This is my thread about how to tweak a 4.9 to make power. I want it to stay civil, and I would request that if yo don't have anything nice to say. Please refrain from hitting reply. The thread is going to be looking at why the 4.9 only makes 200hp and 290lbs of torque out of the factory and were it makes that power and what to do to make the motor better suited for people driving styles.

Everyone knows the 4.9 if just UN bolted from a caddy and put into a Fiero using the stock ECM, Stock Cam, Stock Exhaust and Stock Automatic it is overall an average of a mid 14 second car. This is FACT not fiction. The only time a 4.9 did a worse time was with a problem. To my knowledge many have cracked 13's with just a cam swap, more below on that. I think one person got into the 11s with nitrous.
We know that thanks to a few people turboing a 4.9 with even mild boost ran really wake this motor. But that is a big mod. This thread is for small mods.

The motor I am talking about is the later model 4.9's with the dual O2 system. One O2 in each manifold so it can tune either side of the banks separately.

GM Programed this motors to be smooth and made the timing and fuel curve to support that, they also made to give max power at low rpms They wrote the program for a lower hp cruiser smoother grandpa motor. (also cam but we are getting to that.)

It is commonly aware that a re-tune on the caddy chip while still in the caddy brings up an average 20hp and 15lbs of torque. Waking this motor considerably. So a chip with a reprogrammed fuel map and timing helps the 4.9 greatly. In a caddy "fast chips" showed the Dyno increases with there fuel maps. So this is a fact that the 4.9 program can be re writing to unlock a great deal of power.

Cam the stock cam is not just average performance it is a down right torquer RV low rev cam. I cam be idling along at rpms, yes 1200 rpms and stand on the gas and blow the 245's right off the rims. The came is meant for hauling a big car. So got to swap that. Delta cams are $130 USD plus a $30 core charge.

The New Delta cam is worth 15% increase because it is a drastically changed grind this motor is no longer the same motor. You end up with a very broad power band getting much closer to a real V8 and less like a tractor trailer motor.

Exhaust. OMG what a difference. I have 2 systems that can be changed quickly on my car. My "race/loud straight side exit exhaust, (still in city noise limits) and my Silent daily cruiser emissions test exhaust. There is a HUGE seat of the pants diff between the 2. So exhaust swaps and larger piping with a good exhaust really helps. I need to get this system dynoed to see what it makes and I will when time and money permit.

Allante Intake. Prices seem to very all over the place. Some places with blown allante motors or complete cars will nearly give you them. Then the prices goes up to the guys that know we want them, so they and pull them right from the free or cheaps cars then post them on ebay for 200-300 bucks.

Injectors 19# ones with an adjustable FR yep the 5.0 Mustang injectors are direct replacement for the Caddy and offer slightly better atomization they are only .5 larger, Caddy is 18.5 , Mustang is 19 and they just clip in without problems.

No one has made the true answer to how much power you get simply removing all the extra caddy accessories or freeing up the intake so but estimates are had at 5-8hp going to a true cold air induction kit.

I think just buy installing the chip, a good exhaust and removing the accessories you should be in the 230hp range and 290 lbs of torque.

I am almost sure, that you can take a 4.9 and without changing the block or heads, you could get 300hp Whit the precious small mods and then toss in the cam and intake.

I mean it has an improved fuel injection system, nearly 5 liters of displacement. It just needs some tweaking to make it a real V8. I am slowly working on making it go faster.

For me having an aluminum block V8 that was almost identical weight to my V6 was just too much of a tantalization for me. It is just so cool to have something that normally is REALLY expensive. No kits to need to install, The engine fits in there like it was made for it.

If I can run 15.0 out of a 2.8 V6 on motor along and 14.6 with a baby shot of nos. I am sure I can get the 4.9 into a low 13 or high 12 second run. It might be easier with a 3.8SC or Building a Turbo 3.4 DOHC. but that is simply not the motor I want behind my head.

Please people lets try to keep this thread civil.

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85GT 5spd MSD Everything,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. Cant wait for Dyno Time and Track Results. Not Your Average 4.9 245/50/16's www.captfiero.com Cadero Pics

I've always woundered myself why this engine is such a boat anchor. I went 3800 sc in my fiero but our sunfire just blew up and I'm seriously considering a 4.9 for no other reason then I wanna see the looks on peoples faces when it goes down the track with open exhaust.

