Well as most of you know I completed my 1/2 Na-t Conversion. For my oil feed I teed into the oil pressure sender port. For my return I used the oil cooler return port that is already on the 7MGE oil pan. I was told by a couple people it would work and by others it wouldn't work. Well after about a week my turbo seals are blown so I would say it didn't work . I tried to take a short cut and it ended up just creating more work in the end. So anyone attempting this conversion I would strongly urge you to take the time and either pull the engine or drop the front crossmember so you can remove the oil pan and have at least a 3/4 fitting welded on. Later.
Warning For All 1/2 Na-t Guys, Oil return WOES
- Thread starter JT87NA
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You'll probably find the oil level was above the port the Turbo is gravity drain so if the bottom of the return is blocked by oil it will back up and overflow the labyrinth seal and make smoke!
Good news is fix the drain the turbo should be fine!
Good news is fix the drain the turbo should be fine!
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IJ. said:You'll probably find the oil level was above the port the Turbo is gravity drain so if the bottom of the return is block by oil it will back up and overflow the labyrinth seal and make smoke!
Good news is fix the drain the turbo should be fine!
It is the stock oil cooler return that I used so no the oil level wasn't above the return. And I don't think the seals will be ok.
If the stock cooler return is in line with a crank throw that can cause enough back pressure to stop the gravity return.
If your pan is slightly overfull again same dal (doesn't take much back pressure to flood the seals.
If there isn't a big enough oriface for the return ditto.
People get all stressed about "seals" in a turbo there are usually 2 different seals one a plain piston ring type seal the other a labirynth seal each on their own not great but combined they work.
There's nothing to "Blow" as in a rubber lip seal and the only times they leak is if they've been coked (Hot stop shut the motor off and the oil burns to the shaft/seal) sometimes they just plain wear out or if they've been flooded as in no return.
If it's the later it's usually good to go once you correct the return (It'll smoke a little till all the oil that's in the exhaust is burnt).
This is just my experience take it as that.....
<edit> Just thought of one more thing if your PCV system isn't right that can cause positive pressure in the pan/crankcase and back the return up.
If your pan is slightly overfull again same dal (doesn't take much back pressure to flood the seals.
If there isn't a big enough oriface for the return ditto.
People get all stressed about "seals" in a turbo there are usually 2 different seals one a plain piston ring type seal the other a labirynth seal each on their own not great but combined they work.
There's nothing to "Blow" as in a rubber lip seal and the only times they leak is if they've been coked (Hot stop shut the motor off and the oil burns to the shaft/seal) sometimes they just plain wear out or if they've been flooded as in no return.
If it's the later it's usually good to go once you correct the return (It'll smoke a little till all the oil that's in the exhaust is burnt).
This is just my experience take it as that.....
<edit> Just thought of one more thing if your PCV system isn't right that can cause positive pressure in the pan/crankcase and back the return up.
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IJ is right on target here. Also I'm thinking the banjo in the n/A oil pan maynot be big enough to allow the oil to drain fast enough from the turbo. I don't have any N/A blocks at home right now but isn't there a block off plate you can remove and put a custom drain pipe for the turbo on there? Just get a Drain fitting and cut the Stock CT tube at the top and then connect it with a rubber hose or somthing. That would be a better drain option then the oil pan.
PIONEER said:I don't have any N/A blocks at home right now but isn't there a block off plate you can remove and put a custom drain pipe for the turbo on there? Just get a Drain fitting and cut the Stock CT tube at the top and then connect it with a rubber hose or somthing. That would be a better drain option then the oil pan.
Nope nothing like that on the n/a block.
Pioneer: The pad for the Turbo drain is on the NA block it's just not drilled and tapped!
I did mine and it was a PITA as you can't just drill straight in, I used an 8mm bit drilled in about 15mm then turned the block over and drilled a connecting hole from the bottom.
I then opened both holes up to 14mm and used the dremel to blend the corners, drilled and tapped the pad for a pair of 8mm studs and made a plate with a 3/8bsp hole for a fitting.
I can get away with the 14mm hole as I'm using a BB Turbo and they don't flow much oil at all, for a plain bearing turbo I'd go minimum 16mm ID on all of the drain parts.
I only jumped into this thread as it would be a pity if JT87NA took his turbo in to be repaired when there's nothing wrong with it (No repairer is going to tell him "No it's fine it's just flooded" and not charge him)
I did mine and it was a PITA as you can't just drill straight in, I used an 8mm bit drilled in about 15mm then turned the block over and drilled a connecting hole from the bottom.
I then opened both holes up to 14mm and used the dremel to blend the corners, drilled and tapped the pad for a pair of 8mm studs and made a plate with a 3/8bsp hole for a fitting.
I can get away with the 14mm hole as I'm using a BB Turbo and they don't flow much oil at all, for a plain bearing turbo I'd go minimum 16mm ID on all of the drain parts.
I only jumped into this thread as it would be a pity if JT87NA took his turbo in to be repaired when there's nothing wrong with it (No repairer is going to tell him "No it's fine it's just flooded" and not charge him)
IJ. said:Pioneer: The pad for the Turbo drain is on the NA block it's just not drilled and tapped!
I did mine and it was a PITA as you can't just drill straight in, I used an 8mm bit drilled in about 15mm then turned the block over and drilled a connecting hole from the bottom.
I then opened both holes up to 14mm and used the dremel to blend the corners, drilled and tapped the pad for a pair of 8mm studs and made a plate with a 3/8bsp hole for a fitting.
I can get away with the 14mm hole as I'm using a BB Turbo and they don't flow much oil at all, for a plain bearing turbo I'd go minimum 16mm ID on all of the drain parts.
I only jumped into this thread as it would be a pity if JT87NA took his turbo in to be repaired when there's nothing wrong with it (No repairer is going to tell him "No it's fine it's just flooded" and not charge him)
Thanks for all your input IJ, I am currently going to do a compression check and see where I am at. I think I am going to try a leakdown test also by just putting some compressed air into the clinders and trying to listen for air escaping from the exhaust, valve covers, oil dipstick, intake manifold.
Very welcome JT!
I just hate seeing people spend cash needlessly!
(If it's as simple as the drain/pcv it's easy and cheap to get right!)
I just hate seeing people spend cash needlessly!
(If it's as simple as the drain/pcv it's easy and cheap to get right!)