Thread: 454 fiero

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I had a problem that was very much like yours. i went for two years before i found what was wrong. the cam was bad. i had no lifter noise. the car ran just fine around town even on the highway as long as you did not get in to it. it was a gutless dog and would start to backfire under a heavy load. i got a new cam. just because i wanted a bigger one. and the trouble was gone. but in the two years before the cam change. i changed fuel pumps, fuel lines,carbs, exhaust,distributors,wires. nothing helped. I like your fiero. and am building one using a gm transaxle. i would like to see more pictures. and find out more about the build. thanks and hope this helps. Gary

well the car is till broke down. I bought a holly avenger an I need to rejett it an what not an the starter still grinds new starter new flywheel new shims new bolts new everything new bracket on the back mounting it to the engine block. It sucks it driving season an im still down all well. thought Id post a up date .

I also just changed the malory ignition to a stock HEI to try an see if it was the ignition still didnt change anything.

with all the changing of the timing I'd be wondering if the gears on the cam & crank are lined up maybe the chain is off a tooth. That would answer a lot of your questions.

I may have missed this in the posts, but what is your vacume at the un ported side, or at manifold, at both idle and cruze, or from as much as I could get to buffer, on easy throttle advance, does it drop sharply,or heaven forbid increase? remember this is at steady reasonably slow throttle advance. Vacume is an indicator, or if you will a good start as to what is going on, as a carb. needs a vacume signal, unless of course pressurized. One more thought came to mind, how is that coil or have you allready been there it takes some power to light a fuel charge. look... don't go buying new stuff on my questions as I am learning the hard way but at least we have great support! That new hei is that coil in cap? and CFF yea I have fought the cam to crank gear timing myself my bad...yea I missed it. Ran pretty lethargic and with two fours just increased the problem.

well.. what has happened? I really like your build!!! love the Fiero

Well its done for now the car is running fine. I changed the malory distributer to a HEI for no real reason. an I brought the starter to a starter professional an he new exactly what I needed instantly a milled nose cone. changed the nose cone an now there is no problems. An well I finally found a 20 dollar quadra junk, an bam the car runs getts like 10 - 12 miles to the gallon. still has a flat spot when you slam it but the car runs with no surging or stalling an getts great gas milage. I have all winter to figure out why the car has the flat spot in the throttel for now im crusing this thing an its a great feeling it has plenty of power even with the flat hesitation. once I can figure that out I know this car will move. she seems to run hot around 210 i might put a thermostat back in it but Im not to sure. but thank you guys for everything I will keep working on it an posting it. now its gonna be more cosmetic then running stuff but thank you all very much.

Hi guys, just read this thread right through and man how I have felt the fustration and pain for you guys that have freely given advice and to you fieroboy for thinking you had it won then to find not.
One thing that jumped out at me is when one is buying any sort of modified car,get as much information as possible on who did what,phone numbers to contact them, etc so that one knows exactly what has been done. Or if something isn't right, be prepared to pull the engine and strip it to measure and check everything internally and that it has been assembled correctly. That may sound like a major job but for the price of a gasket set,fresh liquids,etc., it is cheap insurance to know that it is right. I brought my 350 sbc with a semi hi rise intake and q/jet and boy that baby ran so good. When I rebuild the car I purchased a Off, 3x2 intake with rochester 2barrels and had the carbs rebuild by a specialist carb. shop who reassured me they new what they were doing. It was a load of sh*t and I ended up sending the manifold complete with carbs. to the other end of the country to an expert on tripowers,the best thing I ever did and now that motor flys sweetly. The carb shop rebuild the carbs as three seperate carbs and not as one primmary and two outer secondary carbs with proggressive linkages.

Well that flat spot is probably just the cam thats in there, but if it's running good now beside the flat spot, enjoy it for a while. I am glad you've finally got it worked out.
It's hard to figure out stuff when you can't be there in person to see it.
Like whiplash said I think all the guys on here could feel your fustration, mostly because we have all needed a hand at one time or another with something we could not figure out. Glad you finally got it and I bet thats one heck of a fun ride.
Kurt

Ok so the car has been running pretty good so far this summer. Got a quick question for u gear heads . I have no idea what my cam specs are. I was wonderin if i messure the valve travel by takin the valve cover off an turnin the motor over by hand . will that give me a acurate messurement of my cam specs?.

