Hi Jay, Yes, we used the correct length bolts. The lower bolts are longer than the upper bolts. The Ercoupe parts manual shows the bolts as being equal length but the original blueprints show the correct lengths. We did not use all of the threads on any of the bolts.
Thanks, David N95CV --- In [email protected], "jayschu...@..." <jayschu...@...> wrote: > > Are you sure that you are using the right lenght bolts? If the grip lenght of > the bolt is too long you will reach 60 pounds before the rubber mounts are > properly squeezed leaving excess slack in the whole mounting system. > > Sent from my iPod > > On Aug 15, 2010, at 9:52 PM, "drdlhammond" <drdlhamm...@...> wrote: > > Hi John, > > How can I/we tell if the rubber motor mounts are bad??? The AP thought they > looked normal (i.e. compared to others he had replaced). His torque wrench > was "validated" about 1-2 months prior to my job (he questioned both the 60 > inch pounds - too tight - and his wrench but a second, older wrench was > almost identical). Should we further tighten the mounting bolts? > > Both magnetos checked good during the March annual and both have been acting > "normally" since (i.e. no difference has been noted during engine run up > prior to take off). Yes, the right exhaust pipe vibrates enough to touch the > cowling at its exit hole (has since I bought the plane a little over 2 years > ago). Otherwise, we have not found anything that touches the cowling. I will > pass along the suggestion to check for valve spring and lifter malfunctions. > > The engine vibration reminds me of the old K&B 0.35 nitro/methane/castor oil > model airplane engines we used in the late '60s and early '70s. These engines > were mass produced and inexpensive. Regardless of how well the prop was > balanced, they vibrated! At the time, older modelers told me these engines > were not internally "balanced" and thus their vibration. How much engine > vibration is "normal" for a 43 year old 4 cylinder 4 stroke engine??? > > Thanks for your input! > > David > N95CV > > --- In [email protected], John Cooper <john@> wrote: > > > > On 8/14/2010 10:32 AM, drdlhammond wrote: > > > We could NOT tighten the mounting bolts to the prescribed 60 inch > > > pounds (we had metal to metal contact between the engine and the > > > mount). At 45 inch pounds there was very little clearance so we > > > settled on 40 inch pounds. > > > > OK, there's something wrong there. Bad rubbers, bad torque wrench??? > > > > Once that's corrected, there are many possible causes of vibration. > > How's your mag check? Any baffles, exhaust or intake parts touching the > > cowl? Broken valve springs? Bad lifters?.... > > > > -- > > John Cooper > > Skyport East > > www.skyportservices.net > > >
