917 Scratch Build

[Chris Huck]

Chris,

good work as usual, but am surprised you are not making your door stiffening "frame" from metal tubing with your hinges welded to it, as well as the door lock. The nature of the 917s doors makes them very vunerable to weather-human-unforeseen "abuse".

I know you are doing your own thing and not following originality, but the doors can be a right pain for keeping "tight" so to speak, and with you wanting to put it to road use I can,t help thinking that just GRP ribbing will not really be sufficient, especially when pushed against rubber weather sealing strip or tubing.

Good work though.

Thanks for your feedback Graham, did try the alloy tube route, took me a morning to get the front door section bent, it fitted ok but was not happy with it so opted to try the moulded route, I hope to use Carbon/Epoxy for the door itself then the stiffening rib with flanges will be from carbon too. I am hope full that the shape should give it the strength around the inside edge of the frame. I shall use alloy for the crossbar which the door catch/lock is located.
Will suck it and see, no great loss if I have to revert to alloy/steel tube just a few days wasted. I will try the one door and see how it comes out before I do the same on the other side if successful!!!
Hoping the light and stiff approach should work!!!
regards C

 

[Chris Huck]

Managed to get the frame done using filler, done the door latch block and had a fiddle with the hinges, only made out of some 4mm alloy just to get an idea how it would or wouldn't all go together. First lower hinge not great but lucked in with the second version!!! Did the top and the door opens and closes with no rubbing, so a start and gives me a clear indication of how the real ones will be done, save a lot of hassle later on.
Anyway a pic for you, much better than my ramblings!

And one from the rear to give a rough idea how the hinges go!

 

[Alex]

The nature of the 917s doors makes them very vunerable to weather-human-unforeseen "abuse".
.

How so?

 

[Jack]

They were very thin and floppy Alex.

 

[Graham T]

How so, you ask Alex?

As Jack has said, they were thin, lightweight and flexy, rather than floppy. If the wind or anyone was to catch on them you could bend the hinges and misalign so easily. Will not keep the rain out at all well, especially when stationary. As top edge of door wraps over roof and is directly over seat, you are always liable for a wet bum, as seat will fill with water.

OK while you are moving.

The shape of the door guarantees that when you open it, water will just run off the front edge like a jug pouring out and the sills will get very wet. Trust me, I know.

 

[Jack]

Graham, Alex has an RCR 917 in the works.
Sorry for my poor description, flexy is a better anology. I know a couple of real 917 pilots and we always speak of all things 917. Almost had a deal on two original engines 15 years ago, but missed it. They were for a Porsche boat project that never got off.

 

[Graham T]

Graham, Alex has an RCR 917 in the works.
Almost had a deal on two original engines 15 years ago, but missed it. .

Jack, sacrilegious to put in a boat, but wow, if only you could have pulled that deal off.

I do not suppose you and Alex have too much rain out there in Florida to worry about door sealing up much, but over here we do get a bit of the wet stuff. I don,t bother much as my 917 is race only, but Chris is wanting his as a road car and they can sure fill up with water fast.
A few years back my 917 was representing Gulf Oil at LeMans and was on static display behind the pit area with the Gulf/Barazzi/Epsilon team. In one of the regions epic downpours the poor car filled up like a swimming pool, a good two inches in the bucket seat and probably half an inch over the entire chassis floor as the oil cooler nostril outlet acts like a funnel. A week later when transporting it back there were still puddles of water under it ...
thankfully fibreglass does not rust !!
As the whole rear deck hinges forward any water will also pour straight into the engine bay area so builders need to be aware of that as well. Keep the electrics well away from water ingress and don,t forget the cockpit air exit vent on top of the roof. Wind and rain in the right direction will give you a wet neck and shoulder!!!

All OK though as long as you keep moving forward !!!!!!!!!!!!!!!!!

 

[Chris Huck]

Just a quickie, just received picture of my front uprights, should be arriving soon!!!
Look very nice, too good to use!

