Another Radial RV-8R

[flyboy1963]

if you like radials, go Lycosaurus!!!
...the 'little' R680 puts out 225 hp, and as an added bonus, will be 100 years old .....before too long!

ummm, ok, at 500+ lbs, you're gonna need a little ballast in the tail!

[VA Maule]

F1R-Yes I believe I do want the radial, hopefully someone will allow me to experience their 8 (I'll do gas & lunch)

rvbuilder2002- This was actually suggested by Robby Grove of Grove Gear. My intent here is to tap into the wealth of knowledge here to get the understanding.

brad walton- Rotec had some cylinder base stud issues in the beginning and changed the hardware grade & some cam gear rivets issue prior to 2009. Warranty 12 mo. or 200 hr. after first start and or 3 years after delivery.

[Dave_Boxall]

Hey Scott,
If Vans ever start supporting the Rotec I'll be building another RV!

(I think once is enough for a home-Brewed engine installation).

[rvbuilder2002]

Originally Posted by VA Maule

rvbuilder2002- This was actually suggested by Robby Grove of Grove Gear. My intent here is to tap into the wealth of knowledge here to get the understanding.

I am not sure what exactly Robby recommendation was, but my point was that if a one piece gear was added, the transfer of the vertical bending loads into the fuselage would be very different than for separate gear legs. It is possible that the gear towers would not even be needed. At least not for the type of loads they are used for now.

[sblack]

Originally Posted by F1R

A 150 HP O-320 will fly an 8 just fine, provided C of G is kept proper.
If you lower the nose a few degrees in flight you will still exceed VNE.
Only climb rate will be reduced along with a slightly longer take off roll.

The only question is do you really want the radial and the work to build the aircraft.
I might go for a flight in a few different 8's if I was not 100% sure about the Rotec.

All those things you say about the effect of less power are true, but you missed the top speed, which is pretty important.

It will fly, but 180hp 8s will leave it in the dust. The 4s and 6s fly well on 150hp but the 8 is a bigger, heavier airplane. The RVs are all about performance. 30hp is a BIG difference-almost 20%. I have never seen an -8 with an O320. I think the 150hp would be disappointing compared to the standard setup.

[Don Patrick]

Not to digress, but a good thread on RV-8s and O-320 engines.


http://www.vansairforce.com/communit...&highlight=320.

Don

[Snowflake]

Originally Posted by rvbuilder2002

I am not sure what exactly Robby recommendation was, but my point was that if a one piece gear was added, the transfer of the vertical bending loads into the fuselage would be very different than for separate gear legs. It is possible that the gear towers would even be needed. At least not for the type of loads they are used for now.

I think Scott meant to say "wouldn't" be needed? If that's correct, I have to wonder if Van would consider making a switch to one-piece gear on all -8's... Those gear towers in the fuselage make the footwell quite cramped, in my opinion.

Of course, everything is a tradeoff, so switching to one-piece gear and losing the gear towers inside may lead to a less desirable change elsewhere...

[rvbuilder2002]

Originally Posted by Snowflake

I think Scott meant to say "wouldn't" be needed? If that's correct, I have to wonder if Van would consider making a switch to one-piece gear on all -8's... Those gear towers in the fuselage make the footwell quite cramped, in my opinion.

Correct I meant would not

Originally Posted by Snowflake

Of course, everything is a tradeoff, so switching to one-piece gear and losing the gear towers inside may lead to a less desirable change elsewhere...

Exactly my point.
The gear tower structure might be able to be deleted, but other structure likely would have to be added.
Doing this type of mod. properly, requires a full engineering evaluation with the new gear and then drop and pull tests to verify the engineering.

[flyboykelly]

Originally Posted by VA Maule

Thanks for the quick replies ,and getting up with Brian is defiantly on the list. He chose to deal with the prop issue by going CS-electric I'm thinking of taller gear and the recommend 84". As I read in here there has been some discussion about gear "weak links" my thought is this may be elegant solution as I would prefer to avoid electric prop control. So as to be as simple mechanicaly as posable. I have been fllowing Radial Conversions FB for about 18 months and am quite familiar with Brian's posts. Besides I do not want to copy his just to be inspired by it, after all the goal is to unique and have that radial KOOL factor.

Morgan,

First off congrats on deciding to be different! I could go into the why's and how's for a long time, but I'll just say I went down every road you've talked about. In my experience and the by using the experience of other Rotec owners I can definitely say that the CS prop is the only way to go with this airframe and that engine. The 84" prop is mainly used on WWI replicas and frankly it's way to much prop for the engine. Will it fly? Yes, but at a major speed disadvantage. I'll post a couple of pictures from my flight back from Sun N Fun. You can see all of the data there from my current installation. I still have some development to do, mainly with cooling. I'm currently overcooling. Once that is solved I should pick up another 5 kts. Please feel free to call me and chat. I'll pm you my personal number. For everyone concerned about performance. It's not a 180hp rv, but she's plenty fast for me!

All the best,
BK
[IMG][/IMG]
[IMG][/IMG]

[VA Maule]

The thought behind the potential added gear tower panels is the gear would be 9" taller and 6" wider, with a 5" top flang . Since the tower is set for 3" stock flang would it not make sense widen the loading area accordingly as the fore & aft forces of longer gear needs more support to compensate for the increased leverage at the attachment point. Remember my objective is prop clearance.

I believe my thought process here corresponds with the "Breaking News " and related threads on gear bolts.

This aircraft will be operated off a grass strip adding to the stresses on the gear.