Oil starvation prevent modification

[kalin]

Hi there,
I've read some articles here and in other forums, and I found some useful info about that how to prevent the oil starvation of the bottom end of CA18DET's...
I'm sorry, if that's was discussed here before..but I was unable to find a thread

So, I found this thread in the nissansilvia.com forums:

http://www.nissansilvia.com/forums/i...ic=190115&st=0

after a guy from that forum advises me to find the author of the post(boot_it), in answer to my question why the big ends bearings failed on the good maintenanced motor.

So, the main thing of that thread is the modification of CA18DET head:













That was made to help the oil to drain back to the sump when running at high engine rpm's for a long time.

I think it's good modification, is any negatives of doing that mod?

And it is true that the oil can't drain fast enought back to the sump?
Probably it's true, because I've noticed that at high rev's the oil was sucked via breather pipe, that comes from rocker cover to the elephant trunk, from the turbo

What do you think about that mod, people?
Thanks for the attention

[Fake Ben Taylor]

its certainly interesting

[kalin]

So, it wasn't discussed before?
Oh, thank God

[Fake Ben Taylor]

it hasnt to my knowledge

looks like it could work quite well too

[kalin]

I've spoken with the guy, I asked him how exactly to perform the modifications of the head, and he answered me:
"You get a thread tapped into the head as low down in the head as possible then you just put 1 or 2 90 degree barbed fittings in to the head and put a return pipe in to the rh side of the sump (opposite side to the turbo return pipe ) as the motor spin clockwise the oil returnin to the sump from the head will enter the engine under vaccum"

I also asked him what should be the internal diameters of the pipes/fittings, and he told me to get 6-8mm .

I want to read/hear your opinions/comments, before to do that on my engine

[Fake Ben Taylor]

cant offer many opinions myself but if it works id be tempted to do it to mine too

[Sideways Danny]

I like the theory, but I think it's a way round the breather problem without solving the breather problem (you can see standard case breather still being used)

I can't see any down sides though tempted to do it myself

[kalin]

And that probably will reduce the risk of further big end bearings problems....

I found that the SR20DET's suffers from big end bearings failure by the same reason. Interesting, the guys from nissansilvia.com uses a "quick" mod on their oil pumps by adding a washers or stiffer the spring, that push the oil pressure valve into the pump to increase the oil pressure...

Was wondering is that will any help to CA18DET's, as part of "I want my bigends to stop with me"

[Fake Ben Taylor]

washers to increase the oil pressure? any pics?

[kalin]

Nope
The thread, from I learned this, is:

http://www.nissansilvia.com/forums/i...owtopic=239182

I hope anyone will put a pictures soon

[mushtafa]

My only concern would be the oil in the head wont stay there too long, perhaps not long enough?

[spesh]

washers to increase the oil pressure? any pics?

theres enough oil pressure anyway


to raise it you'd need to undo the pressure relief cover on the oil pump (5 or 6mm allen key) and pop a washer or two between the cover you just removed and the spring in there to pack it tighter. Hardly an exact science and will lead to crazy pressures when the engine is cold.

Too much pressure makes for weepy turbo seals no?

[Sideways Danny]

I've got washers in my relief valve and I think it might be why my oil seals have all leaked getting a new pump to go with my new crank soon

[bren]

Ive seen external drain pipes added to RBs before so its a tried and tested mod. I looked at it for our Skyline but have something much simpler to try first.

[Fake Ben Taylor]

Ive seen external drain pipes added to RBs before so its a tried and tested mod. I looked at it for our Skyline but have something much simpler to try first.

and that would be................

i did consider getting the oil galleries drilled out but think it may end up more expensive than this. also been speaking to people and this is a well used mod on the rb's as bren says.

think im gonna do it....cant hurt can it?

[kalin]

I think to do it too, who knows, maybe that will "cure" really big end problems
Probably that mod of oil pressure valve is valid for old pums, where the spring is a little bit "tired" ?

[bren]

Just to run two catch tanks to relieve the pressure in the crank case, se how that helps the head to drain. At the moment our Skyline will fill its catch tank as its breathing excessively.

[kalin]

Bren, is any picture(s) available how exactly are catch tank(s) connected ? And do you think that the fitting of two catch tanks can sort the problems with ventilation of CA18DET, right?
Cheers

[bren]

I dont know if it will work on a CA, Im trying it on a Skyline to see what happens.

[ByReaL]

Just to run two catch tanks to relieve the pressure in the crank case, se how that helps the head to drain. At the moment our Skyline will fill its catch tank as its breathing excessively.

i do not have a picture handy but if the catch tank is positioned above the breather level, this way will be verry hard for the oil to go up throgh the pipe to the catch tank (above means 1-2cm max or how high you can place the catch tank without touching the hood.)