oil starvation -> external returns from the head to the sump?

[raziel]

hi

I was just lookin around, and found somethin that wont be that common on here - but will ask about it anyway...

this is sitation from nissansilvia forum or maybe other forum - it was a reply from one guy on the question about "how to fix oil startvation and make rod bearings last longer on CA engine"
the answer is:

" Most CA bearing problems come from lack of servicing, not oil starvation. But like the RB's they can pool oil in the head @ constant high rpm. Larger dumps will allow more oil to be left in the sump but it's a band aid, not a solution. If you want a descent fix for it, there are two large grommets at the back of the head. Remove these and put a descent size dash fitting in each one and run lines down into high on the sump.

If the engine was still apart I'd also spend I little time 'deburring' or cleaning up the oil returns on the head and block"




my queesition is - I know its quite common on RB engines - to do somethin like this : http://www.spoolimports.com/spool-oil-drains

or this :



- but how helpful it would be on a CA engine?
also - if you add this mode - doesnt it cause the overall oil pressure to drop due to larger return line (or added lines) - thus lowering back resistance of it etc...? or the return itself has nothin to do with it - and if someone is up for it, just do it??

[skyshack]

Can't do any harm. Put connection in sump on exhaust side as air pulled round by crank rotation will whip it around if on inlet side. On exhaust side it's whipped down into the sump first and not over the top.

Do not T in to turbo line. That will make the turbo smoke.

Can't do anything bad to oil pressure. The oil has no pressure in return system it's been pissed out of the bearings and it just flowing back to the sump by gravity.

If it it does as claimed it may reduce residency time of oil on head. Good for the oil but could give higher head temp.

[raziel]

Hi skyshack - great, thank you for the info - especialy on that return line's position - the best place would be weld somethin just next to the turbo oil return - in the same height I presume - closer to the back of the engine or to the front (left or right side from the turbo oil return)??? or either jsut as close to it it can be will be fine?

and then - the guy on the forum was talkin about these two welsh plugs ?



so removing them both and somehow gettin the oil conncetions in instead those plugs?

as I can see - on this picture (found them on this forum )



the welsh plugs are sittin somewhere in the middle of that passage - which means that the oil wont be flushed right away from the head - as would happen in the case of fittin the return lines too low in the passages - as is shown here (again - found it on the forum - sorry for using the pics)



- the hole on the pic sits jsut in the bottom of that oil passage - which could cause oil to exit the head too quickly - thus not lubricating/cooling properly...?

any ideas on the size of fittings & hose & connection in the sump??

as someone mentioned in some old thread here - if fitted in the level of those welsh plugs - it will make oil to leave the head only in the case when needed - once the actual oil starvation occurs...

any other ideas pros and cons?

thank you in advance

[ANDY black s13]

I have looked into doing this as well,same on zilvia like you have and the spool site,I never found anyone say it was bad lol,more mixed opinions on its effectiveness,
I'm in the I can see it as a very good thing and worth doing as my current head leaks oil down the back of the rocker covers regardless of gasket condition, high revs + hard acceleration and the rocker covers are probs near full of oil for short periods as stock oil returns on the side of the head half way between 2/3 So something Im looking into doing this on CA I'm rebuilding atm,
I will probs copy the spool design and via a mate with a lathe and cool stuff get something made up and tweak it as I see fit,as in the side of the sump to return too was debated iirc on the zilvia thread,some were saying stuff about the cranks rotation meant it needed be on turbo side, others the opposite side due to heat from turbo etc,
As its all draining back oil, its pressure wont be reduced at all with this mod,this wont increase pressure either but it will ensure there's more oil returning back to the all important pick up pipe a lot faster and in greater amounts imo
But well worth doing for the easy job it seems to be with motor out of the bay
edit: Skyshack beat me too it smoking and typing gets so slow

[R3K1355]

Those plugs are so high up the head would have to be completely flooded with oil before they drained anything out. You can see on that section of head where the oil usually gets to as there's a clear oil line around the bottom of the gallery.

So your only option is to put the oil drain where that hole is in the second picture, and hope it does more good than bad.

[skyshack]

Looking at those photos it's hopeless trying to fully drain the head. The head is canted to the exhaust side. The exhaust side appears to have the head bolt boss cast as part of the outer wall and manifold stud anchor block. That will dam flow to the back of the head. The inlet cam box drains over the top of the head to the exhaust side.

