vwdave

How smart/stupid would it be to connect the oil return to the valve covers?

a73camaro

As long as the turbo outlet was higher than the valve cover, you're ok. Another place is the block off plate for the fuel pump.

vwdave

I am more worried about the hot oil going back through the engine.

Steven89Iroc

Hot oil goes through the engine anyway. It'll be fine. My (uninstalled) kit does it this way as well as the other identical BBS kits and I'm not worried about it.

84z28350

I have seen some pictures of guys piping the oil back into the valvecovers. whether it ever became a problem or not i have no clue...

junkcltr

iTrader: (1)

The amount of oil that flows through the turbos is very small. I run a .060" hole brass fittings at each turbo inlet for the journal bearing turbos. It is common to have .030" to .040" restrictors on Ball Bearing turbos. I wouldn't be concerned about the oil temperature.

vwdave

Arent you the guy running 2 Nissan Z31 turbos? Thats what I am going to try running.

junkcltr

iTrader: (1)

Yes.

ttypecamaro

iTrader: (2)

I send my oil drains to the fuel pump block-off on one side and to the valve cover on the other. the only problem I have with the valvecover drain is that it is difficult to seal. no matter how many breathers i have.

vwdave

What boost are you running? I was planning on a HSR, 950 Commander, LT4 Standard cam, maybe 8.75-9.0 Compression on mostly stock internals.

I was thinking of how much boost I should run, how is the power going to be delivered, and what injectors to run. I was thinking 7psi off the wastegate to start off with. I was thinking at 7psi it should be able to keep up with my engine till redline. As for injectors....42# maybe?

junkcltr

iTrader: (1)

I am running 7.5 PSI max. using stock wastegates, No intercooler, No water injection, 93 octane, 23* BTDC timing under boost, Crane 216* at .050", .454" lift single pattern cam. LT1 intake, stock 48mm TB, 355ci, 8.6:1 compression hyperuetectics, 993 heads, X-rods, GM cast crank, Ford 42#/hr green tops (currently at 80%ish DC peak at 11.8 AFR), 43 PSI fuel pressure, 730 ECM with $58 BBZB Syclone code(custom PROM).
Rev engine to 6000 RPM max., HEI dizzy with MSD2 coil (no CDI box), Autolite 24s gapped at .030".

The engine is beating up the TH350 TCI trans. clutches. It will probably be wiped out by the end of the Summer if it stays together. I don't beat on it as much anymore because WOT tuning is OK now and the novelty of the turbos is wearing off (my first turbo car I ever drove). No 1/4 mile times yet.

The $58 code works fine, but I have been looking at going back to the 730 ECM with the $8D code. I want to try different injector firing schemes and the $58 fueling seems like more work than it is worth to fix. So I have been looking at the $8D as an alternative to the $58. I haven't really made up my mind in which direction I want to go with the code.

That sounds good in terms of your part choices. What are the cam specs for the LT4? 83 Crossfire TA gave me some great turbo cam info earlier this year / late last year. I think it might be worth reading for you. Do a search for his username and "crane" or "cam".
Using theoretical calculators, my setup is around 410 - 490 FWHP. My worst case injector duty cycles are a little under 80%. So yeah, the 42#/hr would be fine......but it all depends on how much you want to up the HP later. I looked at the 42#/hr on the ECM testbench and I am not afraid to run them up to larger DCs at stock TPI fuel pressure. I went with the Ford 42#/hrs because they are cheaper than all the other stuff out there. If I could have bought 55 - 72 #/hrs for the same price......I would have bought them. I would have bought P&H is I had the choice. Overall, my cheapy Ford 42#/hrs work fine for my application. They might work for your application too.

In terms of valve cover oil drain lines. I would weld a pipe on the breather hole and clamp the drain line to it. No oil breather type grommets, under boost it wants to try and leak out air there while at the same time oil is trying to enter the valve cover.

vwdave

Well, most of that is setup is because its already there and the engine is disassembled already. When I get the funds, I will build a big boost engine. But for now, I think all this stuff should suffice. Not to mention, I just want it working for right now. Then I can cut my flange off, put a T04 Flange on it and go nuts.

I'm going to run intercoolers. Most likely 2 side mounts so I can up the boost later and still run a little bit of timing on 93 octane. I also already have nitrous in the car if later on, I can crank up the boost, shoot a 30-50hp shot to cool the intake temps and maybe run race fuel. But thats getting way ahead of myself here.

For the valve covers, I was thinking of getting aluminum covers and welding a -10an male fitting to the outside and putting catch cans in each downpipe for ring seal.

I am thinking with most of the stuff I have in mind, 400whp should be possible without too much worry. Hopefully get rest of the drivetrain going and bring that power level up to 500whp on pump. *Shrug*

The cam is mostly because its already in the car and has less than 5000 miles on it. I'll put a turbo specific cam in there with the other engine.

junkcltr

iTrader: (1)

That is how my setup came about. The JY turbos were reasonably priced and I want ed to see how well boosted gas engines work and learn some of the GM boost code. I figured the same thing as you...............go to a T04 flange later on, but then I started looking at big singles.

I picked up a 24"x12"x4" for my rig. Haven't found the time to install it yet. I will probably up the boost after I get it in there. HHhhhmmm, already got juice. Go with a giant single and squirt it to spool it. The N2O would last a long time and the setup would make big HP.

That sounds good, but the length of two -10AN fittings, oil outlet adapter....will you have enough room?

vwdave

I got these for $275 shipped. I know a bit about boosted cars from doing performance work on VW's. But I still have some to learn.

I always liked the thought of two big turbos over one massive single turbo. Seemed like a better way of doing things to me.

I would more use the nitrous for its cryogenic effect than for the quicker spoolup. Kinda like swapping to a much larger intercooler on demand. A 50 shot shouldnt stress things too much and increase power depending on how much intercooling you need. I seen a 434whp GTI shoot a 35 shot on the dyno and hit 497whp. His intercooler was too damn small.

As for the room, I donno. I guess I'll find out when the time comes.

junkcltr

iTrader: (1)

Two Z31 turbo shipped for $275.....good deal. Bad deal if they show up and they are the later 300ZX T28s though. They are very small for a V8.

Don't get me wrong, I like twins. Both of my setups are twins, but my next setup will be a single. One less air cleaner, more simple IC, one less turbo rebuild kit, one less oil feed & drain to fab (and possible leak later on)........and I am cheap when it comes to car stuff and hate buying things twice when once will do......unless I have two of something kicking around.

N2O makes a great IAT cooler but really jacks the cylinder pressure from all the charts I have seen. I never tried it......the pressures would blow the heads off my stock GM head gaskets and ARP bolts. I would rather squirt it with a water mix to cool the IATs. There are some good papers on the web explaining the chemical process....and the dyno results are good.

Not sure with the third gens. I know they have a little more hood clearance than my rig. I know I that I couldn't use that setup. Take a look at the BBS kit that dumps into the valve covers. Maybe someone running that kit around here can measure the line length to give you an idea.

vwdave

They are supposedly off two 85s. We'll see.

Water/Alky/Meth injection does work very well. We usually use Wiper fluid because its plentiful, it works pretty well and its cheap. I already have the nitrous. I figure a 30 shot wouldnt hurt too much.

junkcltr

iTrader: (1)

Are they good to go or "may" need a rebuild?

vwdave

Theyre supposedly good.