Jamara 330L
10-23-2008, 01:35 AM
#176
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RE: Jamara 330L
ORIGINAL: BaldEagel
Zee
Isolation mounts are one of those things that people talk about without having tried them, hearsay will tell you they do not work, but if you take it to a logical conclusion if you isolate the engine from the airframe correctly you isolate the vibration and reduce the noise created by that vibration, better all around, do look at the MVVS mount it is one of the best around and works very well.
Be carefull on the Jamara Extra the front of the fus is weak as the firewall is only supported by the fibreglass shell, look back on this thread and you will see the mods I carried out to satisfy myself, there is also a link to another thread where they had trouble with the front without an isolation mount in case someone wants to blame that.
Mike
Zee
Isolation mounts are one of those things that people talk about without having tried them, hearsay will tell you they do not work, but if you take it to a logical conclusion if you isolate the engine from the airframe correctly you isolate the vibration and reduce the noise created by that vibration, better all around, do look at the MVVS mount it is one of the best around and works very well.
Be carefull on the Jamara Extra the front of the fus is weak as the firewall is only supported by the fibreglass shell, look back on this thread and you will see the mods I carried out to satisfy myself, there is also a link to another thread where they had trouble with the front without an isolation mount in case someone wants to blame that.
Mike
Thanks for the support, Mike. I HAVE followed the thread and have tended to all the faults that were mentioned.One person suggested a way to test the airframe for 'harmonics'. I like it and it shows great forebearance in not shooting down the iso. mts! My 330 may be a bit heavy, as I'm using a Fuji50sb(magneto), but then I'm not an IMAC person. I'll probably set the mts. soft , for a start. Then on to a more firmer setting.
It took some doing to get it in.
Again, thanks for the backup.
Zee
AMA129570
10-23-2008, 05:08 AM
#177
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RE: Jamara 330L
Zee
I note you say on a soft setting, the MVVS mounts do not have an adjustement, what mounts are you using?
The Fuji being heavy may require a stiffer mount rather than softer.
Mike
I note you say on a soft setting, the MVVS mounts do not have an adjustement, what mounts are you using?
The Fuji being heavy may require a stiffer mount rather than softer.
Mike
10-24-2008, 01:53 AM
#178
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RE: Jamara 330L
ORIGINAL: BaldEagel
Zee
I note you say on a soft setting, the MVVS mounts do not have an adjustement, what mounts are you using?
The Fuji being heavy may require a stiffer mount rather than softer.
Mike
Zee
I note you say on a soft setting, the MVVS mounts do not have an adjustement, what mounts are you using?
The Fuji being heavy may require a stiffer mount rather than softer.
Mike
Yeah! The Fuji is a 4 pounder +.[
] The iso. mounts came from Great Planes. The rubber composition is a bit soft. They are easy to mount and they seem pretty solid. For the price(<$10.00) it seem too good to be true! I didn't use the ply mount that came with the setup. I spaced them further apart. The Fuji mounts were further than the ply mount holes. Thing are coming together nicely now. I inserted a hardwood dowel in the c/f wing tube. Added 2oz to the weight. I located it right where the weak point was. It's about 4" long and will, I think, reduce the stress on the c/f tube at that point.
You may be right about a stiffer setting.
Very large washers on both sides of the rubber iso's. Adjusting the tension is a simple matter of tightening the through bolts.
More later as I mess with this thing.
Ciao
Zee
AMA129570
10-24-2008, 06:26 PM
#179
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RE: Jamara 330L
Speaking of mounting the engine, I am using a Brilleli 46GT with the Brillelli T style mount. I noticed that when I put the cowl on and checked the spinner back plate to cowl distance, I noticed about 5/32" up thrust. I checked the mount-box-firewall and nothing appears to be outwardly out of wack. I know I'll have to do some shimming to get it right but did anyone else notice or is mine just the odd duck of the bunch. Thanks Joe
10-25-2008, 01:17 AM
#180
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RE: Jamara 330L
ORIGINAL: JL636
Speaking of mounting the engine, I am using a Brilleli 46GT with the Brillelli T style mount. I noticed that when I put the cowl on and checked the spinner back plate to cowl distance, I noticed about 5/32" up thrust. I checked the mount-box-firewall and nothing appears to be outwardly out of wack. I know I'll have to do some shimming to get it right but did anyone else notice or is mine just the odd duck of the bunch. Thanks Joe
Speaking of mounting the engine, I am using a Brilleli 46GT with the Brillelli T style mount. I noticed that when I put the cowl on and checked the spinner back plate to cowl distance, I noticed about 5/32" up thrust. I checked the mount-box-firewall and nothing appears to be outwardly out of wack. I know I'll have to do some shimming to get it right but did anyone else notice or is mine just the odd duck of the bunch. Thanks Joe
I rebuilt my engine box, so my rt thrust came out spot on! If there's some way you could measure your thrust line, it would be benificial! I don't think even a little bit of up thrust on these machines would help at all!
DuBro makes an incident meter that can also be used to check engine thrust lines. They are indispensible if you fly Biplanes or want to be certain of AOA , incidences and such.
Also the cowl may be off....You're never certain....are you?
Have a ball!
Ciao
Zee AMA129570
10-26-2008, 08:30 AM
#181
Thread Starter
RE: Jamara 330L
ORIGINAL: JL636
Speaking of mounting the engine, I am using a Brilleli 46GT with the Brillelli T style mount. I noticed that when I put the cowl on and checked the spinner back plate to cowl distance, I noticed about 5/32" up thrust. I checked the mount-box-firewall and nothing appears to be outwardly out of wack. I know I'll have to do some shimming to get it right but did anyone else notice or is mine just the odd duck of the bunch. Thanks Joe
Speaking of mounting the engine, I am using a Brilleli 46GT with the Brillelli T style mount. I noticed that when I put the cowl on and checked the spinner back plate to cowl distance, I noticed about 5/32" up thrust. I checked the mount-box-firewall and nothing appears to be outwardly out of wack. I know I'll have to do some shimming to get it right but did anyone else notice or is mine just the odd duck of the bunch. Thanks Joe
Mike
