Hi Folks!
I have a few (actually quite a few..) questions I need some more or less qualified inputs on before I make some descisions. I have searched on the forum and have found some answers, but not all... Hope some of You out there with experience can help a rookie from Norway out a little...
The almost ready to fly RV-4 I bought a few months back, has the short landing gear and a 72" Hartzell c/s two blade prop (HC-C2YK-1BF/F7666-A-4) in front of a Lyc. (I)O-360-A1AD (Bendix fuel injection refitted) with dual Lightspeed ignition.I'm planning to operate about half the time on a 400m/1200ft grass RWY that is not always as a pooltable, actually hardly ever...
I guess 60% will be CC flying, the rest aerobatics and formation.
Case 1:In the two-point position, my ground clearance is about 17cm or 6,69".
To me that seems to be a little less than I would desire, but am I wrong?
Do anyone have experience with the short gear and 72" prop?
I see the "standard" propdiameter now is 72", but for comparison, can anyone tell me what is the groundclearance two-point with the long (now standard?) legs?
Do anyone have any thoughts about my groundclearance?
Do I have a propstrike just waiting to happen, or will I be fine?
Does anyone still fly with the short legs, or is changing to the long legs done easily?
Case 2:The prop was overhauled/0-timed in 1995, inspected in 2001, run for a few hours between then and 2005, and has not been used after that.
When sent in for inspection again two weeks ago, the Prop-shop said it had to be overhauled/0-timed again and the hub needed to be NDI'd every 100hours because it was of a old type. Besides, the combination of blades and hub was not approved by Hartzell to be used on RV-4's. They also said the blades had been cut to it's minimum length and the internal vibrations could be unfavorable due to the relatively thick blade.
The prize for the OH and a new hub was, at least for my wallet, substantial, (approx $7270,- pluss taxes and shipping). Then I will have a prop with a new hub and old blades that still may be too long, and I am now considering spending a few $$ more and get a prop that is more suited for the RV-4 and my type of operation.
Fixed pitch is not an option!
I guess some of the following questions will strongly be influenced by the answers to case 1, nevertheless...
I assume that I am keeping the short legs and have to go for a shorter diameter prop.
What diameter should I go for, ie. what will be sufficient groundclearance?
Should I go for a 2 or 3 blade prop, and what would be the benefit/sacrifice going for one or the other?
Will a shorter diameter be compensated by adding another blade?
I have received an offer for an MT MTV-12-B/175-59b 3 blade prop with spinner at $10225,- plus tax and shipping.
Is that a reasonable prize?
Any other suggestions ot thoughts?
Thanks for any advise or comments!
Morten Raustein
Norway
I have a few (actually quite a few..) questions I need some more or less qualified inputs on before I make some descisions. I have searched on the forum and have found some answers, but not all... Hope some of You out there with experience can help a rookie from Norway out a little...
The almost ready to fly RV-4 I bought a few months back, has the short landing gear and a 72" Hartzell c/s two blade prop (HC-C2YK-1BF/F7666-A-4) in front of a Lyc. (I)O-360-A1AD (Bendix fuel injection refitted) with dual Lightspeed ignition.I'm planning to operate about half the time on a 400m/1200ft grass RWY that is not always as a pooltable, actually hardly ever...
I guess 60% will be CC flying, the rest aerobatics and formation.
Case 1:In the two-point position, my ground clearance is about 17cm or 6,69".
To me that seems to be a little less than I would desire, but am I wrong?
Do anyone have experience with the short gear and 72" prop?
I see the "standard" propdiameter now is 72", but for comparison, can anyone tell me what is the groundclearance two-point with the long (now standard?) legs?
Do anyone have any thoughts about my groundclearance?
Do I have a propstrike just waiting to happen, or will I be fine?
Does anyone still fly with the short legs, or is changing to the long legs done easily?
Case 2:The prop was overhauled/0-timed in 1995, inspected in 2001, run for a few hours between then and 2005, and has not been used after that.
When sent in for inspection again two weeks ago, the Prop-shop said it had to be overhauled/0-timed again and the hub needed to be NDI'd every 100hours because it was of a old type. Besides, the combination of blades and hub was not approved by Hartzell to be used on RV-4's. They also said the blades had been cut to it's minimum length and the internal vibrations could be unfavorable due to the relatively thick blade.
The prize for the OH and a new hub was, at least for my wallet, substantial, (approx $7270,- pluss taxes and shipping). Then I will have a prop with a new hub and old blades that still may be too long, and I am now considering spending a few $$ more and get a prop that is more suited for the RV-4 and my type of operation.
Fixed pitch is not an option!
I guess some of the following questions will strongly be influenced by the answers to case 1, nevertheless...
I assume that I am keeping the short legs and have to go for a shorter diameter prop.
What diameter should I go for, ie. what will be sufficient groundclearance?
Should I go for a 2 or 3 blade prop, and what would be the benefit/sacrifice going for one or the other?
Will a shorter diameter be compensated by adding another blade?
I have received an offer for an MT MTV-12-B/175-59b 3 blade prop with spinner at $10225,- plus tax and shipping.
Is that a reasonable prize?
Any other suggestions ot thoughts?
Thanks for any advise or comments!
Morten Raustein
Norway