BlackBeaut

Is this the sort of thing you mean John? My MIG is natch not a pro model so I guess it does the short circuit arc transfer. How would you recommend coping with distortion? I was going to put a few tacks on first before giving it large. I was also thinking of doing some cunning bolt/dowel set up so that the parts are held solidly in place togther to start with. This is only one joint in the finished piece, which will be made up something like this: So I was thinking of tacking all the parts together first in the hope that would combat distortion. Have I been sniffing too much welding fumes again? Cheers, Rob

Cool, thanks guys. Should've said it'll be MIG welding on mild steel as that's what I've got and can just about cope with. Seems like I've got some major grinding ahead of me then! Cheers, Rob

Hi all, Looks like I've set myself up for a big job with the welder in the near future. I'm looking at joining up 18mm thick pieces like this: I believe the thing to do is grind away the edges to be joined to allow greater penetration, which looks pretty straight forward for the outer edge of the joint. I've heard/read that 30degrees is the magic angle to grind to: But what about the inner edge of the corner? Do I just build up a big bead like this: Or should I also grind away here to get better penetration, and if so what angle should it be ground to in this situation? Or...? Joint strength is paramount here, so what's the best way forward? Cheers, Rob

D'oh! I got everything mounted up on the car yesterday to check the fit, and discovered off course that the fore-aft bars won't fit due to body interference. Only a couple of mm off mind but enough to totally screw things up. So after a bit of swearing I decide I would move the rod end points on the rear frame inward slightly. Well by 60mm each side actually, I figured I might as well get them in as much as possible without interfering with the diff. There was another issue caused by me not remember exactly how the rear frame located to the chassis rail, as it it's practically flush with its rear edge. This meant the rod ends where not free of the chassis rail so fitting the fore-aft bar wouldn't be too easy. So I decided to move the rod end mount point an extra 30mm forward. Hopefully now when I get it all back under the car things will fit and my neighbours won't be forced to blush Cheers, Rob

Minor progress. I've made and welded in the threaded inserts to take the rod ends on the rear frame: Used a bit of scrap tube to check that it'll work and the top bars will be able to get in to the right positions. And made up some little spacer things that will keep the rod end centred in the tubing and stop things rattling too much. I'll weld these suckers on to the top bars. Annoyingly I'm away this weekend so I won't be able to get the top bars made up and trial fitted. First I need to clean off all the crappy undercoat on the frame rail so that I can seat the rear frame solidly to get accurate measurements, time to dig out some scrapers and a few choice grinder attachments me thinks! Cheers, Rob

When you're moving the torch along do you feel like the wire tip is constantly bouncing of the metal pushing the torch back in your hand? If so the wire speed is too high, if not and you've got an nice even burning arc then pretty much the best you can do is move along the join quicker. It helps no end that the areas you're working on are non-structural. Once the pieces are in place you'll be grinding the beads down and no doubt adding a little bondo stuff to smooth the works out, so it'll look great in the end. BTW are you putting little tack welds along the join an inch or so apart before going back to do the full length weld? Anyway, you'll definitely get there and pick up a useful skill on the way. Cheers, Rob

I'm pretty new at the welding game, only been working on thick steel really, body work yet to come. However this bit: "i have wire speed up to full blast" stands out, you should adjust the wire speed to suit the job - granted it may be in this case that full speed is the appropriate speed. Have you done any practice beads on bits of scrap metal of the same gauge so you can get the power and speed settings just right? What gauge metal are you using? 24 sounds very thin, like I said though I haven't got to body work yet so I may be in for some fun myself! Another thing is that you're doing butt welds which are pretty much the hardest as there isn't the metal around to soak up the heat and so blow through is difficult to avoid, however in the places you're working on I don't think it'd be possible to do a joggled overlap join. Finally, as I suspect you know, flux core wire doesn't produce the nicest welds to start with, and it burns hotter so more chance of burn through. Ideally you want to be running with gas, thin wire - 0.6mm/0.023" - and practice a bunch on scrap. Cheers, Rob

Eeep! Are they 2.1/2" I/D springs Jon? I'm going to be using 2.1/4" (just more common over here) which would in theory produce worse results quicker than 2.1/2". Granted for the time being I'll be running them with the stock rubber mounts so the top perch should move in relation to the bottom perch. Hmmm, food for thought! Cheers, Rob

Nice explanation John, thanks! Out of interest has anybody made up an assembly that has a female rod end simply screwed on to the threaded end of the shock which then mounts on to some cunning clevis thing bolted to the 3 original mounting holes? Seems to me like it would work, might change the pivot point location at the top by a few millimeters, don't know how critical that is. The only real downside I can see is that if you've got adjustable dampers with the adjuster at the top of the threaded bit you're a bit screwed. Sorry for slight thread hijack! Cheers, Rob

