Charger with 440 won't pull and rev enough?

Posted By: AutoEngineer

Charger with 440 won't pull and rev enough? - 05/19/12 10:20 PM

Hi guys,

Please give me some fresh ideas what might be the trouble maker.

After a long winter period was taking today the 69 Charger R/T out of the garage for the maiden pass at 1/4mile with the new setup of 440 and could not get the motor to rev past 5500 rpm.

Today's best time at our local airfield 1/4 mile strip was 12.467s @ 112mph, with best 60ft time 1.944.
The track was very slippery, but traction was getting better after each run.
By the butt dyno the engine has capabilities for better times, but the engine won't rev past 5500rpm...

The new engine combo is as follows
ENGINE:
440 .055 over, SRP flat top pistons with valve reliefs
Compression Ratio: 10.5:1
Cylinder Heads from 440Source, fresh professional valve job and a mild bowl blend
Roller rockers with 1.6 ratio

Cam, Lunati hydraulic roller 60312
Intake Duration @.050: 231
Exhaust Duration @.050: 239
Intake Duration: 282
Exhaust Duration: 290
Lobe angle: 110 deg
Cam centerline: 106 deg, straight up
Intake Valve Lift: 0.571 with 1.6 rockers
Exhaust Valve Lift: 0.587 with 1.6 rockers

Valve springs: Lunati 73124: 150lbs seat pressure, 350 lbs open, as recommended by Tim @ Lunati.
All valve springs shimmed for exact seat pressures
Roller Lifters: Lunati by Morel, preload 3/4 turns, .0375"

Intake Manifold: Holley SD
Carb: 850 cfm Demon, mech. secondaries. Secondaries opening full.
Air filter K&N 14" with XStream Air Flow Top
A/F ratio on the track, constant 12.2...12.5, by an AF meter

Exhaust: Hedman Headers 1 3/4" primaries, 3" collectors. 2�" full length exhaust with X pipe,
BUT tried today also with open exhaust, NO help with open exhaust still would not rev past 5500 rpm

IGNITION
Distibutor: Mopar Performance, .008 reluctor cap.
Even two different dist. used today
#1 With recurved mechanical advance, 18 deg.initial and 34 total, vacuum advance NOT connected
#2 With stock mechanical advance, 15deg initial and 39 total, vacuum advance NOT connected. Pulled better with this dist. and no pinging.
Dist bushings are tight on both dists.

ECU, tried today with two different ECU's,
#1 Vintage Mopar Orange box from the 80's with MSD Blaster 2 coil and matching ballast
#2 FBO ECU with FBO coil and ballast
No rev limiter
Spark plugs: Denso with .042 gap
Dist, coil and ECU wiring double checked.

Fuel pump: Old work horse, mechanical high volume Carter M6903, 120 GPH flow rate. Has brand new push rod with brass tip for the steel cam.
Fuel line: stock of a 69 Charger R/T 440

Weight of the Car: 4100
Transmission: Automatic with B&M converter, 3000 stall
Gear Ratio: 3.73
Tires ET Street radials, 28 x 11.50R15

Car runs great down low and pulls hard, just seems to run out of steam at about 5000 rpm and is hitting a wall at 5500 with little banging or sputtering.

Do you have any new ideas on what might be the reason???

Posted By: Dodgem

Re: Charger with 440 won't pull and rev enough? - 05/19/12 11:03 PM

Where up north?
anyway nothing jumps out.

Did you degree the cam?? I would have installed it at 105.

Usually three four things things limit your RPM
1. Fuel delivery but if you AF number did not suddenly climb doubt that's it

2. Valve spring float since you have new and I assume checked to see if it was not coil binding should not be hear.

3. ignition since you tried some different not hear although I like .004 gape.

so likely one of these two and most likely the first.

4. way too much pre load on the lifters and it's forcing the valve float.

5. spark plugs I would have used Chanpion RN12YC or RC12YC

Good luck!

Posted By: Streetwize

Re: Charger with 440 won't pull and rev enough? - 05/20/12 12:35 AM

The very FIRST thing I'd check is for corrosion in the fuel line...usually the pick-up/sending unit sock.

