Are both of the hoses replacement hoses or is one of them the original hose? They may be collapsing because of the full vacuum being drawn by the plenum connection. If the hose is not designed to handle a vacuum (i.e. fuel line that would normally see pressure) then it could easily collapse under full vacuum conditions.

What happens if you rev the engine? Do the hoses return to their round shape?

 

Dave
great reply, That is my guess. A ridged line should be used.

 

Thanks for the answer guys. I'll try to find a hose similiar in rigidity to the original one.

I don't know what happens when the engine is revved. We just got home from dinner and I don't want to make a bunch of noise for the neighbors to hear.

 

Andy,
Along the lines of DaveZ's comment...is the ID of the 1/4" barbed connectors vs. the tube from the collector the same diameter? Just thinking that if you're constricting the airflow, it may cause the tubes to constrict.

 

Good point . . . The OEM connections at the PCV valve and the lower collector are 3/8" dia. I.D.The inlet and outlet connections of the filtering assembly are 1/4" dia. I.D. So, the filtering assembly connections is smaller.

For myself, the results of this experiment have warranted seriously looking into a traditional Oil Catch Can. I will be installing the said when I can find one which is G35 friendly to install.

 

Andy that's a great DIY mod!

I was in the market for an oil catch can ever since I saw the oil when I was installing my MREV+. I noticed that they are offered in 15mm and 9mm.

Where did you see the Stillen one? What size is right for the G35 Coupes? 15mm or 9mm?

 

Thanks, Chris. I noticed the oil when I did the MREV+ install, as well. When my brother installed a MD spacer there was oil in the LC too. I never gave it much thought . . . Until I read comments from fellow forum members, whom I respect and trust, mentioning that the said oil can be detrimental to our engines over a period of time. I would imagine, it depends on how hard you drive, as well.

I saw the Still oil catch can in their catalog. I e-mailed them and asked if this unit was G35 install specific and if instructions and all required hardware was part of the kit.

The PCV valve and LC connections are 3/8" dia. I.D. So, I would think that it would a 9mm size in lieu of the 15mm size, in answering your question.

Tomorrow, I will replaced the fuel line hose, which I have installed for this set-up and replace it with something more rigid like the OEM hose. This should hold me over until I get a real oil catch can installed. I'll keep you informed about the Stillen info, as I get it. What catch cans have you been looking at?

Hey, do you know of a local place where I can get a dyno? I don't really want to drive down to San Jose. I want to get a local dyno of my current set-up and then another one after I install a some new toys in the next week or so.

 

Unfortunately everyone I know goes down south to get their cars dyno'd.

The ones I found online were Cusco and Greddy. I was trying to see what the Stillen one looks like so I checked their website and it seems like their website is not working properly.

 

It is pretty easy to locate it out in front of the radiator....
Although mine is sitting on top of my intercooler, I have it attached (zip tied) to the center radiator support, which should be fine on its own.

 

Thank you, Brando . . . I will definitely look at that location.

 

BINGO....That is Exactly the problem!!!

When I installed my oil catch can, I installed the flimsy soft tubing that came with it.

After driving around the block, I noticed the whistle sound and looked at the hoses. Both were sucked flat.

I went to Lowes and found some thick walled, braided, high pressure hose. So far, it is working like a champ.

 

My brother, Al (SFG356MT) came over, this morning. I show him this catch bowl set-up and ask for a hand. At running temps the 3/8" fuel line definitely collapses. However, while at idle rpm and blipping the throttle, the hoses swell up and go back to their normal shape. I was not satisfied with this . . . So, I went on a hunt. I finally found some "Fuel Injection" hose, which is much more rigid than the regular fuel hose. I replaced the fuel hose with the fuel injection hose . . . The new hose holds up perfectly. After some 35 miles of driving to allow the new fuel injection to soak up plenty of the engine compartment's heat, it holds to its original shape 100%. At idling rpm there is no noticeable deformity in its shape at all.

Update: Since I posted the pic with the oil at the bottom of the catch bowl, I have driven another 82.1 miles. After having taken that said pic, I emptied it of the caught oil. In the last 82.1 miles it has filled right up to the bottom of the sticker. Since I have installed this catch bowl set-up, I have driven a total of 144 miles. This appears to be a bit of oil trapped. What amounts of oil vapor which may have gotten pass the catch bowl, I have no clue.

 

If it is catching this much oil which is significant, when it was going into the lower collector pan area, where was it going? I mean I have 22k of miles on my G35 now. And I know that thing would have been over flowing of oil. So it has to be going somewhere! My guess, it is getting into the intake system.

 

Russ,

I think that you are absolutely right. That is what GEE PASTA was eluding to earlier this year. I am going to settle down on my driving habits and see if that makes a big difference in the amount of oil which is trapped.

 

Well I will say the first 50 miles I drove, my tube was empty. I drove easy. Then rest I drove harder and it started to fill up.