Any way about the engine As you stated with the low hood line I'd imagine that the intake would be pretty restrictive but what are the heads like? How big are the valves? Being a smaller displacment engine I'd imagine it could go a little higher into the RPM range. Oviously i dont' know much about the 4.9 and i prolly jus created more answers then helped any one but hopefully we can all learn from this long needed (IMHO) Thread.

My 4.9, done by Fiero Factory, was my first converted car, my next was the 3800SC, followed by the 3.4 TDC. I always wanted more out of the 4.9 and didn't know how to get it. I'm very interested in how this all works out. Though I'm not into drag racing, the same issues plague my 4.9 when auto xing. I really wish someone would develop a set of headers, I've seen one or two sets of custom made sets, but the cost is prohibitive. Keep up the good work.

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Ron
Freedom isn't Free, it's always earned.
My imagination is the only limiting factor to my Fiero. Well, there is that money issue.

[This message has been edited by blackrams (edited 12-24-2005).]

quote Originally posted by markviiisvt4: I've always woundered myself why this engine is such a boat anchor. I went 3800 sc in my fiero but our sunfire just blew up and I'm seriously considering a 4.9 for no other reason then I wanna see the looks on peoples faces when it goes down the track with open exhaust. Any way about the engine As you stated with the low hood line I'd imagine that the intake would be pretty restrictive but what are the heads like? How big are the valves? Being a smaller displacment engine I'd imagine it could go a little higher into the RPM range. Oviously i dont' know much about the 4.9 and i prolly jus created more answers then helped any one but hopefully we can all learn from this long needed (IMHO) Thread.

another forum member (whos name escapes me right now) had his 4.9 heads done with larger vlave put into them, 1.94/1.50's which is a popular small block chevy valve size. now sure if he had the heads ported but hes running an allante intake with a reground cam. I bet he'll see in the 250hp 320lb-ft range

I saw a picture here of a 4.9 with a holley 4bbl on it and tried to find out more but couldnt. Id like to see of the 4bbl was mated to the intake

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+ an 88 Caprice 9C1 Police Package
--Adam--
IM AOL: FieroGT5speed

quote Originally posted by GTFiero1: another forum member (whos name escapes me right now) had his 4.9 heads done with larger vlave put into them, 1.94/1.50's which is a popular small block chevy valve size. now sure if he had the heads ported but hes running an allante intake with a reground cam. I bet he'll see in the 250hp 320lb-ft range I saw a picture here of a 4.9 with a holley 4bbl on it and tried to find out more but couldnt. Id like to see of the 4bbl was mated to the intake

I can't wait for spring as most recall I went thru my 1st bottle of spray on the 4.9 with 70-100 shot jets. I was Very disappointed in the track performance as it never broke my best ET (14.1 no power adder and 14.3 on the N20 My MPH drastically changed from 97 to 105 so it's making more power, and I never sprayed at launch so I have to find the right launching etc.) I wish I had the cash this year to do some testing but I think that the 3.33 Final Drive might be the best choice I have the 2.97 and my 60ft are horrible, then again the stock stall of 1200 hurts also. I have driven Ed parks car and I have tons more upper end then his. So yes Rock crawls programming helps. (Of course when I drove his car it was pinging real badly above 3000 rpm so it may have been gas, tuning etc.)

The forum member you are talking about is 'GT" and here is the thread. I'm very anxious to see how the larger valves help out.
https://www.fiero.nl/forum/Forum2/HTML/061613.html

I disagree that the above mention upgrades are easy. Being that I'm not even shade trees they are out of my reach unless I find the money to have someone knowledgeable do them for me.

IIRC When PBJ just slapped the turbo on his he hit mid 13’s he really didn’t see the huge improvement until he opened the intake up. Breathing is the 4.9 Achilles heal no doubt about it. Rock crawl even notes that the cars just don’t perform right when not geared correctly. I know I need to get my tach calibrated as mine is shifting at 6000 RPM (on the tach) at WOT. I do notice a power drop of where I fall forward around 5500, The spray removed that power drop off.

Honestly there is a lot I love about my 4.9, however I'm really thiinking hard about Selling/trading and going 3800Sc route. IMHO the 3800SC is the best choice for our cars.

