Backdate hood latch idea
 

I am doing an all steel backdate of my 1985:

http://forums.pelicanparts.com/porsche-911-technical-forum/819396-so-how-backdate-project-starts.html

Doing research on the hood latch situation I have the following options:
a. buy a long hood and have it modified to relocate the upper latch location to the short hood location
b. have my short hood modified with an extension to be a long hood
c. get a fiberglass hood that is made for this backdate
d. buy a long hood and replace the nose piece of the car to the long hood style
e. buy a long hood and find a different way to latch it.

I don't particularly care for visible hold downs as this is not a RS tribute or hot rod that I am going after. So for the latch, I need to come up with something to fit in this space. I wanted it to be fairly bolt on with minimal cuts to the car. It has to be simple. I want two latches for backup safety.

http://forums.pelicanparts.com/uploa...1505176588.jpg

I found some micro latches for hotrods that just might work...there is enough space there to come up with something that will work.

So I spent about 3 hours mocking up the latches and trying different locations.
I wanted two latches and to have them spread out on either side of the original latch location
The actuating arms are long and I first tried to located them to be in the indent areas of the hood either side of the original latch plate:

http://forums.pelicanparts.com/uploa...1505490344.jpg

but the interference was there - just slightly enough for me to punt this approach. Then I figured if I make some small cuts out of the front metal, I could their swap sides and tuck the latches inside the frunk (darkened area of blue tape to be cut out) with the latch actuator arms pointing inside:

http://forums.pelicanparts.com/uploa...1505490344.jpg

Then I had to come up with a bolt-on plate that would be at the correct angle so that the latching shoulder bolts would be at the right angle and location to intercept the latches. I had some aluminum sheet lying around, so I started to mock this up. This will bolt into the hood at the original two locations but will span further apart and to this I will bolt the latch shoulder bolts:

http://forums.pelicanparts.com/uploa...1505490344.jpg

The angle turned out perfect and the clearances are very good.

http://forums.pelicanparts.com/uploa...1505490344.jpg

As they are oriented now, the latches can either be push actuated by a rod on each side or pull operated by cable or rod. The latches are hidden out of the way under the wire runs in the front. I like this approach. If my hood plate work, I might have to find someone to make a nice one for me. I have limited sheetmetal tools.

I will start cutting the front soon.

oh, here are the latches and one of the shoulder bolts:

http://forums.pelicanparts.com/uploa...1505497118.jpg

You know they make a long hood that can bolt onto a stock short hood car and use all factory latches

Of course, but where is the fun in that?!

Mine is an all steel backdate and I have an original hood. This solution is minimally invasive and the latches were less than $30 total. Anyone can do this...

http://forums.pelicanparts.com/porsche-911-technical-forum/819396-so-how-backdate-project-starts-9.html

so a couple of hours later and I have the latches installed. The bottom of the slot is right where there were holes drilled by the factory for the smile or something (I don't recall). All I did was slot down to them. The brownish stuff was there from the existing hole. The holes are still rough openings and need to be cleaned up and the area painted:

http://forums.pelicanparts.com/uploa...1505514283.jpg

http://forums.pelicanparts.com/uploa...1505514283.jpg

http://forums.pelicanparts.com/uploa...1505514283.jpg

From inside - perfect locations. The actuators are right under cable straps so that the wiring is kept out of the way. These latches seemed to be perfect for this application.

http://forums.pelicanparts.com/uploa...1505514283.jpg.

http://forums.pelicanparts.com/uploa...1505514283.jpg

I slotted the mount holes for the hood plate:

http://forums.pelicanparts.com/uploa...1505514283.jpg

and installed it:

http://forums.pelicanparts.com/uploa...1505515176.jpg

Looking in from the side, you can see the clearance between the bracket and the latch:

http://forums.pelicanparts.com/uploa...1505514283.jpg

The red shows where the shoulder bolt will pass through. I am going to source slightly smaller (in diameter) shoulder bolts than the ones it came with. The head is too big.

http://forums.pelicanparts.com/uploa...1505514283.jpg

I will also trim the hood latch plate to remove excess material and prep for paint once I dial everything in. I am thinking I will use rods behind the horn grills (one for each side) to activate the latch releases. The movement to release is only about 5 degrees.

