Best $12 Dollars I've Spent

[JTO]

I just finished installing the cam oil line adapters (part no. 901.105.361.01) I obtained from PP. What a deal. I went from barely having 30 psi at 3000 RPM hot to having 60 psi at 3000 RPM hot. What a cheap and effective mod. I have to recommend it to those who have marginal oil pressure.
Thanks to Souk and the rest of the GruppeB guys who helped me with the part number and install.

Troy

[Chuck Moreland]

Though the restrictors are effective at bumping oil pressure, I am concerned about their affect on head temp. Less oil flowing through the head means a hotter head.

Yes, the factory used it in the 3.6 heads. This may not be a fair comparison, the twin plug heads should run cooler to begin with.

I admire your willingness to try, but have caution here.

[JTO]

Hi Chuck,
I was slow to do this mod even though my oil pressure was quite low at times. I read what I could find on this topic and had not heard of the head temp concern. I certainly hope I haven't made a bad choice. Hopefully others have done this mod and can chime in.
Thanks,
Troy

[Randy Webb]

I'm sure PAG wouldn't put it out there w/o testing it. I would have no compunctions doing this in a stock engine.

You can monitor cyl. head temp.s if you are concerned about that.

BTW, less oil flowing to the head may or may not mean a hotter head -- depending on foaming and other fluid flow characteristics of the oil. There is no way to tell w/o measuring the temperatures (or the heat exchange - but nobody is going to be doing the latter).

[KobaltBlau]

That would be the way to go, if somebody with CHT gauge(s) like RoninLB or bell measured temps before and after in a somewhat consistent test.

[Chuck Moreland]

PAG put it out there for the 3.6 motors. Is there a tech bulletin recommending its use on the earlier motors? Not that I am aware of.

[Quicksilver]

PAG superceded the earlier parts to the smaller restrictor. The initial use of the new restrictor was on the turbo which is where heat would be more of an issue.

Unless you were running a turbo and generating excessive heat, I can't see that it could be a real issue. If it was that much of an issue I would still choose a an oil cooler upgrade as a better solution to a top end heating problem.


Wayne

[Randy Webb]

The Exl. article says to do it on all motors. I have not seen the TSB itself. I haven't done it BTW - my motor is quite modified.

[HarryD]

Troy,

This was recently discussed at the Early S BBS. You can see the thread here: http://d240157.u39.zeonhost.com/forum/showthread.php?t=4054

My personal opinion: The restrictors reduce flow to the cam towers and increase flow to the piston squirters and bottom end. There is a case for reduced foaming as well. While I feel the Porshe engieers are pretty sharp, I still wonder why the change. See mycoments at the oterh BBS.

I have not seen the TSB but it seems to have came out about the same time as the capacity/pressure of the oil pump was increased. I have mixed feelings about reducing flow to my cam towers when my "wimpy" 2.4 L T engine is not that stressed to begin with. Bear in mind that the APPARENT oil pressure increase is due to the restrictors being downstream of the pressure transmitter. If the transmitter was on the other side, you would see a significant drop in pressure.

Pretty confusing, eh?

[chrisp]

FWIW, my engine builder recommended against it. Can't recall exactly why though.

[Wil Ferch]

Although the restricted flow may reduce oil effectiveness at the heads ( uncertain as to net effect because we don't know if the change reduces foaming and hence may actually be "more" effective at the heads *with* restrictors)....

...the other unknown is that with restrictors....you increase pressure at eh squirters. This increased pressure should also allow incresed flow of oil to the underside of the pistons. That in itself could lower piston crown operating temps...

Jury is still out......

Maybe we take the new restrictors and drill them out to be "half-way" between new ( 6mm) and old ( 2.5 mm?) ... ???


---Wil

[Elombard]

I know this is not relevant to head temps but my overall temp did not change, if anything it went down slightly. I decided the reduced foaming and resulting increased efficiency in the oil system were the way to go. Again I defer to Wayne - advanced degrees in Mechanical engineering - he likes them.

[JTO]

Thanks for everyone's comments. Some say its good, some say its bad. I guess all I can say is that I feel good about the higher reading on my pressure gauge. If my engine's life span is shortened then maybe its God's way of saying I need a 3.6 .
Thanks,
Troy

[banjomike]

Originally posted by Elombard
I know this is not relevant to head temps but my overall temp did not change, if anything it went down slightly. I decided the reduced foaming and resulting increased efficiency in the oil system were the way to go. Again I defer to Wayne - advanced degrees in Mechanical engineering - he likes them.

Reduced oil temps could be because less heat is being transfered from the heads.

[sammyg2]

I put em in my engine, my oil pressure went up but not quite as drammatically as posted above.
I feel it was a a good move and would do it again.

[Zeke]

I would think that the condition of the lower end would have some bearing (yes, it's a play on words) here. A new, tight lower end with proper clearances may not benefit from increased oil flow. In that case, the available oil might want to go to the heads.

If the lower end is somewhat starved for oil due to worn out clearances, then maybe all of the oil needed at the far end of the passage circuit could be increased by a higher volume. I know I'm not properly addressing the laws of hydraulics here, but I'm just thinking out loud, not writing a book.

The point is, maybe some older engines benefit more than others by the mod.

[Randy Webb]

I guess we'll know a lot more about this whne hundreds or thousands of us have another 200k miles on our engines....

I would agree with Zeke but am still recovering from the pun....