Also in my spare time I have been anticipating the hood tilting. I have gone through many different setups/scenarios. I want the hood to come forward at the beginning on the arc, then swing normally and then rotate/pitch forward near the end of the travel. I'm far from an engineer and have left lots of room for options. I've done scale models on graph paper to get an idea of what may or may not work. I've made arts and crafts versions to try and see a real world arc. Lately I've come across this simulator its a "non-grashof" linkage, this uses the "ground and floating links" has the 2 other links, but I picture them as hood and frame mounts. Really helpful in see what small changes can do. I'm thinking I want it to start/rest closed, just pre-apex. When pulling forward the links will pull the hood forward in a relatively straight line until the apex then start pivoting and pitch forward when nearing the end. This isn't the final version, but one I have a picture saved of. Its finding out how much I need it to go forward, and how far down and roll it will be when open. It is easier to accomplish if I start the links closer to laid right down, but then will have to pull the hood up over the apex, not sure how the mechanic advantage of that will be? Probably ok, but then it also ends out quite far forward, which might not be a problem. Lots to figure on this still, but thought I'd give insight on the process.. I believe I will go with a 3 link setup to keep the clutter down. One middle bar has the short bar, and two longer has the outside bars. I am going with 7/8" bars and poly bushings. I will make the mounts adjustable and just tacked in, once I get the supports welded to the internal hood frame and glued to the hood. This is a link to the simulator, pretty fun to play with, I've gone from long links, to short links, different angles, mounting locations, etc. Getting close to nailed down at this point, I hope. https://dynref.engr.illinois.edu/aml.html
Small update, this hood setup takes awhile. Spend a couple hours every night working on it. I've used jacks and straps to tweak the rear bar just perfect and have built some plates. The plan is to use 3M 8115 to glue where the bars are touching and I have been adding plates to glue as well. I did a lot of research and I think the adhesive will be the ticket, just trying to get it all clamped at once will be tricky. Thought about screwing through the hood into the plates to clamp that way, not sure if having a hole to repair over top of dissimilar materials will induce cracking later on? I'd prefer to have it on the car while gluing just to ensure everything is in the correct location. Will cross that bridge this weekend hopefully if I can get the rest of the plates cut and shaped, and the final side supports done first. Heres and example of the plates, I ended up making this one smaller as that large of a plate is hard to get to sit correctly. For under the front lip, The hood has a natural curve up, between the rear main bar and cowl. I had hoped with the larger plate I could get it to sit flatter, but really to get it to work I would need to remove material and make relief cuts in the hood, just wasn't a great option. So I lowered the hoop down, and added another piece to tube to match the curve up and a smaller gluing plate at the back. The main middle bar and this extension all sit tight in the center bead, so should keep it sturdy. Even just sitting on this frame the hood feels solid, I think it should work out ok. Also welded in the front plate. I added dimple for rigidity, though the will probably make gluing a bit more of a pain. All the plates are 16 ga, so they give a bit and let the fiberglass move if needed but also hold it in place. Should look pretty clean when its all finished and painted. I'm going to add a few more plates and the rear/side tube braces, then start gluing.
Found this online posted by the last owner, pretty slick looking back in the day. I had asked for old photos but haven't received any yet, so seeing this one is pretty cool from back in the day.
Just FYI, we use adhesives for attaching any metal brackets, etc. to fiberglass hoods for production pieces of construction equipment all the time where I work. I don’t believe it is a 3M product, but can’t remember. I know I used it on a custom fiberglass hood I built for our hot rod marketing tractor a few years back and those pieces are all still holding on well too. As long as the right adhesive is used, I have never seen the joint come apart unless the glass actually broke and the fiberglass came apart.
Good to hear. Everything I read when searching adhering fiberglass to metal said the same thing. I found that lots of the "wide body" guys glue fiberglass flares on their cars. Seems like a hack thing to do to me, but it seems to be widely accepted. I got the 3M stuff as I knew from research that it bonded fiberglass to metal, and it was available as some other stuff wasn't able to ship, or they marked it up too much.
