Having trouble with my zz4 crate motor

[ba60]

Well I got it in the car, but I had to use my fuel pump off my other motor which was fairly stock with a mild cam. What I'm concerned about is cylinder no. 1 3 &5 are running at about 560 degrees on the header and the rest all seem to be at about 180 degrees. I checked the plugs and they are all different with #3 seeming to be pretty rich and# 1 still white. I'm getting about 34 degrees of timing at 2500 rpms and I have the idle at about 1100 rpms so it won' t die in gear. I'm also getting some backfiring when I try to accellerate in gear. I'm running 3/8 fuel line. Could maybe the fuel pump is not enough? It is just a stock Chevy pump. I have the idle mixture screws at about 1 1/2 turns out. Max vacuum is at about 15. I checked the headers for leaks and the seem ok. I have the D shaped exhaust ports going into round 1 5/8" headers. Compression is 10to1 on this engine. The carb is a Holley 770cfm that came with it. Seems like a lot on a 350. Any advice is appreciated. I'm really concerned about damaging the engine.
Bill

 

[2old2fast]

Intake leak , missing vacuum cap...???

dave

 

[ba60]

Dave, I sprayed carb cleaner around the intake. All seems good. All the vacuum lines are plugged. They said to leave the vac. advance plugged and not use it. When I bring the idle down below 1000 I get popping from carb and exhaust. I assume popping from carb might mean intake valve not closing? Or too much advance? Popping through exhaust would seem to be lafter TDC correct? Or maybe a problem with exhaust? I'm still getting a backfire too.

 

[Gerry]

you need scrreaming metal on this one

 

[2old2fast]

Did you set the valves , or was that already done? Sounds like you might have some tight ones.....
dave

 

[ba60]

I didn't check the valves. I asummed they were done during assembly. I was thinking it my be the valves. I will check them tomorrow.

 

[2old2fast]

Easy to do ! Remember EO_IC exhaust begins to open-intake almost closed...
dave

 

[Screaming Metal]

Hey, back at my room, fixin' to watch a movie or 2. OK, check to see all is sealed, if no vacuum leaks, before you go screwing with your adjusters, it might be the motor is tight, new, adjust your timing to where your not running so much advance. If that doesn't help, then loosen off on your valve adjusters.
Is the cam a hydraulic? Could be one is too tight. All kinda things happen with motors. But, since its a new motor, I'd think that its probably in the timing. Check that first. Make sure that your centrif. advance is working smoothly and returning all the way.

 

[ba60]

It is a hydrolic roller cam. Itt won't run if I back off the advance. I makes it backfire. It doesn't like it if I try to set timing at 12. It backfires when I try to start it. Could it be a bad dizzy?

 

[roadmonster]

2 things:
1. You NEED vacuum advance on a T.
2. The carb is way too much.

A crate motor that's fine to drop in a Camaro or C10 will not work properly in a T. I had 2 350s to choose from, one from my '71 truck with 882 heads and Quadrajet, and a Frankenstein motor with small-valve PowerPack heads and a Holley 600. The tamer setup required minimal adjustments to turn it into a real rocket. If you go with a 4160 series Holley on a crate 350, you will not go wrong.

 

[Screaming Metal]

It is a hydrolic roller cam. Itt won't run if I back off the advance. I makes it backfire. It doesn't like it if I try to set timing at 12. It backfires when I try to start it. Could it be a bad distributor?