Finished up the front mounts today: Think they came out OK. Also did a little work on the rear frame again. I welded in the 4 crush tubes and drilled some vent holes. I cunningly managed to snap the tip of the drill bit on the last hole though, so I now have little rattle to remind me in the future to do all drill of parts before assembly Cheers, Rob

Not had much time to do anything today which is a shame as it's been nice and sunny. Anyway, I've managed to get this sorted: I figured that I might as well bolt the front parts to my cross member as well as to the strap mount points, can't hurt to tie things in even more! Had fun assembling everything on the car and tack welding the bottom tabs on. First time I've welded in very limited space (cars on axle stands), boy what a fun new experience! You can just see on the far upright where I've notched it to fit around the exhaust hanger bracket. I also whipped 20mm off the top of them to give me a bit more room. One interesting thing I found whilst everything was fitted to the car was that the right hand strap points were 2mm further forward than the left ones - joy! Still 65mm apart I'm happy to say though. Hopefully tomorrow I'll get the top tabs on that the rod ends will sit in, and a supporting web between the two tabs and then this bit will be all wrapped up. Cheers, Rob

Just rustled these fellas up: And more remarkably they fit! I did 10mm holes at 65mm centres, so I guess I was lucky. I had been tempted to enlarge them to 11mm before trying, but figured why not see. Naturally I offer no guarantees that these measurements will work for everyone else Well OK, the right hand side (UK drivers side) fits no problems. On the left hand side there is interference with the exhaust hanger bracket, so I'll need to tweak the mount in that area to fit. I'm also going to reduce the overall height by an inch or so to give a bit more room up top for the rod end and bar. Just got to wait for a bit more material now and I'll be able to crack on. Cheers, Rob

Here's a quicky of what I'm thinking for up front to connect the diff ears up to the top frame: I had a slightly insane idea about fitting some spherical bearings in the upper frame and running a long bolt across and through the bushing, but I think I'll assign that one to the sanitorium, mainly because mounting the bearings in the frame will mean drilling big holes in them which will weaken the of course (even with chunky mounts for the bearings) and I can't find a 9" 5/8" bolt for love nor money. What I'll do instead is have a couple of cross bars running between the two longs beams and then inbetween those a couple of fore-aft pieces that I can hang the bush from: Cheers, Rob

I took my strap off last night so that I could do some measuring around there. From the results I've got I'd say that the dimensions given for the Ron Tyler mount should cope OK. I found the bolts to be M10 at 65mm centre-to-center. The holes in the strap mount are 11mm diameter, with one elongated to 13mm wide, I guess Datsun weren't too sure themselves Of course now I'm going to go back and measure the other side of the car to make sure! Tim, I like your idea of hanging the front using a clevis/rod end system. The one draw back for me in using the S13 diff is it doesn't have the big fat ears with built-in bushings, so I wouldn't have any damping up front. I've got a rough idea at the moment of how I'll add in a bushed mount that I'll render up later. Life would've been much simpler if I'd have found a big eared diff in the first place though! Cheers, Rob

Yep I appreciate that once it's in it should stay in and I can forget about it. The big advantage that I can see with this solution is that it's simpler to fabricate (well simple and me and fabricate are all relative terms of course ). The 3D render doesn't show things too well but the front end of things is around 2-3" lower (depending on how I make up the Ron Tyler mount) so we start having to deal with some awkward angles as things, erm, angle in to the end of the tranny tunnel. Using the rod ends means that they'll deal with the whole tricky angle side of things and I can just make the top frame on a flat surface then just bolt into place. Thanks Dan, I've really enjoyed getting my head around this one and boucing ideas of other people. I also find it quite amusing that after going through all this Dave at ARZ comes along and bangs out exactly what I was after in the beginning without breaking a sweat Well it's good to keep everyone on their toes. I actually work for a US company based in SF so I may speak a little more mid-atlantic English than most Brits, but it's always fun to throw in some weird little english saying to get the heads scratching Engine is stock L24 at the moment with a KA tranny on it in the near future. Plan is to stick with the L but hopefully work my way up until I get to a 3.0l stroker running EFI ITBs and any other fun combination of letters that'll make it sound flash! I'm planning on making the final connecting part that'll bolt to the two front ears on the diff and up to the top frame have a fair amount of adjustment in it, most likely I'll keep it simple and users spacer washers, so that I can get things like the pinion angle somewhere acceptable. Using my machined cross member I already have about 10mm extra room to play with under the prop compared to the stock member. This is a good point and I must admit I've been thinking of welding them in anyway (at the top at least where they're easy to get to ) If I do go with a hot zinc job then I'll need to add a few vent holes in anyway so it wouldn't be as much of an issue.

