Block Ventilation

[dat521gatherer]

here's what i did with mine. l20b. after i took the pic i drilled a hole in my new block off plate and screwed in a pcv valve.

[HRH]

That setup works great if you have a good motor. The 620 I sold had BAD blowby issues (still ran hard) and leaked all sorts of oil out onto the top plate of the weber and down the valve cover.

 

I have the open vent on the racecar, and I lengthened the section of hose as when it was really short it dribbled oil out the breather on extended 6500 rpm pulls. Works fine now though.

 

An oil catch can is ideal, because everything is caught. I still can't figure a decent place to stick one, not much fender or firewall area left.

[lynchfourtwenty]

HRH,

 

My engine seems to blow out oil (or something) when driving hwy speeds, or going up hill. This lands on the firewall and header causing smoke.

 

Do you think if i capped or blocked off the tube that comes from the engine block that the breather i have on the valve cover would leak oil an crap everwhere?

[dat521gatherer]

i was using a hose from my valve cover hanging to the street with a small plastic cylider type thing taped to the end of it with holes poked in the top. it caught all the blowby.

 

my old engine had sooooo much blowby the valve cover hose looked like a tail pipe blowing white smoke and blue.. people would honk and point under my truck.:eek: rings were missing and a piston skirt was laying in the bottom of the pan. the tops of the pistons deformed looking. it still started and ran though.

[dat521gatherer]

i used to just block off my crank/block pipe.

[banzai510(hainz)]

Yes REDDAT PCV hose will work it looks like. maybe soem L18 has L16 type set ups. Im not positibe as my L18 was like a L20 set up. I guess depaends on the exhaust manifold used as the later manifold you had to go around as there was no space to let it come right out.

 

as also mentioned hook the powerbrake to the 4th runner on the intake manifold.

 

L16 crankcase to pvc hose 11828-23002

go to nissanpart.cc and enter in the blank space up top and see if it comes up

You got to figure in shipping($$$$) and sales tax and decide which works best for you.

 

http://www.nissanparts.cc/cart/?pn=11828-23002

[79D50]

L16 crankcase to pvc hose 11828-23002

go to nissanpart.cc and enter in the blank space up top and see if it comes up

You got to figure in shipping($$$$) and sales tax and decide which works best for you.

 

http://www.nissanparts.cc/cart/?pn=11828-23002

 

I just ordered this and paid $21.99 to my front door. Thanks for the link and part number. If it does not fit properly it will be up for sale to other members here that may need it.

 

Now I need to go back and order the Brake Booster Line....

[datzenmike]

That number is also used on the 610. The L18 in the truck and the 710 use 11828 U6001 but I'm sure it can be made to work. Too bad you motor was transplanted... do you know what it's out of???

[79D50]

11828 U6001 yielded no results on the Nissan Site or the mydatsun site. I am pretty sure from the looks of the hose that this will work. I will just make a brake booster hose.

 

I have no idea what this motor came out of. On page 2 of this thread is a pic of the engine block. you can clearly see L18 - 178024. I do not know how to decipher the latter half of that sequence but I can take a stab at the manufacture date of 1978?

[datzenmike]

Negative. The L18 was only used in '74 +- six months. I'm sure it will work or you'll make it work.

Edited December 11, 2009 by datzenmike

[datsunaholic]

HRH,

 

My engine seems to blow out oil (or something) when driving hwy speeds, or going up hill. This lands on the firewall and header causing smoke.

 

Do you think if i capped or blocked off the tube that comes from the engine block that the breather i have on the valve cover would leak oil an crap everwhere?

 

If you have blowby and block off the PCV, then the top breather becomes an outlet and it'll blow everything that the PCV and the breather was sending, everywhere.

 

You block both, the blowby will find a way out- either through the first weak gasket, the crank seals, or by simply building up enough pressure that the mix ignites. As someone who has seen the result of a crankcase explosion, that's not somewhere you really want to go.

