Installing Spool Head Drain, Rb26

[VSPECII33R]

Guys, wanting to install a Spool (or similar) head drain to my 33 GTR as i want to start increasing boost levels above & beyond 25psi. My question is, what is the easiest way to do this, short of dropping it to a workshop & saying 'Fit this please"??

Does the engine need to come out of the bay to gain access?

Does the head need to be removed from block?

Does the head need any type of drilling/machining/welding for provision to attach the drain fitting(s)?

Does the sump need to be seperated from the block?

Does the sump need any type of drilling/machining/welding for provision to attach the drain fitting(s)?

If it's just a case of removing engine (or box to gain access to rear of engine), then playing around with existing fittings, i will attempt on the driveway. If not, i will look at other options including dropping it at a workshop! Lol

Cheers in advance

[Shoota_77]

Does the engine need to come out of the bay to gain access? Yes, unless you pull the head off.

Does the head need to be removed from block? Only if the engine is still in the car.

Does the head need any type of drilling/machining/welding for provision to attach the drain fitting(s)? Yes, knock out the welch plug then drill and tap two holes.

Does the sump need to be seperated from the block? No but if you pulled out the engine you possibly would to plumb it into sump.

Does the sump need any type of drilling/machining/welding for provision to attach the drain fitting(s)? As per above, only if you remove engine.

The biggest part is removing the engine. Personally I would remove the engine and coincide it with other bits and pieces to make it worthwile.

[VSPECII33R]

Engine is already built, it's just that whoever built it didn't have the forsight to install a drain. I'm not interested in stripping down & refreshing/replacing anything further as it's not required.

Simply put, just after the easiest & most efficient way to install the drain. Seems as though it's an engine out job, drop sump & leave head attached. Maybe throw some new shells in whilst sump is off, pending condition as that is very straight forward??

Edited January 10, 2013 by VSPECII33R

[89CAL]

Drain has to go to the sump and needs to be welded so you HAVE to pull it off

You'll get a -10 weld on fitting in the spool kit

[Shoota_77]

I don't want to start an argument but you can just tee it into one of the turbo oil drains. The preferential way is definately into the sump but not mandatory.

[kitto]

To be honest mate, Its not worth pulling out the engine to fit just a head drain.

If the engine was built properly with oil control in mind then you technically shouldn't need a head drain. I have just finished building my engine with two head 'drains'. One at the rear which technically isn't actually a drain, its a breather. And the other one is on the exhaust side of the head between exhaust ports 3 and 4. I am a bit on the fence as to whether the rear drain actually doesn't anything or not, but for the low cost of installing one and the fact i was assembling the engine i was able to easily do it on the stand.

But it really isn't worth pulling the engine to fit a rear drain.

PS, if you really want to do it, get a Nitto drain fitting as they work with the RB26 lines at the back of the head much better than any others.

[VSPECII33R]

Fitting being welded onto sump is the least of my worries, i am more concerned about being able to gain access to rear of head & knocking out welsh plug. Doesn't seem i can do this unless engine is pulled, so that's what will happen

[VSPECII33R]

To be honest mate, Its not worth pulling out the engine to fit just a head drain.

If the engine was built properly with oil control in mind then you technically shouldn't need a head drain. I have just finished building my engine with two head 'drains'. One at the rear which technically isn't actually a drain, its a breather. And the other one is on the exhaust side of the head between exhaust ports 3 and 4. I am a bit on the fence as to whether the rear drain actually doesn't anything or not, but for the low cost of installing one and the fact i was assembling the engine i was able to easily do it on the stand.

But it really isn't worth pulling the engine to fit a rear drain.

PS, if you really want to do it, get a Nitto drain fitting as they work with the RB26 lines at the back of the head much better than any others.

Cheers mate, solid info.

Engine was breathing a bit on the dyno last time we ran it up with anything over 24psi, so i am looking for a solution to overcome this as i want to put more boost through it.