[This message has been edited by linenoise (edited 12-24-2005).]

David - the 4.9 was never designed to make horsepower - it was designed to have a commendably flat torque curve for a luxury car. You can certainly liberate a bunch more power via the usual - less restrictive exhaust, different cam etc., but to really change the profile of the engine I think you'll find that the heads are the bottleneck (just like they are in our V6 Fiero engines).

I doubt there are any shortcuts to power except for turbo or supercharging, which works when less brute force methods fail. I also don't know if anyone has bothered to do much with the heads, although you might want to spend some time googling that engine. Most engine swappers I've seen go for the NorthStar alternative which at least has better breathing potential.

Maybe better to just reduce any bottlenecks in the intake and exhaust and glory in all that torque you have!

And the guy who used the Attlante top manifold and polished it? Ravishing! Killer looks! Get out the Dremel, Dave.......

[This message has been edited by BillS (edited 12-24-2005).]

I agree that there is a lot of potential in the 4.9 but I like it for what it is and that is a torquey motor with the distintive sound of a V8. Any motor can be modded to produce more power but you reach the point of diminishing returns quickly. For all the effort of modding the 4.9 you are quickly going to be in Northstar territory in terms of cost.

For me just unbolting it from the Caddy and bolting it in is good enough.

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88 GT T-Top, 88 Fastback Chop-top (Archie #14), 1984 Indy, and 88 Chop Top T-top
Firebird Interior Installation Website

[This message has been edited by jscott1 (edited 05-16-2006).]

It is in "my humble" opinion, that the 4.9 should be able to run 260-280hp very easily. I am going to be the test mule. If I can find the time and money to blow on the Dyno runs, I will get a baseline before I start mods and I will try to test after each mod. Peak Numbers are not nearly as important as the entire curve. So a graph would really be helpfull.

Well Wish Me Luck.

P.S. if I were to choose a different motor it would be a DOCH V8 with a Turbo.

quote Originally posted by Capt Fiero: T Cam the stock cam is not just average performance it is a down right torquer RV low rev cam. I cam be idling along at rpms, yes 1200 rpms and stand on the gas and blow the 245's right off the rims. The came is meant for hauling a big car. So got to swap that. Delta cams are $130 USD plus a $30 core charge.

Where can I find the specs on this cam?

Are special springs/lifters/pushrods required?

[This message has been edited by DanielKJenkins (edited 12-25-2005).]

.300 lift at lobe, but don't remember the duration, I think it was around 210 at .050 single pattern grind. They sell it as a drop in cam, many people are using it.

So this isn't the cam ground to the Ford racing 5.0 spec.

This reminds me of another engine that pontiac built, the 400 and 455, about 1972 the 400's and 455's made roughly 200 hp and around 320-350 ft/lbs torque, but 3 years earlier the exact same engine was making 400 hp and around 450 ft lbs torque factory, the only differance in the engines was a high flow 4 barrel intake and high flow large valve d port heads, if im not mistaken the cam was roughly the same in both engines, so from the sound of it i figure the same thing could be done to the 4.9 caddy, even though it would be hard to find a good set of heads for one, a set could probably be built out of the stock heads with opened ports larger valves and shaved. In the 1972 pontiac engine the valve size was 1.92/1.66 valves with a 119 cc combustion chamber, where as the 1969 valve size was 2.11/1.77 and 67-72 cc combustion chamber. Even though the 4.9 is a much smaller displacement than the 6.6L 400 pontiac engine, i figure the same could be done with one making slightly less power on a factory engine but just as much with a tweeked engine. These mods shouldnt be terribly expensive concidering you would use the stock heads and intake just have them worked ported polished shaved bigger valves ect.

well thats just my $.02 gl with the 4.9s out there

later

---Tim---

quote Originally posted by DanielKJenkins: So this isn't the cam ground to the Ford racing 5.0 spec.

Delta has different grinds available - with the 5.0 spec you need to modify the valve train.

I myself have noticed a difference with changing the exhaust, I seemed to have lost some once I had the resonators installed.

Currently I have ported out the heads, intake and exhaust manifolds - waiting for my cam to come in.