Yes, No, Maybe, Probably Not.

Got that?

Pull the valve cover, if it's a hydraulic lifter cam there is a casting hole in the head big enough to pass a lifter tool that will pull the lifter out and replace one intake and one exhaust lifter with solid lifters. Then replace the pushrods and set up a dial indicator and you can measure lift at the pushrod. Multiply by 1.7 (BB rocker ratio) and you have lift.

For duration you will need a degreed damper. Now, when the pushrod reaches .050 note the reading on the damper and rotate the engine to peak lift and back down to .050. Now you have duration.

OR, pull the intake and do it at the lifter. Be sure to use solid lifters.

WHEW, I need a libation!!

Yea if i have to tear the whole top half of the motor apart i will just wait till winter when i chang the heads to the 396 heads that i bought. I was just thinkin. That the torker in tak is a 2500 - 65000 rpm intake. I want instant power an my motor is gonna rev past 5000-5500 rpm so i was gonna change the intake to a lower rpm rated intake. Just thought if i get the cam specs with out tearin the motor apart it would be easyier to pick the intKe. I want power at 1200 - 5000 rpm

I just discovered this thread and read it all. I'm not a carburetor man by any stretch of the imagination, but I've had enough Holleys to know that I am not compatible with them. They are great for racing, easy to adjust and service, but they require constant attention. One good backfire and the power valve is shot. The carb then has to come apart to be fixed; no thanks. Of the 6 or 7 Holleys I have owned over the years, only 1 was dependable. On my coupe I run an old Quadrajet that came off of a '78 El Camino I once owned. This carb is 32 years old, has never been apart or serviced in any manner, and still performs perfectly. Many of my friends run Holleys with great success, but those things just don't like me.

As mentioned above somewhere, your "flat spot" problems could be the fault of the cam and head combination. Many years ago I had a '68 Olds 442 with 400 cubic inch engine. Someone gave me a cam for a W-33 Olds 455. I thought that cam would really wake up the 400... WRONG!! If I fiddled with the timing and carb to get a liveable idle, it wouldn't run above 2500 rpm (belch and backfire); if I adjusted it to run at speed, it wouldn't idle and had to be constantly revved. After 2 days of trying I put the stock cam back in it...

With that Torker you are gonna have a flat spot at low rpm's.
I almost hate to say this but I bought one of those back when I was gonna run my 351 cleveland only at the drag strip. The Edelbrock Performer RPM Air Gap are supposed to be really good and have a great broad pulling power band through the entire rpm range.
It's something like 1,500 to 6,500 rpm. You know that guy probably put a cam in that car to match the intake manifold. If you have to pull the heads are you gonna have to pull that motor? If so I would give serious thought to changing the cam as well.
If you don't know exactly whats in there. Talk to Pat McCarthy he can hook you up.
A lower rpm cam would probably be more in line with what you want, but then you could match your cam and intake up to the same rpm range. Probably a Air gap intake or a nice Weiand dual plane intake would work best for what rpm's you want to run for the street. Then a cam that pull's just off idle to about 6,000 rpm's.
Kurt

Yea i was gonna pull the motor in november right around when i need to park the car. I plan on doin the heads then. I just dont have enough money to buy a whole upper end kit if u know what i mean. But after researchin intakes online. I learned about the rpm ranges an what not anrealized that no matter what i do the torker intake isnt goin to start to pull till 2500 rpm regardless so i lose 1500 operating rpms. Thats alot of rpm when the motor only makes 5500 rpm. So im thinkin that if i got a difrent intake that oporates at like hell 1000 -5000 rpm that would be ideal. The 396 heads i bought cheap off a friends dad N hes the one rhat mentionded the intake issue. He said the cam i hVe is just over stock specs . He said tht the intake was probably to high a rpm ratinf for the motor an he said i should get a duAl plain not a single wide open intake. He said that intake was more for like circle track kinda racin were ur already in the rpm range for operation . Wre as i want somthing that will be more like drag aplacationwere i can run hard from light to light.sorry if the spellin really sucks . I do theses posts from my phone.

Ok so I took an replaced the intake that was on the car with a stock intake. Put the holley carb on an a couple hours later the car runs a million times better. It a huge difference in comparison. I was too poor to go threw with the upper end kit but hey there is the future as long as 2012 doesn't kill us all right.