Turbo D16

First and foremost, the disclaimer. These mods are to be done AT YOUR OWN RISK! If you do this correctly or incorrectly and you somehow screw up your motor, don't come knocking on my door. Also I would highly recommend not doing ANY mods to your oil pump unless you have an oil pressure gauge to check your work.

A little background:
I recently lost #4 rod-bearing on my turbo 97 EX. Being the kind of person who asks why a lot, I decided to do some research. Was there any correlation between why this rod bearing went out first and the fact that it's the farthest one from the oil pump? Why are all of these guys running around with Z6 SOHCs at high boost and not having any problems with rod bearings? Why are there countless posts from guys like me with Y7s and Y8s who have lost rod bearings? Why does this crap always happen to the financially challenged?

Two Main Differences; Z6 vs. Y8 Oil Delivery:
From doing some comparison research on the Z6 and Y8 motors, I found that there are 2 major oil delivery differences between the D16Z6 and the D16Y8s. One main difference is the crank. The 92-95 cranks were made with reliability and forethought in mind. Not only do they have dual oil galleys for each rod journal, but they're also chamfered. The 96-00 cranks have only one un-chamfered oil galley per journal. Translated, this basically means not as much oil gets to the Y8 rod bearing and it doesn't get spread to the outside edges of the bearings as quickly. The other huge difference between the two generations of SOHC is the oil displacement of the pumps, or volume. According to the 92-95 and 96-00 manuals, the earlier generation oil pump displaces 11.89 gallons/minute at only 6000 rpm. The 96-00 oil pump displaces only 8.8 gallons/min at 6800rpm. In basic terms, the Y8 oil pump has 35% less flow and doesn't reach max flow until nearly 1000 rpm later than the Z6. To me, thats a pretty big difference, and for a turbo motor thats a huge difference.

Shimming the pump:
Simplest and cheapest thing we can do is shim the relief valve on the oil pump. This isnt necessarily the perfect fix for a problem like getting oil to that last rod bearing, but it will help by pushing the oil there faster. On the other hand, if you use too big of a shim youll also push oil right past your newly blown seals. Stock pressure on your Y8 motor at operating temperature is 10psi minimum at idle and 50psi minimum at 3000 rpm. If you have these numbers already, using a shim thickness of approximately .025-.035. You should get a slight bump in pressure to somewhere in the vicinity of 70-90psi at 3000rpm. Updated shim thickness as of 10/9/07, refer here for why: http://www.turbod16.com/viewtopic.php?f=3&t=32661&st=0&sk=t&sd=a&start=40

From what I can tell, installing the shim in your relief valve does not necessitate removing your oil pump, but I had a hard time getting my Sealing bolt out even though the pump was sitting on my bench.

D16Y8 Oil Pump:


1. Drain your oil, or if you have your pump out, get a clean surface ready to work on.
2. Unscrew your sealing bolt, its a hex bit. One thing to remember, the Sealing Bolt is spring loaded, so be ready to keep it from shooting off under the workbench. Once you get your Sealing Bolt out you should cover the hole with tape because any dirt or debris inside will cause your Relief Valve to stick.

3. Get your shim ready. I had to find a .050" thick washer (pictured below) and modify it to a final thickness of 0.025-0.035", inner diameter of 0.30" and an outer diameter of 0.45". Also make sure the hole is centered to ensure a correct fit.
*NOTE: The thickness below is 0.050", the ACTUAL thickness should be 0.025-0.035"

4. Next, clean your Relief Valve extremely well, again, any dirt or debris can make the Relief Valve bind.
5. Put your shim between the spring and Sealing Bolt and put the Relief Valve on the other end of the spring.

6. Coat the Spring and Relief Valve with a light coat of motor oil.
7. Put the assembly back into your Oil Pump.


8. Watch your oil pressure! Remember, stock is 10psi warm at idle, 50psi warm at 3000rpm. We are looking for 70-90psi or so at 3k.

Next up, Porting the Oil Pump:
Coming soon...

(preliminary before and after porting pics)

Before:


After:


Before:


After:



Before:


After:



Some numbers I'd like to add:
I'd love to see some numbers of people running X shim thickness getting Y oil pressures. Also, have any of you guys out there blown seals, and at what pressure?

I am not the authority on anything, so I'd love to hear any ideas, flames, comments, or questions.

Thanks for the input guys.

*note: edited on 06/08/07 to correct the shim thickness, was 0.050", should be 0.025-0.035" refer to this thread: http://www.turbod16.com/viewtopic.php?f=3&t=32661&st=0&sk=t&sd=a&start=40

the ports are really that restricted? holy crap!

good job!

Do the DIY i'm interested.

do it!

Plz show a larger pic of the entire pump, and circle the ports that you ported.

yup.....DO IT!!!! take many many pics.....i r no read good

go for it lots of pics please.

Vote to make this a sticky.

good tech writeup

You cleaned up the output from the Oil Pickup boss, but did you clean up the input and match it to the boss on the Pickup itself? That would help a lot more than cleaning up the output area.

I opened up the inlet from the pick-up flange to where it opens into the pump as large as the gasket, which is already larger than the pick-up tube. I think the pick-up will be the restriction but there's nothing I can think of doing to it except getting a different one all together.

you should be able to flare out the output on the pickup a little to get it close to the gasket and input size, Endyn does this on their oil pumps as well.

was it hard to not F up the threads behind here...???
it looks a little hairy in that area...

That's FAQ right there

good write-up

Thats a good idea dema, I just might try it once I get a new gasket.



Those threads are pointless from the tip of that plug into the pump, I wasn't worried about screwing them up =)

wow great info so far.
i'd love to see a detailed picture by picture writeup on the porting and polishing(i assume polishing helps oil flow? i know you polish exhaust but not intake manifolds. excuse my lack of fluid dynamic knowledge)

-Luke

good job i gotta do this soon

Am I the only one that see's [X]'s?

im assuming with the raised oil pressure from the pump, it would be a good to suggest an oil restrictor as well to save your rods AND your turbo seals !!

Im in for numbers. Lets see it.

what size shim and what pressures.