There is not too much material you can remove from the exhaust manifolds as they are fairly thin - however there is a incredible amount of material that can be removed from the heads and intake, in some spots I removed close to 1/8" of material. I also opened up the throttle bores to 2" and removed the plate from between them.

Now, I just have to find someone that can open up my throttle body bores to 2" as well. I am kind of iffy to do this myself as I am not sure if I there are any thing that I should be aware of - or would I be ok just to bore and install bigger plates?

Tim.

quote Originally posted by jscott1: For me just unbolting it from the Caddy and bolting it in is good enough.

Just for the record, I have never taken my car to the track, I have never taken any car to the track, I have no plans to take any car to the track...

but it seems that most stock/auto 4.9 run in the mid 14 range.

[This message has been edited by jscott1 (edited 05-16-2006).]

Most of the dynos I've seen are in the 158-170 rwhp range. Don't know what the Allante intake adds but claims are 20 hp or about 13 to 15 more rwhp. With proper mods, this engine should easily make 220rwhp. A 3" exhaust and headers will probably make the biggest difference. GM notoriously undersizes exhausts.

Besides the exhaust, here's what I'd do:

rebuild it, balanced and blue-printed with the sleeves bored out to make it a full 5.0L
Get the Northstar pistons in there with the appropriate overbore to match your rebuild specs. This will raise the compression ratio.
Take the heads to an experienced machine shop and see if they can modify the combustion chamber to accept bigger valves.
Port and polish them while you are there. Don't use stock GM valves. They are not ideal flowing. They probably have a rough valve surface. Use valves like the Fiero Store's v6 SI stainless steel valves. This will help with getting the air flowing smoothly.
Definitely go with a Delta cam, don't bother with higher ratio rockers...go with the cam for better lift.
Turn up the fuel pressure a little.
If you can't get an Allante intake, have someone build you something similar using an LT1 or LS1 throttle body. I believe someone on the forum can do this for ya.

Then get it tuned properly. In total, a 25-33% gain in rwhp can be had.

[This message has been edited by lou_dias (edited 12-28-2005).]

I wonder if any vendors would be interested in offering up turn-key 4.9's in the 250 HP range? Considering what I could save on the rest of the swap (wiring, trans, etc) it might be a real alternative to 3.8 SC or SBC. Would work for me since I don't have enough time to hunt down parts and organize the build up.

Well,
good luck and have fun. We love our 4.9 and plan on doing two more 4.9 conversions this year.
But to me adding 60hp and a gob of torque is Plenty. I love it.

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Proud Member of the North Florida Fiero club

4T60E Parks harness/ Rockcrawl chip-- more to come--

ASG 5.0 Engine Technical Specifications
The ASG 5.0 System was designed to update the GM W class cars to modern, fuel injected V8 power. It can also be used as a direct, drop-in replacement for the Cadillac 4.9L engine and 4T60-E transmission in cars so equipped.

ASG 5.0 engines begin life as a new GM Goodwrench Cadillac OHV 4.9L V8. This engine was the mainstay for Cadillac from 1991-1994 when it was replaced by the 4.6L DOHC Northstar Engine. The 4.9L OHV V8 is rated at 200 HP at 4100 RPM, and 275 ft-lbs of Torque at 3000 RPM by Cadillac. Cadillac mated the 4.9L OHV V8 with their strongest front-wheel drive automatic transmission of the day -- the Cadillac 4T60-E.

ASG 5.0 Engine Modifications:

The engine is balanced and blueprinted. This is a process wherein every important tolerance in the engine is optimized to produce maximum power.
The heads are decked, which helps raise the compression from 9.5:1 to 10.5:1
Heads are ported and polished
New, higher performance pistons are used
New, higher performance fuel injectors are used
Hardened crank shaft and rods are used
Cooper retainer ring is embedded into the head to improve head gasket retention under higher compression
Replacement air box for improved air flow
ASG 5.0 Transmission Modifications:

A new 4T60-E transmission is used, with valve body and pump modifications to handle the additional power.
*********************************
The above from http://www.angelfire.com/stars/mycaddy/asg.htm

Perhaps an important point here is that the entire drivetrain is involved. ie. serious consideration should be given to the transmission upgrades, due to the limited alternatives for the engine, if nothing else.

While this particular engine mod is no longer available, it's technology certianly is.

