firewall for my series 5 Vixen

[jacques]

I am flying evry day with my 5 Vixen with smoth cool. I have a 912 UL 80 HP and I have recently bought a 912 ULS 100 HP. I want to use it asap but I need to built a wooden firewall to instal and prepare for the swap without loosing time during the swap. I have ordered a new heavy duty mount, arms and rubbers for my new engine (with some other parts for around 1400 us$ + 500 shipping to France) from John at Kitfox, but he told me that he have no numbers to built one and that I will need to get the dimensions and make the mock-up from my aircraft..(maybe he prefer to sell me one new one.)

So my question is : does some one can tell me numbers for that or just PM me a drawing of the firewall by following the contour of a new piece on some paper.


Thanks for your help.

[Slyfox]

I'm confused at what you want. I switched my engine from the UL engine to the ULS engine and took the new mount and pieces and installed on the new engine and went out to the airport and did a swap in 1 hr. You see the ul and uls engine are the same. So I swapped with no problem at all. In fact I did this in the dead of winter with 5degrees outside. It was easy as pie. A little interference with starter to firewall, but nothing a big bar didn't take care of.

OH when I did this in my shop I did most of it with the engine just laying on the floor, installed the new mount with insolators. When it was time to install I took out the 6 or so bolts on the firewall, used a chery picker and removed the engine very fast. Than hooked onto the new engine and stuck it in place and put in my firewall bolts. Basically done.

[jacques]

In fact, I want to improuve all accesories and radiators position for a better cooling and efficiency. I understand that engines are same, it just to improuve all.

No one have a plan with dimensions for the firewall?

[Av8r3400]

What you are asking for is an engineering drawing. These are usually not published, as they are considered intellectual property.

Why not make the drawing you need from the components you have there? (remember, they are not metric dimensions) You have all the dimensions you need right there on your own plane.

If you are looking to modify your plane to "increase the efficiency" you would be on your own, anyway. The design from Kitfox is what they considered the most efficient, any better is up to your engineering skills to discover.

[jacques]

The design for the Kitfox is what they consider the most efficient?...Why did they change the cooling with smaller air inlet, oil inlet and naca for water? Just to improuve...Even accesories are in differet position inside.

In fact, and it is fine, a plane is always improuving with builders indication and factory thinking.

THere is a kitfox 1 and now a 7 or SS. Just to change the name?..

I flew the 747 100, SP, 200, 300 and now the 400 and I can tell you that taking off with a 400 with 35°c is not the same story than with a 100. The only thing I miss with the 100 is the flight enginer, the one who know!

For the firewall, I bought a Vixen 3 month ago with an old 912 UL 80 hp and I have a nice new 912 ULS 100 HP and before swapping engines, I want to built a wooden firewall to install the new heavy duty engine mount I bought to John from Kitfox and just increase efficiency for maintenance and better position of all air, oil and water houses, electrical parts and so. Very simple. I dont want to make a new plane. And at the same time I want to fly evry day with my old engine until I swapp.

The fact is that my firewall is with a protective for fire and it is difficult to have good mesurment.

[jtpitkin06]

This replay is in English and French.

Cette rediffusion est en anglais et en français.

Jacques,

J'ai la même difficulté que je suis l'installation d'un moteur différent sur ​​le Kitfox. Il n'ya pas de dessins ou les dimensions disponibles.

Ce n'est pas un problème si vous avez le temps d'enlever le moteur et de construire un nouveau moteur personnalisé monter. Si vous êtes pressé et que vous voulez changer le moteur en seulement un jour ou deux, il peut ne pas être possible.

Je vous suggère de simplement accepter les temps d'arrêt et d'un plan sur l'aéronef étant non-opérationnels pour quelques semaines.

Jacques,

I have the same difficulty as I am installing a different engine on the Kitfox. There are no drawings or dimensions available.

This is not a problem if you have time to remove the engine and build a new custom motor mount. If you are in a hurry and want to change the motor in just a day or two it may not be possible.

I suggest you just accept the downtime and plan on the aircraft being non-operational for a few weeks.


Regards,
John Pitkin
Greenville, Texas, USA

[jacques]

John, thanks for your french.

It is really my concern to swapp the engine in a very short time.

My fox is at an airfield that is around 35 milles from my home with small roads so around 1 hour driving and if i need to check something it is not easy.
It is why I want to do a mockup and work at home, stop for a coffe or kids. I also have my job with long flights and so on.

I had before a Vans RV4 and guys from Vans factory where really more helpfull : they answerd all questions, send drawings, help with technical and delivered parts very fast.

It is not the same with Kitfox. I asked John from kitfox to tell me an AN equivalent for the rod end on the wing and horizontal stab as I have to change them due the French civil aviation and he just told me that he had some in stock and other in back order.
I do not understand why because it is not a special part from kitfox and I can find some at AC spruce europe. Mine are painted and on the plane and if I want to know what AN they are, I have to dismentle all, remove the paint, check if there is numbers, etc...so no flights during this time.

I saw that you are from Greenville. I was there 20 years ago, when I was in the French Navy during a trip with our VOUGHT F8 FN from the West indies. We landed at the Naval Air Station Corpus Christi then at the Naval Air Station Joint Reserve Base Fort Worth. One of the US Navy pilot was fom Greenville and we spent a weekend for a BB at his home. and we flew his Pitts at the Greenville municipal Airport!

[jtpitkin06]

Firewall bolt spacing
Mid point bolts 31-3/4 inches (806.45mm) on center. These bolts establish your horizontal reference line.
Top bolts 13-3/8 inches (339.73mm) on center 8-3/4 inches (222.25mm)above reference line
Bottom bolt 11-1/2 inches (292.1mm) below reference line.

Top and middle bolts are 1/4 inch
Bottom bolt is 5/16 inch
Recommend high strength MS bolts.

John Pitkin
Greenville, TX USA

[jacques]

THANKS VERY MUCH. I will start a firewall mockup.