Thread: 454 fiero

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Even if that BBc was built with low compression at 8:1 it should still be a blast to drive and should smoke those tires all day long. The amount of work it took to get that motor and trans into that car, and the details like the dial oil filters etc I bet the motor build is solid with no cut corners. I bet your timing is way off and your carb needs to be tuned. I suggest you get a book. DVd on tuning holley carbs and read as much as you can, and buy a good timing light and again get a bok and read. You bought a unique car that is always going to be a project. Its not like you gonna go to an auto store with most idots behind a counter and ask them for a part for your car. Everytiing is unique and your mecahnical abilities are gonna have to improve greatly if you want to put any miles on that car.

Sweeet ride dude.
I dig the non-transverse engine setup myself,
and the Chev engine should be easier on the wallet
as far as parts costs go.

wondering myself how accessable the front
of the engine is here.

Thanks for posting! Njoy!

ok so I got all the timing set the points an what not the timing advance is working right. I noticed all the spark plugs were carbon fowled an were gapped almost .50 so I cleaned them off an re gaped them. I set the timing points in the distributer 4 degress ahead, i did all this with a budy that knows somthing or the other about these kinda motors. An there still was a dead spot in the throttle, that stalls the car when you really get on it. So he said that I should just go to a junk yard an buy a quadra jet an rebuild it an try it on the car. he was saying that holy carbs have always been junk to him an that hes replaced many proformace carbs with stock gear an gotten better results. So I was wondering if you guys have ever heard of that down grading to achevie more proformance. I have a holly 750 DP right now on it. he really thinks that its the carb just being a peice of shit.

Ok so I decided to get a rebuild kit an rebuild the carb. The timing is spot on top dead center an advanced 4 degress. I then was adjusting the carb an it started to back fire an well catch on fire. so I stoped tuning the carb. Im buying a rebuild an I got a guy that im going to pay that will come to my house an tune it for me. an teach me a thing or two about tuning the carb he's also gonna double check my timming. I also noticed that before hand i checked the spark plugs an they were all gapped to .45 so I regapped them to .35. I also noticed that all the spark plugs were black so I cleaned them up. an what not. ever since I have been getting carb fires. So do any of you know what would cause the carb fires possiably?also I was on holly an they have a chart that says that I should have at least a 850 DP carb but I have a 750 DP could that do somthing. any who thank you.

ok so I dropped the car off at the shop today an he instantly said that the jets in the carb were too big. which is why it die's when floored. so one thing down. he's also gonna adjust my valve lash. he said that the valves where out an that that can also effect the car alot. He never said why the car was starting hard after it was warmed up, but Im sure its a combo of the two.

I want to see it pop a wheelie...

Sounds like good news.

alright I went down to the shop to drop off my cut off valve cover so he could adjust the valves. an he had the carb apart. So he was showing me the internals of the carb needless to say the rear float was stuck open so the secondarys were always getting fuel which is why the car boged out an didnt want to idel that good. the carb its self had alot of crap in it. an the second thing was that the base plate that was used to adapt the carb to the intake wasnt big enough for the carb so it was sucking air from the front an the back of the carb. so hes machining a new base plate thats big enough for the carb to seal proper with a new gasket an hes rebuilding the carb an thats a pretty good start so far. he said This will be a whole new car when its all said an done. I asked him bout the stall converter an he said more then likely its stock but not to worrie too much about it. stock or not he said this thing should get up an go. so im all excited.

Nice car!
Looks like who ever put it together took their time and did a good job. Carbs get junk in them and floats stick easily when they sit. Make sure it has a fuel filter, in-line is best to use, don't rely on the in carb type. I've seen many adaptor plate that were the wrong one. Do you know the guy you got it from, you seem to know what was done to the motor & whats in it.
Nice find!

Pat

While those heads might not be "perfect", a 454 in a fiero should be pretty nasty... you might be better off (econimically) to change your cam/intake to match the heads. Get something with a power band from idle to 4-5000 rpms....You should have a TON of torque. You could get more HP out of your engine with different heads, but torque is what you feel in the seat of your pants. Are you going to be driving it around at high rpms? If not, go for the torque... and start buying tires.. :-)

well there is a ton of tourque ( LOL i can spell) It def puts u back in your seat. but its not pulling wheelies. the funny thing is it doesnt really burn much of a tire since all the weight is on the rear tires it just goes but the thing that sucks alot is that there is still a dead spot in the throttle. so you have to kinda get in it soft at first. instead of just slaming it in the floor boards you kinda got to be gental with it for the first second. Even after rebuilding it changing the adaptor plate on the intake to carb changing the jet size in it to 3 difrent settings it still has the dead spot. I was thinking bout going to a junk yard an getting a quadra jet an just putting it on an tryin it out just to see what happens. its got a holly 750 DP on it right now. The guy that was helping me said that he thinks that the heads just arnt breathing enough. I figure I can get a set of the more desireable oval port heads for like 200 at a junk yard. an just change out my roller rockers an what not an try them out. I dont know its def fast I need to get a speedometer an a rpm gauge that works.

Could be differential gear ratios.

You might try a 50cc accel pump and/or play with the nozzle diameters to cure the flat spot. That's a smallish carb for that motor IMO ............

Kitz

Originally Posted by stovens

Could be differential gear ratios.

yea I thought about changing the differential gears it currently has a set of 308 gears but I figure with enough power I would push thou's gears with out a problem.

As for the Carb size I thought it might have been too small as well but everyone tells me it not. I'll try an get a video up an posted in a couple of days of the car running an the flat spot just so everyone knows what I mean.

the carb probably has an internal vacuum leak. pull the carb off remove the 4 screws that hold the float bowl remove the float bowl and jet plate put a good strait edge from screw hole to screw hole if you see any light under the center of the straight edge that's your problem experienced mechanics over tighten those float bowl screws and bend the carb body cut a piece of glass to the width rap i piece of 600 wet and dry over it with wd 40 carefully sand that surface until you have contact across the that surface reinstall the float bowl and jet plate with new gaskets. and DO NOT OVER TIGHTEN THE SCREWS what I think is happening vacuum is leaking not only from the transition circuit but also the main circuit vary common problem .......ted