calZ Posted February 22, 2022 Share Posted February 22, 2022 14 hours ago, 240Z Turbo said: For new panels I am welding in 2" increments for increased rigidity. I also plan to add additional welds to the lap joints as well as TIG braze the seams with silicone bronze. Once the unibody is finished with all of the patch metal repair I plan to have a custom cage built. Ah, that'll do it. I was going to say it you were not going with a cage, having the rockers off would give you a good opportunity to add some interior tubes for strength. Probably a good idea to have a cage in a 240Z with 600hp anyway. Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted February 22, 2022 Share Posted February 22, 2022 1 hour ago, calZ said: Ah, that'll do it. I was going to say it you were not going with a cage, having the rockers off would give you a good opportunity to add some interior tubes for strength. Probably a good idea to have a cage in a 240Z with 600hp anyway. 100%. even if you are less concerned with the primary purpose of the cage (safety), strengthening the chassis is a must at the torque you are looking at. To be clear, the torque is the “problem”, but everyone just asssociates HP with torque 🤷🏽♂️. Close enough I guess. the 240z chassis is one of the lightest (and flimsiest) Nissan has made since. I saw significant body flex even at 300ft-lbs. the sheet metal is nearly 20-gauge, which you can “tin can” with your bare fingers. I agree with @calZ that you should absolutely look at opportunities to stiffen the chassis. I have some ideas if you need help getting started. Quote Link to comment Share on other sites More sharing options...
Alexander240z Posted February 22, 2022 Share Posted February 22, 2022 18 hours ago, 240Z Turbo said: When do you say enough is enough? I guess the answer depends on how much time and effort you want to put into the project to treat the rust. My next step will be removing the door hinge mounts because they are rusted on both sides. This requires that I remove the dash so I can drill out the spot welds from the inside of the car. I will sandblast them and then treat them with POR-15 before welding them back into the car. It looks pretty bad, but it's mostly surface rust. Ah man I know the pain. Are you planning to work on the upper rails that run along the engine bay (I think they are called horns? correct me if I'm wrong)? The corner where the driver side fire wall meets the shock tower support sheet and the sheet of metal that connects the door hinges was completely rusted out for me. PO did some botched work that you guessed it made the rust worse. Then the car sat on the side of the road in Chicago 👌. I didn't go as far as you did for the piece that you just took off. (I just POR-15 and let the paint spill towards the bottom). You are doing the better route. Keep it up. I didn't like how Nissan didn't include a weep hole (at least I didn't see one and no, open seem welds don't count as weep holes!). They did for the front where your hood hinges bolt on to. This made is so that the water would just go down the horns and into the seams where it meats the column that supports the door hinges and then straight down into the inner and outer rocker! Water also came In through the top and along the seam where the weather strip is supposed to be. So much for that 😕 Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted February 23, 2022 Share Posted February 23, 2022 I have replaced 30% of the steel on the race car. The issue I see is all the unprotected lap joints. There are many that are facing areas that would naturally have water splashed onto them in wet weather, or drip-down through them like the cowl. Once water gets ON a lap joint, it gets INTO the overlapping steel by capillary action (like a wick) where it "sits" and starts rusting the steel. All it takes is for the primer to fail at the lap joint, which is very common with overlapping steel that is only being held-together by spot welds. Rust needs a steady feed of moisture and O2 to continue deteriorating. The problem is the more it rusts, the more porous the surface becomes. This accelerates the oxidation over time. Once rust is formed, it will "hold" moisture like a sponge and keep feeding the raw steel the steady diet it needs to turn from grey to red. If it makes you feel any better, It has been one full-year of rust repair on this car, with around 4-6 hours spent per week. Then you have to replace all the fastener attachment points and check fitment, which takes several months as well. The one lesson