Methacrylate style adhesives should suit this job perfectly. Here is a comprehensive guide from Plexus on applications, they have quite a range of products for bonding dissimilar materials. https://www.google.com/search?q=Ple...&hl=en&sa=X&ved=2ahUKEwidx5ealLDuAhVPFzQIHTqO
Got the frame part all done and glued this weekend. Doesn’t look like much but took quite some time to get it right. You can see how the catches work on the side. The hood does have a good curve when new so this ensures final fit with the doors when closed. Obviously the firewall part will have to be finished and cleaned up when I’m test my hood tilt and make sure this will work. All glued together, got it in place and clamped with hood on car then removed to clamp the rest of the areas. Hopefully will have the right shape when stuck back on. Lol.
yeah. I ended up using the whole tube as well, I thought I’d have lots left, but the fiberglass took a lot as it’s pretty rough on the inside. I wanted to hold in the front really well, along with a couple of rigid and flexible areas. I think it turned out ok. The garage heat is cranked and I’m not looking at it for a few days. Hopefully get my linkage figured out and finalized next week and call the hood done until it’s body work time.
Honestly I'm not too into tri 5's but your fab work is badass and I'm loving this car. Yeah not my personal power train choice but makes sense for you and everything else just makes it so easy to focus on that.
Front end is all stuck together, seems pretty good. still manageable to lift by myself. fits like a glove as well. I’ve moved to the hood tilt, still waiting for parts but I built some adjustable brackets. Just some flat tabs and angle iron, nothing too fancy. Should give me enough room to experiment to get it just right. flat 1/8” Nothing fancy but functional Brackets tacked in place the hood fit looks pretty darn good, happy with it for sure.
Well I’m close but not close enough. Hood tilts exactly as planned... just needs to go out a bit further. It doesn’t quite fit far enough forward, or if it could just keep rotating, but it hits the frame, which is stopping it. To make one small change, I need to consider the whole thing.. so back to drawing board to figure it out. Also I started with three links, I thought the poly bushings would resist flex enough, but there is a tad bit of wiggle there, so I think I’ll go with a four bar setup. Frustrating, I tried lengthening bars but you induce bind if everything else doesn’t match. I’ll see if this video works. I cut the frame horns off hoping it would be enough but it’s pivoting at that spot, so I need it to continue to arc below frame rail then twist, or further ahead.. Not too far below the frame either as it’ll just hit the ground. It sucks when things aren’t perfect off the bat on the first try lol.
Thanks it’s close, but the dilemma is the bottom part of the fenders will be smacking my head lol. It looks more manageable than it is but the car is on stands currently too. The other problem is I don’t want that initial action of the hinges to come any further forward and get closer to the tire. I mostly need to figure how to get the last action either down further or out further or a small combination of both. like I said it is so close, it works exactly like I planned it, but I found it difficult to plan for the front clearance part. Here’s a closer picture of the linkage. The middle bar was testing to try to get the front mount longer and lower but didn’t work. ended up binding. The centre part needs the two mounts further apart than in this picture as well, to be more stable in the travel. im going to go with a wishbone top link, so I can still use the top bar for mounting and the center of the hood. just a little bit to figure out and it should be good. Hopefully.
Finished the new upper link last night. everything takes so long. hopefully this weekend I should have it all tuned up. I’ve increase all the link lengths 40% which will should give it 4” more at the front. I will probably also reduce the angle of the stationary mounts and lengthen it, which will bring it down slightly and decrease the increase this will bring to the angle of the first stage of the tilt. I think I probably will increase the hood separation points fore and aft to add a little more stability. All this could make it work great or not at all lol. At the view in the video it wasn’t too wobbly, but there was a little twist so I think the wishbone will be the answer for that.
Not much to add, I did change up the brackets and trued them up to make it even. Works a bunch better, found out where I messed up and fixed it. I also made some frame horns, using the original frame horn ends for the end round part. Added some zip tie brackets for running the headlight harness, as well as trick tabs for future use on rh side, for AC and heater hoses I think. Almost forgot about shocks on the front so welded up some brackets for them today as well. Finishing up some small things maybe the wheel tubs and trunk, and separate the body again and get this frame cleaned up and painted.
Great Thread! I really enjoyed your model A thread and just found this one. Awesome fabrication skills. I used the Welder Series parallel 4 link and their universal transmission crossmember on my 59 Chev truck project. Great kits and it was actually about the same cost as rebuilding/replacing the leaf springs when I priced it out.
Nice work and project photo coverage, I think I would rather see this sort of stuff than finished cars, this no doubt caused more than a few sleepless nights.
The Jalopy Journal
