Race Engine Forum UK

yes, it should be in the oil. If it is above the oil level you get oil blown out of the breather,

GC

This problem I know when the oil level is very low.
I asked because I never found any discussion about the pipe and I ask here because it's a SOHC thread.

Sure Martin, it is a SOHC thread, no worries, I didn't read the header properly, my mistake, sorry.

GC

Ok thanks Guy. Sometimes I wrote to fast.

Do you have some information about the displacment volume from the oil pump?
I know that the turbo SOHC has a bigger oil pump with a higher volume.
But I don't know how high.
I have installed in my turbo block oil piston cooling from BMW with 2.5l/min (each injector, opens at 2.5 bar).
I have forged con rods (Pauter) without oil holes in the rods (the standard rods have 2 holes for this) and a Garrett Gt Turbo (the turbo don't need much oil, restricted oil pipe).
But I'm scarred that I get no oil pressure about 2.5bar because the oil cooling injector (what's the correct name for this?) opens then. The standard injectors are much smaller and opens at 1.2 bar oil pressure.

Martin, hi

sorry, those BMW oil sprays, well I don't know if they are too big or not! They are off a bigger engine with a bigger oil pump... The increase in delivery will be the ratio of radius squared of course, not that it will tell you much. You did not need bigger ones, in fact I'm not a fan of them at all, I don't see the need for them. To stop detonation? Better to calibrate the engine's fuel/ignition and keep the motor running cool (coolant, charge temp) and keep it out of the detonation zone in the first place. You have to ask yourself why it would detonate at all..
I'm sure I wrote elsewhere on this site about oil sprays, half the reason they are used now is to wet up the rings and bores quickly to reduce emissions, even the little Fiat Fire atmo engine (Punto thing) has them....!

Slots in the rod cheek (GC Cunningham rods style) will give you all the bore lubrication you need. Incidentally, the flowrate thru the standard ones is pretty high - have you tried forcing hot oil thru them? I have..

The turbo pump is not bigger than the X19 1500 (from memory but I'm pretty sure), it just has a stiffer oil pressure relief valve spring.

G

The SOHC nonturbo engines have 10 teeth on the oil pump wheels. The SOHC turbo engines have 8 teeth on the oil pump wheels and because of this the pump has a higher volume.
The oil pressure valve is different (turbo is a little bit stronger, I have Fiat papers about this, but not about the volume...).

Sure through the holes on the rods came enough oil but without controll. The injectors closes when the oil pressure fall down.
And I get more temperature away from the piston. Not to prevent detonation. But I think it's one step in the right direction.
On other cars (Opel, VW) it works very fine. The all "kick" the oil holes and install bigger oil injectors. To cool the water down because the oil cools there.

Are you sure? Fewer teeth on the turbo vs more teeth on the n/a unit? I had both back to back a couple of years ago and I don't remember any gearing difference. Maybe different series Unos? No matter.

Either way it is neither here nor there. Fewer teeth but much bigger? You'd need to measure the entrained volume between tooth and casing, no easy task and compare gear delivery rates. Tooth pitch root-tip diameter only affects shaft load via meshing frequency and has a bearing on pump inlet port caviation but without knowing the transfer rate per gear rev you couldn't say it's a higher or lower delivery volume...

If the entrained volume between the two meshed gears and the casing is the same - the one with more teeth will to deliver at a a higher rate. The determining feature of an oil pump for given internal running clearance and crank leak-down rate (bleed/loss rate - hot - at bearings etc) is the ability of the pump to sustain delivery pressure. That's a function of two things, the internal pump clearances and the relief valve setting. It is pressure against a 'head' after all that determines whether the oil can get where it needs to go, eg: a properly designed low-pressure water pump (like a centrifugal pump) can produce huge flow but put a pressure drop in the way and none of the fluid will reach the height it's meant to. In engines with low back-leakage positive displacement pumps (like spur gear or crescent gear types) that's where the relief spring comes in. Put two pumps of equal pumping capacity - the one with the high rate relief valve spring will generate higher line pressure under all conditions, the one with the low rate spring will just bleed off all the time. And of course it is important to get the right settings, because otherwise the pump will blow the seals out of the engine. The capacity of the OE pump (of either type) is massive if the relief valve is locked.

