Safer setup for Oil Tee

[simplegreen]

By: Crimson490

Two things get talked about a lot when it comes to turbo oil feeds: pipe threads (NPT, BSPT, JIC, AN, etc), and configuration of fittings. I've seen this issue treated thoroughly on other forums, and since I didn't see it addressed here, I may as well do it (if it is here, oops!).

#1 - Pipe Threads
Regardless of what kit you get/make (assuming the turbo requires oil), you will need to tap into the block for oil supply. Most if not all people tee into the oil pressure sender and block. IMPORTANT: The threads on the civic block/sender are 1/8 BSPT - not NPT. I got my turbo used, didn't come with fittings, didn't realize this BSPT/NPT issue, and just got NPT fittings. Well, here I am now 1 year and 16,000 miles later and I have a small oil leak at the sender. The threads were close enough to sorta fit, but not good enough to hold over time. I've heard many other horror stories of people who had to retap the block, etc because they fouled up the BSPT threads on the aluminum block. This is an important, but often overlooked issue. I know I overlooked it, and it bit me in the rear.

The oil line that comes with the Greddy kit uses NPT threads. So, you need to be able to go from one thread to the other.

How can I tell if I've got NPT or BSPT threads? NPT and BSPT threads have different angles (60 vs 55), shape (flat vs round peaks), and thread pitch. The flat/rounded thread peaks are usually a good indicator from just looking at the two. They should be difficult to thread beyond a few turns, too.

#2 - Fitting Configuration
Now that you know what type of thread you need, you've got to plumb everything up. You need to consider a potentially safer configuration than what Greddy supplies: another reason why I'm writing this up is because I've heard some people say that if you just plug a tee into the block, it may crack and fail due to vibration and the fact that you've got this tee sticking pretty far out of the block - it can tend to put a lot of stress on the threads. If you're turbocharging your only car, like me, you want to be very careful with your setup. I know I can't afford a lot of down time. There are a thousand different kinds of fittings, and a million ways you can do it, and the way that I'm presenting is by no means the greatest. But, it's cheap, safe, and easy.

Common configuration:

You can see how the stackup of fittings sticks far out from the block with no stress relief.

Proposed configuration:

The section of tubing is thought to act like that stress relief to the bulky tee fitting.

You can get all these parts from www.mcmaster.com for about $25 shipped.
-(1) 12" SS Braided Teflon tubing with NPT male (M) fittings on each end
-(1) BSPT (F) TEE
-(2) NPT (F) to BSPT (M) adapter
-(1) NPT (M) to BSPT (M) adapter

You can relocate your tee fitting above the sender, and mount it to the firewall (one way is to ziptie it to the brake line manifold).

If anyone has better/alternative configurations - even if they are more expensive, post some pictures for others to compare and choose.

HTH

(If this needs to go to DIY section, please move it.)