That's allot of nice work. It's going to be interesting to see how you address the attachment of the long hood extension and required rigidity for the latches and hood flexing against the rubber.
Johan

Not sure what you are saying. My long hood is a Porsche factory new piece. I am simply attaching it with latches near the original factory attachment points on both the early factory hood and the late factory front end. The attachment points (you know this well) are only offset about 2 inches axially along the length of the car, and I am latching about mid point between them.

Oops! My mistake, was looking at your pics on my iPhone in the blazing sun at the beach Nice and tidy solution. Are you proposing to need both hands free to actuate each latch thru the grills?
Johan

I will unlatch one at a time...the latch opening is spring loaded and moves out of the way. Might need a slight spring lid popper, I will see.

Actually, I could use the hood release feature of my remote locking system to actuate the latches simultaneously....hmmm. That would be too easy.

A remote actuator would be nice, but, if you had one, you should consider a secondary safety hook latch. Imagine if you inadvertently hit the remote while driving. :(
Johan

I hear you...I would still need a manual way for times when the battery is dead. Yesterday I prototyped a simple small bellcrank where the original latch was located. It works fine to pop both latches simultaneously. I might be able to connect it to the original hood handle wire for single point actuation.

The latches work great...the hood is down and locked with no vertical movement.

As usual great work here Mike. I really want to keep the factory latch & striker. I had considered the rubber latches but I want a cleaner look. I found a photo here on pelican with a remote pull to release the secondary latch. I have a hard copy but I cant find my electronic one so I can post it.

Keep up the good work

David

Found it

http://forums.pelicanparts.com/porsche-911-technical-forum/379658-here-we-go-again-zuffenhaus-ms-rsr-project.html

First page post 3

I couldn't readily find a shoulder bolt meeting my needs, so I created one with a steel spacer and some hardware. It works perfectly in this application:

http://forums.pelicanparts.com/uploa...1505690345.jpg

http://forums.pelicanparts.com/uploa...1505690345.jpg

I cleaned up the holes with a small file (I still need to paint the exposed metal):

http://forums.pelicanparts.com/uploa...1505690345.jpg

The latches allow the hood to fully seat and the hood doesn't move at all. I have some lockwire attached to the latch release levers and coming out of the side of the frunk so I don't accidently lock the hood down with no way to release it.

http://forums.pelicanparts.com/uploa...1505690345.jpg

Then the conversation with Uwon on this thread got me to think of a way to release both latches with one pull. I figured a simple bellcrank should work and I could use the original location of the single latch. I had some L angle aluminum laying around so I made this prototype in about 15 minutes. You can see my safety wires. It works like a charm! I think I can design this to actuate by pulling the original handle in the cockpit.

http://forums.pelicanparts.com/uploa...1505690345.jpg

The safety wires will all be replaced with nicer covered swagged cables or with rods.

David,

I am not sure there is clearance to pull that handle in a backdate...the front lip of my lid sits very close to the bumper top:

http://forums.pelicanparts.com/uploa...1505691167.jpg

I have some thoughts about coming out of the frunk behind the horn grills with either push rods or pull cables. I also see a couple of options to exit under the car through holes in the frunk (I got rid of the spare, the jack and the A/C system)...so reach under and pull down to release would work for me too.

harpo, i did something very similar on my backdate. i used a small cable thru a contoured tube mounted under the lip. when you pop the hood, you just reach under the front lip and the pull is right there, works very well. no pics handy.

by the way, mike, i got mine all done. my car is in for final fitment and paint. really happy i went with all steel instead of FG.

i only made one cut on the car to remove the tow bracket on the driver side rear bumper. everything is bolt on and easily reversible...

congrats dwelle! Where is your build thread? I want to see your car!

