quote Originally posted by Dizzixx: MAGNESIUM AND ITS ALLOYS 1. Vapor degrease with stabilized Trichlorethylene. 2. Immerse in 10% Sodium Hydroxide for 10 minutes at 76-870oC. 3. Rinse 5 minutes in a cold water spray. 4. Immerse in a solution of 1 1/2 lbs. Chromic Acid, 1/4 lb. Sodium Nitrate in 1 gallon of water for 8 minutes at room temperature. 5. Rinse approximately 3 minutes. 6. Immerse in a 20% solution of Hydrofluoric Acid for 5 minutes at room temperature. 7. Rinse 1/2 - 1 minute. 9. Rinse 1-2 minutes. 10. Dry in hot air blast (71-98 degrees C) for 10 minutes. 11. Bond immediately or apply a Zinc primer for protection of freshly etched surfaces. from -- http://www.paintcenter.org/rj/mar06k.cfm hopefully there is an easier way. A bunch of people have done valve covers at least, hopefully they will have input.

That sounds like a lot of work! I called a Powder Coat guy in Houston, got a quote of $100.00 for solid colors. Sound sorta high

In all fairness if it does actually require a procedure that complicated then it sounds right. Thats probably an hour alone just in the prep work.

quote Originally posted by josef644: Ok, whats the trick to painting them? I have a set of fronts at the machine shop, getting a bead blast done. I'm gonna paint them asap after I geet them back.

I bead blasted mine first. Then used a propane torch to remove all excess moisture (carefully ). Then a zinc primer. Then I used an acrylic enamel followed by a clear coat (also acrylic enamel). I found that the bead blasting still wasn't quite rough enough for the paint to stick as well as I thought it should. It looked great but they chip fairly easy still. I thought I might try a medium grit sandpaper next time. I need to pull mine and redo them so I'll try to figure out what works better then.

[This message has been edited by Fieroseverywhere (edited 06-19-2009).]

I'm going to powder coat mine. Will probably abrasive blast them first, probably aluminum oxide. Then wash 'em in water and bake 'em for 20 or 30 minutes at 350. Apply my color and/or design, bake again, then clear powder to finish 'em off.

The guy at the powder coating place I callers said that the clear yellows when used on valve covers, and recommend the use of a solid color without the clear topping.

A older thread on 4.9 Valve Covers:
https://www.fiero.nl/forum/Forum1/HTML/069514.html

[This message has been edited by josef644 (edited 06-19-2009).]

Nothing affects power potential as much as how well the heads get the ait into and out of the engine. But once you've done all you can for that, the best way to get more peak HP is centrifugal supercharging because it tends to extend the useable powerband, the power peak moves up by a few hundred rpm. Provided your springs and rods can take it. Turbocharging won't really alter the rpm range of your powerband, but it'll add the most average power, far more than the centrifugal supercharger. Nitrous is cheap at first, but there's the issue of refilling the bottle. Where Dizzixx lives, there are places that will, but when the bottle runs dry, the fun is over until you can get back to the refill place. And nitrous being cheaper initially is only true if you don't also get all the accessories that will be needed for nitrous addicts. Things such as the Jacobs Nitrous Mastermind, a remote bottle valve, a remote purge kit, an electric bottle heater, gauges, extra bottle with mounts, et cetera. Dizzixx lives above 4200' elev, so running 9.5:1 with boost is possible, but 9.0:1 would be best. That high, 8.5:1 usn't helpful, the 4.9 won't take enough for it to be any advantage.

I always thought a supercharged 4.9 would be a blast to drive. Low mount the Alternator, make adapter plate and use a supercharger that will bolt the the intake manifold. My particular setup leaves 6 1/2 inches from top of throttle body to decklid. More once the throttle body is removed. Of course this is just a rough idea and the real problem comes in the form of a transmission to handle even more torque. Manual would suck, auto would be OK though. Just tossing out ideas...

[This message has been edited by Fieroseverywhere (edited 06-19-2009).]

no, you don't want a positive displacement supercharger, even if you could get a free used one from an '03 -'04 Mustang Cobra. There's no way to add an aftercooler without a custom fabbed intake manifold, and then it won't clear the decklid. Plus those superchargers don't extend the rpm range the way centrigugals do. The pos. disp. will add even more low-rpm torque, which is NOT what's needed. The centrif. will be adding virtually nothing below about 1500 rpm, depending on the pulleys and which style of impeller. Either straight vane or curved vane. I forget which style helps what, but I have that info in my files. And I wouldn't hesitate to try an F40 6 speed with it, but as good as all this might sound, I'm still going LSx.

There's nothing wrong with more torque. I'm talking 5-6 PSI max roots style blower. Not much of an innercooler needed (if any) at that level of boost. Just a little kick and something thats never been done before with a 4.9. Not necissarily looking to extend the RPM range either especially since I would want to go auto with it and reset my shift points. My 4.9 revs freely to 5500 rpm as it. More for fun then anything else. I'm looking at about 8" total space between the intake manifold and the decklid with the throttle body removed. I'm not really a boost guy so obviously alot of research would have to be done on my part.

[This message has been edited by Fieroseverywhere (edited 06-19-2009).]

In this scenario, You would need a rear-feed rather than a top feed. Top feeds being like B&M or Weiand, (both now made and sold by Weiand) I just don't see the point in supercharging, to gain less than 40%, when gains of 80% are possible. And with an automatic eating more of what the engine makes, ...

quote Originally posted by Isolde: Nothing affects power potential as much as how well the heads get the ait into and out of the engine. But once you've done all you can for that, the best way to get more peak HP is centrifugal supercharging because it tends to extend the useable powerband, the power peak moves up by a few hundred rpm. Provided your springs and rods can take it. Turbocharging won't really alter the rpm range of your powerband, but it'll add the most average power, far more than the centrifugal supercharger. Nitrous is cheap at first, but there's the issue of refilling the bottle. Where Dizzixx lives, there are places that will, but when the bottle runs dry, the fun is over until you can get back to the refill place. And nitrous being cheaper initially is only true if you don't also get all the accessories that will be needed for nitrous addicts. Things such as the Jacobs Nitrous Mastermind, a remote bottle valve, a remote purge kit, an electric bottle heater, gauges, extra bottle with mounts, et cetera. Dizzixx lives above 4200' elev, so running 9.5:1 with boost is possible, but 9.0:1 would be best. That high, 8.5:1 usn't helpful, the 4.9 won't take enough for it to be any advantage.

the allante pistons are 9.0:1 compression in stock form, and they are the same exact bore as the 4.9L pistons

What do the northstar pistons make it?

quote Originally posted by Dizzixx: What do the northstar pistons make it?

somewhere between 10.5:1 and 11:1

quote Originally posted by Isolde: In this scenario, You would need a rear-feed rather than a top feed. Top feeds being like B&M or Weiand, (both now made and sold by Weiand) I just don't see the point in supercharging, to gain less than 40%, when gains of 80% are possible. And with an automatic eating more of what the engine makes, ...

Rear feed or top feed would work. There is no reason you can't pull the air through the decklid. A 40% gain on a 4.9 is approx 80HP and 120 ft/lbs or torque. That should be more then enough to propel you into a 12sec quarter, or even better, have one hell of a lightweight autocross car. I doublt the 4.9 would take an 80% gain and there is not much you can do to beef up the internals so why bother. Now your LS1 is a completely different story. 80% is not only possible but exactly what you would want.

The only reason for me to want to do this is..
1 : Because its never been done before.
2 : Just to make the car a little more fun.

Anyone know the specific application for the roller Rockers Jon used on his build? He just refers to "ford" rockers on his site but no specifics. I'm wondering if these will work: http://www.jegs.com/i/Crane/270/44746-16/10002/-1 I know some modification to the rocker mount s will have to be done. Specifically I'm guessing re-drilled and tapped for the right size studs. ANyone have any further insight into using these or which ones will work?

The light weight disappears with the extra weight of iron heads, supercharger and automatic transmission, and I don't see why you wouldn't want to run forged pistons and methanol injection and try for 80%, especially with an automatic, but it is your build.

quote Originally posted by Dizzixx: MAGNESIUM AND ITS ALLOYS 1. Vapor degrease with stabilized Trichlorethylene. 2. Immerse in 10% Sodium Hydroxide for 10 minutes at 76-870oC. 3. Rinse 5 minutes in a cold water spray. 4. Immerse in a solution of 1 1/2 lbs. Chromic Acid, 1/4 lb. Sodium Nitrate in 1 gallon of water for 8 minutes at room temperature. 5. Rinse approximately 3 minutes. 6. Immerse in a 20% solution of Hydrofluoric Acid for 5 minutes at room temperature. 7. Rinse 1/2 - 1 minute. 9. Rinse 1-2 minutes. 10. Dry in hot air blast (71-98 degrees C) for 10 minutes. 11. Bond immediately or apply a Zinc primer for protection of freshly etched surfaces. from -- http://www.paintcenter.org/rj/mar06k.cfm hopefully there is an easier way. A bunch of people have done valve covers at least, hopefully they will have input.

I sure hope there is a better way, Hydrofluoric Acid is hardly something I would want to mess around with at home. FYI: HF acid does not affect the skin it feels just like water, HOWEVER it is quickly asorbed though the skin and it attacks the calcium in the bones and nervous system - needless to say it is not a pleasant death.

quote Originally posted by Taijiguy: Anyone know the specific application for the roller Rockers Jon used on his build? He just refers to "ford" rockers on his site but no specifics. I'm wondering if these will work: http://www.jegs.com/i/Crane/270/44746-16/10002/-1 I know some modification to the rocker mount s will have to be done. Specifically I'm guessing re-drilled and tapped for the right size studs. ANyone have any further insight into using these or which ones will work?

I would also like to know what roller rocker set up works on the 4.9's. It's the next project on my list.

quote Originally posted by Dan_Seattle: I would also like to know what roller rocker set up works on the 4.9's. It's the next project on my list.

I have the block at the machine shop now getting cleaned and new cam bearings. They specialize in heads. I might take one of the rocker assemblies in and get their opinion on what might work. With any luck he may have some used ones he can lay on me for cheap. I'll let you know what I find out. It should be Wednesday maybe.

quote Originally posted by Isolde: The light weight disappears with the extra weight of iron heads, supercharger and automatic transmission, and I don't see why you wouldn't want to run forged pistons and methanol injection and try for 80%, especially with an automatic, but it is your build.

It would be great to be able to do that. There are no forged pistons that I know of for a 4.9. Might be able to find some N* ones but the compression would be WAY too high to run forced induction. Even with the iron heads that are already on the 4.9 it only weights 365lbs. I don't know how much a supercharger weighs but I would expect 30-35 lbs total. Yes, the auto will be heavier but only about 50-60lbs. Not having to deal with a clutch or find one that would hold that much torque in such a small space would more then make up for the added weight IMO. Disc, pressure plate, & flywheel together weigh about as much as the flex plate and torque converter so thats a wash. You would also have added weight from the wider wheels/tires you would be required to run. May need stronger rear springs also. Total added weight would be about 125lbs.

80% would be great but it still comes down to the fact that the 4.9 probably won't handle that much more power. Seems overkill to me for an engine that is not performance oriented from the beginning. Guess I just have no interest in turning the 4.9 into a high RPM motor. I love the torque it produces and a some more wouldn't be a too bad thing. You just can't look at a 4.9 the same as you would look at an LS1. Totally different class of motors. Either way even if I did decide to do this it would be a few years down the road. I'm too busy enjoying my 4.9 for what it is now.

