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Crankcase breathing
Posted: Wed Dec 17, 2014 10:48 am
by Jono
What would the wise counsel of the forum be for a moderately tuned 1310 with around 85-90bhp and never (willingly) to be revved over 6k?
I have a vented drop gear housing - should I have a vented timing case and rocker cover as well?
Cheers
Jon
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 11:11 am
by Charlynsane
Dear Jon,
As for me (rally engine) I vented the crank case housing, the timing cover and the rocker cover
I have exactly the same set up as nick swift car
Cheers
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 11:23 am
by Chalkie
I have on a 998 running sw5 cam, stage 2 head, twin carbs, megajolt and exhuast
Transfer housing breather, Fuel pump mounted breather (no mech fuel pump) and rocker cover breather.
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 11:26 am
by Jono
...that's a great idea about using the fuel pump hole as a breather, how is that done then? (I'm using a facet leccy pump)
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 12:18 pm
by Chalkie
DSN classics still sell them
http://www.dsnclassics.co.uk/retrosport ... let-alloy/
Mine was a thing a mate made up its just a blanking plate with a 12mm hole drill in it and a bent bit of steel tubing welded to it works haha be buying one of the top ones when engine comes back from machine shop as had new pistons fitted
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 2:14 pm
by mk1
I used the fuel pump hole the rocker cover & the clutch cover on my racer. I have never used the timing chain cover because it all gets too tight to move down there.
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 7:13 pm
by Spider
I have a similar set up in one of the Minis. I did initially have a stock breather on the timing chain cover, but found it all too easy to get oil surge on Right handers (and that blue smoke on the exit). I've swapped to the one on the transfer cover, problem gone. You really only should need one breather.
Re: Crankcase breathing
Posted: Wed Dec 17, 2014 8:35 pm
by Cheeser
With my inline 1380 (putting out just over 100 at the flywheel) I had trouble with oil getting passed the scroll on the crank and dripping out the bellhousing.So now I have a breather from the timing cover to the front of the rocker cover, then a breather from the top of the rocker cover to 2/3 the height of a sealed catch tank, then from the top of the catch tank to a 'y' which then goes to the twin SU carbs.Although may be a bit over the top and not ideal feeding into the induction, it has got over the original problem.