Small Breather Pipe?
Discussion
I was rather hoping and looking forward to someone explaining this.
It's the tee arrangement I don't get,
there's strong vacuum behind the opening to the small pipe, exhaust gasses passing from the flame trap and the other end goes to a port right next to the throttle butterfly.
The only thing I can guess is maybe when vacuum is lost due to open throttle the breathing is taken in at the throttle butterfly port.
And even if that was the case why is the flame trap not on the n/s rocker cover adjacent to both vacuum feeds?
It's the tee arrangement I don't get,
there's strong vacuum behind the opening to the small pipe, exhaust gasses passing from the flame trap and the other end goes to a port right next to the throttle butterfly.
The only thing I can guess is maybe when vacuum is lost due to open throttle the breathing is taken in at the throttle butterfly port.
And even if that was the case why is the flame trap not on the n/s rocker cover adjacent to both vacuum feeds?
Sardonicus said:
Yes, it's a vital part of the positive crankcase ventilation system
SardonicusThanks for your reply, it got me researching a little more It seems that the small pipe is to give positive pressure when the engine is idling and the butterfly closed (the larger vent pipe would be inoperative at this time). Makes sense now!
Thanks
MPO
As an update, I purposely blocked this crank case vent system (that would stop the large and small breather pipe operating) last year and tweaked my 14CUX maps accordingly getting the AFR I’m looking for.
I have seen no adverse effects in doing this, no lifting of the oil stick no oil seepage either . So, I will be blocking off both the small and large pipe on a more permanent basis to prevent it entering the combustion chambers and probably effecting performance. Everything will be reversible…
Temporarily, I am venting to the atmosphere with the original flame trap in place and a suitable filter on top. I may add a catch tank this year…
Cheers
MPO
I have seen no adverse effects in doing this, no lifting of the oil stick no oil seepage either . So, I will be blocking off both the small and large pipe on a more permanent basis to prevent it entering the combustion chambers and probably effecting performance. Everything will be reversible…
Temporarily, I am venting to the atmosphere with the original flame trap in place and a suitable filter on top. I may add a catch tank this year…
Cheers
MPO
Gassing Station | Chimaera | Top of Page | What's New | My Stuff