58 Apache with C4 Flatout Engineering

[daveshilling]

Originally Posted by lexteak

Sorry, I got a big project last winter and had to hold off on the build. One more little project I hope to finish this weekend and its back to the 58 project. I'll post again as soon as I get restarted. Thanks

Even if you never finish this one, I'm glad the IRS details and the angles of those half-shafts are preserved in this thread. Don's paper instructions could definitely use some freshening up.

[lexteak]

Ok boys I'm back at it with a vengeance. Lots of stuff sidetracked me over the last two years. I retired since the last post and am currently under lock down here in Omaha, so its now or never. I just wasn't thrilled with how the modified frame was going. Attaching the new section was problematic boxing in frame was not very clean and filling the 200 plus holes was going to be frustrating. I decided to build frame from scratch. I picked up a super heavy table to use as platform, and am now starting to build out the to side frame rails. I used my old frame, attached the bed and cab rolled it out of garage and got all measurements I needed. I will be building the frame rails from 2x6 tubing and transferring Flat Out kit over to the new frame. Just some preliminary pictures to show you were I'm at on the restart.

[Rickysnickers]

Wow, impressive undertaking!

[dsraven]

frame dimensions are in here.
looks like fun to me.

https://www.trifive.com/55-59Assy.pdf

[lexteak]

Thanks I do have the assembly manual with the frame specs, very helpful. I got the rear frame rail sections tacked on and I mounted both rail assemblies to the table. I imagine it will be on and off a dozen times or so until final frame assemble. Going to have to give thought today about sequence of events. I think for today i'll get everything level and square and drill 4 locating holes for pins. That way I can take it off and on and keep original location.

[dsraven]

not sure what your overall plan is but a lot of guys seem to want big fatties on the rear and so have tubbed their box sides and some have made the frame narrower. if that is your plan it would be pretty easy to do at this point of the build (the narrower frame). I wonder sometimes because guys will cut the front end off and weld in a sub frame, then cut the rear end off and make their own C notch or narrow the frame back there. really, the only stock part of the frame is where the cab is bolted down. overall, that is a pretty easy thing to match up if you just built a new frame, like you are doing.
I am sure you have a plan going forward but don't forget about the little things like where will the exhaust route through, where will the shocks mount up etc. I have seen a few builds where they get to the little things and go "ahh, crap. no space for the exhaust".
do you have a plan for the rear suspension? leafs, 4 link with coils or bags, etc? just curious. looks like a nice set up you have there.
another thing to consider is possibly.
good plan on the pin idea. I was thinking possibly a dowel set up welded into the frame on 4 corners so that a tight fitting pin could be slid into the dowel in order to eliminate the possible slop from a regular bolt or pin. some tabs on the outside of the frame would keep the jig effect square. looks like you have it under control though. please post pics as you go, you have me hooked now, lol. I was going to do that for my 57. I did a frame swap instead, with a bunch of other stuff added just to keep me busy for about 12 years now, haha. seems like something always comes up to take my time and shop space. i am sure you know the feeling.

[dsraven]

these guys have a web site that shows how they do their frames. nice stuff, I have seen their shop. lots of thought went into their frame. some stuff is hidden inside the frame, brake lines etc. just hope there is never any service required or they would need to be clamped on the the outside of the frame as a repair.

https://www.canadianhotrodsinc.com/frames-chassis/

[dsraven]

I like the stiffener that runs down the middle. just an idea for you.

https://www.canadianhotrodsinc.com/p...chevrolet-gmc/

[dsraven]

pic 5 shows how they did their rear corvette suspension mounts, if interested.

https://www.canadianhotrodsinc.com/p...chevrolet-gmc/

[lexteak]

Thanks guys tons of info and ideas for me to sort thru. As far as narrowing, I think when I mocked up I had plenty of room for my tire size. I want something big diameter, maybe 29-30 inch diameter, but I plan on driving this all the time so probably not to wide that it wont fit. I really like the design I saw on the No Limit engineering site. They have a c10 frame that looks great. I plan on basing my design on that. I ran into the first issue today. The Flat Out Engineering cross member is based on the stock 2 1/4 frame rails and the boxing plates. Im about 1/2 narrower because i used 2x6 tube. Trying to decide if I shim that out and stay stock or narrow the whole frame 1/2. Have to decide what that does to the rear. I will already be remaking a set of brackets because the new frame is slightly different shape. Here is the stock frame contour on the front in cardboard layed over the 2x6 . I think I have to notch it to create appropriate clearance for control arm travel. Probably combine that notch and the tie rod notch together. Wore my tape measure out again today.