About piston temp. I've said before on this site (please do a search) - I have a good friend, respected race engine builder I've known since NHRA days, in-house dyno. Reports definite , measurable power loss on n/a engines with oil spray, now isolates them. knowing the source well, that's good enough for me. Lower the piston temp and you just increase energy transfer from the combustion. Like I said I am not a great 'fan' of the oil spray practice, sure, not a bad idea on a high boost unit or an F1 engine..

If you want to post a new thread on pumps and oil sprays please take it out of GC Q&A at this time.



GC

Hello Guy,

The oil sprayer are installed in my turbo block (with forged Pauter rods). For my brother I do a 1.6 NA engine with 2 DCNF carbs WITHOUT sprayers (Uno Turbo WITHOUT CAT rods - leighter then the rods after 1987 as far as I know!), of course!

Here two pictures from the oil pumps:

1.4,1.5,1.6 NA engine


1.3 and 1.4 Turbo engine

Some guys had problems with there turbo's when they used the NA oil pump that the turbo didn't get enough oil.

When I know more I will make new threads! And I will bring more pictures. I have some ideas, maybe you like them :)

Regards, Martin

Are they both Uno Turbo pumps, early model and late? I'm not clear.

GC

The bottom pump is uno turbo/racing.
The other is NA SOHC.

Different numbers in ePer.

thanks for the good photos Martin,

we've spoken on pm and there is some uncertainty as to whether the 1.3 Uno Turbo had the later pump with fewer teeth or not, not a big issue but I'd be interested.

The photos at first glance indicate that the capacity (flowrate) of the later pump must be higher. But is it in fact? To get the free-delivery flowrate you have to burette the volume contained between on pair of teeth, multiply that by the number of teeth in train (remember the oil is pumped between the teeth and the casing - not gear to gear). The 1500 X19 pump has 5 teeth carrying oil, the Uno 1.4 T has four.

I know Martin (Acki) is a careful guy, so I figure we can assume the X19 1500 and Uno Turbo 1.4 gears are the same length, because that is another design feature that varies, eg: 1600 131 TC pump gears are same tooth form but much shorter than the 2 liter ones. We know they spin at the same speed - or I guess they do, I assum same gear ratio auxiliary driveshaft to driven gear in both engines.

Anyone care to measure the volume thing? Just for interest.. I don't know! Bigger pump capacity would make sense.

BTW - I don't want to tie up this thread too long on oil pumps, it's about tuning a SOHC engine (not an Uno engine as it happens!)..

GC

The gears have the same length. You can put them into a other pump without problems.

The capacity maybe knows a friend of me, he will look into his papers.
I will tell you when I know more.

Back to the SOHC's. I have some problems with the water-pumps. I have bought new pumps and I messaured the distance between the pump wheel and the housing of the pump. The distance is out of the limit in my Fiat papers. That means the capacity is lower. I'm thinking about this fact now. Maybe it's good because the water has more time to "bring" the heat away...

(for Uno drivers, the biggest water cooler I have seen is from 1.5 MPI! This cooler is 1cm thicker than the uno turbo water-cooler. Length and weigth are the same! Part number I will post later. When I order a cooler I get the same now. Must be changed years ago...)

Oil sprays: Quick cautionary tale kindly emailed to me by respected GC client Martin Baker (non member but a frequent site reader nonetheless):

Guy,

I have just been browsing your excellent forum as I often do, and came across the use of the BMW oil jets to be installed in a SOHC engine.

I thought you might like to know that I fitted the same jets to my 131 blocked 16 valve turbo engine. With the standard oil pump the oil pressure plummeted to around 5 psi at idle with Mobil 15W50 oil straight after a rebuild, and was pretty low when reving, not good at all.
I then fitted a dry sump system and the oil pressure is now around 25 psi at idle and fine at all rpm, should have dry sumped it ages ago.

To use these jets, you really need to dry sump the engine with the pump sized to suit.

Hope this info is of use.

Regards

Martin Baker


GC

But is this 131 oil pump the same as we/I have?

Yes, prior to dry sump fitment. That engine was a 16v conversion on a 131 2 liter block.

GC