Next, as said that cam is in way late for a heavy car....105-106 would be where I'd put it. Actually with a HR a single pattern 239 in at 102-103 would be even better. Lunati's are notorious for requireing Degreeing from my experience, never trust the factory ground-in advance without verifying it.

Also I agree the pre-load may be tight, try backing them off 1/4 to 3/8 of a turn from where you got them. if no improvement tighten them back up. I set them at 3/8 to no more than 1/2 and never had issues and my 517 turns 6800 with a (Bullet) juice roller.

That's not a lot of stall for what you have, I like about 3400-3600 FB/stall and 4200 flash for that combo. with what you describe you should run a very low 12 or even high 11 without too much trouble.

Check the fuel line first, corrosion will choke that thing down big time, People have brought me cars that had all the goods but wouldn't fall out of a tree....I pulled the fuel pick-ups where I was amazed it had enough fuel flow to IDLE, let alone take full throttle under load

Posted By: Exit1965

Re: Charger with 440 won't pull and rev enough? - 05/20/12 01:41 AM

Sounds like you know your specs. But I didn't see jet size listed. My mighty demon came with WAY undersized secondary jets and I couldn't figure out why it ran like crap when getting on the gas. Yours doesn't sound that bad but I would verify that the right jets are in there.

While you're in there you might find metal shavings, incompletely drilled passages etc which could be plugging something up.

Posted By: 10sec440

Re: Charger with 440 won't pull and rev enough? - 05/20/12 02:38 AM

Quote:

Fuel pump: Old work horse, mechanical high volume Carter M6903, 120 GPH flow rate. Has brand new push rod with brass tip for the steel cam.
Fuel line: stock of a 69 Charger R/T 440

This is your problem IMO. You're making well over 500HP with that combo I would think, in a 4100lb vehicle you need more fuel than that.If you don't want to upgrade your fuel system for whatever reason, get some float bowl extenders. Moroso makes them.

Posted By: JAKE68

Re: Charger with 440 won't pull and rev enough? - 05/20/12 03:09 AM

I wouldn't think based on your a/f ratio that you have a fuel system problem,but your symptoms sure seam like it. I have found in the past that a hyd. roller likes 0 lash to get them to rev??? Just saying. I have dyno tuned some cars that would hit a wall at 5000 rpm and then pick that extra rpm when we backed off the preload.

Posted By: Joshs68

Re: Charger with 440 won't pull and rev enough? - 05/20/12 03:44 AM

What balancer is on the engine and if it is the stock unit has it spun? I had one that did and I reset the timing after it had moved. Otherwise I have nothing.

Posted By: blue_stocker

Re: Charger with 440 won't pull and rev enough? - 05/20/12 08:45 AM

Hi Jukka-
If you haven't verified 6-7 psig fuel pressure or verified the fuel line from the tank is adaquately delivering fuel, do that first. REGARDLESS of what components you're using, verify the fuel is getting to the intake both in volume and in pressure. You should also have some (gauged) means to ascertain fuel pressure at top end/going through the lights. Next, verify fuel level is correct in the carb bowels, then check and read your plugs for proper jetting, make sure she's not banging from being lean on the jetting, you won't like dropping a hole in a piston! Hope all else is going well for you and drop me an email when you feel up to it...wb

BTW, junk the Mopar ECU-ballast resistor and install some form of GOOD box, Mallory/MSD/Crane/Jacobs, something that won't leave you hanging.

Posted By: JAKE68

Re: Charger with 440 won't pull and rev enough? - 05/20/12 11:45 AM

Quote:

Hi Jukka-
If you haven't verified 6-7 psig fuel pressure or verified the fuel line from the tank is adaquately delivering fuel, do that first. REGARDLESS of what components you're using, verify the fuel is getting to the intake both in volume and in pressure. You should also have some (gauged) means to ascertain fuel pressure at top end/going through the lights. Next, verify fuel level is correct in the carb bowels, then check and read your plugs for proper jetting, make sure she's not banging from being lean on the jetting, you won't like dropping a hole in a piston! Hope all else is going well for you and drop me an email when you feel up to it...
BTW, junk the Mopar ECU-ballast resistor and install some form of GOOD box, Mallory/MSD/Crane/Jacobs, something that won't leave you hanging.

those kind of fuel problems should show up in his a/f.

Posted By: 10sec440

Re: Charger with 440 won't pull and rev enough? - 05/20/12 05:59 PM

What are you using to measure A/F? is it 12.2 while its actually acting up? Either way that's not enough fuel for that combination.If it isn't starving for fuel now, when you get it to go over 5000rpm it surely will be. Also you have jet extensions on the rear jets right?

Posted By: AutoEngineer

Re: Charger with 440 won't pull and rev enough? - 05/20/12 08:33 PM

Hi guys,

Thanks a lot for all your valuable input.

Here's some more information from the setup.

- Before the first run that Demon carb was disassembled, cleaned and checked for all possible manufacturing faults.
- Primary jets are #80 and secondaries #86.
- Correct fuel level checked and adjusted
- Max fuel pressure set at 6 psi with Holley regulator
- A/F ratio is measured by an old A/F meter and lambda sensor is placed on the left header collector.
However I have now a strong assumption that either the A/F meter or sensor is out of order, or the meter is not acting fast enough for quick A/F ratio changes if the carb is running out of fuel at WOT.
- Vibration damper is a new fluid damper, and TDC is checked
- Valve spring coil bind was checked during the head assembly
- Cam was degreed, checked today my memorandum of this rebuild and set it at 106 deg. Cam gear was straight up, not 110 deg like Lunati announces when straight up.
- Rotating parts, crank, rods, pistons professionally precision balanced.
- Fuel line, I am a little bit shamed to make a confession, but it's factory original

- Fuel pump, the high volume Carter M6903, is also relatively old. If I recall correctly it's from the beginning of the 90's and it was unused for many years before taking into service again.

Based on your feedback I'll concentrate on the fuel issue and at least the following improvements will be done:

- New 3/8" fuel line
- Fuel pick-up/sending unit sock, checked and replaced if needed or in any doubt of it
- Lifter preload adjusted, 3/8 to 1/2 turns, depending on if it starts making noise with less preload.
- Will test also .006 reluctor cap

What do you think this engine combination might be capable at 1/4 mile if it's pulling like it should?

My target is a low 12 or preferrably .01 under

Posted By: BSB67

Re: Charger with 440 won't pull and rev enough? - 05/20/12 09:04 PM

Not sure you are getting what is being said about fuel pressure. Its not throw money at it. Simply check the actual fuel pressure at the carb when the car is going through the traps. At your power level with a 3/8" line 5 psi is enough.

Posted By: tex013

Re: Charger with 440 won't pull and rev enough? - 05/20/12 11:07 PM

looking at your jets seem a little low to me.
in comparison my 440+0.055 with a M1 plus 1" open spacer and 825 mighty demon is jetted F78,R92 and when i run a Prosystems 1000HP Holley based carb is F84,R92
i do race with an air plate sealed to a six pack scoop
motor is 10.78:1,258/258 solid flat tappet
3/8 line for my motor was good with a holley black 150 pump to mid 11.3's then needed -8 lines
good luck

Tex

Posted By: imfixinmopars426

Re: Charger with 440 won't pull and rev enough? - 05/21/12 01:09 AM

sounds stupid,BUT check the wiring to the dist.from the ecu. i have had the two wires switched around...dont ask,lol...and the engine acted strong down low,maybe to 3500-4000,and then laid flat.some of the stuff we have,has the wire connector cut off.others have had home made wiring,so...just check it for the fun of it...might just be it???? good luck,mike

Posted By: JAKE68

Re: Charger with 440 won't pull and rev enough? - 05/21/12 03:23 AM

If your fuel curve is within what you say you have all the way down the track that is not a symptom of a bad o2 sensor!!! It would have been most likely all over the place. If you had any fuel delivery problem the o2 would have gone dead lean. It dose not mater how many jets are different to other motors in comparison to yours your a/f didnt show that there was a problem. Just saying.

