1985 Fiero build

[ejs262]

Practice helps, alot!



old on the left, new on the right. still a bit hot, but way better!



One log and runner are assembled, unfortunately, I can't really make any more progress until I get the new flanges made. tomorrow, when I get off work I plan to triple check all of my measurements and find someone to cut them ASAP. my fabrication plan is to tack weld the 45's to the flange, and then set the log on top and trim both until I have a proper fit, then weld everything up.

[ejs262]

I've spent the past few days hammering out the flange for the new turbo manifold, I'm pretty sure I've got it spot on, now. I've had it 3d printed twice, and I think I'm already approaching the point of diminishing returns.





The final step before the laser will be a thin sheet metal "flange", as my friend's 3D printer wasn't exactly accurate for the hole sizes. once it's "proved", I'll have them cut in at lead 3/8" 304 SS and get hot on finishing them up.

[SuperBuickGuy]

it's far easier to make round pipe fit a hole, as long as your exhaust doesn't impinge the exhaust port, it's fine. Put another way, it can go into bigger area and as long as you're not going to have trouble putting the bolts in - using round will pay dividends now and later...

[ejs262]

it's far easier to make round pipe fit a hole, as long as your exhaust doesn't impinge the exhaust port, it's fine. Put another way, it can go into bigger area and as long as you're not going to have trouble putting the bolts in - using round will pay dividends now and later...

That lower bolt hole gets really tight at full diameter, either way I'm going to have to adjust the pipe for the bolt, in the end, it will be round, but it will be several small steps as opposed to one big jump, helping to preserve energy for the turbo.

[ejs262]

Not much going on ATM, I drew up this adapter to adapt the 09 impala gas pedal to the Fiero, I'll have it 3D printed to test fit, and then make adjustments from there. once it's "done" I'll have it cut out of metal.

[ejs262]

I did a bit more practice running beads last night, I think I'm starting to get the hang of it, I think one of my biggest problems with producing nice beads earlier, was that the torch was too far from the material, resulting in the torch melting the filler, not the puddle, I tightened the gap, and was more careful about filler addition, and the result was the top bead in this picture:



I did several like it, and think that I'm getting to the point where I can observe the problems or poor technique better, and make corrections on the fly. I think all this stainless practice will make a huge difference in all of my weld quality, not just stainless. it seems some of the other materials are more forgiving they're appearance doesn't change as much with poor technique, whereas stainless changes alot!

[ejs262]

I did a little junkyard digging today and scored a couple of small wins.

a new UIM and a/c compressor.



and a few more 3500 injectors, I'm going to decap them and send them to Derr Injector services for cleaning and flow testing, I have 16 of them, so I'll have them flowed and I'll take the best 6 matching and use them.

I also did a little work on the "coolant tree". Normally there's a pipe that goes over the valve cover to the back side of the engine to act as a return path from the heater core. I decided that I am going to plumb my heater return into the passenger side coolant tube running under the car, and eliminate one of the pipes under the car. it is necessary to keep the tree in place though, because it receives the recirculation line to prevent dead heading the water pump.

I started by removing the pipe





then welded it up and painted it.





The welds are a little nasty, I think there was still some antifreeze residue in there that kept trying to gas off.

I cut the neck out of the new intake, and have begun fitting up the new one, it's a bit bigger, and will better accommodate my 76mm LS4 throttle.







I still need to finish it up, but it's coming along nicely.

[ejs262]

this is my current alternator and tensioner bracket. it uses an LT1 F-body tensioner, and an Astro van alternator. it also requires an idler at the top bolt hole the holds the bracket to the head. I made it a few years ago, it's a bit bulky, and holds the alternator pretty far from the block, it works, but I'm not too happy with the execution, the welds are shit...





I'd prefer the alternator hug the block, but then I have to find a new tensioner. the one pictured appeared to be the ticket, until I started lining the belt up and realized it would need an additional idler to work, and there isn't really room.



I found a fairly compact tensioner, that pulls the opposite direction. it has a ribbed pulley that I swapped for a smooth pulley, I'm going to make a mount to hold it in between the a/c compressor and the block, the mount will bolt in using the A/C compressor bolts, which acutally works out well, the A/C compressor requires a spacer between itself and the block, as the original application for the engine had an anti rotation mount sandwiched there, so now the space will be used for something.



mounting the tensioner there will also eliminate an idler pulley as well, which did require the mount boss on the timing cover to be ground off.



I'm done for tonight, but I hope to have this mostly done tomorrow as long as it's above freezing...

[ejs262]

so... I lied I wasn't done...

I did a little CAD(Cardboard Aided Design) work:



then to the plasma and drill press:



and now I have a finished mounting flange for the tensioner



I need to smooth it out a bit, but I think it turned out pretty good, I'm planning to brace it in three places to ensure a solid foundation.

[ejs262]

I tacked it together about 10 times, before finally settling on this:



the belt will be routed as such, maintaining the tensioner on the slack side of the belt. with the tensioner fully retracted, the belt still has clearance, between the tensioner and waterpump.



I used the stock engine lift bracket as a guide, and cut the foundation for the alternator mount to match the shape, except extended lower so that the alternator will have something to mount to.



My goal is to tuck the alternator as close to the block as possible, the back is going to get kinda close to the exhaust, so I'm going to make a thin heat shield to protect it as best as possible.



what I have left, I need to add gussets to the tensioner bracket, I dont' see any flex as is right now, but I don't want to revisit it later because I got lazy. and obviously, I need to mount the alternator still, and the last thing, find a belt, I hope that goes easier than last time... lol.

[ejs262]

belt tensioner bracket is gusseted, I need to clean it up and paint it, but otherwise it's done.

a quick go with the plasma cutter and some tack welds got me a kinda functional bracket.



it needed significant bracing, as well as something for the bolts to tighten into, so I heated up some 2" flat stock, and bent it to approximately match the contour of the alternator case. I also notched it so it would nest into the offset parts of the bracket.



Then I put a small spacer between the alternator and the new back brace, and welded it to the bracket. I should have cleaned the material better before welding, but I think it should hold fine.



I then put the whole assembly back on the engine and verified the belt alignment, as well as gave it a trial fit to see how everything will look. in this picture, the belt is bypassing the crank pulley to give it enough length to go around the alternator, water pump, and tensioner. I'm considering adding an idler pulley at the mounting bolt for the alternator, to increase the belt wrap around the alternator pulley. at this point, all that is left for the alternator bracket is the above mentioned idler, the mounting ears on the back of the brace, the gussets for the brace, and cleanup/paint.

[ejs262]

quick tip, if you need to add an idler and don't have a boss for one, a 15mm hex head, like found on most M10x1.5 bolts, fits nice and snug inside the bearing of a pulley, is the the best way? no, will it work? yes.

Here is the proposed idler arrangement. it would be attached by a threaded rod going all the way through to the back of the alternator, a boss to hold the pulley on top of the bracket, and then a nut to tighten the whole assembly.



much more wrap.

[ejs262]

but using the tensioner mount on the timing cover is way less work....

[cstmwgn]

Do you really need the second idler pulley on the timing cover? It looks like you would have a pretty good wrap on the alternator pulley without it.

[ejs262]

Do you really need the second idler pulley on the timing cover? It looks like you would have a pretty good wrap on the alternator pulley without it.

I'd rather have it and not need it, than need it and not have it.


a bit of trading with belts and pulleys ended with this:



I think I have a winner. I liked the belt routing better with the the idler on the bracket, as it netted quite a bit more wrap on the alternator. the problem was the belt got really close to itself, and belt stretching would only make the problem worse, so I went with the timing cover idler.