262's 85 Fiero SE LX9 F23 swap thread lots of pics

[ericjon262]

still a work in progress, but it's coming along nicely.





a couple of pics comparing the two alternators. you can see that they are pretty much identical except for the mounts.





sorry about the crappy pics. I'll try to get better ones with daylight...

[neophile_17]

Looks like good progress. I'd say the switch in alternator cases was a good move, much simpler mounting. If you find that you need mounting points 180 degrees apart instead of 105 or whatever the 4.3L alternator is then the 3300 alternator might be the ticket. It's pretty small but puts out similar amperage as the stock Fiero unit. Ditching the remnants of the aluminum bracket was also a good move. I broke 3 those before I switched to steel on my LA1.

[ericjon262]

I had never heard of the aluminum brackets breaking, glad I ditched it for sure now. the 4.3 alternator is pretty easy so far. it also used the same wiring as my 3400 alternator, so it's plug and play assuming the wiring is long enough. do you have pictures of your mount?

[neophile_17]

I low-mounted the alternator on my LA1 swap and used the alternator bracket for a dog-bone mount. It seemed to have ribs/gussets that would make it plenty strong enough. The 1rst bracket held up for about 100 hours of street driving and probably 50 hours on track before failing. I assumed it's failure was due to an off track incident and got 2 more from the junkyard. The next one failed after probably 30 hours on track at which point I resolved to make my own aluminum bracket but needed a stop gap. Well 8 hours later I needed a solution fast and used the engine lift point. My custom aluminum bracket didn't quite fit and we decided to keep the lift bracket as a permanent mount while mumbling "Weight Savings". It's been working fine since but I'm still a little surprised how weak those brackets really are. Their shape should make them quite strong but the metal must be just awful.

Unfortunately I can't seem to find pictures. If I remember I'll grab some next time I get out to work on the racecar.

[ericjon262]

I can see why you had problems with it breaking now, using it as a dog bone puts way more force on it that it would see with just an alternator.

[ericjon262]

still don't have better pics of the "new" alternator in daylight, but the new low mount alternator is about halfway done. still need to get the tensioner mounted, and add some bracing so it won't flex under load.

[ericjon262]

the promised pictures of the "new" alternator in daylight. also, in case I didn't already say it, I am only using this JY alternator as a mockup, it will either be replaced or rebuilt as necessary.







and here's some more pictures of the new alternator/tensioner bracket.





installed:



right now, there are two big things left. the tensioner is currently through bolted to the bracket, for the rear bolt, that's fine and good, for the front, it's a no go as it hits the nut hits the block and doesn't let the bracket sit flat. to combat this, I'm going to weld a stud to the bracket and have the nut on the opposite side. the other thing, if ti wasn't clear in the "installed picture, is to make a mount for an idler pulley above the tensioner. other than those to big-ish things, I'm also going to add a few supports to limit the amount of flex the bracket can see. I'm pretty happy I've been able to make this work with "wear parts" that are all available off the shelf, without having to be modified for installation, so if I blow and alternator, or tensioner, a quick stop anywhere should be able to yield a replacement.

[ericjon262]

so at this point, the bracket is about 80-95% done, seems pretty strong, the only thing I'm concerned about is belt wrap on the crank pulley. right now, it looks like the best I'll be able to get is about 180*. I'm gonna give it a shot and see how it does, if it squeals like a stuck pig, I'll try a few ideas I have.

In other news, I'm also working on converting the valvetrain to a full roller, adjustable setup. on a 3500, there are a few problems to overcome to make the conversion.

1. no guideplates available. I've got a solution I'm working on for that now though.
2. no conversion studs in long enough to make me happy, I've got about 25mm of threads in the head. the longest conversion stud I've seen only extends 20 mm into the head, which would be ok if it would be threaded directly into the head, but there's going to be a custom guideplate in between the head and the stud, which will further reduce the thread engagement. if it was in iron, I would have no worries at all about it, but going into soft cast aluminum, it's a spot where overkill is underrated. Thankfully, I have an extra set of heads I can use to test fit components on.

[neophile_17]

Looks good!

I think you should be OK with 180* of belt wrap. I haven't had a problem and I'm pretty sure I have less than that.

[ericjon262]

thanks! belt wrap looks to be slightly less than 180* so we'll see.

I test mounted the new alternator bracket, looks pretty good, just hope belt wrap isn't an issue.

in other news, I made up a quick drawing of an idea I have that would allow me to use fully adjustable rockers on my 3500, assuming I can find studs that will work...



the stock pedestal mount rockers have a groove that aligns the rocker to the valve, my thought, if the groove is good enough for the pedestal, why wouldn't it be good enough for a guideplate. nobody makes guideplates for a 3500, and because the valve are canted, a off the shelf guide won't work, as the angles won't match up.

Thoughts?

[Guest]

Why not do like everyone else does I that situation and use gen 2 guide plates?

[ericjon262]

Why not do like everyone else does I that situation and use gen 2 guide plates?

I was under the impression that the gen 2 guideplates didn't fit the 3500 heads.

[Guest]

If you mill down the pedistals, just like is done with the 3400 heads, then they work.

[ericjon262]

I'd rather not pull the heads if it can be avoided.

[Guest]

I think by the time you stack everything up like you prose you'll find that everything will be too high to have proper geometry.

I like your idea, I just don't think it will work out like you want.

The adjustable studs need to be a certain height so that the adjustment can be made and the bottom of the rocker have clearance to the hex of the stud, etc.

If you have the studs already, stack some washers under the stud equal to the thickness of the part you have designed and see where it all lies.