Posted By: Red440

Re: Charger with 440 won't pull and rev enough? - 05/21/12 04:36 AM

Ditch the carter and get a holly blue or black pump,run at 7 pounds and also back off on the lifter pre load I have seen lifters that were not completely pumped when set and then were to tight when ran,and as Wise says check fuel pickup and line completely for any kinks or obstructions

Posted By: ZIPPY

Re: Charger with 440 won't pull and rev enough? - 05/21/12 03:54 PM

Quote:

If you had any fuel delivery problem the o2 would have gone dead lean. I dose not mater how many jets are different to other motors in comparison to yours your a/f didnt show that there was a problem. Just saying.

It might not be a bad idea to confirm the a/f readout is working correctly, though. Unfortunately that would probably mean installing it on another car for awhile?

Where is the lifter preload set?
Any chance it could be lifter pump up causing it

Posted By: JAKE68

Re: Charger with 440 won't pull and rev enough? - 05/21/12 04:02 PM

Quote:

Quote:

If you had any fuel delivery problem the o2 would have gone dead lean. I dose not mater how many jets are different to other motors in comparison to yours your a/f didnt show that there was a problem. Just saying.

It might not be a bad idea to confirm the a/f readout is working correctly, though. Unfortunately that would probably mean installing it on another car for awhile?

Where is the lifter preload set?
Any chance it could be lifter pump up causing it

.
3/4 of a turn or .375 sounds tight to me for that. The only thing that he has not said yet is what the a/f ratio is for sure going down track and top end. If it is 12.2 it is not a fuel problem.

Posted By: AutoEngineer

Re: Charger with 440 won't pull and rev enough? - 05/21/12 05:13 PM

Hi guys

Will try get an other A/F meter for the next weekend to verify the AF readings.
At the moment I am suspicious for the meter more than anything else.

And for sure will also have to check the fuel line and the pick up for corrosion or anything else that could be clogging the fuel line. Will try also an other HP fuel pump, a brand new that has been sitting on shelf...

Lifter preload might be a little too tight. Tried to avoid a ticking noise that comes with too less preload, but can try to loose the preload gradually.

I am targeting to break the 12s barrier on the 1/4mile. Into our neighbourhood came last summer a big bad Chebby that's been terrorizing the streets of our village now for a too long time. It has been burning tire on every main street and corner

It's time to kick the a$$ of that chebby after having the Charger performing like it should with this combination

Posted By: Mr.Yuck

Re: Charger with 440 won't pull and rev enough? - 05/21/12 05:54 PM

well you are losing at least 4 tenths at the 60 foot mark. You should be around the 1.65 60 foot. Now on to the rpm problem...I'd think if you had a fuel problem it would be ok thru 1st and maybe 2nd. From my experience when you have a poo poo pump it's at 3/4 track when you find out. Are you running it w/ an air cleaner assembly? If so remove it and run just the base plate. I'd think with that MPh you should be real low into the 12's and if you can pick up 2-3 mph maybe high 11's.

Posted By: AutoEngineer

Re: Charger with 440 won't pull and rev enough? - 05/21/12 06:29 PM

Quote:

well you are losing at least 4 tenths at the 60 foot mark. You should be around the 1.65 60 foot. Now on to the rpm problem...I'd think if you had a fuel problem it would be ok thru 1st and maybe 2nd. From my experience when you have a poo poo pump it's at 3/4 track when you find out. Are you running it w/ an air cleaner assembly? If so remove it and run just the base plate. I'd think with that MPh you should be real low into the 12's and if you can pick up 2-3 mph maybe high 11's.

The track was very slippery like all those old airfield tracks we have here around. They don't have even close to that traction you have with dedicated and prepped race tracks. That's one reason why I like running the cams in the straight up position or slightly retarded. Advancing the cam will only add low end torque and possibly even worsen the traction problems. I might be also testing a taller gear ratio like 3.55 after solving first this rpm problem. On a slippery track it's really difficult to have a good launch and hook hard.

After this rpm problem is history, I assume it will pick up some mph's, because it was almost 200ft before going through the lights when it hit like a wall. At the moment I can only imagine what the ET would had been, IF would had driven on a prepped track and without that rpm problem.

Was running it w/ an air cleaner assembly like this http://www.knfilters.com/images/l/66-3000.jpg

Posted By: Streetwize

Re: Charger with 440 won't pull and rev enough? - 05/21/12 07:40 PM

Not sure what A/F monitor you Are using, a fair number of them out there are either slow response or have a fairly 'generous' +/- % range of accuracy....steady state they're 'fine', but many of them (not allthough) out there can't be trusted to read real time on a 1/4 mile pass.

