Crankcase/cambox ventilation path

[alpa]

Hi,

I'm modifying a Lancia Delta HF ie 1585 engine to put in my 124 Coupe AC. It's very close to the Fiat 131 1585 engine except that it has oil sprayers under pistons and oil pump is on the crank. It's basically the ancestor of the Delta Integrale 8v 1995 engine.

In Lampredi 8v engines I own and all I've seen there is an oil separator on the crankcase and no oil ventilation on camboxes.
There are 2 oil passages descending from each cambox to crankcase, they are quite near and they stop above the crank.
I understand crankcase and camboxes are under the same pressure and there is no air flowing between them.
However if oil flow is high this may create oil starvation in these passages, which is bad.
Also oil exiting descending passages drops on the crank which spreads it all over, with the consequence of charging oil with air (aeration). Which is not good as oil needs to rest more time in the oil pan to release this air.

Adding ventilation to camboxes is even worse as it would create ascending air flow preventing oil to go down (something quite common in stock engines).

What do you know about all that and have you ever seen modified engines with modified oil passages ?

If I remember well later Fiat 16v and I believe Lampredi 16v had oil passages going to the bottom of the block, this way avoiding descending oil to drop on the crank. One could add tubes to drive oil from passages to the bottom of the oil pan, preventing air traveling through these pipes. And oil passages were much larger.

[131]

Not worth worrying about. If you're running a high revving race motor and an oil cloud around the crank concerns you, get a crank scraper.

[alpa]

I'm concerned by oil aeration (air in the oil which reduces its efficiency). These engines have small oil pans so oil does not have time to rest there to release air. Also oil takes more time to reach the pan when it's spread over by the crank.

[131]

Still not worth worrying about. People have been using variants of this engine for 40 years, they've produced over 20 million of them, the oil path is not a newly discovered design flaw. People I know who race them add an extra litre of oil, other than that, basically stock oiling system.

[alpa]

Thanks