Guest bastaad525 Posted November 28, 2003 Share Posted November 28, 2003 in the Jan. 04 issue of Hot Rod magazine, of all places Very informative and technical article, geared more towards turboing a V8, but with lots of good general info... and some SWEET pics of a twin turbo 350 setup (I know there's been a lot of hoorah about this type of setup on the board lately). One thing it mentions that has me a little concerned, regarding the turbo oiling setup: "Be sure there's vacuum in the crankcase or the turbo lube oil can't drain back into the pan; this may require a crankcase evacuation system" This brought back up a thread I had posted a while ago about routing the crank and valve cover breather vents into the downpipe... an interesting thread that got a lot more responses and produced a lot more info than I had expected (here it is if you're interested: http://hybridz.org/phpBB2/viewtopic.php?t=27605) but this quote from the magazine has made me wonder something else entirely, which is... is it safe for guys running turboed L6's to run their crank and valve breathers open to atmosphere? Would this in any way inhibit the turbo's lubrication? I've been running my motor this way for some time. Or is the writer of the article specifying something that is particular to V8 setups? Just wondering if I need to prioritize this 'evactuation' setup or not.... Anyways, back to the subject... if you guys see this mag on the stands you may seriously want to consider picking this up, this applies moreso to people considering swapping to a turbo setup. Very informative stuff in there Oh... and this article is just part of an ongoing series (part 2, to be specific) so it may be something worth keeping up on, I know I'll keep my eyes out for future issues... and am gonna try to track down the dec. 03 issue as well Quote Link to comment Share on other sites More sharing options...
Turbo Meister Posted November 29, 2003 Share Posted November 29, 2003 I believe the Hot Rod magazine article cautioned against developing positive crankcase pressure which would act as a barrier to the oil draining from the turbos. This could develop since the larger ring endgaps, required for boosted engines, provide a wider path for pressure to enter the crankcase. I am routing this blowby, on my TT383SBC, through valve cover breathers into a catchcan via 3/4 inch heater hoses. I have not had any turbo oiling problems. I am looking forward to the coming turbo articles because there is so much more I want to learn about turbocharging. I have the Mcginnis book and Corky Bell book, but would like to get other up to date turbocharging technical material. Hanns Quote Link to comment Share on other sites More sharing options...
Guest 240zxt Posted November 29, 2003 Share Posted November 29, 2003 yeah, I picked up the dec issue. It was very informative. I have to go get the jan. issue. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted November 29, 2003 Share Posted November 29, 2003 Run a PCV on the intake manifold to the valve cover. From the block you can run a tube to the inlet of the turbo before the AFM. Under boost the turbo inlet creates vacuum to evacuate the block. I have been doing this for years with no problems. You can place a catch can between the turbo inlet and block to keep from sucking oil into the turbo. You can see the canister in the pics that is hooked directly to the block. On the bottom of the canister is a one way valve(PCV) that drains oil back into the pan. So, under boost the turbo inlets decrease block pressure and also suck some oil. When not on boost the oil accumulated in the canister is then drained back into the pan. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted November 29, 2003 Share Posted November 29, 2003 When I first build a turbo engine, I hook the valve cover breather hose to a nipple on the J-pipe. Then it smoke like crazy under boost. two positive pressure isn't good for a turbo. Now I run a catch can. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 30, 2003 Share Posted November 30, 2003 Run a PCV on the intake manifold to the valve cover. From the block you can run a tube to the inlet of the turbo before the AFM. Under boost the turbo inlet creates vacuum to evacuate the block. I have been doing this for years with no problems. You can place a catch can between the turbo inlet and block to keep from sucking oil into the turbo. You can see the canister in the pics that is hooked directly to the block. On the bottom of the canister is a one way valve(PCV) that drains oil back into the pan. So' date=' under boost the turbo inlets decrease block pressure and also suck some oil. When not on boost the oil accumulated in the canister is then drained back into the pan.[/quote'] I was thinking of doing exactly that! Good to know it wasn't a crazy idea I kept thinking... the turbo itself would be a really good way to actively suck air out of the block. Did you get any increase in power from doing this? Apparently the Hot Rod writers did... well they used a full fledged seperate belt driven vacuum pump.... and got some 20 hp more out of the engine when using it (on a 500+hp engine). I think using the turbo as a vacuum pump would be WAY more effective than just routing the breathers to the exhaust.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.