Topic: 850 oil sump

[bibito]

I have got the fiat850 coupe al. oil sump to install on the 1050 engine, the oil pump  from the 1050 is about 20mm longer ,
 any suggestions how to modify or replace the pump.

Thank you!

[viotti600]

I have got the fiat850 coupe al. oil sump to install on the 1050 engine, the oil pump  from the 1050 is about 20mm longer, any suggestions how to modify or replace the pump.

 Quite simple...replace the oil pump pickup (extension/screen) on the 1050 pump with one from a Fiat 600 or Fiat 850 engine.

-JS.

[bibito]

Thank you for the tip!
I couldn't find a 850 oil pump, as for the 600, thought it is as long becouse of the deep oil sump it has.

[alapimba]

I have got the fiat850 coupe al. oil sump to install on the 1050 engine, the oil pump  from the 1050 is about 20mm longer, any suggestions how to modify or replace the pump.

 Quite simple...replace the oil pump pickup (extension/screen) on the 1050 pump with one from a Fiat 600 or Fiat 850 engine.

-JS.

are u sure it's that simple?
it can be used on 903cc engines too?

[Paul vander Heyden]

Viotti600 is correct.  The reasons are two fold.  1) The 600/850 pickup is shorter  2) On the A112 pump there is a metal plate between the pickup tube and the pump gear housing.

TIP:  When you have the pump apart, inspect the pump housing and the top plate of the pick-up tube.  If the housing looks like an army has marched through it, replace the pump.  If the top plate has circular grooving, then place a piece of 300-600 grit sandpaper on a FLAT surface ( ground flat plate or a granite surface plate) and sand the top plate carefully until the marks are gone.  Then put a straight edge across the bottom of the pump gear housing.  Then see what thickness feeler guage you can put between the straight edge and the gears?  If it is more than 0.002 inch (.05mm) then pump clearance will be greater than the rod and main bearing clearance (presuming that these are correct).  A pump like this will be overworked trying to keep up with the pressure requirements of the motor, as it is bypassing a significant quantity of oil. Take the gears out and perform the same sanding technique on the pump housing.   I run both the 850 and the 1050 pumps at clearances of 0.001-0.0015 inch (0.025-0.030mm). 

Further, resist the temptation of running more than 60-70 PSI (4.14-4.83 bar) of pressure HOT.  More pressure for a street engine is not required and has several negative impacts.  1)  Higher pressures require MORE horsepower.  2)  Higher pressures will cause deflection of the gear shafts in the oil pump (remember the shafts are only supported on one end) and cause damage to the walls of the pump housing. 3) Excess pressure will cause pre-mature wear
of the pump shaft drive gear and the opposing camshaft gear.

For competition use I recommend having longer pump shafts made.  Then it is possible to put a thicker plate between the pump housing the pickup tube (similar to the 1050 pump) and put two small roller bearings in the plate.  This will help take up the load on the shafts and eliminate any deflection of the pump gear shafts.

Hope this information is of help.

Regards,

Paul Vanderheijden
www.scuderiatopolino.com

[bibito]

Hello, Paul,

I found F600 pump, and now have two problems:
- would removing the pressure valve/as it goes with the pick up/ on tha 1050 pump, cause any problem?
-do I have to use the plate between the pump and pick up/1050 setup/ or eliminate the plate as it is in F600 setup?

Thank you!

[Paul vander Heyden]

Bibito

If I understand you correctly, you have a pump with the pressure valve located as part of the pick-up tube (aka A112 - 1050).  As your Fiat 600 block has a pressure relief valve built into the side of the block, you do not need the one on the pump pick-up.  You could use the one from the Fiat 600 pump.  Using the steel plate is a much butter alternative to just the aluminium pick-up.  Make sure that all the holes line up in the pick-up and plate.

Make sure that the plate or the pick-up are flat and do not have any major scoring, as this will affect pump performance.

Regards,

Paul Vanderheijden

[bibito]

Hello,Paul,

I'm a little bit confused here...let me try to explain:
I want to use the 1050 block and install the F600 oil pump pickup/in order  to clear the F850 al.oil pan/, when I remove the oil pick up
from the 1050 oil pump, I'm left with no pressure relief valve on the pump and the block/only F600 block has the pressure valve built in/.
How and where can I install a pressure relief valve?
I hope this makes clear what I'm trying to do....

Thank you for the help!

[Paul vander Heyden]

Bibito

You need to find two things.  From a Fiat 850 you need the metal tube that went from the oil pump to the #1 main bearing cap.  Then you need the pressure relief valve from a Fiat 600 or 850.  Cut the tube about midway, and then silver solder or braze the relief valve to the end of the tube.  I would also braze a small support strap to go from the relief valve body to one of the main cap bolts.

I have done this many times when using the normal relief valve location as the output location for an external oil filter on a 600 or 850 block where I have done the reverse oiling modification.

Good luck,

Paul Vanderheijden

[bibito]

Thank you ,Paul,
only now it looks "quite easy "as Viotti600 said.

Cheers,Lubo

[viotti600]

You need to find two things.  From a Fiat 850 you need the metal tube that went from the oil pump to the #1 main bearing cap.  Then you need the pressure relief valve from a Fiat 600 or 850.  Cut the tube about midway, and then silver solder or braze the relief valve to the end of the tube.

  For folks interested in the modified Fiat 850 oil tube/oil pressure valve unit that Paul is referring to, here is a photo of what it looks like after fabrication as instructed: