ZZ4 initial startup observations and questions?
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
ZZ4 initial startup observations and questions?
Just fired up the new engine last couple of days...QUESTIONS??
Only gauge hooked up is oil pressure (interior is out). It pegs out at 70 psi. The gauge worked fine with the old 350 at around 35psi...
All the hooker pipes glow red EXCEPT #1 and #3. Is that normal?? For that matter, is the glowing red normal? Maybe I didnt run it long enough for 1 and 3 to heat to glowing?? I'm running a Holley 670 SA out of the box. Lars' paper says they are too lean. Going to swap out for larger jets.
I set initial timing at 12 degrees, it fires up with a touch of the key. I havent refined the timing any further yet. Need to go purchase a dial back light. It does have a slight tendency to " run on" when I shut it down (not everytime). Timing may be a little off??
So far I havent put maybe 5-8 minutes on the motor at fast idle. Was initially running open sidepipes, but this morning reinstalled the old glass pack inserts that came with the Hookers, so I could run the engine with tolerable sound. It sound really good, no odd noises.
Once I'm comfortable with the oil pressure and temps, I'll do an initial oil change...
Thanks!
Only gauge hooked up is oil pressure (interior is out). It pegs out at 70 psi. The gauge worked fine with the old 350 at around 35psi...
All the hooker pipes glow red EXCEPT #1 and #3. Is that normal?? For that matter, is the glowing red normal? Maybe I didnt run it long enough for 1 and 3 to heat to glowing?? I'm running a Holley 670 SA out of the box. Lars' paper says they are too lean. Going to swap out for larger jets.
I set initial timing at 12 degrees, it fires up with a touch of the key. I havent refined the timing any further yet. Need to go purchase a dial back light. It does have a slight tendency to " run on" when I shut it down (not everytime). Timing may be a little off??
So far I havent put maybe 5-8 minutes on the motor at fast idle. Was initially running open sidepipes, but this morning reinstalled the old glass pack inserts that came with the Hookers, so I could run the engine with tolerable sound. It sound really good, no odd noises.
Once I'm comfortable with the oil pressure and temps, I'll do an initial oil change...
Thanks!
Last edited by MakoShark72; Jun 23, 2008 at 12:22 PM.
Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
The oil pressure is normal, mine idles at 80 psi. The red exhaust is NOT normal. Either your timing is way off or you're running rich as heck and combustion is taking place in the headers.
What rpm is fast idle?? Remember you don't have to break this in at 2,000 rpm like a solid tappet motor.
What rpm is fast idle?? Remember you don't have to break this in at 2,000 rpm like a solid tappet motor.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
The oil pressure is normal, mine idles at 80 psi. The red exhaust is NOT normal. Either your timing is way off or you're running rich as heck and combustion is taking place in the headers.
What rpm is fast idle?? Remember you don't have to break this in at 2,000 rpm like a solid tappet motor.
What rpm is fast idle?? Remember you don't have to break this in at 2,000 rpm like a solid tappet motor.
Last edited by MakoShark72; Jun 23, 2008 at 12:57 PM.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I agree, this is not normal and will really hurt you. First off, you need to be sure you have it timed right but the mixture is more than likely the problem.
Topgunn, isn't it a lean condition that causes excessive exhaust heat?
I would be looking for an air leak...probably around the intake base, carb base, or throttle blades.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Thats what I was thinking (lean)...When I shut it down, I get gas fumes belched back up thru the carb.
OK, heres what I have WRT TIMING...I set it initially at 12 degrees. I dont have a dial back light, just a plain old inductive timing light. Now with the engine running at about 2000 rpm, WITH vacuum hooked up, the timing light shows 32 degrees. With the vacuum advance PLUGGED, it reads 2 degrees BTDC, and idles rough. I'm not an expert with the timing light so will need some help here.
ALSO...my vacuum advance is connected to the port on the Holley CARB designated for the distributor. It IS NOT connected to a manifold vacuum port. Is this correct?
Thanks for the help!
Last edited by MakoShark72; Jun 23, 2008 at 01:31 PM.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
DB,
Thats what I was thinking (lean)...When I shut it down, I get gas fumes belched back up thru the carb.