Power isn't what breaks parts. Excessive rpm, and detonation are the killers. With polished combustion chambers and a set of JE pistons, plus some charge cooling and a modest advance curve or boost retard, 13 psi should be feasible, and you would need stiffer intake valve springs, but I'd be very surprised if you had any trouble with the rest of the 4.9 surviving 400 hp under 5500 rpm. Probably the weakest link would be some risk of cracking the thin iron heads. I'm not an armchair theorist, I build performance engines for a living. I'm not the most experienced with either the 4.9 or the LSX, but I am getting comfortable with the LSX.

Isolde you are in utah as well? I hadnt noticed until just now. You ever in the SL area? Drop me a PM.

With unlimited money couldn't you have whatever made for the motor that you wanted. Cast rods. Roller rockers. Turbo. Supercharger. etc etc...

I am afraid that I am going to have to side with the naysayers on this one. I would be interested in a decent 50hp more or something but even that probably would not be worth the money for what you get. The Idea of an LS or Ecotec or something else different that already has an after market would be an interesting alternative.

We should start a 4.9 mods on a budget thread and see what happens.

What does it take to add a knock sensor too the 4.9? Do you just need an ecm that can handle it? What about an after market knock computer or something?

quote Originally posted by Dizzixx: What does it take to add a knock sensor too the 4.9? Do you just need an ecm that can handle it? What about an after market knock computer or something?

I believe someone found a knock sensor that screws into the 4.9 block. It works with the 7730 ECM which is the one a lot of people go with for the 4.9. You can basically plug and play that ECM with a 305 camaro harness from painless. The stock caddy PCM does not work with a knock sensor as you can imagine.

I agree fully on the starting with another motor. For any serious mods, the 4.9 just doesn't have what it takes. Still the thought of a supercharged one sure sounds like a real kick in the pants to me.

On a side note... I just finally took my 4.9 out for its first test drive last night since the rebuild. New clutch, flywheel, transmission, slave and master cylinders, and some tweaking to my crossover pipe was all it needed. I still can't believe how fast it killed that isuzu trans but hey, what you gonna do huh?

[This message has been edited by Fieroseverywhere (edited 06-23-2009).]

Those Isuzus can't be that good, they weren't deemed suitable for the 2.8, and the V8 guys all kill second gear right away.

quote Originally posted by Isolde: Those Isuzus can't be that good, they weren't deemed suitable for the 2.8, and the V8 guys all kill second gear right away.

Actually for me second gear was just fine. My 4.9 took out the differential. I didn't expect it to last very long. I was shooting for just through the engine and clutch break in period and maybe while getting some tuning in. Didn't work that long even though I was "playing nice". I suspect that the trans probably wasn't that good from the start and the weak pressure plate I got from SPEC both contributed to its demise.

Anyways: Hey Dizzix, When we going to see a build thread or pics or.... something?

[This message has been edited by Fieroseverywhere (edited 06-23-2009).]

A funny story about the valve covers, I decided to cut the fins off of the ones I had but I used alot of water while power sanding them (even using water while sanding is a bad idea) , A guy decided to follow suit and do the same thing, Well he decided to not use water in doing it, The guy almost burned down his garage, I don't know if the valve covers was saved or not, But it sure almost cost him his house.

Never ever even attempt to weild those bad boys, I would even reccomend not trying to sand the fins off of them, And if anyone tries to do it (YOU HAVE BEEN WARNED)

Yeah powdered magnesium is just asking for trouble. Or fun, depending on the situation.

I beat on the Isuzu in my 4cyl and I can feel it taking its toll I am not surprised it didn't survive. Something about them just doesn't feel right, like they are rough around the edges. Maybe its more that I have never taken the time to properly adjust it.

What did you end up doing for a replacement clutch? I have the spec stage 4 and I like it, not to mention it looks nifty and you get a whole extra +1 stage-ness, who can argue with that. Did it take the flywheel when it went?

