the oil before you saw it running (rookie guess)? I'm !
I can check the pump tomorrow. When I pulled the dipstick it was greyish, but the radiator (I pulled the lower hose to drain it maybe 2mths ago) was filled with green fresh looking coolant, so I didn't even bother to look into it any further. If I saw oil filled coolant come out I probably would have looked into it sooner. When I drained the oil it drained out pretty much like water for a good 2 minutes before I took the picture posted above, so it seems like the whole pan was filled with coolant.
The only other thing I can think of is that I power washed the engine bay a few days before, but that wouldn't create a grey mix like you're seeing. I'd assume if water did get into the engine (I have the exhaust off, but plugged the holes with towels) it would just run down as water and not have time to mix into a grey milk shake.... So I'm assuming it was like this while running. But it doesn't seem caked on at all, so I don't assume it ran for any significant amount of time with this issue.
rectangle intakes run good on oval heads. and didn't cause any water issues. 396 is a tough motor. i want the casting numbers off the heads. probably 215 or equivalent. and stamp number on the block. but most likely this beastie needs head gaskets, closer pic of the lifter valley. but i don's see water stains. and a pic of the bottom of the front of the intake. what is the intake? torker 2? where in joisey?
Last edited by derekderek; Jun 2, 2021 at 10:26 PM.
Someone was in there before. The lifter valley is painted with Glyptal which is a nice detail, that tells me at sometime at least someone did some nice work in there
Do a leak down test from here to determine if you need to replace the head gaskets. If the head gasket is breached, it will show up pretty easy, especially with the intake off. Have all eight plugs out when doing this to see if it is breached from adjacent cylinders. If the intake was hand tight then it certainly will leak coolant into the valley from the four cooling ports at the end of each head. From what I can see of the intake........the back of the intake that covers the two rear coolant ports is garbage.....looks corroded and this combined with it being a rec port intake would have me buying a new intake, some quality Fel-Pro 1210 intake gaskets that block the dreaded heat riser port in the center and some ARP stainless 12 pt bolts to hold it on. The Torker 2 oval port is a decent and one of the only choices for hood clearance. That intake is an ancient Weiand X-Cellerator and even the Torker 2 flows better.
As mentioned.....the 396 is a tough cookie....the block has a ton of meat between the cylinders and the deck is very thick. BBC head gaskets issues are almost always caused by botched installation......the clamping of the head to the block is pretty damn robust........
Pull the pan and clean everything....you can go so far as to pull rod and main caps if you trust your abilities, and check for scoring, this is the make or break point, are the bearing ok? Pull the oil pump apart and clean it, flush the pickup. Prime the hell out of it with a oil pump primer, reassemble and go.
I have fixed a lot of issues like this over the years and been relatively successful as long as the bearings are ok.
rectangle intakes run good on oval heads. and didn't cause any water issues. 396 is a tough motor. i want the casting numbers off the heads. probably 215 or equivalent. and stamp number on the block. but most likely this beastie needs head gaskets, closer pic of the lifter valley. but i don's see water stains. and a pic of the bottom of the front of the intake. what is the intake? torker 2? where in joisey?
I can get better pics when I get home, but this is one I just so happened to snap yesterdayIntake looks like a weiand 7508?
Head casting looks like it's possibly 10141279
Someone was in there before. The lifter valley is painted with Glyptal which is a nice detail, that tells me at sometime at least someone did some nice work in there
I agree. Glyptal rotor paint is old school. It got some love at some point.
My guess - The intake manifold gaskets leaked and let water into the oil. If you run it at all, it will mix very quickly.
Overhaul it. Gaskets, rings, bearings and anything else small that it needs. I would not bore it as the additional expenses escalate very fast on a 396. Check for cracks and reassemble it.
is the grey oil sticky. hen I milkshaked my 327 it was a sticky mess. It ruined all the bearings in my motor
Wasn't really sticky, it flowed like water - it had the consistency of cooking oil. Wasn't tacky at all.
Originally Posted by Jebbysan
Do a leak down test from here to determine if you need to replace the head gaskets. If the head gasket is breached, it will show up pretty easy, especially with the intake off. Have all eight plugs out when doing this to see if it is breached from adjacent cylinders. If the intake was hand tight then it certainly will leak coolant into the valley from the four cooling ports at the end of each head. From what I can see of the intake........the back of the intake that covers the two rear coolant ports is garbage.....looks corroded and this combined with it being a rec port intake would have me buying a new intake, some quality Fel-Pro 1210 intake gaskets that block the dreaded heat riser port in the center and some ARP stainless 12 pt bolts to hold it on. The Torker 2 oval port is a decent and one of the only choices for hood clearance. That intake is an ancient Weiand X-Cellerator and even the Torker 2 flows better.
As mentioned.....the 396 is a tough cookie....the block has a ton of meat between the cylinders and the deck is very thick. BBC head gaskets issues are almost always caused by botched installation......the clamping of the head to the block is pretty damn robust........
Pull the pan and clean everything....you can go so far as to pull rod and main caps if you trust your abilities, and check for scoring, this is the make or break point, are the bearing ok? Pull the oil pump apart and clean it, flush the pickup. Prime the hell out of it with a oil pump primer, reassemble and go.
I have fixed a lot of issues like this over the years and been relatively successful as long as the bearings are ok.
Jebby
Good advice -- after I pull the pan I'll make a determination of pulling the caps or not. I may do the leak down test 1st to see if I need to replace the head gaskets or if this whole thing was due to the intake manifold gasket. Appreciate your help!
you can use a water pump too. doesn't have to be a race boat crossover. get a couple of good straight pieces of hardwood. clamp them to water ports on the intake. drill through the bolt holes. now get a cheap intake gasket and silicone the gasket ends up and bolt the wood onto the 4 water ports in the head. now you can pressure test the engine without the intake. if you get a leak, block off one side of the water pump and bolt it on to one side and test. then the other. leaving the other side sticking out sideways. the intake valley can crack if left to freeze and that engine looked like it had straight water in it. this way you can see and use soapy water to check for valley leaks. and hear leaks coming out from under the head if it is head gaskets.
Last edited by derekderek; Jun 3, 2021 at 08:29 AM.
a 279 is a gen 6 head. these are old school. gen 6 doesn't have the pipe plug on each end of the head. look in the intake ports. there is a well defined ski jump ramp that gives the swirl that vortec is named for. 100 cc chambers. good truck or street head. you wanna rev it, get something else. either way i think the heads need pulled.
a 279 is a gen 6 head. these are old school. gen 6 doesn't have the pipe plug on each end of the head. look in the intake ports. there is a well defined ski jump ramp that gives the swirl that vortec is named for. 100 cc chambers. good truck or street head. you wanna rev it, get something else. either way i think the heads need pulled.
Quick update before I drop the pan:
Heads are: 336781 -- looks like off of a 454?
Intake is: Weiand 7509
is that flange rotted through right below the water passage on the left front of the manifold? if so, there is your water. 781 heads. 396. can you see piston domes through plug hole? this may be a seriously low compression engine with those big *** chambers on the smallest BBC. with 25cc dome, .041 gasket and .020 deck clearance i get 8.5:1.
Last edited by derekderek; Jun 3, 2021 at 05:46 PM.
Help me save another engine 🙃
