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View Full Version : Jings crivens, help ma boab


Roy
Feb 27, 2004, 07:01 PM
Despite 4 foot of snow at the side of the road, I decided that today was a
good day to visit GTI models in Aberdeen (running low on the red 10% stuff)
Having gotten just a wee bit hacked off at the state of the raptor after
flying it I decided to get one of those wee rubber thingies for the end of
the exhaust (I didn't have one before and model was covered in keich after
every run)
Fitted said wee rubber bittie to the zorst thinking I would probably have to
lean out the Webra as there would be more back pressure in the exhaust hence
more pressure in the fuel system.

WRONG !

What a difference to the engine, absolutely unbelievable.
I had no idea before when the engine was actually in it's powerband as it
sounded pretty much the same whatever I did to it.
with wee rubber thingie fitted you _KNOW_ it's running in it's powerband.
I have opened up the idle to 3 1/4 turns and the main to 2. it's still hot.
Not burn yer skin hot, but hot.
That's an extra 1/2 turn on the idle and an extra 1/4 turn on the main
(which without wee rubber thingie fitted it just wouldn't run at before)

the webra 52 aar with new piston and hammer straightened conrod at 50%
throttle 0 deg pitch (running in normal mode on radio) is absolutely
singing.
In fact I think it going just a wee bittie too fast, but don't have the
equipment to be able to tell for sure.
(before wee rubber thingie I had it at 60% throttle at this point in the
normal curve and it sounded like it was running lower headspeed than it is
now)

Is this normal?
(monster increase in power from fitting £2.25 piece of rubber)

the zorst is the standard TT supplied with the Rap 50 kit

I don't want to take the idle needle out any more as the needle is
completely clear of the cats eye at full throttle at this setting.
I feel that I may have to open up the main a bit more but the recomended
setting is 1.5 to 2 turns, so the needles are pretty much opened up as far
as they should be.

Any way I can tell what the headspeed is without a tacho?

regards
Roy

david
Feb 28, 2004, 07:01 PM
> Any way I can tell what the headspeed is without a tacho?
>
> regards
> Roy
>
>

Roy, by definition, no.

I know yer a canny scot, but 20 quid for a tacho, man. Spend it ye great
scootish tightwad! ye know it machs sense.

D

Roy
Feb 28, 2004, 07:01 PM
"david" <david_perry@btconnect.com> wrote in message
news:c1qc9k$ru3$1@hercules.btinternet.com...
>
> > Any way I can tell what the headspeed is without a tacho?
> >
> > regards
> > Roy
> >
> >
>
> Roy, by definition, no.
>
> I know yer a canny scot, but 20 quid for a tacho, man. Spend it ye great
> scootish tightwad! ye know it machs sense.
>
> D
£20.00 ! you do realise that ASDA are selling Grouse for £17.50 for a 1
litre bottle
£20 for a tacho
£17.50 for some cheap whisky . . . . . .

erm, any way I can borrow a tacho?

regards
Tounge firmly in cheek
Roy

david
Feb 29, 2004, 07:01 PM
> >
> > D
> £20.00 ! you do realise that ASDA are selling Grouse for £17.50 for a 1
> litre bottle
> £20 for a tacho
> £17.50 for some cheap whisky . . . . . .
>
> erm, any way I can borrow a tacho?
>
> regards
> Tounge firmly in cheek
> Roy
>


ROTFLMAO!!

I'll swap ye me tacho for a new bottle o' the falluin doon watter!

I know some guys can tell by the sound, I tried it once and chopped me left
ear clean orf!!

D

Roy
Feb 29, 2004, 07:01 PM
"david" <david_perry@btconnect.com> wrote in message
news:c1sttg$ge0$1@hercules.btinternet.com...
>
> > >
> > > D
> > £20.00 ! you do realise that ASDA are selling Grouse for £17.50 for a 1
> > litre bottle
> > £20 for a tacho
> > £17.50 for some cheap whisky . . . . . .
> >
> > erm, any way I can borrow a tacho?
> >
> > regards
> > Tounge firmly in cheek
> > Roy
> >
>
>
> ROTFLMAO!!
>
> I'll swap ye me tacho for a new bottle o' the falluin doon watter!
>
> I know some guys can tell by the sound, I tried it once and chopped me
left
> ear clean orf!!
>
> D

Ah well, today was bright, sunny and almost wind free (and according to el
cheapo temp guage in mondeo it got up to the tropical hieghts of 7 deg C !)
So took toy out to play at the AAM field.
Thought the gyro was playing up and on investigation at home it was in
heading hold whatever I did with the switch. doughball. must stop changing
the programming on the radio when drunk.
The Webra is now through it's 11th tank and hasn't siezed yet . although I'm
not sure whether its
a) a better piston than the original (which fell to bits in a most
suspicious manner, not burnt, not overreved, not nice)
b) The quick UK fan now installed instead of the TT plastic original
c) Less abuse from me as it now seems to be smoking more than it was. Though
the old (shagged) piston only showed signs of failure rather than cooking.

As to the headspeed, I guess hovering at 2.5 - 3 deg on the collective
probably means that it running a pretty fing high headspeed, so have knocked
15% off the throttle setting at that angle on the blades. The webra seems to
sing at that speed and I get the impression that it's fully into it's
powerband there.
The only thing that makes me think otherwise is that at full (+10Deg)
collective it bogs down a bit, but stays at the slightly lower revs
whatever.
So maybe it just sounds as though it's in it's powerband when actually it is
overspeeding a bit.
In this (halfway through a tacho state) ((read previous posts to get that
one)) I feel that the only solution is a throttle jockey.
however, I don't have any spare channels on the RX (so, need a new RX)
I don't have a throttle Jockey (so need a throttle jockey)
I don't have a tacho to check the throttle jockey (so have to carefully
balance need for tacho versus need for whiskey) ((that one could take some
time))
so, it'll be next month (having a bill from the gliding club for well in
excess of £350 this month)

By god a rap 50 doesn't half go at some rate of knots across the field.
I was absolutely gobsmaked at how fast it was traveling. (practising 180 deg
turns and then trying to bring it to an auto stop beside me) ((when I say
beside me, I mean, in the same field))

Ah well, that concludes the mutterings from the sozzled scotsman in
Stonehaven.
Have a nice Monday Y'all !
(nice to make the septics feel welcome, musn't aggarvate that chip on their
shoulder)

again, tounge firmly in cheek,
Roy