I'm in the middle of building a 4.1. The machinist is against trying to drill and tap for the turbo oil drain into the block because he was concerned of the block cracking while attempting to tap. I have read on these forums that the turbo oil drain can be brought down to the oil pan so I'd like to do the same. Can anyone share photos of this being done so I can use for reference? It would be greatly appreciated. Also, has anybody had a problem with Molnar Tech. rods? Thanks.
Looking for turbo oil drain to oil pan photos
- Thread starter drew87gn
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No disintegrations
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- Dec 27, 2015
total bs, how would GM drill and tap it then? If it can't live though tapping a hole how does it handle 6500 rpm and 650 torque? (Random numbers for illustration)
The 3.8 has a much thicker wall where the oil drain is tapped, almost like a boss was cast directly into the block which is why he has concern.
No disintegrations
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- Dec 27, 2015
Still bs
- Joined
- May 26, 2001
We have drilled and tapped a hundred or so early blocks for the turbo drain back and never any issue?
I have known Tom for years and his rods are our first choice!
I wouldn't trust a machinist that can't confidently tap a hole in cast iron.
...and I DAMN SURE wouldn't trust a machinist that can't confidently tap a hole in cast iron to build my engine.
That being said, I decided after I put my engine in, that I want to do some wiring mods and engine compartment mods, so hopefully it'll make it out today after I finish roll forming some 3" up pipes. If it's not dark I'll snap a few pictures.
...and I DAMN SURE wouldn't trust a machinist that can't confidently tap a hole in cast iron to build my engine.
That being said, I decided after I put my engine in, that I want to do some wiring mods and engine compartment mods, so hopefully it'll make it out today after I finish roll forming some 3" up pipes. If it's not dark I'll snap a few pictures.
That would be great if you can get a few pictures. I appreciate your opinion. With that said, why did you make the decision for the drain to dump into the pan?
Thank you...Is that a custom pan?
Couple of reasons... One is because that's how it should have been done in the first place. I built a 4.1 so I had to go through effort either way. I wanted to run a flexable braided line instead of that PIA stock tube,.. and, I didn't want that hot oil hitting my cam then splashing through my crankshaft if I can avoid it.
If you look at this thread you can see you need to be careful with where it comes close to the frame.
http://www.turbobuick.com/threads/oil-drain-too-close.437866/
I have the same fitting Turboclam has I got mine on Ebay with gaskets its hard to guesstimate location if the engine is on the stand.
http://www.turbobuick.com/threads/oil-drain-too-close.437866/
I have the same fitting Turboclam has I got mine on Ebay with gaskets its hard to guesstimate location if the engine is on the stand.
you can also drain it back into the timing cover
pass side of the pan works too .. Earls makes fittings just for this and are a snap to install and weld to the pan .. just make sure you use a big enough drain to the pan
If you're wanting to use the fuel pump plate, it's not possible to drain it there and have a constant downhill slope. When draining a turbo, you really don't want a P-trap.
Here's what I built on my 4.2. It was tight as I didn't want to hit the oil pump, block any pan holes or interfere with the motor mount AND I wanted to maintain a constant downhill slope. That last part is the trick, I notched the pan lip to get the threaded end as high as possible yet not letting the outlet be submerged below the waterline.
Here's what I built on my 4.2. It was tight as I didn't want to hit the oil pump, block any pan holes or interfere with the motor mount AND I wanted to maintain a constant downhill slope. That last part is the trick, I notched the pan lip to get the threaded end as high as possible yet not letting the outlet be submerged below the waterline.
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Thanks for the reference photos!! From reading other threads also it sounds like the turbo oil drain should have dumped into the oil pan from the factory.
that's the correct way to do it.... but the factory has to make compromises when building cars. In this case it doesn't seem like that big of a deal. It would have required a TR specific oil pan with a drain nipple but that shouldn't have been that big of a deal since the pan stamping gets fixtured and welded on anyway.
The correct way is a provision in the block .. not the oil pan .. there is a lot of reasons they didn't put it in the oil pan..