Well, yes it could be a bad distributor, make sure your getting a good hot spark. Make sure all the dist. wires have a good tight bond and thats its grounded good. Is it a MSD? make sure your 1-8-4-3-6-5-7-2.... and make sure all your plug wires are seated good. Is your cam one of those that has 2 of the cylinders reversed? This could be your problem.
Now, fire her up, idle her up about 1200 rpm, yea, I know its high, but, it'll work for what we're gonna try. Does it still seem to backfire and spitback?
Loosen off your dist. hold-down, don't worry about your timing light now, grab your dist. turn it so the motor starts to idle up some more by itself and smooth out. The motor will sound like its gonna run away, and start to sound shallow. Stop there, now slowly start turning nack the other way, you wanting the motor to just barely start laboring and the rpm will just start to drop. Lock it down there. I call this the preliminary sweet spot. Hook up your timing light, and see what you have.
Now, Idle her down to 875 rpm, set your 2 front corners about 1/4 turn to the fat side....if its still popping and backfiring, shut her down, pull your valvecovers and back off about 1/8 turn on your adjusters. This sucker ought to Honk at this setting.
Write down all your settings, where your timing is at, where your idle screws are set. Now, you should be able to fine tune from here and give her a extreme attitude!

 

[Screaming Metal]

Run your motor in some to help seat the rings and valves some, then if you had to back off that 1/8th of a turn to get it to stop popping and backfiring, crank her up and reset your valves. Use a old set of valvecovers and cut the tops out....makes a lot less mess than trying to run them without valvecovers.
Let us know how she likes her new home!

 

[ba60]

I think I found the problem!! When I bought the engine it was prewired and looked great, but the only wire that was right was no. 1. I can't believe they could screw that up. That sure would explain the backfires. I know I should have checked it. I now know to check everyones work, even GMP. Anyhow I'm looking forward to firing her up tomorrow. Thanks again for your help, this forum is the greatest.

 

[Screaming Metal]

Well, I hope that you have it, if its a SBC, it'll be 1-8-4-3-6-5-7-2. Double check it agian. I used to screw up the firing order on purpose on some of my guys to make sure they were looking for that sorta thing.
Like I said, on certain motors, they revised the firing order and reversed 2 cylinders to smooth out the firing pulses and it also added a few horses. I've seen guys set them up for a std. firing order, then try and start the motor, then it'd run like a 3 legged dog. If they had that on your motor, surely it's be in your paperwork. Competition Cams grinds the majority of the cams for that motor, since the cam had to be changed when they revised that firing order....
If you want to check it, loosen all the plugs about 2 or 3 turns, squirt some oil on the threads and start off on #1 bump the motor over 1/2 rev at a time, looking for the bubbles at the base of the plug where it screws into the head. If your bubble trail has the same order as the smallblock, its a std. firing order. If 2 of the cylinders are reversed, you have that other firing order..
Just a quick way to tell....

 

[ba60]

There were more than 2 wires in the wrong place. Most of them were. I set them in the order cast into the manifold which was the same as you show there. It would certainly explain alot about how she was running. As some as everyones awake around here I'll give her a try.( I live in a development) I think it was wired by the guys I bought it from not GMP. So who knows, maybe a new guy. Thanks for all your help.

 

[Screaming Metal]

Have you tried to lite her off yet? Let us know how its coming so we can help you get things sorted out....

 

[Screaming Metal]

If it still seems like things are a little off, pull the distr., pull #1 plug, hook up your remote start button, bump it up on top of #1 TDC. Stick your dist. in pointing directly at #1 plug wire tower on distr. cap, look at the wires again in that order, then give her a whirl.
Got to thinking, if they screwed up the firing order, chances are they could've stuck the distributor in off, too.
Good luck, we'll be waiting in the wings for a progress report....

 

[Screaming Metal]

With all respect, there are guys I've been in the racing business with for the last 35 years, and this one guy knows fords like the back of his hand, theres another guy I know and put a Hemi together with his eyes closed. We usually specialize, but a Ford firing order is diff. from a Chevy, yep, new guy, looking things over, probably put the cap and rotor on, not thinking....

 

[Screaming Metal]

He must be cruisin' around....I'm gone to lunch....

 

[ba60]

I'm back! She is a real tire shredder. Everything seems to be working great. total timing at about 36 degrees at 3000 rpm. Screaming your the best. I used your method for setting the timing and then checked it with the light. Starts right up and no bog. even liveable with the stock torque converter. Will do pics soon.