But if it's as bad as Andy says then the plugs are OK to use as they will drain off the excess oil when present and before it fills up to the cam box.

[raziel]

btw just got trough this thread- theres the guy who actualy tested the setup

http://www.sxoc.com/vbb/showthread.p...ht=ca18det+oil

after 10k kms he claimed no probs with shells etc... though no mention on what power he was running, what temp of oil / water he was gettin etc...

though the way he did the connection in his hand-made "welsh plugs" - is very nice... its surely much better solution than be drillin into the head itself...


btw - theoreticaly - larger capacity sump along with this mod would / could improve all the problems with bearings fail on CA engines.....? honestly - 3.5l of oil in a turbocharged engine (let alone modified) is quite interesting...

[ricardomendes]

Igoman made that but the engine after 15.000km of rebuilding start to knock main and rods bearings, he was running very good oil, and stage 3 h-DEV with t28r. But we don't know what was the real result of this mod.
He's using sr20 now.

Maybe he see this thread and post more info.

[skyshack]

Igoman made that but the engine after 15.000km of rebuilding start to knock main and rods bearings, he was running very good oil, and stage 3 h-DEV with t28r. But we don't know what was the real result of this mod.
He's using sr20 now.

Maybe he see this thread and post more info.

Maybe people with tuned engines run frequently at near max output for any length of time should run a much more intensive maintenance program. At a minimum for CA that means pulling it apart and changing the big end shells every 5K miles (180bhp/L = stage 3), 1K (300bhp/L). But if the stuff I've quoted and linked to below is anything to go on that's too long for a properly used tuned engine (why do it if you don't use it?). Rings need attention too - that's where the blow by comes from. Pistons need crack tests, a crack can grow to failure very quickly, hope you catch it in time (more frequent strip and test?), just one DET ping mark on a tuned engine means replace it. If you want 100K+ miles put it together stock, run it on stock power and only run over 5K rpm though the gears - a few seconds / day, when you get on the D/C or M-way. With maybe 4 times a year a max speed run over a mile or so.

I've said most of this before but with different sources / examples.

A 4 stroke motorcycle production racer may go a full season on an engine - if the regs don't allow rpm limiter removal. If limiter can be removed life is short - one meeting with practice, race 1 and race 2 and maybe a final. Tightly regulated Moto2 with 140bhp 600cc Honda engines use identical sealed units, supplied and maintained by Geo Technology, on behalf of the organisers (sic) have 1500k rebuild life.
http://motorsport.dunlop.eu/moto2/regulations?lang=en

Before new regs BTCC would consider it insanity not to rebuild the engine quite often.
ALFA 700Km - 80hr rebuild! @ £100's/hr. (this is a bit over the top)
http://www.touringcartimes.com/news.php?id=3234

http://www.xpowerforums.com/K2000_Judd.htm
K2000 2 litre K series engine £12,900. if you use it as its made to be used you HAVE to rebuild it. If you pussy around it will last longer - how much, who knows? Cheaper to rebuild than find out by having the engine innards appear on the outside.

Rebuilds

The engine will require a full rebuild after 3,000 miles of track use. A rebuild will constitute a full strip down and crack test of all engine components, and the automatic replacement of pistons and valve springs. Other parts will be replaced as deemed necessary from our rigorous inspection procedures. All engines will be dyno tested and inspected after test to our normal high standards.

Routine rebuild costs will be £3,750 labour plus parts. If for any reason non-routine repair or rebuild work is necessary as a result of damage caused by mis-use of the engine this will be charged additionally.

The stated rebuild interval of 3000 miles is for racing or competitive track day use, not 3000 miles of road use. For example we would expect this mileage to consist of approximately 40-50% running at full load. If actual running was with a lower duty cycle than this the rebuild interval could be extended accordingly.

Our intention is that the rebuild interval should be no shorter than the Caterham R500 engine, and our quoted figure is what we believe to be the minimum that the engine will be capable of. When we have built up more experience of running the engine to and beyond this figure it is likely that the rebuild interval will be increased.

I would suggest new rod bolts every 4th or 5th rebuild.