On the 7730 ECM mod. How much is a painless harness? Could it possibly be made to work with my existing caddy setup, wire my own adapter or just hack off the ECM connectors and do new ones? I would guess the knock sensor goes to where the dummy temp light is on the top back left of the block, but I dont know much about knock sensors, as far as how they actually accomplish their task so that could be way off.

I have a build thread. Sadly it isnt much. I lost the cable to the camera that I use (not mine) and some of the pictures are stuck on the camera because they were shot without the mem card in (doh!) I even tried the whole updating it thing but have been failing pretty bad. I am taking real classes this summer semester and it is really killing my free time..

the thread -- https://www.fiero.nl/forum/Forum1/HTML/076351.html

quote Originally posted by Dizzixx: On the 7730 ECM mod. How much is a painless harness? Could it possibly be made to work with my existing caddy setup, wire my own adapter or just hack off the ECM connectors and do new ones? I would guess the knock sensor goes to where the dummy temp light is on the top back left of the block, but I dont know much about knock sensors, as far as how they actually accomplish their task so that could be way off.

The 7730 uses the same connectors as the caddy ecm and has many of the same pin locations for the circuits. If you were dead set on reusing the caddy harness for the 7730 it could be possible, but would require repinning at the ECM connector to match the 7730 circuit locations, rewiring for 2 injector ground wires from the injectors to the ecm for batch fire vs. the 8 in the caddy harness (use the left over 6 wires for knock and IAC), installing some type of IAC (swap out the caddy throttle body with a traditional TBI throttle body minus injectors), and probably a few more steps I have forgotten. Then you still have to modify the stock caddy harness to fit the fiero chassis... in my book it is just easier to build a new harness.

For a good knock sensor location - dead center of the pic below. It is from an aluminum block saturn 4 cyl and is compatible with the 7730 and just threads into and existing bolt boss:

I meant using the built fiero/caddy combo harness that I have already made but the answer is the same.

Sounds like its more work than it is worth at the moment.

quote Originally posted by Dizzixx: What did you end up doing for a replacement clutch? I have the spec stage 4 and I like it, not to mention it looks nifty and you get a whole extra +1 stage-ness, who can argue with that. Did it take the flywheel when it went? On the 7730 ECM mod. How much is a painless harness? Could it possibly be made to work with my existing caddy setup, wire my own adapter or just hack off the ECM connectors and do new ones? I would guess the knock sensor goes to where the dummy temp light is on the top back left of the block, but I dont know much about knock sensors, as far as how they actually accomplish their task so that could be way off.

Yea. I didn't realize how bad that isuzu was til I got the 4 speed installed and finally drove it. Was a difference. I love the 4 speed even if it does kill my gas mileage.

For the new clutch I went with Clutchnet. Red level 2 pressure plate and 6 puck, sprung hub ceramic disc. I expected a stiff pedal but was pleasantly suprised to find that its not bad at all. Easily good for city driving. Actually it feels like I think a clutch should. The SPEC was so soft it didn't feel like I was pushing anything, but again it didn't hold above 4000 rpm. The clutchnet holds perfectly so far and it is not yet fully seated. My flywheel survived but I went ahead and replaced it anyway since I made the first one as part of the testing. It was never meant to be permanent. I went with an LSC performance flywheel for the new one. Once the new clutch was in the stiffer pressure plate was too much for the master and slave seals. Both were original and both started leaking. Then last night I found a new problem. Looks like the clutch pedal is also bent. I ordered a new steel one this morning. Hopefully I will have it by saturday and can actually have the car on the road this weekend. I bent the pedal back by hand so its driveable now but I really have to compress the carpet with the clutch pedal to get into first. Literally pinned to the floor. Sometimes it still wants to pop out of gear. Just not worth driving it yet.