I also got some thin rod material, some "throttle cable swivels", and some hardware to finish off my bellcrank front hood latch. Pretty happy with how it works. I need to figure out a single point pull and a spring return and I am set. That will have to wait until I get my rear pumpers and panel on.

ha! no build thread, i'm just trying to get this one back on the road and start driving it so i can get to the '73 RSR that's right behind it...

Mike, this is how I dealt with the secondary safety latch. It's obviously a different approach. You will likely recall that I grafted the short hood latch sub-frame to an original long hood. Maybe consider a long hood secondary safety latch installed on your longhood, A pin sticking horizontally out of the slam panel, and a pull wire/handle similar to the pics below.

http://forums.pelicanparts.com/uploa...1505930953.JPG
http://forums.pelicanparts.com/uploa...1505930953.JPG

Cheers,
Johan

Johan,

I am thinking of reorienting the latch release bellcrank in a vertical plane to tuck it up out of harm's way and then relocating a pull handle to exit under the car in the area where I removed the front condenser blower. Updated current setup with new hardware and rods (that have yet to be trimmed) prior to reorienting. There is plenty of room under the front panel overhang to tuck it under:

http://forums.pelicanparts.com/uploa...1505941376.jpg

Where did you source your pull handle setup?

The pull handle/wire is a standard 911 deck lid puller variety which came off the donor crashed car.
Latch is standard short hood.
Johan

http://forums.pelicanparts.com/uploa...1506046801.jpg
http://forums.pelicanparts.com/uploa...1506046827.jpg

mike, this is what i ended up doing. lengthened short hood with original latches, and i used i thin wire pull to actuate the latch release. marc zurlinden's little design. pretty cool.

i love all the different ways guys find to get this stuff done...

dwelle, cool solution. Is the spring on the latch strong enough to return the hook arm to the lock position?
Johan

yes. it actually moves quite freely.

i had the tube from marc, and i whipped that wire up to get me thru paint. i'll engineer something a little nicer ultimately. but as it is, works nicely...

Great solution! Simple and functional.

I just finished up an altered design that I am going to stick with for now. I was able to get the original hood pull in the cockpit hooked up to a bellcrank. I have to move on to the fenders.

We just extend the catch so the bonnet opens a little further so the gap is large enough and fashion a small 'hook' to make it easy to press.

We also make a wheeled closing panel to bridge the inevitable gap.

http://imagizer.imageshack.us/v2/xq90/924/zsK2Hx.jpg

^^^^^
Chris, that extended catch is a great solution.
I'm going to PM you re that good looking closing panel.
Johan

indeed. chris, what's up with that panel? are you making them?...

Here was my solution.

First in order to release the lower latch notice inside the horn grill. If I didn't point it out you would never see it.
http://forums.pelicanparts.com/uploa...1506115428.jpg

Then when the hood pops up there is plenty of clearance to pull the top release.
http://forums.pelicanparts.com/uploa...1506115542.jpg

Then to fix the gap in the slam panel .

http://forums.pelicanparts.com/uploa...1506115633.jpg

http://forums.pelicanparts.com/uploa...1506115679.jpg

I removed the metal conduit that led into the interior as it added unescisery weight.:D

Oh, I finished off the latch enough that it works reliably. This may not be my final solution, but it is one that works for now - using the interior pull handle. It still needs a return spring though. I have to manually return the bellcrank prior to closing the hood.

http://forums.pelicanparts.com/uploa...1506633821.jpg

http://forums.pelicanparts.com/uploa...1506633821.jpg

Not yet quite as elegant as I wanted but...easy enough to work on once everything else is "done".

Good man!

Old post but thanks, I'm figuring this out right now. This is a great solution to both the latch release and slam panel mesh (will also make securing the seal easier).
JC

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