 

If you have so much blowby that you have oil exiting out either the breather or the PVC, and considering BOTH have baffles (or are supposed to) obscuring them, then it's time for a new engine (or at least a rebuild). Catch cans and blocked vents are a band-aid on a bullet hole. You've already got the domino effect of engine failure started when blowby is that excessive- it's NOT going to improve. It's wearing out at a faster rate since the oil is getting blown past the oil control rings. Well on the way to having oval cylinders. In fact they probably already are.

 

I realize that RACE cars use catch cans (or more modern ones simply run the vent back to the oil tank) but race engines are generally built intentionally loose and to a different spec, PLUS you aren't running oil 3000+ miles.

[hang_510]

If you have so much blowby that you have oil exiting out either the breather or the PVC, and considering BOTH have baffles (or are supposed to) obscuring them, then it's time for a new engine (or at least a rebuild). Catch cans and blocked vents are a band-aid on a bullet hole. You've already got the domino effect of engine failure started when blowby is that excessive- it's NOT going to improve. It's wearing out at a faster rate since the oil is getting blown past the oil control rings.

:thumbup:

 

 

:lol: mine lasted ~5000 mi before failure (catastrophic??? = reason not to rebuild :D )

id get ~1 liter of oil in the can after a tank or 2 of gas :blink:

all it really was for was to keep oil from getting everywhere = bandaid! :lol:

[lynchfourtwenty]

If you have blowby and block off the PCV, then the top breather becomes an outlet and it'll blow everything that the PCV and the breather was sending, everywhere.

 

You block both, the blowby will find a way out- either through the first weak gasket, the crank seals, or by simply building up enough pressure that the mix ignites. As someone who has seen the result of a crankcase explosion, that's not somewhere you really want to go.

 

If you have so much blowby that you have oil exiting out either the breather or the PVC, and considering BOTH have baffles (or are supposed to) obscuring them, then it's time for a new engine (or at least a rebuild). Catch cans and blocked vents are a band-aid on a bullet hole. You've already got the domino effect of engine failure started when blowby is that excessive- it's NOT going to improve. It's wearing out at a faster rate since the oil is getting blown past the oil control rings. Well on the way to having oval cylinders. In fact they probably already are.

 

I realize that RACE cars use catch cans (or more modern ones simply run the vent back to the oil tank) but race engines are generally built intentionally loose and to a different spec, PLUS you aren't running oil 3000+ miles.

 

lol, SAY IT AINT SOOOOOOOOOOOOOOOOOOO :(

[datzenmike]

Some race events insist on a catch can. It's to catch the oil mist from a grenading motor.

[79D50]

It's best just to hook it up the way it was designed. No mess, no smells = good for motor!

 

I just picked up a tri-y for the l18 today...This will run with my Offy Dual Plane. The header is a quality design with the proper inside 1/2 washer flange. So mounted next to the intake it makes a lever tightening surface. It has never been installed as he bought it on liquidation from ?? 15 years ago.The welds are quality and it is designed like my Doug Thorley for the 2.6..It was advertised for a 620 and he paid $150 bucks for it.It also was designed for Cali use as there are lots of emmission hook ups. Some tasteful bungs...:blink: haha..and it will look nice once it is ceramic coated. I got the nice dished OEM washers to. With a good gasket..hahaha...goodbye leaks!

 

I got the good brake hose off the spare as well....PCV problem will be fixed 100%.

 

I have to dry fit everything as I think the torsion bar is going to be a challenge...If it doesnt work then at least I get the chance to change the intake/exhaust gasket.

 

BTW - I got news on that L18 I advertised earlier. Sorry to those I didnt have time to repsond to..I will write on this later.

[dat u racing]

I agree with roadraceral #45my lower vent is connected to exhaust via diveter valve. small percentage of axcelleration gain.

[lynchfourtwenty]

acceleration

[HRH]

Yeah Lynch, what datsunaholic said. There are generally two sayings associated with that.

 

1. Loose is fast.

2. You need a rebuild.

 

The 620 I sold had the same issue, but she ran like a raped ape. Still managed 96 mph out of the leaky, abused L20. But eventually they go.

 

Fortunately it's not too hard to rebuild an L motor. And if you don't want to, you can pay me to do it! :)

[lynchfourtwenty]

Yeah bro, she runs like a raped ape thats for sure.

 

I get about 125psi accross all 4cyl.