[This message has been edited by Fieroseverywhere (edited 06-24-2009).]

when I had a 4.9 in my car I Went through 3 transmissions the first was the th125 that lasted a week before it was junk, Then I installed a auto transmission from a older caddy (it was the non electronic transmission) that lasted awhile but it had a harsh 2 and 3rd gear shift, So I swaped a exact replacment out of a junkyard (with my crappy luck) That transmission was bad and slipped in all gears, I finally got tired of the automatic transmissions and bought a parts car with a isuzu inside, I loved that tranmission but I installed a fiero store clutch that practally exploded, After that I installed a spec clutch and the car ran very nice with that combo, There is nothing wrong with the isuzu, I was kind of cautious with the 2nd gear at first but after that I would row through gears, I know first gear was useless but that was the only downside to using a isuzu with a 4.9.


I ended up selling the entire drivetrain with the isuzu to a guy and installed a 3800 sc 2 engine, To this day that engine and tranny is still running in a guys car (seen it at the 2009 daytona show)


I reccomend going fuel injected on the 4.9 but the carb works good to but was not soo good on gas mileage, im suprised that ppl are getting 20+ miles per gallon on this engine, because in my friends caddy his gets crappy gas mileage and his engine has no trouble codes and only has 70k miles on it

I too had too replace a bent clutch pedal. I noticed that the fierostore one seems like the OD where the large plastic bushing sits (?, the one that the spring rides on) is too large, just barely. Also the weld is larger so even if you get the big bushing back on it is then too long because it hits the back. I ended up going to home depot and finding a makeshift that was more or less the same size after I broke the original plastic one trying to get it to fit with some elbow grease and a dremel. I had the same problem with the bushing when I replaced the pedal in my 84 but I managed to dremel it out and get it to fit snug without breaking it.


According to the EPA the combined average on the 92 caddy deville was 17mpg. But it should be remembered that the cadillac deville, seville, etc were all more or less 3700 pounds whereas the fiero weighs 2700 pounds. Thats a full half ton difference so I am not surprised when people gain 10mpg over the original epa rating for the car the 4.9 came out of. Some people even say they are getting 30+ mpg. Too soon to tell for me, but I dont actually care.

[This message has been edited by Dizzixx (edited 06-24-2009).]

Izusu 5 speed 4 years now - no issues with the transmission (1/4 mile, 100' and slalom racing done with it) - 1st gear does suck. I also tore apart the transaxle and replaced bearings/etc BEFORE installing it in the car. You get a junk yard tranny, don't be surprised if it craps out.

Gas milage, in a Caddy, yes it is low - but it is a big car. I 'can' ( <- notice 'can') get 26 mpg - but I drive it too hard. With my 86 fuel tank I can easily get close to 500 km to a tank of gas going easy on the throttle and keeping it under 3000 rpms - on the flip side that can drop to 200 km per tank if I spend the weekend racing. The car weighs 2850 lbs with a full tank and me in it (vs the Caddy which is in the upper 3000 IIRC).

I got mpg in the mid to low 30s with my '97 Bonneville 3800-II, and I mention this because I don't think weight is much of an issue when you're just cruising along as a steady 65 mph, trying to get good mpg.

quote Originally posted by Isolde: I got mpg in the mid to low 30s with my '97 Bonneville 3800-II, and I mention this because I don't think weight is much of an issue when you're just cruising along as a steady 65 mph, trying to get good mpg.

Thats a good debate there. Does the added weight help by maintaining momentum as cruising? Or does it just hinder by needing more power to keep it moving? Either way the aerodynamics of the fiero add significantly to the gas mileage. Less drag is a huge advantage there.

I would make a gander and say that the rolling friction of components and what not is increased by the weight put on them. So even if you save mpg by maintaining momentum I bet its a wash. Its really the highway vs city that I bet makes the biggest difference. I bet you could get 30+ if you roadtripped somewhere on a tank of gas vs taking it easy in stop and go traffic. Of course if you have the 4spd and are trying to go 75 to keep up with traffic on the freeway that may be a different story. Not to mention that drag increases exponentially with speed.