The White Bug (Page 24/46)
pmbrunelle NOV 22, 05:54 PM

quote
Originally posted by fieroguru:
put the calipers back on the car with the bleeders pointing down.



That's the sort of redneck design that I want to avoid with my newest iteration of Fiero brakes... hence my question.
ericjon262 NOV 23, 07:26 AM

quote
Originally posted by pmbrunelle:

Unsurprisingly, my sketchy water injection system failed. Eric called this one!

It's been more than a year since the initial setup, so I figured that the stagnant water might corrode things enough to cause problems.

Therefore, before cranking up the boost further, I wanted to make sure that the system was functional. I didn't trust it...

I removed the upper and middle intakes; this gave me a view of the intake runners and the water nozzles:


Then, my plan was to turn on the water; long enough to observe the water spray, without flooding the engine with water.

Well, the nozzles just dribbled a small amount of water. Good thing I decided to check up on things before increasing the boost.

I then removed the lower intake, and the nozzles.

Here is a view of one of the nozzles:


The (previously) white object is a plastic foam filter that is pushed in the inlet hole of the nozzle.

It seems like green bacterial slime grew on the filters (all six), blocking the filters.

I then reinstalled the same nozzles into the intake, but with the filters removed, and they sprayed like usual. Problem identified!

I think I'll be reassembling the engine without the filters on the nozzles, since the bacterial blockage could return if I reinstall new filters. They seem to like this plastic.




I don't remember specifically, so maybe you already have it covered, but there are plenty of manufacturers that make inline filters that could be installed external to the manifold and provide filtration of the water/meth. That being said, a higher methanol concentration may provide more protection against biological fouling.

pmbrunelle NOV 23, 09:16 PM
I have an external filter (meant for fuel injection). It is the red anodized aluminium cylinder on the firewall:
http://www.fiero.nl/forum/F...HTML/142133.html#p24

That filter has a fine stainless steel mesh, and it didn't get clogged with bacterial slime.

I have no methanol in the juice, only distilled water. When I poured some windshield washer fluid (i.e. water/meth mix) onto the intake manifold, it caused corrosion, despite the nickel plating. Therefore, I decided to stick with pure distilled water.

Methanol would prevent bacteria from growing, but it's a no-go due to the corrosion reason.

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Actually this is the second time in my life that I have faced slime with distilled water.

In my student summer job (a while ago now), I made a conductivity meter to measure the conductivity of deionized water in a tank. It was pretty much an Ohmmeter with two electrodes submerged in the water.

If the water were to become contaminated with dissolved salts, then its conductivity would measurably increase, and then users could know that the water no longer met their requirements.

After some time (two weeks perhaps), the conductivity meter no longer worked; the interior surfaces of the tank, and the electrodes became covered in insulating slime. Smelled a bit off too.
ericjon262 NOV 24, 01:29 AM

quote
Originally posted by pmbrunelle:

I have an external filter (meant for fuel injection). It is the red anodized aluminium cylinder on the firewall:
http://www.fiero.nl/forum/F...HTML/142133.html#p24

That filter has a fine stainless steel mesh, and it didn't get clogged with bacterial slime.

I have no methanol in the juice, only distilled water. When I poured some windshield washer fluid (i.e. water/meth mix) onto the intake manifold, it caused corrosion, despite the nickel plating. Therefore, I decided to stick with pure distilled water.

Methanol would prevent bacteria from growing, but it's a no-go due to the corrosion reason.

********************************************************************************

Actually this is the second time in my life that I have faced slime with distilled water.

In my student summer job (a while ago now), I made a conductivity meter to measure the conductivity of deionized water in a tank. It was pretty much an Ohmmeter with two electrodes submerged in the water.

If the water were to become contaminated with dissolved salts, then its conductivity would measurably increase, and then users could know that the water no longer met their requirements.

After some time (two weeks perhaps), the conductivity meter no longer worked; the interior surfaces of the tank, and the electrodes became covered in insulating slime. Smelled a bit off too.



I'm familiar with conductivity meters like you describe, they're frequently used in condensate systems for steam plants to detect seawater inleakage on the condensers. in that application however, the water purity is pretty extreme, and great lengths are taken to control the purity to avoid corrosion in the boilers that would be difficult and expensive to repair.


