Immobilising 3300 prop for leak down

[gregv]

Hi all.

 

Complete newbie question here, but what have others found to be the best method to immobilise the prop on a 3300 when performing a leak down test?

 

Was always easy on a motorcycle - sticking it in gear with the rear brake on!

 

Any suggestions / experiences / sage advice gratefully received.

 

Greg v

 

Northland, NZ.

 

 

[Derby]

Hi Gerg, I just hold on with my hand it's not too hard. it is only 80 psi

 

Rory

 

 

[gregv]

Good point, and thanks!

 

 

[Tomo]

Yep, TDC and hang onto the prop.

 

Welcome along. :thumb_up:

 

 

[facthunter]

Hang on.

 

There is no turning moment untill it moves away from TDC. If you let it move, then it will want to turn. Treat it with respect. It can clobber you even though there is only 80 psi. Hold it near the tips...Nev..

 

 

[frank marriott]

If you get it right on TDC then there is no pressure - otherwise the pressure is quite manageable with one hand - after you do it a couple of times you won't think twice about it.

 

Frank

 

 

[jetjr]

It is permissable to rock prop back and forth to find TDC and correct leakdown reading (highest one), as said theres no pull when in this position but dont let go all the same

 

It can turn very hard if you let go - be very careful, stay clear, also make sure compressor hose and elect leads not draped where prop can grab it

 

 

[ahlocks]

There was a photo posted on the forum a while ago of someone who got clocked by the prop while doing a leakdown test.

 

It gave him a fairly painful whack and cut on the eyebrow just from the compressed air used for the test.

 

CRAFT disease has struck though, can't remember who posted it or where.

 

 

[frank marriott]

Re rocking the prop

 

The recommended procedure is exactly that to ensure you have the accurate leakdown result i.e. find the peak.

 

This is from a LAME who showed me how to get the correct results - so not an opinion from an unqualified pilot which I am.

 

Frank

 

 

[Steve Donald]

stopping the prop

 

Hi Gerg, I just hold on with my hand it's not too hard. it is only 80 psiRory

Hiya not so long ago whilst fiddling with the air tap i had just fitted to my leak down gauges, i had the prop fly around and smack me fair in the nuts, man never again will i stand in such a posi, voice is ok now, on the serious side yep real danger be careful cheers :black_eye:

 

 

[pudestcon]

and smack me fair in the nuts:black_eye:

Don'tya just hate that?

 

Pud

 

 

[nong]

Hey Rory....Is'nt that 80 PSI multiplied by the number of square inches of the cylinder bore ? Have you seen what 80 PSI can do to human flesh and bone. Respect....

 

 

[Derby]

Hi Nong, might be, all i know is if you don't let go of the prop it's ok, if you let it go or your hand slips of it will hurt (a lot). But it's helps if you have help.