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131mirafiori home => The Garage => Topic started by: benjack on March 11, 2017, 05:48:41 AM



Title: Fiat Engine Oil problems
Post by: benjack on March 11, 2017, 05:48:41 AM
All
I'm hoping someone can help solving the problem with the crank case breather system on my 131 race car.
I've run a 131 on the track for two years. We have now put together a new race car which will hopefully be a little quicker. (I've put up a build thread in the projects section)
But we are having huge problems with oil.
Engine has a big wing sump and crank scraper.
Crank vent feeds into a catch can.
And we have added an oil cooler.

The track where I race (Killarney in Cape Town) has two consecutive long and fast right hand turns.

Two problems:
1. Oil is half filling the catch can (about 500ml) within 5 or 6 laps.
2. We are losing oil pressure on both the RH bends as well as the
LH hairpin bend.

We are now re-looking at the baffles in the sump. Also deleting the crank scraper but adding a windage tray.
I'm also taking off the oil cooler till things are sorted out as this is then one less complication in the oil system.

We have no idea about the oil pushing out of the breather.
Any advice, suggestions or comments?

Picture of the big wing sump and oil scraper (not competed in the image) below


Title: Re: Fiat Engine Oil problems
Post by: parrish on March 12, 2017, 03:34:27 AM
Not sure if this is going to have much to do with either of your problems but:
Have you prised that Gauze off the oil filter pick-up?
If not,do it regardless, I did on mine and found a load of crud inside which couldnt be accessed any other way.
I have a pohoto somewhere and if I ind it ill post at a later date
Regards
Steve



Title: Re: Fiat Engine Oil problems
Post by: mick131 on March 12, 2017, 09:38:37 AM
Do you have a spare standard sump available ?. If so, I'd change the baffled one for it and see if that helps. It could be the design of the baffles is holding oil in both the right and left hand bends and hence it's escaping to the catch tank and giving you the low oil pressure.

If your not losing pressure in a straight lime, the cornering forces and movement of the oil would point to the baffles. That amount of oil going to the catch tank in5/6 laps is a lot :o.


Title: Re: Fiat Engine Oil problems
Post by: benjack on March 13, 2017, 05:10:32 PM
Thank you for the replies.
We are planning to slowly work through all options.
I'll keep everyone updated as thing progress.

Or be back on here asking for more advice.

Thank you


Title: Re: Fiat Engine Oil problems
Post by: vode131 on March 15, 2017, 03:00:37 PM
You need to use bigger or better yet multiple breather piping. With one too little pipe the flow is so fast that it moves lot of oil mist in the breathertank.

And there is another thing that I would do. Put a drain back pipe from your breathertank to block distributor blocking. This is easy to do and you have all the oil in the engine.

Its hard to say without pictures, but I think more or better desing baffling in the oilpan will also help.

I have tested my own oilpan with water under the shower to see how oil will go to pickup. You can also see where the oil is going when you turn oil pan side to side.