[lexteak]

That center frame stiffener is almost exactly the same as the no limit engineering frame. That will be close to my final design. Ive seen a few come off the side rail and return back and also some that end in a perpendicular connection with the rear cross member. Still undecided at this point. Mine will be very similar either way.

[lexteak]

That stance on the truck in the picture is close to what I want. The Flat Out left the rear to high for me. That is when I originally decided to remake the rear section to get it lower. Looks like they solved that issue by mounting it higher in the frame. Essentially that is the same thought process I have on the higher rear section. Great info thanks for the links

[Jason 56]

Complete frame is a good idea. I did the same on my 56 with a helix IFS kit. I just tapered the front. I have a lot more pictures than what are on my build if you’re interested... just let me know. Big thing is not to weld on the sides of the frame( just top n bottom) until the cross members are in place. The cross members will prevent the heat from pulling it out of square! Wish I knew that when I started!

[lexteak]

Thanks Jason great info on the welding, I will definitely try and remember that going forward. Scanned your build looks great I will look it over in detail next few days, If I have questions I'll give you a shout. I took a look and it seems the front frame is for the most part ok being a 2x6 all the way to the front, except for the core support mount. I plan on leaving it that way and dealing with any problems later down the road. If i have to notch the support or make a
smaller frame section at the front I'll deal with that once I start fitting the fenders. Appreciate the help, please shout at me if you see me doing anything stupid. My first build and I'm blundering my way forward.

[dsraven]

in post 85 it looks like you have a template stuck to the side of the frame and the contour would indicate that you need to cut away a bit of the frame on the under side plus you say you may go a bit deeper there to accommodate the control arm travel. you also say the new frame is possibly 1/2 inch too narrow outside to outside, if you make the inside to inside dimension like the stock frame, and this is due to the size of the tubing you chose. if that's what you are up to, and you need to add 1/2 an inch to the outside overall dimension, then why not simply cut away the section you need to make the contour correct on the under side of the rails and then when you replace that section use steel flat bar bent to fit to fill the gap in the box cross section, then use some 1/4 inch steel plate up the outside of the frame to give you that added 1/4 inch per side. that solves the outside frame dimension issue where the cross member is welded in and also adds a bit of strength in the area at the same time. especially if you make the side plate a bit longer than the cut away required so the stress is paced over a longer section of frame. bear in mind that if you don't want to make new cab mounts for the front you could put the frame wider to match the original outside dimension and then do the same theory on the inside of the frame to add the material so the cross member fits properly there. this would possibly mean less work fabbing on the other affected parts down the line like cab mounts or rear suspension mounts etc. when I was in the TCI plant and also the Canadian Hot Rods Plant I noticed that they make their frames from flat sheet. each side rail is cut to the contour and welded to the top and bottom parts and then ground smooth to form a tubular frame. if you used that mentality you could get the contour you want in the cut away section plus add strength to the area where the cross member sits. 1/4 inch per side equals 1/2 inch overall width added like you need. a bit wider inside frame would mean a bit more room for the steering column shaft and also things like exhaust etc. I know, it's only 1/4 inch per side. lol.
for front cab mounts I assume you will be fabbing up your own, if you go with the original inside width of frame, so adding the extra width to the mounts wouldn't be a big deal because you are starting from scratch anyway. the ones I have seen were simply made from square tubing and looked great. if you went with the frame spaced apart to match the outside dimension then you could use the original cab mounts. for rear suspension mounts I also assume you will fab something up to fit the corvette stuff. the Canadian Hot Rods brackets look good so you could likely fab something like that from a mental pattern. there are other prefabbed ones available but not if the frame width is narrower. same for bumper mounts. you may need to drill the box mounting holes to fit but that is also just a hole you need to drill a bit different than the original ones. possibly run a tube through so when you bolt things down the rectangular tubing doesn't crush or "give" some over time. rad support brackets would be included in the "mount as required" category. the frame may need to be tapered for the rad support brackets to be at the correct height or fab some new brackets with slightly less rise. as long as the sheet metal clears the frame without trimming. again, if you're fabbing a new frame a couple of brackets shouldn't stall the assembly line too badly, lol. the drop dimension from the cab mounts to the rad support mounts is in the assembly manual drawings. this is sort of a critical dimension since that is how the door to fender gap and hood to cowl gap is established. too low of a rad mount would be better than too tall of a mount because you can always shim to get the fit correct then. since you have the old frame plus the drawings from the assembly manual you should be able to figure it all out. I think that dimension is based off the top of the frame rail. the rear cab mounts simply bolt through the cross member so that should stay the same no matter the frame width.

dunno if any of that jibberish made sense. hope it gave you some ideas.

