griz

I pretty sure my car is horribly out of tune. I need help figuring out how to time the car and if i need to adjust anything in the carb. I have a 79 cutlass thats mostly gutted and weighs in at 3515lbs with a 1976 455 transplant with a th400 (i bought it like this). i added a 373 posi rear to it an edelbrock 800cfm carb an edelbrock intake, hooker supercomp long tubes. The cam that was in it was a total mystery and i have no clue what the timing was set to. When i ran it at the track it ran consistant 14.2's at about 90mph. it would stop making power around 4200 rpm. So the research i did led me to believe it had a RV cam in it. So i changed the cam, springs timing chain, distributor and purchased some E heads and had a vavle job done on them and added a 10" 2600rpm stall. The car now runs 14.50s and would fall on its face at 4500rmp. What should a car like this run? Oh the cam is a comp grind 230 236 520 523 on 110 lobes. How should i go about timing this monster? Is the carb fine or do i have to re jet it? Sorry for all the questions but i am new to old school. The only car i have built is a 12 sec 96 lt1 camaro. so i know nothing about carbs or distributors.

88 coupe

In all gears?

What tires? What 60 ft times?

What research? Did you degree it?

Did they replace "J" or "Ka" heads?

Did you degree it?

At what speed?

Like the ignition was turned off?

In all gears? Did you check the plugs? What did they look like?

Lots of variables, but low thirteens would be a realistic guess.

Disconnect the vacuum advance (plug the port at the carb) during the entire troubleshooting/tuning process.

Set the full centrifugal advance at 35° then note the RPM where it reaches full advance, and the initial reading, then get back to us.

One thing at a time. You already have a can of worms going, you don't want to make it any worse.

The basics have not changed.

Norm

griz

-yes it would stop making power at 4500 in all gears
-i was guessing it was a rv because it would make massive torque off the line but would run out of breath at 4200rpm and no i didnt degree it. it was the cam installed when i bought the car.
-yes j heads
-no i just put it in the way i know. tdc dot to dot.
-bout 87-89mph
-not sure what power loss was it wasnt complete, just strarted slowing down and yes in all gears. didnt check the plugs
-dont have a clue what full centrifical is and how do you see 32 degrees my timing tab doesnt go that high.

This is why i am asking a lot of questions i have a basic knowledge but a lot of this confuses me.

griz

oh tire are the micky thompson drag radials. dont know exact size but they are 10.5 wide and 26 tall. 60 times are mid 1.90s and with old set up i got high 1.80s

88 coupe

It went right to 4500 and stayed there? Did it run smoothly, as if you were cruising down a highway?

Any strange sounds?

Guessing is not "research". There are many reasons why it might give up that early. Cam timing is not one of them.

"Run out of breath" is just as vague as "falling on it's face". Did it go straight to 4200, and stay there? Still smooth?

If you had degreed it before you took it out, you would have known exactly what you had. Might have saved you from making an unnecessary cam change.

Odds are, it's OK. As long as no symptoms point to it, you can relax.

Working with what we have: 14.2 @ 90 (1.88 and a problem at 4200) to 14.5 @ 88 (1.95 and a problem at 4500) with:

A cam/spring change: In a 455, that cam should go to 6500 easily.

Distributor change: What distributor, and what kind of condition?

Head change: Were the original gaskets made of stamped steel?

2600 stall: What did you take out?

Only two (one before and one after) sessions? Were the weather conditions the same?

It slows down in first, before it shifts to second? Did it do the same before, and after, you changed the cam?

Do it. Plugs, wires, cap, rotor, air, and fuel filters. While you are there, check your exhaust system (catalytic converter?) for restrictions.

This link should cover the basics.

You can use an "advance" timing light, or timing tape is a less expensive alternative.

Or you can measure 1.83" from 0° on your balancer and mark it, for your 35° reference line.

Same reason I ask questions.

Norm

tonycpe

You may want to check your fuel delivery. been there,

griz

The carb is brand new so i might have to recalabrate it. I shift the car myself cause there is no kick down cable and will shift at 3200 if i leave it in drive. the car sounds smooth all the way up and just looses power at 4500, but no bad noises. I dont know what the original stall was but i know it stalled out before my current one so i am guessing it was stock or near stock. what is a safe rpm to shift it at considering the bottom end could still be 1976 original? and fuel filter, air filter are brand new and no cats i have super comp long tubes to true duels to 2 50 series flowmasters. i was told that my 455 wouldnt wind high enough to need a fancy distributor so i went with a summit hei. do you set all 455 to a certain degree of timing or does it depend on cam/carb/heads and stuff like that?

Oldsguy

There should not be a kickdown cable for the TH400, it should have a solenoid that does that operated by a switch on the carburetor or the accelerator foot lever depending upon the car. If the engine and transmission were transplanted and the car originally had a TH350 that may be why the solenoid switch isn't intalled and operateable. Something to look into.

64Rocket

I'm sure the cam degree is way off.
Too big a cam for the compression.
It also has a fuel problem. Fuel line to small, fuel pump not putting out enough volume.
Jetting in the carb.
Sounds like over camed and not dialed in.

Gene