Rally use - this Fiesta R2 isn't even tuned that far but it is going to be thrashed, redline all the way. WRC events have about 400Km competitive distance - you are not supposed to drive at redline between stages.
http://www.google.co.uk/url?sa=t&rct...pAQVwUT44INN8A

Recommended Service Intervals
ENGINE
Rebuild distance is set at 2000km. Oil should be changed after every 300km or at the end of each WRC event.
GEARBOX
Inspection of the gearbox after every 300km. Rebuilds should be at 600km intervals. Oil to be changed after every national event (approx 150 km) or at the end of each leg on a WRC event.

You can get longer life 3000Km from bigger engines 500bhp/3.4L V8 but it's going to cost.
http://encycl.opentopia.com/term/Judd_%28engine%29

F1 engines have since the turbo era until recent "2 race" rule changes run one race between rebuilds. In the turbo era they ran an engine for qualifying, out lap, qualifying lap, 2nd qualifying lap, in lap. If they did a 2nd qualifying lap it normally blew up on the in lap.

As for top fuel drag racing, 2 events, it's time for a new crank.

TUNE IT, USE IT, REBUILD IT LOTS
Much cheaper than buying a whole new set of bits every time it blows up.

And don't buy life expired bits.

[croustibat]

btw just got trough this thread- theres the guy who actualy tested the setup

http://www.sxoc.com/vbb/showthread.p...ht=ca18det+oil

after 10k kms he claimed no probs with shells etc... though no mention on what power he was running, what temp of oil / water he was gettin etc...

though the way he did the connection in his hand-made "welsh plugs" - is very nice... its surely much better solution than be drillin into the head itself...


btw - theoreticaly - larger capacity sump along with this mod would / could improve all the problems with bearings fail on CA engines.....? honestly - 3.5l of oil in a turbocharged engine (let alone modified) is quite interesting...

There is no problem with the oiling system of a CA18DET, except for the breathers. There is a problem with users that cant be bothered to read the workshop manual to get the correct oil viscosity for their usage though, or others that think thicker oil will resurrect a dying oil pump, that kind of things.

considering this mod : the most powerful known CAs dont use these. Because the engine does not need it.

Want more oil capacity and a safer oiling system ? Use an accusump. Want even more ? Go dry sump. Enlarging the sump in any way will create more oil movement and you dont want that.

The reason why oil stays in the head is because it cant go down, and it cant go down because there is more pressure down there than in the head, AKA breathers are blocked or too small, or rings are done for. fix problems, not their consequences.

[cc200sx]

There is no problem with the oiling system of a CA18DET, except for the breathers. There is a problem with users that cant be bothered to read the workshop manual to get the correct oil viscosity for their usage though, or others that think thicker oil will resurrect a dying oil pump, that kind of things.

considering this mod : the most powerful known CAs dont use these. Because the engine does not need it.

Want more oil capacity and a safer oiling system ? Use an accusump. Want even more ? Go dry sump. Enlarging the sump in any way will create more oil movement and you dont want that.

The reason why oil stays in the head is because it cant go down, and it cant go down because there is more pressure down there than in the head, AKA breathers are blocked or too small, or rings are done for. fix problems, not their consequences.

This is it!

[BeerBringer]

I have this mod. See it more as an extra breather than an oil return. If you look att the size of the stock oil return you will see that there is no chanse that the head will be full if there is not a pressure in the crankcase that prevents oil drain.

I also have a winged and baffeled sump. This is mostly to help keep the oil temp down.

[alanjuggler]

I have this mod. See it more as an extra breather than an oil return. If you look att the size of the stock oil return you will see that there is no chanse that the head will be full if there is not a pressure in the crankcase that prevents oil drain.

I also have a winged and baffeled sump. This is mostly to help keep the oil temp down.

agree - this mod is based on the RB which has much more severe problems with oil pooling, though IMO, that's down to the fact that the RB doesn't have an external crankcase breather.

I wouldn't bother. baffle the sump properly and it'd be a more effective solution. the chaps who use the RB25 on track just seem to get away with overfilling the oil by 500-1000ml when using street tyres. when you're moving to semi slicks, it'd have to be different again.

if you're driving on the road, I wouldn't bother with any of this, just properly arrange the breathers.

[raziel]

I have this mod. See it more as an extra breather than an oil return. If you look att the size of the stock oil return you will see that there is no chanse that the head will be full if there is not a pressure in the crankcase that prevents oil drain.

I also have a winged and baffeled sump. This is mostly to help keep the oil temp down.

hey mate, any chance to post some pictures of the sump you made,??