I have learned over and over = Just remove everything and methodically plan ahead. I have tried to "limit" the scope of repair/work multiple times before realizing it is a huge loss in efficiency. If it is bad enough to damage multiple surface is several directions, just cut it all out, start from scratch, and consider primer-ing the whole area when done. you can scroll the progress on IG @240z_restomod or scroll through my dedicated thread on this forum, if you are looking for ideas on tackling a similar repair Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted February 23, 2022 Author Share Posted February 23, 2022 19 hours ago, AydinZ71 said: 100%. even if you are less concerned with the primary purpose of the cage (safety), strengthening the chassis is a must at the torque you are looking at. To be clear, the torque is the “problem”, but everyone just asssociates HP with torque 🤷🏽♂️. Close enough I guess. the 240z chassis is one of the lightest (and flimsiest) Nissan has made since. I saw significant body flex even at 300ft-lbs. the sheet metal is nearly 20-gauge, which you can “tin can” with your bare fingers. I agree with @calZ that you should absolutely look at opportunities to stiffen the chassis. I have some ideas if you need help getting started. My previous twinturbo L28 setup made 509ft-lbs@wheels without the 125 shot of nitrous. It was a stock unibody with frame rails connecting the front and rear along with an 8pt cage, which didn't seem to have any structural issues. Therefore, I don't think 600ft-lbs@wheels will be a problem based on my approach. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted February 23, 2022 Author Share Posted February 23, 2022 16 hours ago, Alexander240z said: Ah man I know the pain. Are you planning to work on the upper rails that run along the engine bay (I think they are called horns? correct me if I'm wrong)? The corner where the driver side fire wall meets the shock tower support sheet and the sheet of metal that connects the door hinges was completely rusted out for me. PO did some botched work that you guessed it made the rust worse. Then the car sat on the side of the road in Chicago 👌. I didn't go as far as you did for the piece that you just took off. (I just POR-15 and let the paint spill towards the bottom). You are doing the better route. Keep it up. I didn't like how Nissan didn't include a weep hole (at least I didn't see one and no, open seem welds don't count as weep holes!). They did for the front where your hood hinges bolt on to. This made is so that the water would just go down the horns and into the seams where it meats the column that supports the door hinges and then straight down into the inner and outer rocker! Water also came In through the top and along the seam where the weather strip is supposed to be. So much for that 😕 The driver's side, in general, is in pretty good shape so the only things I see that need to be replaced are the outer rocker, lower b pillar, dog leg and the bottom portion of the outer wheel well. As best I can tell the inner rockers, floor pan, firewall and "horns" are in good shape. For some reason it is mostly the passenger side that took a beating due to rust. The horns on the passenger side appear to be in good shape, but I do have to replace the lower firewall, battery tray, battery area outer wall, and frame rail. However, I need to get the structural issues on the front pillar addressed along with the installation of the floor pan before I can stick the car on the dolly and start addressing the other rust I discuss above. If you have rust that is hard to access and you don't want to open up a can of worms, you can purchase "cavity wax" that you can spray into hard to acess places and liberally coat the entire area to neutralize the rust. I did consider this, but the surface rust appeared excessive so I took the next step to address. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted February 23, 2022 Author Share Posted February 23, 2022 (edited) 15 hours ago, AydinZ71 said: I have replaced 30% of the steel on the race car. The issue I see is all the unprotected lap joints. There are many that are facing areas that would naturally have water splashed onto them in wet weather, or drip-down through them like the cowl. Once water gets ON a lap joint, it gets INTO the overlapping steel by capillary action (like a wick) where it "sits" and starts rusting the steel. All it takes is for the primer to fail at the lap joint, which is very common with overlapping steel that is only being held-together by spot welds. Rust needs a steady feed of moisture and O2 to continue deteriorating. The problem is the more it rusts, the more porous the surface becomes. This accelerates the oxidation over time. Once rust is formed, it will "hold" moisture like a sponge and keep feeding the raw steel the steady diet it needs to turn from grey to red. If it makes you feel any better, It has been one full-year of rust repair on this car, with around 4-6 hours spent per week. Then you have to replace all the fastener attachment points and check fitment, which takes several months as well. The one lesson I have learned over and over = Just remove everything and methodically plan ahead. I have tried to "limit" the scope of repair/work multiple times before realizing it is a huge loss in efficiency. If it is bad enough to damage multiple surface is several directions, just cut it all out, start from scratch, and consider primer-ing the whole area when done. you can scroll the progress on IG @240z_restomod or scroll through my dedicated thread on this forum, if you are looking for ideas on tackling a similar repair Thank you and I will check out your thread for different ideas. As you mentioned, part of the challenge when removing the panels with the spot weld cutter is that you have a big gaping hole in the panel. My cutter is slight under 3/8" so I purchased box of 100 #8 washers that are 3/8" OD and 20g thickness from Lowes. I used a step drill to slightly enlarge the hole and then pressed the washer into place, which then allowed me to easily TIG weld the washer to the panel and grind it smooth. This was after hitting the metal with a wire wheel and neutralizing the rust with the POR-15 spray. I also sand blasted the hinge cup prior to spraying on the rust neutralizer. Edited February 23, 2022 by 240Z Turbo Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted February 24, 2022 Share Posted February 24, 2022 @240Z Turbo ah! I think we miss understood each other. I was advocating for stiffening the chassis if you did not plan to run a cage. Your past example included a an 8pt cage which certainly checks the chassis stiffening box. No worries! Going to sound crazy, but I have yet to use a spot weld removal tool. I simply removed the lap joints all together with a cut-off wheel and replaced them with a full-seem weld. Ground the weld down with a die grinder. When removing one layer of steel but keeping the layer behind it (like on a welded tab), I use a die grinder to carefully eliminate the material holding the spot weld to the first sheet, and pry it off with a screwdriver. Then I grind the surface more or less flat with a flap disk and fill any small holes with the MIG. So far the only “holes” I had to fill where the floor pan drains and firewall holes like the heater bulkhead. In those cases, I just approximated the disk out of 20-gauge, welded and used a flap wheel yo make it flush. nothing wrong with the spot weld removal tool. I just didn’t want to deal with Swiss cheese. Also, this ain’t a street car so not too concerned with eliminating the OEM-looking spot welds. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted February 24, 2022 Author Share Posted February 24, 2022 ^ I'm not opposed to doing butt joints and in many cases that is the only option. However, a lap joint will be stronger than a butt joint so I prefer to use this approach when possible. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 1, 2022 Author Share Posted March 1, 2022 Got the door hinge cover back on with everything rust treated underneath. I mocked up the door with the fender and the alignment looks great. I even coated the inside of the window pillar with rust treatment using a long tube so it would reach up to the roof area. Just need to finish stitch welding and then I will move on to replacing the passenger side floor. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 3, 2022 Author Share Posted March 3, 2022 I finished the door hinge cover and it actually turned out very nice considering I've never done this before. Just taking my time and not over grinding the metal gives a nice result. You can barely tell where I stitch welded across the top, but once the body work is done it will be perfect. Moved on to mocking up the new floors on the passenger side. I really like how the KFV pans go up the wall of the trans tunnel. Gonna take my time fitting it in place, but I hope to have it knocked out this weekend if possible. Quote Link to comment Share on other sites More sharing options...