My catch can at the time was just vented to atmosphere & had 1 of the breather holes on the passenger side rocker cover blocked off, but it was connected to the drivers side rocker cover breather by a 'U' piece of rubber hose, then went through a single piece of hose to the can. If i were to run dual hoses (1 from each rocker cover breather) into a catch can, then plumb it into the intake pipe, do you think this would help rid the head of excess pressure/fluid if there is any?

[The Bogan]

Engine out is the only way I would do it, if your tapping or welding the head you will get swaff or other crap inside which will f**k your motor, sump must be removed and a fitting welded to the highest point on the cold side.

Is oil spewing out? if not dont worry about a head drain/vent, if it is what restrictors are in the block and what oil pump are you using?

If its just breathing a bit hard just get the cam cover vents sorted, 1 line for each vent and at least 2 30mm vents on the catch can.

Hows the compression?

[VSPECII33R]

Not spewing out, was just noticeable out the filter on catch can when doing 'high boost' runs so we backed it off.

Unsure on restrictor size as i didn't build the engine & have not had a look inside. Oil pump is N1 which i am thinking strongly about swapping out for something decent after doing a little research on this forum.

Will just sort out breathing lines as suggested & fit a new catch can. Should i be plumbing back in to the intake pipe for a vacuum source, or just vent to atmosphere as it is currently for best result??

[KiwiRS4T]

Don't bother.

There is no evidence that they do any good.

More important is restrictors, relieving / boring out existing drains, sump breathers to catch can, oil air seperator from cam covers, mines cam cover baffles.

Its not increased boost levels that does it anyway - its just sustained high revs at wot.

Ideally if you are not spewing out litres of oil your cam cover breathers should go through an oil air seperator and into the intake.

[VSPECII33R]

Great, that's certainly an acheivable task for the weekend!

Where's the best place to buy 30mm hose for the breather lines to oil/air seperator?

[The Bogan]

Great, that's certainly an acheivable task for the weekend! Where's the best place to buy 30mm hose for the breather lines to oil/air seperator?

You dont want 30mm hose, I think its about 22mm ID, but dont trust me on that, pull a hose off and measure it mate, the 30mm bits I was refering to was the vent filters on the catch can if you are running it to ATMO.Ive attached a pic of my can for referance.

[STATUS]

biggest mythical mod... total waste of time....

[R31Nismoid]

^ 100% agree. Just another case of a company making a product, and people thinking they need it

Engine is already built, it's just that whoever built it didn't have the forsight to install a drain.

See below, it's spot on as breathing issues don't neccessarily mean you've got a return problem

To be honest mate, Its not worth pulling out the engine to fit just a head drain.

If the engine was built properly with oil control in mind then you technically shouldn't need a head drain.

So before you go down that road:

Do you have issues currently with the head filling with oil?

What oil restrictors were used in the build?

Returns enlarged?

Is the catch can setup/vent correct? (incorrectly setup will cause all amount of issues)

So identify the cause of the blow-by, which could just be an adjustment to your vent setup more than anything else.

[r33_racer]

If you have blow-by then its a poor ring sealing issue mate. The more boost you run and the more power you end up making is only going to make it worse. More power will generate more blow-by, unless your rings can magically seal up better then what they are now.

The root cause of all these issues is blow-by pure and simple and that starts and finishes at ring seal. All the breathers and crap is a band aid fix to help vent all the excess crankcase pressure. If you can keep the crankcase pressure under control you wont end up with oil spewing out everywhere, as I'm guessing you don't want to build the engine again with some proper sealing rings.

But to help your cause for now. You want at least a -12 breather off the sump pan above oil level from the inlet side of the motor to your catch can, the two from the rocker covers to the catch can. If you can accommodate it then a drain back to the sump on the exhaust side from between cylinders 3 and 4 though this shouldn't be needed, but if you are doing it with engine out you may as well cover all your bases to be sure, also a drain from the catch can to the exhaust side sump too though once again this shouldn't be required either. With that setup even with a reasonably heavy breathing engine you shouldn't get any oil blowing out the filters and messing up your engine bay.