Been thinking about the top frame again. Think I've come up with a decentish idea making use of rod ends to connect things up, which means it should go together and come apart more easily too making installation a bit less of a work out. So four rod ends. Two up on the rear frame and two down on a modified Ron Tyler mount. Then a cunning frame work connects them which the front of the diff can be connected to. Cheers, Rob

My S13 200SX short nose R200 has a hole in pretty much the same place that the oil cooler return line was hooked up to. I've just stuck a bolt in to the hole as I'm not ready to be messing with oil coolers yet. I've got the large finned rear cover which will hopefully keep things quiet for the time being. Cheers, Rob

Yup, those are the ones Tim. Here's a pic of one of the inserts and one of the studs I made as well. Hand threading a M16 thread is a biatch! Plan is to plate the frame somehow then screw in the insert and over paint it all , probably with POR15 Glisten PC which should do a damn fine job of sticking it in place forever. I was reading up on hot zinc galvanising and it seems like frame structures like this need a vent hole in each otherwise sealed tube otherwise they might explode when dropped in the tank of hot zinc - nice, I'd be so happy if that happened after all the work I've put in Cheers, Rob

Hi John, My cross member is mild steel, rather than ali as it was planned to be welded to. I can send you the plans for it though if you want, then you can get a local shop make one up for you in ali? I suspect it would be a lot cheaper that way then having my local shop make it up and then sending it to the other side of the world Drop me a PM if want the plans. And thanks for the welding tip, I'll slap a bead round there the next time I'm welding. Cheers, Rob

Hi Owen, I've got the machined cross member to use up front. I had that made up as the original plan was to use a fore-aft pair of bars running underneath the diff to support it from below, like Tims solution, but I'm really liking the idea of isolating the diff fully now. I'll still use the machined front member as it gives more clearance for the prop-shaft and exhaust than the stock member anyway, plus I got it so might as well use the sucker! I remember checking out your front mount back in the day, it's a nice simple solution. For the Ron Tyler mount check this thread: http://forums.hybridz.org/showthread.php?t=95128 It's primarily designed for the long-nose R200 but as it provides a good mounting solution at the front I'll work up something similar. Cheers, Rob

I so don't want to weigh it!! It's definitely hefty, getting it into place under the car makes me regret not going anywhere near a gym for too many years, but it sure won't take no sh*t from nobody! At least it's sprung mass anyway! Here's a rough idea of an overhead frame connecting to Ron Tyler type mount, that should fit in the available space - man Datsun could've been a bit more generous under there Angles and general dimensions definitely to be taken with a pinch of salt! Obviously it's missing a vital connection between frame and front of the diff but like how hard can that be :D Cheers, Rob

Hi Tim, Thanks for the comps, can't remember if I said but I managed to get on a weld course at the local tech college which finished a few weeks back so I'm a fair bit more confident waving the mig around, still doesn't mean I'm any good or why some welds come out fine and the next one I do looks pants but never mind Regarding the big holes, yup I've got some inserts that go in. For reasons that seem lost in the mists of time, they're screw in things I made. Its possible I was thinking that leaving the holes open would mean when I get it zinc plated then the inside of the top tube would also get done. Cheers, Rob

OMG I'm back and working on the rear mount again! There's nothing like a bit of winter hibernation and then some sunshine to get the juices flowing! Today I made up the cross piece, in effect moustache bar. OK I did cheat and get my new found (and very good) machine shop to knock up the 'clevis ends of doom' out of some 100x60x6mm rhs I happened to have. The rest is pure Rob! The main cross piece is 50x8mm and the 4 little triangle web/braces are 5mm thick, so I reckon it should be strong enough. The really amazing bit is that it all fits together!!! Also I've got the front cross member machined a few weeks back: Which I've test fitted on the car and it seems to fit. Oh yes, I'm well overdue for a calamity Now all I've got to figure is how to connect the front of the diff. I'm going off the two rails running fore-aft under the diff and thinking some OTT () braces connecting to a Ron Tyler-esque mount up front, as that allows most of the suspension to be removed without dropping the diff too - something that appeals. So, time to get the thinking cap on again and see what ludicrious solution I can come up with Cheers, Rob

Indeed, sorry for the hijack Jim But I reckon we can get you sorted one way or another! Steve, what exactly is the master plan behind hording all the ZXs in the UK anyway? Ans where the heck are you getting them all from, it's not like they come up for sale that often?!! Cheers, Rob

Ah! Current project is this: Once that's finished I'll have something decent to work on so I can get on with more interesting projects without catching pneumonia Cheers, Rob