I imagine a balance could be found with enough methanol to preclude biological growth, but not enough to be a severe corrosion concern, but then again, that may take more R&D than desired considering regular flushes could clean the system.
pmbrunelle DEC 31, 02:49 AM
I've started working on the brake modifications for the White Bug. I'm largely reusing the brake setup I had on my previous Fiero (Zettner/Kohburn brackets with GM Metric calipers and 11.25" rear LeBaron rotors). I do however want to fix some unresolved issues.

One issue was the lack of steering stops on my old car, so the calipers would end up hitting the shocks. Not the stuff of a premium car. Therefore, I decided to retain the steering stops of the stock caliper bracket.

My Zettner brackets (and spacers) will be attached to the outboard face of the knuckle (could be machined) using M12 bolts, threaded into the stock caliper bracket on the opposite side of the knuckle. This setup brings the advantage of more bolt stretch, though loosening wasn't a problem before.

Stock caliper bracket:


...

Chop-chop
Mill
Grind/Dremel
Sandblast
Paint
Heli-coil M12x1.5
...

Completed steering stop:


The stops weigh about 1 lb each. Kind of heavy for what they are; I could redo some from scratch out of aluminium, but for now, these ones will do.

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The rotors were still in good shape, so I decided to sandblast and reuse them. I painted the hats so they don't rust too quickly.



I'm debating if I want to drill/slot these rotors, or maybe just leave them plain.

For the moment I'm leaning towards slotting, because:
I need practice on the semi-automated milling machine at work (don't want to get rusty)
Drilling apparently leads to cracks, whereas slotting does not
I already had drilled rotors on a previous car (my Saturn), so this would be different

I don't think I need slotting, it's more because it would be fun to do and give a subtle tuner car look. I would have to buy a small ball-nose mill for the job.
La fiera DEC 31, 09:47 PM
You can buy them slotted & drilled or slotted or drilled. For your application I'd leave them plain.
I have the plain and with Hawks DTC 30 I have never had any brake fade. (I'm a very late braker)
The only things I have are lots of dust and noise when cold, but not brake fade.
That was with the 173WHP 2.8. Now with the goal of 350+WHP with the 3.7 I'm getting slotted and drilled rotors!
pmbrunelle JAN 01, 01:32 AM
It's more for machining practice/fun, so if I don't do it myself, I won't buy them pre-done.
longjonsilver JAN 02, 05:29 AM
i dont know much about mechanics, but a little about physics. As i recall from my college days, we have a rotational force here and want to stop it, Thats a tork. A tork is force times arm. With 12" brakes instead of 9" brakes you are increasing the arm by 33%. With the S10 brake booster mod you are increasing the force by 40% cuz equal vacuum with 40% greater area, makes 40% greater force. The S10 booster mod is cheap and easy, even i could do it. The Corvette brake mod is not cheap or easy, am i right. imho the S10 booster mod gives more bang for the buck hour.

just my thots, cud be rong. Great looking car by the way...

jon

------------------
Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

fieroguru JAN 02, 10:27 AM
You really don't want to drill and slot the rotors yourself. They are cast parts with thicker and thinner spots. When you drill the holes, you are not removing the exact same material from every hole, which will lead to the need to have them rebalanced. When you buy drilled/slotted rotors, they have already been balanced post drilling.

pmbrunelle JAN 02, 11:38 AM
I would say that going for bigger rotors, and reduced hydraulic pressures is in the goal of creating a firmer-feeling pedal. To me that's part of what makes a high-end car, so that's my objective.

I don't find the stock brake pedal effort to be excessive, so I don't think a bigger S-10 booster would give me the feeling I'm going for.

Besides that, I'm not really into the idea of becoming more dependent on the output of a stronger booster. That could create a Jekyll and Hyde car.

Pretty much like the Boeing 737 Max; flies one way in normal use, then when the electronics quit, it turns into a monster never before seen by the pilots.

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Getting to use my wheel balancer is going to be a fun part of this project:
https://www.youtube.com/watch?v=7cTWQ5_5w4Y

I've done many wheels with it; I've never done brake rotors yet, so that will be something new to try.

My plan is to remove material from the exterior with an angle grinder. I'll practice on junk rotors first.

[This message has been edited by pmbrunelle (edited 01-02-2021).]