rc1honda

Hello everyone I have a problem.

I am now putting together a new block, and the head and block are ready to be mated. Well I noticed the the new block has a large metal plug where the crankcase vent hard line used to go into.

For reference this the line that goes from the block to the back of the "T" on the valve cover.

So is there another place I should for vac? I always thought it was needed.
It also should be known this is a race spec SR.

Any help or suggestions are welcome.

Pics for refernce

Stock hard line to back of T on the valve cover.







New block with the access deleted.

hobbs

It's not a vent, it's a oil drain from the valve cover, have a good catch can setup and you'll be golden.

rc1honda

Oh so it really just a oil drain? It's not keeping the case under vac at all?

So just the front of the "T"is all you really need?

So should I just cap the back end of the valve cover T?

jr_ss

S13's have less than ideal valve cover vacuum setups. You could use that port where the metal plug is as an additional vac source, however most people just block it off. Adding vac sources on the VC are not unheard of and could benefit you. Some people use the PCV port as their additional source, but I like having vac at idle in my engine as well.

I run an exhaust scavenging setup for under boost conditions and the PCV for idle periods. I have two -10 male fittings welded to my VC and the factory PCV system.

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rc1honda

Yeah I really want to keep the crankcase under VAC as much as possible. That metal plug is pressed in there not theaded, it not coming out without a lot of work.
Maybe I can just run 2 lines and conjoin them with another T fitting it to the catch can with one line.

I am also looking for 3 port catch cans but there are not many to be found. Was think of just running 2 lines off the valve cover T to catch can, then back to the turbo intake. Just to retain vac.

Im not sure I understand your setup too well.

g2ic02

He is just using his exhaust to create a low pressure, pulling blow by out of valve cover. Think of it like a venturi in a carb.

EsChassisLove

He pulls the pressure out through the exhaust during boost. Hope there's a check valve there.

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jr_ss

Come on now, you actually think I wouldn't put a checkvalve in-line? It obviously has to be a very low spring pressure rating as well. I used the Vibrant pieces for my setup.

I have a Venturi plumbed into my exhaust, that has a line connected to my catch can. Under boost the Venturi will pull a vacuum on the can, which in turn pulls a vac on the VC. Two lines from my VC to the can. Then, in the factory location, I have my PCV setup.

You can get a normal two port can and have a third welded to it, or have a custom one made.

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slideways2004

Going through the exhaust is the ideal method, but be sure to keep an eye on the check valve.

I've heard of multiple people having problems. The check valve has problems with the high heat of the turbo

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waxball88

Why not just go back to intake? Constant vacuum.

If your catch can is doing its job no oil should get into the turbo if any does it should be very slight.

jr_ss

I mounted mine low and a good bit away from the turbo so heat shouldnt be too much of an issue.

I choose not to run it that way incase I decide to pull my intake off for dyno pulls/runs. Without a filter restriction on the intake you won't pull any vacuum through the catch can.

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EsChassisLove

JR_SS get a stainless steel filter for the dyno.

Breathes the same as no filter at all. Still protects from small contaminants. And it makes your turbo LOUD. My GTX sounds like a semi.

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Kingtal0n

S13 valvecovers will lose some oil to the T by design, so having a drain back to the oil pan is necessary... unless.. you want all that oil to wind up in the catch can.

Catch cans are more for old engine's with blow-by, or as a safety precaution for when your piston rings come apart and you start pushing quarts of oil out the valve cover. A high performance "Raceing engine" that is warmed up properly, has round cylinder (because deck plate) and the right piston-wall clearance (because mazworx) with the right grade oil should not produce significant amounts of blow-by.


I have seen a sloppy 1000RW horsepower 2.5L Engine that depends on nitrous for 30% of it's power and spooling its GT42r- Those I have seen fill catch cans no matter what you do, probably due to the excessive piston-wall clearance and enormous blow-by produced. Again, if ring seal is good, no need can.

// hello world

As for crankcase pressure, I recommend you either use the factory setup with the inlet fitting facing the compressor wheel (angle the fitting in the intake to point towards the inlet) and use small diameter plumbing to help create a vacuum source.

OR

If this is getting more serious as a race car, either a vacuum pump or dry sump. If it's a cheap race car I've seen people use EGR pumps from chevrolet engines on their small displacement four... just a thought for those with welding skills and extra time.

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jr_ss

I'm not sure where in your head you determined catch cans are strictly for old, poorly assembled or unhealthy engines. Either way that's your personal opinion and you're entitled to it.

If you pull a vacuum on your crank case, regardless of the quality of build you have, you are going to pull oil vapor out of it. If one doesn't want to have that oil vapor go back into their motor, lowering octane ratings and potentially damaging their motor, guess what? They add a catch can. Sure, it won't stop all, but it will prevent most from entering your engine.

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rc1honda

It's a pretty serious build.
It stroker SR 91mm crank 90mm bore. And the drain delete is PRESSED into the block. Meaning there is no way to utilize the factory crank drain without a lot of serious work.

That's why I'm looking for 3 port catch can now. And though this SR is spec'd for over 1000hp I will only be making around 500. It not a sloppy build at all and so far no expense has been spared. I not so much worried about blow by as I am of possibly introducing positive pressure into the crank case. The motor was built professionally with nothing but the best.

As far vac pumps, and dry sumps just seem a little impractical.