The route I'm taking is to use a crate motor with an Allante intake....all stock parts at first. Exhaust will be two dual 2" pipes running to two Supertrapp exhaust tubes. I'm thinking seriously about not using the Caddy torque convertor but haven't decided on that yet. The 4t60e has been professionally overhauled. If that doesn't give enough umph, then I might try the Delta cam. I've seen Scrabblegod's results with this mod, and I've got to say that with a revlimiter in place, it is a beast.

BTW: Delta has raised the price of the cams to $137 + $40 core

quote Originally posted by opm2000: ASG 5.0 Engine Technical Specifications

I attended a large W-body meet a while back, and a guy showed up with a white Lumina Z34, rumbling like a V8. He pulled in and lit the crap out of his front tires. Everyone was looking with the expression of, "how the...?" Our factory 3.4s won't spin the tires on demand.

Anyways, come to find out he had swapped in a ASG 5.0 using a 4T60e auto. I took a ride in it for about 30 minutes. It was weird to be in a Lumina with torque. The engine pulled pretty nicely to about 5000rpm, and it shifted out at just after 5k. It sounded really good. Well part of the meet entailed a drag day, and we took it to the 1/4mi with all of the other cars. He ended up running a 15.4. Not too bad, but I'm not quite seeing that their 285hp is making it to the ground, as 285 in a w-body is enough for a high 13. A stock Z34 auto can run about a 15.4-15.6. It shows that even with the ASG 5.0, it didn't make it much faster. But it was a fun ride! The sound was great, and it would light the tires up effortlessly! It is not a swap I'd do of course, but I see clearly why someone might, it totally changed the way that car drove, and for the good in my opinion.

I know this isn't worth much in this thread, just sayin ya know? I don't know where their 285hp is, because it didn't feel like that much. I'd say it felt around 230-240, which is inline with his 1/4mi. And it also didn't pull to 6k like their dyno shows, it definately fell off after 5k when he held it in gear to 5500.

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"all pushrod motor are better than the dohc because it has less rotational mass"
-rick17, MyMonte member, owner of a 3100 Monte Carlo LS

quote Originally posted by AaronZ34: ...But it was a fun ride! The sound was great, and it would light the tires up effortlessly! It is not a swap I'd do of course, but I see clearly why someone might, it totally changed the way that car drove, and for the good in my opinion.

This is what I have been saying all along. I enjoy my 4.9 for what it is, a fun engine to drive with some rumble. My car started life as a 2.5 Duke. The 4.9 significantly improves the fun compared to less than 100 hp. I didn't build my car to drag race, as I mentioned earlier. If I were building a drag car the 4.9 is the last engine I would choose. Sure it can be made fast but there are many other engines much faster right out of the box.

Capt,
I am very pleased with the reburn that Rockcrawl did on my stock chip.
I am thinking after reading 4.9 threads for the past three yrs or so that there just isn't much available because the market is not large enough. But basic hotrodding has found that engines are indeed air pumps. Since there is little you can do to change the internals (because of the small market) why not use boost. PBJ already proved that the engine can handle it over and over without failure.-I know that you stated boost was a "big mod" and maybe it is----but by the time you reprogram--change cams--etc etc etc perhaps the turbo wouldn't be so big or difficult after all.
I would like to know more about PBJ's turbo set up---size--plumbing and especially what engine management modifications have to be made????????
Have Fun--Be Safe
Jeff

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Proud Member of the North Florida Fiero club

4T60E Parks harness/ Rockcrawl chip-- more to come--

Hey-a-Cap'n-

I was speaking to Bud at Bud's Outback a few months back and he was just finishing up a prototype bolt-on for the 4.5/4.9 engines. It's a new set of roller rockers (either 1.7 or 1.8, can't recall) and the steel arms that they bolt to. The arms are aluminum in the 4.x engines and prone to breakage but his are to be steel like the Allante's and will not break. He may have them in production by now. All you do is remove the valve covers, remove the rocker assembly, and bolt the new assemblies on. No adjustments, just bolt and go! Sounded like a great way to pump up the power without tearing the engine down. He's at www.gr8grip.com .

