Sliced the hood today
two reasons
1. want to make hardware to make a rear tilt 90° straight upheld up with gas shocks.
2. want to take aprox 2" off the nose
using two hoods to make one.
any suggestions on hardware design would be welcome!

 

Keith,
That sounds like a project. I whish I had some thoughts for ya. It was all I could do for the single piviot forward tilt with gas shocks. I was going for 90 but couldn't get it.
Are you planning on the whole hood to raise or just the part you cut out ?
Seems if your plan is the whole hood, the rear corners may be a problem the way they're lower, may have to raise striaght up prior to tilting.

Good luck I'll be watching for your progress. I'm sure you'll get there

 

I've been playing around with rear hinge ideas, and think it can be done fairly easily, but would require giving up a little space under the dash. For a rigid rear hinge to have the right geometry it would need to be a "U" shape with the pivot as high up as possible and 4 -5" behind the hood rear edge. I think a skinny box shape ~ 1/2" wide for 3/8" hinge arms, could be inlet into the firewall at the desired hinge points to house the hinges, likely just outside the current hinge mounts and up against the underside of the cowl. The hinge arm would pivot at the upper rear corner of that box. the forward end of the U would have a solid mount to attach to the underside of the hood at the same horizontal plane as the pivot and approx as far forward of the rear edge of the hood as the pivot point is behind it. The shape and size of the U would need to be worked out by graphing it or testing some pattern shapes until it cleared the cowl as it raised. If that doesn't compute let me know and I'll try to do a sketch for you, but we are leaving in the early AM for Topeka to race in our National Championships and won't be back until 10/1. I'll be dropping in occasionally to harass y'all while I'm gone but my access and computer capabilities will be limited.

 

Keith, When I see one of your postings I can harldy wait to click on it to see what wonders you have come up with.

If I understand AX's description right, the hood would open up 90 degress and would actually be above the cowl when opened. It sounds plausible to me. Mike has a good point about the hood corners, just from the looks of it they might rub the fenders when the hood starts to pivot up.
The gas strut my be a bit tricky for a hood that is opening 90 degrees, the danged strut would be out in the open and a bit unsightly. Maybe you could either use a gas strut or a actual spring and mount it to the "U" shaped piece that AX refers to. It could attache vertically from the mount down to the frame/floor board area. Very similar to the hood hinge springs on late 40's early 50's GM cars

Can't wait to see what you come up with
Bobby

 

The hinges I described are based on the hinge arrangement on our Celica and Miata hinges I examined to see why they work. I think the hood corner will even clear but it might be close. Could always change the hood seam line to be horizontal from the top of the fender back to eliminate any rubbing issues and be one of those oh so subtle changes that makes the difference in a good custom.

 

Wow Keith, very ambitious! I think that if you are going to go to all the trouble of reengineering the hood, why not go whole hog? I see a lot of problems with those rear corners clearing with your straight lift hinge design. I propose that the ultimate hood would open to the side like the old Buicks (1950 I believe.) You could open them in either direction!! I know it would be a lot of work, but how cool would that be!

PS: you will notice that I did NOT do that to my truck. I'm really good at spending other people's money.

 

sketch of plan A
Need to get hood up and away from windshield

 

I don't see how the gas shock would function in your diagram. Just a visualization says that there would be little to no change in length as the hood moved thru it's arc? For the shock to function it needs to go from a compressed state in the closed position to extended in the open, and have leverage like a prop. Yours looks more like it would function as a fixed strut and have no real leverage.

 

I see what your plan is now, I have to agree with AX, being that it would be a two stage action, one being the slide forward two being the arc to open, it may very tricky to use a gas strut ( I won't say impossible, I've seen your work).
Myself my main goal for the hood was to avoid the two stage open. To me they just seem to be a bit of a contraption, I've not seen one that functions truly smooth.
Just my thoughts.

 

Keith,
Great drawing! Its hard to tell where the end of the strut attaches. Does it attach to the bearing area or to the fixed part of the cowl hinge? I would think that it would have to attach to the fixed part of the cowl hinge or it wouldn't compress as mentioned above.
It looks to me like the lower hood corners would still be a problem and interfere with the fenders.

Bobby

 

Keith -

I think you've got a plan here. The hinge arm (with roller bearing) attached to the hood, rides down a cam slot to set the rear of the hood. The gas strut counters the weight of the hood.

The first problem I see is that when the hood is up, you can't grab it to pull it down against the pressure of the gas strut. The second is that the gas strut doesn't go over center so that it is always resisting and you can't close it, (but that may just be an easy geometry adjustment).

How about if you swap out the gas shock for an electric linear actuator and use it to motorize the hood up and down. I think that would be WAY COOL, and I think it would work well with the cam slot hinges. The big problem will be timing one side to the other. You could use two actuators, one on each side. The trick to set it up would be to have the lower pivot of the actuators just below the lowest part of the cam slot. The hood rear moves up (to clear the back hood corner and the cowl lip), then the whole hood rotates up. You'll need a different front latch. The stock one won't work.

I would look at the cam slots being circular (a radius), rather than a 45 degree ramp. They would work smoother and make sure the hood clears the windshield coming down. In fact, you want a radius in the first part, then and angle down at the end to seat the hood rear flaps and to get over the cowl lip.

I think you are on to something here!!!! Keep noodling.

 

Keith, I have been thinking about this since yesterday and I remembered that Sasche Rod Shop in Texas makes a hard-tarp hinge that may do just what you want. It has 3 pivot points that lift straight up and then pivot away.They are on the web, check them out.

 

fenders-- I looked at the one in texas cant reall tell but I dont think it opens a full 90°.
ax --you may be right I might have to move the gas shock forward some I just want it as much out of the way as possible when open.
randy- motors sound way to complicated. I tried a radius track just could not get the hood away from the windshield enough.
Thanks guys keep the Ideas comming

 

fyi, you probably know this but I'd be remiss if I didn't say it, the radius track works best when the pivot is a close as possible to the opening, it has the least amount of movement before it clears the adjoining panel. In addition a large Soss hinge might do the trick and they open 180 degrees without a clearance problem. I used them on my tailgate..........

 

Study the rear lift gate on the Chrysler minivan, they open a full 98 degrees and dont touch the rear overhang on the roof. I once used the hinges from a 1986 Plymouth Vogager on a 78 chevy van to "gullwing" a half door the clear the roofline as it opened enough to allow entry and not bang my head.