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440 still running poorly

John Tipps

Active Member
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8:05 PM
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Sep 22, 2019
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Location
Dallas Tx
As stated on a previous thread I changed the heads (Trick Flo) and cam (comp262) and cant get it to run right, the timing marks were set on 12 and 12 (amid some controversy) and it runs but no noticeable improvement in power unless you seriously put your foot in it, tried moving the timing around but anything below 20 and it gets ugly,above that and rpms are up but still shaky also talked to mopar guy and he suggested rpm at 2000 pull and plug dist and set timing at 30 or so and it seemed to help a bit but still sluggish, then did a vacuum test on edelbrock carb front port and no matter which way the adjusters were turned it wouldn't get away from 12lbs,hooked it to manifold behind carb and it barely got off of 10lbs, did a compression check and all were around 150lbs and the #7 was brown but not wet w oil, I also pulled the covers off and reset the lash on the hydraulic lifters and put 3/4 turn this time instead of a full one-can anyone help with this-why for one will the vacuum not change would this an indication of the problem? Im trying all I can before removing the front of motor and restting timing dots
 
2000 idle is certainly too high.... Could you make a hyperlink to the other thread, so I can review??( or repost all standard mechanical troubleshooting performed in order and maybe some specs). Sounds like you could be fighting a vacuum leak, but how does it idle?? I'm not really understanding your timing procedures either. Is this a vacuum advance distributor?? Base at 12? Mechanical advance at 24? Full vacuum at ???
 
If the cam is a Comp XE262 in a 440, the vacuum at idle should be higher than 10-12”, especially with 20* initial timing.

Is adjusting the lifter preload something you’re very familiar with?
If not, that may be an area to explore further.

I would suggest trying “zero” preload.
Using the EOIC method, loosen the adjuster screw for the particular rocker you’re working on until you can detect vertical free play at the pushrod.
Turn in the adjuster screw while jiggling the pushrod up and down until you can just sense all play has been eliminated.
Tighten lock nut......... move on to next rocker.
This will ensure you don’t have any valves hanging open from excessive preload.
The rockers may exhibit slightly more clatter when set this way(don’t worry about it).

Another thing to check is the rotor phasing.
This requires drilling a hole in the dist cap and shining the timing light thru the hole to make sure the rotor is lined up with the terminal when the coil fires.

Beyond that, it might be time to start swapping out some of the basics, like the dist, ign box, carb, etc.

I have to believe there isn’t a sharp hot rod engine guy who “knows” how to troubleshoot this kind of stuff in the Dallas area that you could enlist some assistance from.
 
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2000 idle is certainly too high.... Could you make a hyperlink to the other thread, so I can review??( or repost all standard mechanical troubleshooting performed in order and maybe some specs). Sounds like you could be fighting a vacuum leak, but how does it idle?? I'm not really understanding your timing procedures either. Is this a vacuum advance distributor?? Base at 12? Mechanical advance at 24? Full vacuum at ???
Idle- when the engines first started its shaky AH for a couple minutes then smooths out a bit, I have an idle at 8-900 rpms, anything below that is too low-slams around sounds like...the 2000 rpm I was speaking of was just to turn distributor to 30+ advance w the distributor port pluged at carb the idled back down to 900 and distr plugged back in,as stated it did make it run a bit smoother but still sloppy and no new power,it is vacuum advance distr and I have it timed at 18-19 advance,not sure what the full vacuum is
 
If the cam is a Comp XE262 in a 440, the vacuum at idle should be higher than 10-12”, especially with 20* initial timing.

Is adjusting the lifter preload something you’re very familiar with?
If not, that may be an area to explore further.

I would suggest trying “zero” preload.
Using the EOIC method, loosen the adjuster screw for the particular rocker you’re working on until you can detect vertical free play at the pushrod.
Turn in the adjuster screw while jiggling the pushrod up and down until you can just sense all play has been eliminated.
Tighten lock nut......... move on to next rocker.
This will ensure you don’t have any valves hanging open from excessive preload.
The rockers may exhibit slightly more clatter when set this way(don’t worry about it).