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-Rick Stewart
85GT 5.0CaddyV8/Getrag 5-spd in progress...
www.V8Fiero.com

quote Originally posted by DanielKJenkins: So this isn't the cam ground to the Ford racing 5.0 spec.

no, delta can make the 5.0 racingcam, but it is not a "drop-in" cam, the milder "drop-in" cam from delta doesnt require valvetrain mods

quote it turns out he actually had computer problems that were limiting his performance. he changed to the 19 pound injectors,

Hi Aaron-

What did he change from? I had my stock injectors cleaned and flow tested and each one flowed over 19lbs/hr.

-Rick

The caddy's can use the 19# mustang injectors. The same ones the Fiero's use to my knowledge. I am on a couple of Cadillac Performance forums and they have had good results with them.

The other thing that makes a huge difference is a non stock chip in the caddy. GM gave up performance in favor of making this motor a super smooth motor. A tweaked chip as proven by more than one chip burner. A re-done chip wakes the 4.9 up considerably.

I have no proof myself so I can't go into very much. But I do plan to get Dyno numbers and find out what this motor is making.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Cant wait for Dyno Time and Track Results. Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Delta Cam and Allante Intake Soon.

Bump... any progress?

Nope ran into some other stuff which has kept from doing any serious car upgrades for the time being.

Posted some fun video's last week though.

How is your Caddy coming along. ;0 any progress on that.

I saw those videos and enjoyed them. Actually I saved them to my hard drive- keeps me sane until my car is roadworthy.

The 5.0's coming along. I updated my 4.9 performance thread with the latest. Tomorrow I drive about 100 miles round trip to get a 'real' exhaust put on. That'll be the first real chance I get to test everything out. I'll update the 4.9 performance thread after that.

-Rick

la la la la, connect the dots... bump

[This message has been edited by aaronrus (edited 06-07-2006).]

I have always been interested in doing the 4.9 swap because of that flat torque curve.

It hasn't been all that long since even performance cars had 5000 RPM redlines. A 5000 RPM redline doesn't bother me, especially since I normally keep the engine below 4000. I like a low redline if it means I have gobs of off-idle torque.

It seems to me that an engine with that much torque ought to pull hard, but in a car like the Fiero it will run through the first three gears pretty quickly.

I'm not looking for low ETs; I'm looking for a fun, torquey motor that doesn't cost a lot. If I were looking for low ETs I would go with a 3800SC or an SBC (or perhaps even a Northstar) rather than a 4.9, but "speed costs money" and those alternatives are more expensive and complex than the 4.9 install is.

The later 4.9 stats of 200 HP and 275 ft-lb are not all that far removed from the Mustang motors of the late 1980s, which made around 215 and 300, respectively; and as I recall the late-80s Mustangs had fairly low redlines compared to the cars of today. That's more or less the standard I consider when thinking of "performance", anyway; it may not match up to today's cars, but I don't care about that. I care about what will make me happy.

Isn't that ultimately what ought to drive your engine choice? What makes you happy?

Ed

It is too bad that Racingman24 rarely posts anymore... his 4.9 is beautiful and he did quite a lot to it before he installed it... cam, computer, porting/polishing, Allante intake, etc...

There is nothing wrong with the 4.9, his hauls arse.

I don't post anymore? o, ok.

The 4.9L is a decent motor. I like it. It may not get my ass down the 1/4 as fast as some other motors, but I don't think driving in a straight line is racing. Not to take anything away from it, it's just not my thing.

And as far as mods to my engine, myself and FieroMaster88 have almost identical engines. Mine is a '92 Deville, with ported heads and intake, Delta cam, very short custom exhaust, Allante intake, Rockcrawl chip, and of course all the little things, like K&N filter, platinum plugs, Race wires. For what it is, it moves pretty good.

And I will say this, a 4.9L, in stock form in a Fiero, while decent, isn't all that impressive. I would know, I just drove a bone stock 4.9 with a 6 speed in an 85 se, and, while it's no slouch, it wouldn't hold a candle to mine if I could ever keep it running.

If you mod it out, and spend a little bit of coin, not even a ton, it will go like crazy. Sure it runs out of steam around 5k. So what. You gonna be doing 1/4 mile runs everyday for the rest of your life? Yea, neither will I. Makes a great daily driver, a fun autocross car, and a decent straight line racer.

It's all about what you want. I wanted a V8, but didn't have the money for the full Archie kit. So I went this route. And, while it runs, I love it.