Exposed Posted March 4, 2022 Share Posted March 4, 2022 Great progress and quality of work. Enjoying the build, keep it up Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 4, 2022 Author Share Posted March 4, 2022 2 hours ago, Exposed said: Great progress and quality of work. Enjoying the build, keep it up Thanks and I have some more pictures to share. The DCT trans arrived at my buddies shop and this is the trans just placed behind his VR38 engine for giggles. He already has the VR38 CAD file for the bellhousing so he just needs to create the DCT pattern and then overlay them. The other challenge will be coupling the crank with the DCT input shaft, but should not be too difficult. Is it me or is this a marriage made in heaven? Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 5, 2022 Author Share Posted March 5, 2022 In preparation for installing the floor pans I had to cut out a portion of the rear floor towards the outside of the car. There were a few spots the metal had rusted through so I cut out the old piece and spent about 30 minutes hammering out a new piece of similar dimensions. Although it had a few compound bends I was able to get a close match. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 6, 2022 Author Share Posted March 6, 2022 (edited) The passenger side pan was installed and I'm about 80% complete. I purchased an air powered tool I saw another member using that can punch 3/16" holes in the metal and also offset the edge of the metal to create a smooth lap joint. I spaced the 3/16" holes every 2" and locked the pan in place with some clecos and then MIG welded the pan through the 3/16" to the body. I have a few of the holes that I need to somehow pull the trans tunnel metal to the new pan so there is not gap prior to welding. At some point I will TIG the edges in 1" lengths every 2" for increased strength, but not sure if I want to do that now or wait until I have it on the rotisserie where I can get better access. Edited March 6, 2022 by 240Z Turbo Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 7, 2022 Author Share Posted March 7, 2022 Replaced another rusted area so getting closer each day. The next item on the punch list is the lower B-pillar, which I hope to knock out in the next 2 days. Following that I have a major challenge ahead of me so any thoughts are appreciated. The frame rail, battery area, and firewall are all rusted as you can see from the picture below. What order should I approach this to ensure it stays aligned? Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 11, 2022 Author Share Posted March 11, 2022 I refocused on the floor pans to stitch weld the outer edges. There were a few areas that required me to pull the pan and trans tunnel together prior to welding through the 3/16" hole so I used some 1/8" bolts. When finished you just remove and MIG weld the hole. There is an area in the back of the pan towards the trans tunnel that had a feature in the pan that did not exist on my car. This weird hump would not allow me to properly fit the pan to the trans tunnel. I ended up cutting out that portion of the pan and reshaping it to the car. You can look at previous pics I posted to see that weird hump in the pan, which is how it came from KF Vintage. Not a big deal and took about 45 minutes to correct. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 12, 2022 Author Share Posted March 12, 2022 (edited) I was bored so I decided to TIG braze a small section under the fender that has an exposed seam from the factory. I used silicone bronze, which doesn't require that you melt the parent metal, but hot enough to melt the silicone bronze and it fills the seam nicely. I forgot to take a pic of it after minor grinding, but it makes the seam perfectly smooth and with no ability for water to enter the seam. When I remove the fender and door again I'll snap a picture. The next task was to weld in the new lower b pillar that was rusted out and tie into the new outer rocker. After a few test fits followed by a bit of grinding, I was able to get the new lower b-pillar replacement mocked up. And the finished results. The door is actually pushed back further than it would normally be, but the gap is pretty close so I can manipulate that once I put on the fender and get the gaps perfect. Edited March 12, 2022 by 240Z Turbo Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 14, 2022 Author Share Posted March 14, 2022 Deja Vu....I only thought the driver's side was better. The only thing better is it looks like the frame rail has a good rust free connection with the firewall. However, I have to replace all the same parts as I did on the passenger side, but doing it a second time is definitely much faster because I'm not guessing what to do. I'm going to remove the inner rocker with the floor pan in place this time to see if the car is more aligned. The back portion of the inner rocker is significantly more rusted vs the passenger side and the seat belt bracket that holds the nut is about 1/3 rusted so I'm going to have to figure out how to replace that because I don't see that it is offered anywhere. Of course I had to remove the hinge cover because it had a lot of surface rust and although a PIA to remove and replace, I think it's worth the extra work. The upper fender nut typically welded on the backside of the cover towards the top was gone and a big hole was torn into the metal. I'll post some pics later, but it will be a simple fix. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted March 16, 2022 Author Share Posted March 16, 2022 The process of repairing the door hinge cover will take about 5 hrs as I have to TIG weld in washers where the spot welds were removed in preparation for welding back to the car. The first thing I do is fuse the washers in place and then clean the surface to eliminate the zinc coating on the washer and prep the metal for welding. On the inner door edge you can't just weld in washers so I have to cut out the metal completely and weld in new metal and then drill new 3/16" holes for welding back to the car. It's tedious work, but it was worth pulling the cover to clean out and treat all the rust underneath. Quote Link to comment Share on other sites More sharing options...
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