Another thing to check is the rotor phasing.
This requires drilling a hole in the dist cap and shining the timing light thru the hole to make sure the rotor is lined up with the terminal when the coil fires.

Beyond that, it might be time to start swapping out some of the basics, like the dist, ign box, carb, etc.

I have to believe there is a sharp hot rod engine guy who “knows” how to troubleshoot this kind of stuff in the Dallas area that you could enlist some assistance from.
Good information,Ill try thr zero lash/rotor phasing tommorow and yes I know a mopar guy that races them and I can consult him or perhaps leave it with him if its gets to that point-Thank you...
 
What is the harmonic balancer, and what are you using for a timing light?
What distributor?
 
What is the harmonic balancer, and what are you using for a timing light?
What distributor?
The harmonic balancer is from summit,the engine ran great before w it, the timing light is a quartz(?) and is accurate,the distributor is oriellys special that also ran great before
 
Does the damper have timing marks out to 35*?

Is the timing light a regular type, or a “dial back”(advance) type?

If it’s a stock type distributor, check the pick-up to reluctor gap.
I prefer to run them so it just about touches.
 
The harmonic balancer is from summit,the engine ran great before w it, the timing light is a quartz(?) and is accurate,the distributor is oriellys special that also ran great before
Did you check TDC on balancer with pistion at TDC?
 
@John_Tipps Can you describe the overall build?? B-Body? or bigger car? Rear gear? Intake type? Intake replaced as well? Factory exhaust, or is this car runnng headers??
 
When you say timing set at 12 and 12 you mean distributor or cam timing? If 12 and 12 cam timing thats way off. Should be dot to dot. So the cam should be at 6 o'clock and the crank should be at 12 o'clock.
 
Try a decent vaccum leak test.
Pull the fan belt or shut off the electric fan.
Now take a propane torch and add a piece of hose to the tip.
Start the engine let it idle, turn on a small ammount of flow from the propane.
Using the hose check carb base, intake runners, also use that hose to go into the valley pan area and check the back side of the runners.
Check your brake booster and connections if it's a power brake car.
Your looking for a rpm increase if propane hits the leak area.
Other products can be used, I like propane ,no mess , no paint damage.
 
Stop wasting time. Go back and make sure your cam/crank are oriented correctly before anything else. It doesn't sound like you were sure it was right.
You can look at every other component on that motor, but if timing is wrong, it ain't gonna help one bit.
 
the timing marks were set on 12 and 12

Stop wasting time. Go back and make sure your cam/crank are oriented correctly before anything else. It doesn't sound like you were sure it was right.
You can look at every other component on that motor, but if timing is wrong, it ain't gonna help one bit.

Why do you say that???? It seems to me that this has been beat right to death.
 
If 12 and 12 cam timing thats way off. Should be dot to dot. So the cam should be at 6 o'clock and the crank should be at 12 o'clock.

Right, and where would it be the next crank revolution?
 
Can you elaborate a little more about the 440 Engine combination ?
Because there is far more to "how it runs"....which can be subjective and especially when it comes to tuning, that "TF Heads and a 262 Cam"
WHAT are the TF Heads and 262 Cam installed on for a 440 ?

just say'in....
and I'm NOT saying this is the case here...... but maybe it is after 2 threads ?
Big Ports and small Cams can be tricky/recipe for disaster all by themselves.... and power can be even worse if mounted on a 7.8:1 CR Engine ?

Aluminum Heads sometimes don't like low CR ratios at lower rpm's due to the Aluminum's higher heat dissipation qualities ? And the larger the Port Volume is relative to the smaller the Cam is can cause poor port velocity(mixture) associated with poor lower rpm tuning ?
Once rpm's are UP..... then HP is HP with the Aluminum Heads, but again here until the small Cam runs out ?
 
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