Posted By: Cab_Burge

Re: Charger with 440 won't pull and rev enough? - 05/21/12 07:43 PM

I hate to tell you that the M/T ET Street radials don't work worth a hoot on a bad track, the regular ET streets do a lot better

I have both types for my car, I run the radials on the good tracks, 1.39 60 fts

and the bias plys on the bad tracks, 1.43 60 ft on the same track, same day. The radials won't run 1.60 on a bad track where the bias will run 1.49 to 1.52

Does the motor hit the same RPM limits in all gears or just high gear ?

If in high gear only look at the fuel system, if the same in all gears look at the ignition sytem or tach

Good luck on getting that rat motor rascal

Put the hammer

to him

Posted By: AutoEngineer

Re: Charger with 440 won't pull and rev enough? - 05/22/12 05:37 PM

Quote:

I hate to tell you that the M/T ET Street radials don't work worth a hoot on a bad track, the regular ET streets do a lot better I have both types for my car, I run the radials on the good tracks, 1.39 60 fts and the bias plys on the bad tracks, 1.43 60 ft on the same track, same day. The radials won't run 1.60 on a bad track where the bias will run 1.49 to 1.52 Does the motor hit the same RPM limits in all gears or just high gear ? If in high gear only look at the fuel system, if the same in all gears look at the ignition sytem or tach Good luck on getting that rat motor rascal Put the hammer to him

Practically it's nearly the same in all gears, about 5500 rpm and hits like wall. Almost like there would be a rev limiter somewhere ...
But if it's being rev'd in neutral, it takes in the twinkling of an eye over 6500 rpm

Have tested an other ECU, coil, ballast, dist, triple checked the wiring of all ign components, everything EXCEPT the tach.
It's a replacement Tic-Toc-Tachometer from Y1. Used a Sun tach to compare the reading of it when installed, and there was non to mention.

Could it really be so easy solution that the tach would cause the rpm problem?

In theory the answer is yes, but how about in practice, has anyone had such a problem caused by the tach?

However, it will be easy to disconnect that Tic-Toc-Tachometer from the coil

Posted By: Cab_Burge

Re: Charger with 440 won't pull and rev enough? - 05/22/12 06:33 PM

Quote:

Quote:

I hate to tell you that the M/T ET Street radials don't work worth a hoot on a bad track, the regular ET streets do a lot better I have both types for my car, I run the radials on the good tracks, 1.39 60 fts and the bias plys on the bad tracks, 1.43 60 ft on the same track, same day. The radials won't run 1.60 on a bad track where the bias will run 1.49 to 1.52 Does the motor hit the same RPM limits in all gears or just high gear ? If in high gear only look at the fuel system, if the same in all gears look at the ignition sytem or tach Good luck on getting that rat motor rascal Put the hammer to him

Practically it's nearly the same in all gears, about 5500 rpm and hits like wall. Almost like there would be a rev limiter somewhere ...
But if it's being rev'd in neutral, it takes in the twinkling of an eye over 6500 rpm

Have tested an other ECU, coil, ballast, dist, triple checked the wiring of all ign components, everything EXCEPT the tach.
It's a replacement Tic-Toc-Tachometer from Y1. Used a Sun tach to compare the reading of it when installed, and there was non to mention.

Could it really be so easy solution that the tach would cause the rpm problem?
In theory the answer is yes, but how about in practice, has anyone had such a problem caused by the tach?

However, it will be easy to disconnect that Tic-Toc-Tachometer from the coil

Disconnect that rascal and go see

It wouldn't be the first time a tach caused poroblems like yours

Posted By: Dodgem

Re: Charger with 440 won't pull and rev enough? - 05/22/12 08:17 PM

1 thing you can try is wind it up in 1st to say 5400 let off staring in first then get back on it if it pulls past the wall at 5500 it is fuel letting off allowed it to catch up!

But my feeling is your lash is set to tight floating the valves take a turn of pre load out and try it can't hurt anything. then maybe another assumimg you have them set the same most people struggle setting the lash and are all over the place from .150 to tight to .030 which is close to right.