 

[Alex]

Thanks for the explanation Graham/Jack
...and now back to watching this thread and wishing i knew more than how to use a jigsaw and drill :laugh:

 

[Chris Huck]

Got sorted out on the front wishbones today (in prep for the uprights arriving soon) and hope to start making the door rib mold tomorrow. Need to order up a bucket load of rose joints and some rubber bushed inboard bushes then hopefully can bang on the arms!!
Pic of front wishbones done, shock mounts/plate still to weld on.

regards Chris

 

[Chris Huck]

Eve all, managed to get the door frame stiffener done, a mould taken and popped the first one out today, came out ok, considering the shape of it, put a bit of carbon in where the hinge point mounts are, these will be made from 1/4 alloy, have done one already and am happy with it, just the top mount and door catch to do then trim up and have a go at bonding it to the skin (will use epoxy/flock for this) then see how it weighs, think I've got the lay-up right, won't know until its all bonded together and out the mould.
pic of frame mould

And first one out placed on the door kin (still in mould)

 

[Jack]

Looking very well done Chris, keep the updates coming...

 

[Chris Huck]

Trimmed up frame and bonded in hinge mount point, pic gives you an idea how it should all end up once the frame is bonded in place!

 

[Les]

(Porsche 917 doors) were thin, lightweight and flexy, rather than floppy. If the wind or anyone was to catch on them you could bend the hinges and misalign so easily. Will not keep the rain out at all well, especially when stationary. As top edge of door wraps over roof and is directly over seat, you are always liable for a wet bum, as seat will fill with water.

OK while you are moving.

The shape of the door guarantees that when you open it, water will just run off the front edge like a jug pouring out and the sills will get very wet. Trust me, I know.

How did Count Rossi deal with this problem in his street-going 917? Can we imitate his solution?

Les

 

[Graham T]

How did Count Rossi deal with this problem in his street-going 917? Can we imitate his solution?

Les

Count Rossi did not do anything. He did not have a solution.

 

[Les]

How did Count Rossi deal with this problem in his street-going 917? Can we imitate his solution?

Les

Count Rossi did not do anything. He did not have a solution.

Hmm. That is too bad. I was hoping His Lordship could help us out.

Leaks and all, the Count Rossi still drives his 917:

As I am sure you are aware, though his 917 is driven in Europe, it is registered in the U.S., in the state of Alabama. (Will that assist anyone else in registering their 917 or 917 replica?)

Despite leaks, the car does have a leather interior.

 

[Graham T]

Count Rossi did not do anything. He did not have a solution.

Forgive my rather short reply to your questions. I,d just got back from four long days at RaceRetro.

Your pictures show just how much padding and sealing was done round the doors for a firm fit, but the also highlight very well how, as the door opens, any water on the door will fall directly into the seat (as in a 40 unless you very gently open it) and as it goes up that lovely curve of the door act just like a funnel and shoots the wet stuff forward and into the sill area.

No problems whatsoever if your not in the rain. Please understand though that anything I have said is based on experience and on much lighter racing cars, which ,after all, is what they were. If you want to build one for comfort on the road just beware if you don,t want your wonderful padding, furry dice and bum to get wet!!

 

[Graham T]

Chris,

you really are to be congratulated on your work and the long road to getting it all together and built.

Just a further insight for any of you looking at those photos of the Rossi car is the rear deck. Yes, it is a Kurz or short tail version, but notice the shallower and curving "trough" and the top of the wings. This was the finned rear deck style and to my knowledge is the only one to have the fins removed, an obvious thing to do for a road car. The normal short tail is deeper and flatter and never had fins fitted to it.

sorry if it is going off at a tangent to your build Chris but thought it might be of interest to some with those good pictures being put up by Les.

 

[Chris Huck]

Chris,

you really are to be congratulated on your work and the long road to getting it all together and built.

Just a further insight for any of you looking at those photos of the Rossi car is the rear deck. Yes, it is a Kurz or short tail version, but notice the shallower and curving "trough" and the top of the wings. This was the finned rear deck style and to my knowledge is the only one to have the fins removed, an obvious thing to do for a road car. The normal short tail is deeper and flatter and never had fins fitted to it.

sorry if it is going off at a tangent to your build Chris but thought it might be of interest to some with those good pictures being put up by Les.

No worries Graham, very interesting, doors are probably the worst part so far to do, can only trial/rough fit them until I bond the front body to the chassis, which will be some time away yet!!!
I guess its going to be an impractical car full stop, noisy, hot, crampt, bumpy with limited rear vision, so guess a bit of water added into the mix wouldn't do any harm!!! But some way off yet!!!
regards C

 

[Alex]

Now that I have my 917 I understand EXACTLY what you guys are talking about with respect to the doors.

Oh well, all in the name of weight savings!