Thanks to ALL for the useful information , I think my friend has decided
against using a small tube for crankcase venting , your suggestions probably
saved him a lot of grief and possible danger , Thank You All Again , Phil
Lohiser EAA 12873
"Phil" wrote in message
...
Hello
I have been helping a young fellow EAA member with the restoration of a
EAA Biplane , he is using a rebuilt Lycoming 4cyl. , 125 H.P. 0-290 D
engine in this plane and has a 3/8 " O.D. aluminum tube running from the
firewall and exiting just ahead of the tailwheel , he wants' to keep the
underside of this fabric covered plane as clean as possible , the vent
elbow that exits the top forward area of the crankcase has an I.D. of
approx. 5/8 " , he plans to put a reducer to make the step from 5/8 " I.D.
to approx 1/4 " I.D. on the alum tube , this tube will go from the
firewall to the tailwheel , the question is this , does the engine vent
just relieve pressure and will the long narrow tube cause any problem ?,
am not an expert in the dynamics of this of this area of the engine , any
thoughts or help would be appreciated .
Thanks
Phil Lohiser
EAA 12873