HELP! New engine- will not run!

Put together a new motor, and the thing will not run right!
It's a 455- 30 over with 11:1 compression. The carb (70 quadrajet) has been swapped off of another car that has a similar setup (less compression, similar cam- jetted toward the rich side). The compression is good. It is using an msd pickup in a standard distributor to trigger a MSD 6AL. The distributor / 6AL setup was used successfully 3 weeks ago with a 350, and the gear was changed over for the 455. The motor sounds like it is missfiring all over the place- pops back through the carb, etc. Changing the timing does absolutely nothing- no effect at all!
The cam was degreed in, and is a Poston 112- 240/262 112 deg, set up with 4 deg. advance (built into the cam). All the valves are opening correctly. There dosen't appear to be any valve-piston clearance issues.
I am thinking that there is a problem with the 6AL. Wiring has been checked. Has anyone had these symptoms before?
PLEASE, ANY SUGGESTIONS WOULD BE APPRECIATED! Thanks.
Steve

 

It sure sounds like the timing is 180 off. I would double check that it is firing on number one compression stroke. If that is ok then put a timing light on it and look at how and when it is firing.

 

Have to agree that the distributor is off. Embarrased myself enough times on that to know the symptoms.ou:

 

I would also try to check the firing order
Sounds like that too :Smarty:

 

Thanks,
Firing order is right, will check the distributor.
Steve

 

Diconnect power to your distributor. Pull the #1 spark plug. Put your finger over the #1 plug hole. Crank the engine, when the compression pressure blows your finger off the hole note where the rotor is and that is where the #1 plg. terminal has to be. If it isn't where you want it pull the distributor up and reindex it and do the same procedure over again until you get it where you want it. Easiest way I've found that works well especially if you are "lost". ( I'm usually lost most of the time.) lol Mike D.

 

OK,
He tried a different distributor with the same results... what now??

 

Once I realized that the distributor actually turned clockwise, instead of counterclockwise.. -I'm not saying that that's the problem, but it sounds like a problem with the ignition. -or the cam was installed wrong..

Hope you'll solve the problem:TU: :TU:

 

Have you checked out the RPM Limitor Pill that plugs into the 6A? Perhaps it's a 600rpm pill and you want a 5500 in there... That would keep the limitor ON constantly.. Something to look at...

 

the cam was degreed in, and the timing events were checked a few times. Good thinking on the limiter, however the chip has been pulled out althogether, just in case. This is a strange one.
He's going to try swapping MSD's next out of the other car.

 

What pistons does it have?

Valve reliefs?

Lift of the cam lobe, and what rocker arms?

Just curious on your valve clearance issues.


Once you have the dist close, then just put a timing light on it, as if you were going to time it, and crank it over.. the mark should appear around 10-20 degrees advanced or so, depending on how much mechanical advance it has in it.

JW

 

Heres a real no brainer for ya. Does the car have good fresh gas in it? Bad gas will do the exact same thing. Been there done that!

 

Are your rocker arms or push rods adjustable? If so maybe they're adjusted too tight and the valves aren't closing all the way? o No: I had that happen on a (GULP!!) BBC once - same symptoms.

Larry

 

Is this thing running yet? You didn't go to a Bowtie did ya? :Comp:

 

I hate to say it but is the gas old? Sometimes our projects take longer than we realize....
I once bought a 71 GS 455 conv cheap cuz it wouldn't stay running. Guy thought it had a stuck valve or wiped cam. I pulled the intake hoes off the electric fuel pump stuck it in a jug of fresh gas and it ran fine. Next day it was running 13.0s at the track.

(now it's been sitting outside a bodyshop waiting to get in for 3 years....so the gas is probably crap again)

Bruce

 

Thanks for the replies...
The car is running...
It was quite a process to find out in the end that it had bad lifters! They were pumped up, and would not collapse, even when out of the motor.
My dad worked on this motor for hours on end, and he checked EVERYTHING else. The cam was degreed several times, the timing was checked and was dead on. The MSD unit was replaced (it may have been bad- made a noticable difference in idle quality, but didn't fix the problem).
New lifters, adjustable pushrods, and it was good to go! They always run better when the valves close, you know? This is the second time we got a bad set of lifters- 2 different brands/types too!
Steve