JustinL

I'm at the point of looking for oil to feed a turbo on my 3.0 build. My plan originally was to swap the housing from the 951 block onto the S2 block, but I've since learned why this doesn't work and why it would bind up my bearings on the balance shaft.

So... plan B. I need to get oil from somewhere for the turbo. Can I just drill and tap the hole in the S2 balance shaft cover and call it a day? Is there something else I need to be thinking about? Do I just match the hole size and thread pitch of the turbo housing?

Black51

IIRC, the N/A balance shafts have the provision, but just weren't drilled out. You'll just need to drill & tap this provision, and put a banjo bolt in. From there it's just running AN lines to the turbo. Keep in mind, if you're planning on running a ball bearing turbo, you'll need to run an inline oil filter plus the correct restrictor. I can send you pics of my setup if you want.

PS, pm me your mailing address and I'll send back your TPS this weekend.

Voith

I did it for my project and its not a problem.Just be sure to not use too sharp drill bit. Ask me how I know

odonnell

Not to thread-jack, but what about housings like this one:



I know this is the lower cover, but the upper one is the same. There's not even a blank for where the hole would be drilled. Has anyone modified a cover like that before? It's from a 1982-built engine, and some components had date stamps as far back as 1980 (girdle, and the oil pump was 1981 among others). This style of cover has the outer bearing shell "race" integrated/machined into the casting, so there's no bridge that butts up against the seal for the banjo bolt.

JustinL

Awesome thanks guys. I'll bite though... why should I use a dull drill bit?

Voith

Angle on top of that blank hole is just right so that fresh bit will absolutely bite in to it hard and rotate the piece which will then kick you like angry mule.

Either fix the piece really good or use bit that is not new or sharp like new.

V2Rocket

odonnell just tap an oil feed off the oil sender, lindsey sells an adapter that will work.

odonnell

If you look in the pic, I believe you will see just that Was just curious.

Black51

Keep in mind, the oil line will be in very close proximity to the headers on that side. IMHO, oil lines coming from that side would just clutter up the engine bay.

FRporscheman

Just don't drill all the way through with the big drill bit. If you have a housing from a turbo, look at it and measure it to see how deep to drill the hole for the banjo bolt, because about halfway in, it changes to a smaller diameter.

It's also important to drill and tap as perfectly perpendicularly as possible, so the crush washer of the banjo bolt has a chance of sealing.

Chris White

Yes, i drill and tap them all the time.
As FR said - don't drill all the way through with the big drill bit. Just a small hole to feed the oil from the balance shaft bearing. Also - use a 'bottoming' tap to tap for the banjo bolt.
if its not perpendicular it will never seal.

JustinL

I went over to DAND86951's shop and we took a shot at this. The bottoming tap is an important piece! It is a challenge to keep the tap perpendicular in two planes the whole time, but I think we got it. Having the turbo housing to use as a template was really handy. We just tried to match it as best we could.

blade7

Drill and then tap using a pillar drill to keep perpendicular I'd have thought.

JustinL

I tap threads like I spice my food. Free hand! Sure sometimes I end up with salsa that blows my socks off, but usually it works out ok.

blade7

So do I usually, but after reading here about potentially not sealing, it would have to be like my romance, dead straight.

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