silver3rdgen

Ok, so i've been playing around with the new 20B set-up in the FD and was blowing oil out the oil filler neck nipple under boost. I've had problems slinging oil out of it on the track due to hard cornering forces, but not from pressurizing the crankcase. Anyone else have this issue? Second issue is that i plugged the rear facing nipple and loosened the oil cap until i finished building the oil catch can and someone noticed the loose cap and tightened it back up for me. I did a run down the street and it started smoking BADLY. I'm assuming that it's just oil blow-by on the oil control rings and that the residual will burn out of the exhaust after a lil more driving. It seems to have been smoking less now that i've let it run 15-20 minutes. Anyone have any insight or input on this? Is there any possibility of damaging the oil control rings,etc??

Streetported 20B with GT42R...

RX-Heven

iTrader: (1)

Blowing oil while cornering under boost is absolutely from pressurizing the oil galley (crank case). The problem is that the oil is blocking the only escape path for the pressurized gases to go which in turn pushes the oil out. This is a common problem and it can be solved in various ways, the most effective of which is to vent the other side of the engine. Considering you have a 20b with a single turbo, it would be easy for you to accomplish since you have freed up the rear turbos oil return line on the rear housing. Install a vent line there and keep the lines as short and large as possible. Another method is to drill and tap and vent line into the front cover. This is what did on my 2nd gen and I went from blowing a quart of oil in 20 minutes of track time to hardly a drop at all. Second gen engines don't have the return line on the other side of the engine at the rear iron which is why I opted for the front cover.

Here is what I did for reference and a long thread documenting the problem with many attempts to address the issue, most of which did not work.
https://www.rx7club.com/showpost.php...&postcount=210
https://www.rx7club.com/showpost.php...&postcount=211
https://www.rx7club.com/showthread.p...t+cover&page=5

Also, blowing smoke out the exhaust can be attributed in many cases to an inadequately vented oil galley. Since it becomes pressurized, this prevents oil from draining out of the turbos oil return line and forces it passed the seals along the shaft on its way to being burnt and sent out the tailpipe. Essentially, the pressure is greater at the exit than the entrance and the weak spot is exploited. That weak spot is the seals around the shaft.

Two problems, one solution.

RX-Heven

iTrader: (1)

Fix the link in your sig so we can see the pics of the car

rx7rcer09

my FD with a 13B had this problem i plugged the bottom nipple on the filler neck and started smoking terribly i ran a silicon line and put a cap with a hole to hold it in place, sure its ghetto but it worked no more oil leak onto the floor and no smoking. pm me if you want some pics of my simple fix.

mannykiller

iTrader: (93)

I did the same thing on my car.... It's actually really important this problem is fixed.....especially if you track the car or canyon run it. I'm almost positive this was the reason my Turbo oil seal went bad... even though I had a restricter in the oil feed to the turbo...the pressure is still there... I'll know in a week if it was for sure the turbo or not.. but i'll post up here and let everyone know.

silver3rdgen

Problem seems to be fixed now... i built a catch can and vented the engine from the rear housing turbo drain and from the nipple on the filler neck. I'll post pics of the fix and of the ongoing mods to the car tomorrow.

Thanks for the input!!!

silver3rdgen

Here's what i've done to try to fix the problem... it has taken care of the smoking at idle issue but i haven't had a chance to drive it and see if it's vents enough under boost to work completely yet. There is a -6 AN line coming from the filler neck nipple to the catch can and a -8 AN line coming from the rear turbo return port on the rear housing. I was gonna run a -10 but due to the wastegate placement, i couldn't fit anything larger than the -8... which BTW, BARELY fit in there...

mannykiller

iTrader: (93)

That looks like a race car haha.. Pics of the whole car?

silver3rdgen

it's just your average grocery getter.....

I'm still building all of the duct work for the radiator and oil coolers right now... LOOONNNGGG SLLOOWWWW process.

GoodfellaFD3S

iTrader: (213)

Wow Shannon, so this is what's been taking up all your time when you're not overseas dodging bullets

Pretty damn impressive dude

mannykiller

iTrader: (93)

Very nice..... and not to critique your work...but i'd be a little careful with that front splitter... looks like if it were to nic anything or hit anything it'd take your oil-coolers with it... Very nice though.. Whats the car used for?

silver3rdgen

Thanks!

it's a road course car/grocery getter... and the splitter isn't attached to the oil coolers... the splitter supports run up and over the coolers.. with supports back behind them also. ..it just LOOKS like the coolers are part of the support.


BTW, i do aircraft sheetmetal and structural repair on Army helicopters for the past 17 years... once the nose is finished, anything that would take the splitter out would be a day ending things anyway, and flying debris would probably take the coolers out anyway.