[dsraven]

disclaimer:
when welding a "fishplate", like I kind of suggested to take up your gap, there are theories on how it should be done. most pro welder guys who do truck frames etc seem to cut a plate with angled ends then tack weld the fish plate in, then when they weld the sides of the plate they run the weld out and past the end of the fish plate in an arc so the cat's tail run off weld is not inline with the main weld. this is to prevent stress risers at the fish plate due to the heat affected zone when welding.the fish plate angles do not meet at a point, they leave a section intact at the end of the plate that is just squared off (rounded off actually). some larger fish plates have holes cut into the main part to allow welds to be done in the middle of the plate as well. there are a bunch of theories around the whole thing but most that I have seen are on big equipment and the ends of the fishplates are diamond shaped, so angled in on the ends, and they get welded almost to the end of the diamond then the weld takes off onto the base metal part and arcs away. i asked a welder waaay back in the day and he said " you never weld all the way around the end of the diamond and it is to allow for expansion and contraction of the metal when welding. he called it the haz, heat affected zone. the theory also says not to use a thicker material than the base metal because it can also cause stresses from not moving the same as the thinner base material. use your own judgement on that i guess. one thing I would say, since I have boxed in a frame or two, is to bevel the edges well to allow full penetration of the weld and to weld in short lengths and allow the area to cool before doing another weld in that area. otherwise the expansion from the welding heat and contraction after will warp the frame. one guy I talked to said he lets it cool to the point where he would hypothetically be ok to put his tongue on it. that's room temp I guess. I always weld a bit here and there all over the frame, when I do boxing, in order to let things cool off well everywhere.
anyway, dunno if that just confused you more or not. hopefully not.

[slammed57]

coming along nicely , I'll be following

[lexteak]

Thanks For all the info. Great stuff on the fish plate welds. I will research that some and get a better visual. So I thought about the frame width last night. I think I am going to narrow it the 1/2 inch. Here is my reasoning. It makes the front cross member fit as designed, I still need to trim the bottom and box in for the control arm (either way). The cab mounts will be easy, I can fab like you suggested or just recenter the mounting holes. Rad support will be a fab of some sort, width should not be any additional complications. Rear bed mounts will also be fabbed since I dont plan on dropping the frame back down after the axle. The rear kit I have from flat out is the main consideration. It has 3 brackets. I included some pics. The Corvette IRS batwing mount is the first. That will have to be remade, but it was already in the works, because it is designed to hug the downward slope of the frame after the axle and mine is parallel to the ground. The coilover mount will not be affected at all. The 3rd bracket is the dogbone support. That I think will work in my favor. I will narrow the frame, but end up plating the joint in the rear, so that should put me back to roughly the same width as before.

I have a second truck that I am using for reference, it helps a lot. Long story on how I ended up with two. I will probably sell it but for now it is a great visual reference when I have to plan out stuff like this.

Thanks again for info, I'll post some more stuff tonight or Friday of my progress.

[dsraven]

your second truck looks nicer than my first,haha.
Imanaged to move some stuff and pressure wash the floor today. I can see the concrete now. lol. it's unreal how dark it can be when the floor has black primer dust on it. seems to suck up the light.

keep posting pics as you go, really interested in how you do stuff. I was going to build a frame as well so you have peaked my interest.

[lexteak]

Thank you sir. I shimmed the frame in on table narrower by 1/2 and mocked the front cross member. It fit perfect. There is a step notch in the Flat Out Engineering CM that indexes on the bottom of frame. (see pic) I brought it up to bottom 2x6 and mounted all suspension. I get 5+ inches up upward travel and 3+ going down. That is before the control arms start to get really close to the frame. I think that will work. So by doing nothing to the frame, I just raise the front Ride Height by the one inch because of the original frame contour. My driveway mockup was really low in the front, so I can live with an additional inch up. The high ass end was my dislike and the reason I originally started with the new frame back half. After that I still had a little momentum so I tried to figure out the notch for the front tie rods. You cannot get the rack anywhere close to its mounting home while in the frame. So I pulled the CM and mounted it to my welding table. Ran the rack to extreme left and right and the suspension up and down and measured location for clearance. I think I have it figured out. Flat Out give you a half pipe boxing tube for this cutout. With the location now known it seems a no brainer to cut it out and move to the rear mockup. Thanks for you interest, nice to have a second set of eyes. Jay