Ok, so did I answer any questions, or did I just go off on my own little soapbox rant there????

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Used is such a harsh term. . . I perfer "Previously obsessed over" ;)
88 base coupe: Busted again
Wait. . . Did I just say I can't wait to do more work on my Fiero?. . .what, am I retarded?

quote Said by Crazy Dave "You can take Steve out of the trailer park, but you can't take the trailer park out of Steve."

(\__/)
(='.'=) <<<< Cute Bunny.
(")_(")

Please don't take this the wrong way, but you really need to think these things out. I have bull headedly tried to build some motors in my youth that just would never work. I didn;t listen then, you may not now, but think it thru.
That motor was designed by professional engineers to be what it is: smooth running, low end torque. it was never designed with more than occasional highway passing in mind. someone already pointed out he drops in power of some existing sized motors in newer years. now motors are designed specifically for a function, and that may not include performance options.
A lack of suppliers or available built performance motors is a good indication there may not be as much there as one might think.
read and research. I hope I;m wrong about this, but the lack of aftermarket support is a warning bell to me.
Use a motor for what it is, not what it might be. good luck on your quest, I hope you have better luck than I had.

I loved driving my 4.9 the way it was, Driving a stickshift 4.9 vs a auto is like night and day And I had tons of fun with mine, I liked it alot, But Earl is never happy unless he's doing some sort of engine swap Or work on his fiero. (when my 3800 sc 2 is done im thinking in buying another fiero).


One day I plan on having a Northstar fiero, 4.9 fiero, 3800 sc 2 fiero, LS1 fiero and a ecotech fiero. So instead of swaping out engine after engine, I need to buy more fieros of course I will be 90 years old by the time I have all these fieros.


Like jeff says, One could add a turbo to a 4.9 and do pretty well. A megasquirt pfi system controlling a turbo 4.9 would eliminate alot of nicks in a turbo install. or else one would go through heck getting countless chips programed ( Unless PBJ still has the chip schematics when he did his turbo setup)


Another concern is the alluminum 4.9 rocker bridges ( I kept a extra set with mine but never had a problem in that department, I don't know if you can still get the metal ones But they will help alot. On PBJ's final setup, I believe he had cam work and a port job done.


These engines are actually pretty easy to tear down and put back together (The blocks are mega light as well without the liners), Alot of engine rebuild shops are scared of the liners on these, But there pretty easy to do.

[This message has been edited by 86fieroEarl (edited 06-08-2006).]

Here's a little bit of information that may help you with your project:

Horsepower = (Torque (ft/lbs) X RPM) / 5252

290 Ft/lbs from a naturally aspirated 300 cubic inch engine is pretty impressive. You'll find bigger gains by making changes that'll allow the engine to reach higher RPM. If that engine produced its 290 Ft/lbs at 5300 RPM it'd be a 290 horse engine...

Remember that HP, torque and RPM are all related and you'll do fine...

quote Originally posted by Whuffo: 290 Ft/lbs from a naturally aspirated 300 cubic inch engine is pretty impressive

It really isn't. Most of today's engines make at least that much, and most make 1hp/cid too. The 3.4l DOHC makes MORE than 1 ft/lb per cid, and it is a high revving 24 valve engine. It also btw makes more than 1hp per cid.

An impressive specific output nowdays, for factory N/A, is 1hp/L. Very few motors are at this level, namely the Porsche 6.0l V10 (605hp), Honda/Acura 2.0l I4 (220-240hp), BMW 3.2l I6 (330-333hp), and a few others (Excluding motorcycles, most sportbikes are over 120hp/l). But to my knowledge, no American automaker has hit this mark yet. I want to say the closest was the W41 Quad 4, at 190hp with 2.3l, ~82hp/l.

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"You sit here and try to challenge my intellegence" -vega

Hmm, I wonder why?

Personally I don't care what size it is anymore. A 200hp 290lbs of torque Fiero is no slouch. The 4.9 can be modded can go faster than stock does make a fun street car, is impressive compared to stock, and " I Enjoy driving it" I have made 14.6 passes before with a hopped up V6 and this is seat of the pants much faster than that. Someday I will take it to the track but for now. I am happy with it.

I really need to get my car on the Dyno.