i dont know how many miles are on his new motor right now, but its enough to be broken in by now. . . more than enough. last i checked, he was running castrol syntec. thats what he runs on just about everything. hehe, even the black car. . . that might get an oil change once a year. hahahaha.

ill check with him later on that.

 

Im gettin my BNRs tuned for real boost soon too, so far i made 315rwhp 254ft-lbs tq at 10psi (with 10:1-11:1 AFRs)
Guess this thread answers my question about sticking with dino or switching to synthetic.

 

hey i was just wondering not to get off topic but how much do twin tubro bnrs put out???

 

Comparing the 2 in a short summery will be kind of difficult since most of you have never been inside of a turbocharger.

A dynamic seal is a piston ring type seal that goes into a seal plate inside the CHRA (Center Housing Rotating Assembly). That piston ring (compressor seal) has a .003" Gap and that keeps the oil from getting into the compressor housing and keeps boost pressure out of the crank case. The reason there is a gap is for heat expansion. If its a solid ring, it will conform or worp under heated conditions and not seal in the seal plate causing leakage. However, this ring gap does play tricks on rotary engines b/c the turbocharger(s) see full engine oil pressure and the crank case is somewhat pressurized from the air entering through the compressor side ring gap. Turbos can only take so much oil volume (30-50 psi). The oil gets backed up and it starts spewing out of both the intake and exhaust sides when there isn't adequate crank case ventilation or enough restriction. Single turbo applications are all dynamic seal and most all of them require restictor pills in the oil supply to cut down pressure and volume to keep the oil level in the turbocharger lower than the ring gaps on both turbine and compressor sides. When the level is higher than the ring gaps you will see smoking issues. Wear can also cause leaks as well. Dynamic seal has less resistance and is typically the way to go but keeping issues down with smoking I decided to keep the carbon seal for less hasle and to be more user friendly.

Carbon seals were developed by a company called RayJay. They were one of the first pioneers on turbochargers. They developed the carbon seal way back when for draw through style turbochargers, which had the carb set up in front of the inlet of the turbocharger. The carbon seal kept fuel from entering the oil system. Positioning the carb infront of the turbo helps atomize the fuel as it blew to the engine. But later on other companies used the carbon seals for other applications.

The carbon seal is in the RX7 turbochargers from the factory. Carbon seal turbos can take more oil pressure without having smoking issues and in most cases, don't require restrictors. The carbon seal has contact with the rotating assembly at all times creating a total seal on the compressor side. It keeps any boost pressure out of the crank case. Since the vacume is so poor on a rotary engine, the engine needs as much crank case ventilation to keep the oil flowing through the engine. Vacume is the best way to vent the engine. Atmosphere venting is okay in some cases, but strong vacume is by far better. Although carbon seals are a total seal, they naturally pass some oil into the compressor housings and intercooler pipes.

Vehicles that create more vacume dont have problems with dynamic sealed turbochargers. When you get to putting cams in a piston engine lowering vacume thats when they start having similar issues. Porting a rotary engine will also cause a drop in vacume therefore worsening the problem.

I am tired of typing!

Bryan@BNR
205 640 1193
www.bnrturbos.com

 

great post, Bryan...thanks

I have the Stage IIs

 

Brian:

Does this 2006 post where you opined that a ported-engine (does that include a street-port ?) does not like the Dynamic Seals and running synthetic motor oil, due to poor vacuum.

If this is still applicable in 2009 for your latest Stage III turbos with Dynamic Seals ?

I have a newly street-ported engine with a vented Jaz oil catch-can.

TIA,
:-) neil

 

Very old thread but I will type this today 1 -28- 09 I am running one of the first sets of BNR stage 3 ,and the only set that is supersized .I use syn oil only and inject Amsoil two cycle oil .The turbos have 50 k miles and still are alive and well .They have never been worked on sense Brian built them years ago .I have no desire to go with any other set up .My Rich Mans Non Seq set up has been done and the spoolup is fast and power is very good .I have done the Rich Mans set up on other BNR set as well and the customers seem to be very happy with everything .So to answer the old question,I use syn oil with BNRs and I do not know which seals are in them ,Brian may remember .

 

I'm running Stage 2s, also with syn oil and Amsoil "Interceptor" two stroke injector oil....no issues

yep, I still have David's "rich man's" non sequential manifold, and everything is tip top...car pulls hard all the way to redline and I get full boost at 3600

 

It depends on what you tell Bryan when you order your turbos.

If you want to run synthetic, you get dynamic (iirc) seals

For non synthetic, you get the carbon seals.


That Simple.

 

So who has these oil restrictors for sale or how do I make them, and where do I put them.

I want to run synthetic or semi-synthetic, and I'm going pre-mix . . .


:-) neil

 

I just spoke to Bryan and he mentioned that the dynamic seals (to run synth) are available at no extra charge.

Also, the oil restrictors are simply the pair of stock oil feed banjo bolts that have been spot welded and had a thin diameter drill bit ran through the weld to yield a smaller orifice.

 

When I ran my old set of Stage III's I ran synthetic but switched after I had smoking issues...After I went to Mineral I had no problems.

I'll be running Mineral on the new setup aswell.

 

what is it about synthetic that supposedly causes problems with the carbon seals? I don't get it...

 

As I understand it they have a looser fit/tolerance and the slippier synth leads to blowby issues out the exhaust.

 

Another good reason to run higher viscosity oil

I haven't noticed a problem