Those some very pricey options when it still possible to produce adequate vac from the stock setup.

heychris

Seems to me that in your setup that pulling VAC off the intake manifold would be reasonable and prudent..

Good luck with your build

Ch

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mechanicalmoron

I have nothing to say about most of what you're saying, but:

I'm pretty certain that motor oil is higher octane than gasoline. I don't know for sure or anything, but.... it's AKI should be higher than diesel, given that in order to run a diesel on oil, you need to mix it with gas.

Of course, you don't want it in your intake. But I'm pretty sure you pulled the octane bit out of your ass, or out of SOMEBODY'S ass.

jr_ss

Perhaps you should do some research, instead of ignorantly commenting on something you know nothing about.

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EsChassisLove

If that SR is built for 1000hp then you will have a pretty good amount of blow by.

You need to utilize the PCV too. Except put a check valve and catch can there too.

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Matej

The blow-by oil gets sucked from it to the valve cover.

I would recommend removing the plug and putting an NPT or AN fitting there.

mechanicalmoron

Go light a puddle of motor oil, and light a puddle of gasoline.

The one that burns more slowly, can be assumed to have the higher octane rating.

Care to guess which one it will be?

jr_ss

Oil has a higher ignition point than gasoline, just like diesel oil, yes, but that doesn't mean it's a higher octane rating. Diesel is rated in cetane and has a considerably lower octane(8-15) rating than what gasoline has. Gasoline can be rated in cetane rating but there really is no over lap for the two. Oil is crude compared to the refined gasoline and even deisel fuel. Like I said, go read a book and get back to me.

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mechanicalmoron

Cetane is how fast it burns when it does knock, I believe (though I'm fuzzier on that).

I don't know that it's "octane" in motor oil, but nevertheless, it's AKI is going to be high compared to gasoline, you don't need a physics degree to see this.

Motor oil is highly refined, being thicker does not make it "crude", crude oil is something else entirely. Synthetics are considerably more pure than gasoline, which on it's own has a low AKI, and has all sorts of stuff added to it, partly because of lazy refining (even more so, now that they can add so much ethanol most places. The gas they start with is total crap, and not refined right anymore, unless you're filling up at the airport.)

It does have additives, but they are anti friction/wear, none of them should particularly hurt your motor, unless you burn a large amount of it. And it's surely much less chemically harsh than gasoline.

I'm not saying it's good to burn oil, I'm just saying that motor oil is not going to be more prone to detonation than gasoline. And hey, maybe I'm totally wrong.... but how about you have a source for that, instead of vaguely telling me to read a book? I'm telling you my logic, you don't seem to have any source or explanation.

jr_ss

Why should I supply you the link to read, when you're very capable of doing it yourself? Oil does not have an AKI number, where the hell are you getting information? Oil is a lubricant, not a fuel. It's burnt in two stroke motors for lubrication, not to increase its octane rating. Oil vapor lowers your octane rating. Your logic means nothing. As I stated before do some research then come back, you obviously know nothing about oil or fuel for that matter.

Just because I'm a nice guy though...

http://www.afdc.energy.gov/fuels/fue...ison_chart.pdf

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mechanicalmoron

I see no motor oil in that comparison. It doesn't even list an octane for diesel, or cetane for gas. And it doesn't list aki, which is not the same as octane.

You say that motor oil does not have an aki, because it's a lubricant? So, if it can't be assigned one, it clearly can't cause a problem, can it? (I mean, it could, but you have shit for logic there. Water is a coolant, and raises AKI, for instance)

There's no reason that oil being vapor has anything to do with this, either. It's heavier hydrocarbons than gas, and not very volitile at all, unlike gas, so it's not possible to have anywhere near as much atomized oil as atomized gas in your intake mixture.... especially if you consider that you burn through many gallons of gas (hopefully) without even touching a quart of oil, unless you have something set up totally wrong - it's an insignificant amount, and besides, vaporizing it has nothing to do with it's aki changing, the gasoline is vaporized too.

jr_ss

You see no cetane and octane ratings because they aren't rated that way. Diesel is rated in Cetane, there is no industry standard for its rating in octane and the same for gasoline. Just like oil doesn't have an AKI rating, you're only assuming it does.

I also don't know why you keep saying octane isn't the same as AKI, as I stated, you do not know anything about fuel or oil and are throwing shit to the wind hoping it sticks somewhere.

All of your information is based on assumptions. Just because oil doesn't have an AKI doesn't mean it can't dilute your air/fuel mixture. Sure it's a minimal amount, but people that are making large amounts of power or tuned on the ragged edge of predetonation there could be an issue.

Perrin, HPF, and other companies have done the research and offered catch can to reduce the amount of oil blow by that enters the charged air. This is obviously more serious on an FI engines.

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EsChassisLove

Oil will drop your fuels octane rating.

I know first hand on a dyno that it will

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jr_ss

No it won't, it HAS to have a higher AKI rating than gasoline...

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EsChassisLove

So I guess I have magical oil that makes my engine knock at 1 bar but doesn't when the oil is removed. O.o

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ANDY black s13

I agree with this 100%,its well documented
A petrol engine burning just one drop the size of a pin head will lower octane by 1/2 points I recall from articles years back
In the UK we had the Ford sierra cosworth in 1986 and the development for just the YB series engines alone by many tuning companies proved this way back then