OK, heres what I have WRT TIMING...I set it initially at 12 degrees. I dont have a dial back light, just a plain old inductive timing light. Now with the engine running at about 2000 rpm, WITH vacuum hooked up, the timing light shows 32 degrees. With the vacuum advance PLUGGED, it reads 2 degrees BTDC, and idles rough. I'm not an expert with the timing light so will need some help here.
Thanks for the help!
Thats what I was thinking (lean)...When I shut it down, I get gas fumes belched back up thru the carb.
OK, heres what I have WRT TIMING...I set it initially at 12 degrees. I dont have a dial back light, just a plain old inductive timing light. Now with the engine running at about 2000 rpm, WITH vacuum hooked up, the timing light shows 32 degrees. With the vacuum advance PLUGGED, it reads 2 degrees BTDC, and idles rough. I'm not an expert with the timing light so will need some help here.
Thanks for the help!
Do you get fuel belching back up too like a carb backfire? That indicates timing...maybe a tooth off or a few plug wires backwards.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
I set up the distributor via Lars directions, even lined up the mag pickups at the base of the rotor...
I think its right on.
Thanks.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
You're running lean. Richen it up and hook up that vacuum advance to manifold vacuum instead of ported vacuum - the lack of vacuum advance and the lean condition is running your EGT way high.
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Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Remember I dont have a dial back light.
Thank you!
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
I richened the carb using the idle mixture screws. The engine "idles" at almost 2000 rpm's, and its warm enough now that it should idle normally. The glowing headers is almost gone with the richening of the mixture. Definitely running cooler. Now to get the timing set...
Still belches back thru the carb at shutdown...tendency to run on...
Need more info??
Thanks all!
Still belches back thru the carb at shutdown...tendency to run on...
Need more info??
Thanks all!
Last edited by MakoShark72; Jun 23, 2008 at 02:39 PM.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I richened the carb using the idle mixture screws. The engine "idles" at almost 2000 rpm's, and its warm enough now that it should idle normally. The glowing headers is almost gone with the richening of the mixture. Definitely running cooler. Now to get the timing set...
Still belches back thru the carb at shutdown...tendency to run on...
Need more info??
Thanks all!
Still belches back thru the carb at shutdown...tendency to run on...
Need more info??
Thanks all!
Is the idle adjustment screw backed all the way out?
Open the choke blade, and peer down with a flashlight and see if the primary throttle blades are closing all the way. You should not be able to see past them if they are completely closed.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Primaries are closed..
I MAY have had a little tension on the throttle cable, loosened it up a bit, now idles around 900-1000.
ALSO...
I disconnected and plugged vac advance line. Set base timing to 12 degrees by rotating distributor.
Revved engine, timing goes to about 30 degrees at 3000 rpm, so the weights add 18...Lars says I'm looking for 36 total...So weaker springs??
Hooked up vac advance and initial timing went from 12 to 30, so the can adds 18 degrees. This was verified by revving the motor to about 3000, I get timing of 48 degrees..so thats 18 for the centrifugal and 18 for the can...initial 12+18+18=48...guess the math checks..
I think the temps are down cause pipes not glowing now. I turned the mixture screws about 3/4 turn out (richer).
Readjusted idle screw for about 900 rpm. So far no "run on"...
Have I missed anything? Advice from here?? Is the motor safe now to move around the garage and to drive up on a trailer?
Thanks again!
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Sounds like you have it pretty close. The in park idle is good for now for sure. Why the trailer...where is it going?
Get it broken in as soon as you can without starting and stopping it too many times with no load on the engine. This point is where it's most critical that it sees higher cylinder pressures.
Also, it would be a good idea to have it taken to a shop that has a 3 or 5 gas diagnostic machine. They will hook it up, and can tell you every aspect of your exhaust gas mixture to tell you if your engine is rich, lean, or dead on, and the amounts of unburnt fuel in the exhaust. They use the specs of your engine to properly dial you in, tune the carb, set the timing, and alert you if there are any problems that are hard to catch without the diagnostic equipment.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
