power valve makes my 440 ping??

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timopar

timopar

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Hi fellas, I was tryin to tune out a little rich running condition in my 440 a few days ago, I was running #82's and a power valve blank in the primary, so I dropped to #74's and a 6.5 power valve.
now it detonates like crazy! I backed the timing down little by little now its 25 deg total, 4 deg initial, still Knocking! I jetted it little by little right back to #84's still pinging! dissconected the secondarys still pinging!
Im really not shore what to try next? any ideas??
 
ok so I swapped back to the power valve blank and it pings less but its still pinging. I tryed spraying carb cleaner around the base plate and intake, nothing happened.
anyone got any ideas? change the fuel? I filled it with 98 2 days before the pinging started.
ill change the base plate gasket and have a look in the plenum, but im running out of ideas :angry7: any help would be great, thanks Tim
 
when is it pinging? all the time, under full load, part throttle pulling a hill?
 
well if I drive it normally there is no Knocking, but as soon as I use more than half throttle wile excellerating It pings.
It dos seam to ping less now that the p.v plug is back in.
 
Holley carbs are notorious for not having flat sealing surfaces, I would take the carb off, disassemble it and file the main body flat where the metering blocks and base plate bolt on. Put it back together with some good gaskets, I like the Demon gaskets personally.

Oh and don't forget to clean it real good after filing.
 
You should never plug the primary power valve unless it's a higher rpm drag only engine. You need the extra fuel metering during the normal and sprited driving. So you put the engine way into lean. Without knowing your combo and your timing curve I'd say use a 5.5 valve and primary jetting around 74. Tell more of what you have (be very specific) and we can help more. But as it stands now, you nee to get a PV back in the primary side.
 
Sounds like you have other issues that your trying to make the carb make up for or currect, i would check for vacuum leaks around the base of the carb/intake, then check the fuel pressure, & do a volume test & makev sure your getting good supply, I've had issues like this before, found out it was blockage in the factory fuel lines, you need to currect it "fast" before you really mess up the engine.

Like was said, what all is done to the engine, I'm a BB guy & have built a few over the years, & what you need to "always" remember 1st. hand, "make sure" you have very good fuel supply before you start running it, whether there mild or wild, they are "thirsty", i've seen many lack in this area on there builds, i learned the hard way years ago, never deprive a BB for its quinch for fluids, you'll be sorry.
 
Nice to see you got a bb in your val!

Whats the engine specs?
Might help...
 
I'd start off by pulling all the plugs and seeing what's going on. Also, are you running the vacuum advance hooked up? If everything looks good but still pinging I'd throw in a 1/2 can of Octane Boost, you may have got some skunky (old) fuel at the last fill and that'll make her knock.
 
I have to disagree with Moper on this one. I've had better luck and better driveability in radical cammed engines without the power valve, you just need to jet up for not having it 8-10 jet sizes.
 
wow thanks for all the replys! not shore were to start now.

ok so I checked all the plugs not all of them show signs of ping, all are a nice tan brown thow.

I tryed octane boost n put an other $20 of 98 juice in it (from the same place as befor, dumb) took it for drive 3 or 4 miles engine temp stayed 160-170, stil pinging.

the car is a 65 valiant 4door (no 2doors till 68 in australia) all steel, untubbed, std suspension, no hood scoop.
tyers 275r 175f, 6 leaf rear 2" lowering blocks, 1/2" offset spring hangers spring in the top hole.
shortened c-body 8 3/4 housing n axles, yukon 489 case, 3.91 richmonds, strange spool n yoke.
home made connectors.
home built 727, full manual, hurst shifter.
modified 360 converter, 3600-3700 stall rpm.
.870" small block t-bars, pedders GSR shocks on all 4 corners.

30 over 11/73 440, 10.2 kwench dome KB pistons at .ooo, peened ly rods, stock steel crank, stock dampener checked for TDC.
moded stock windage tray, stock 6kwort pan.
208 valve, unported 906, bronz guides, 5 angle seats, found kwench depth varied from 105 to 125 thou so the heads were milled for 41 thou minimum kwench, some are low 60's tho.

800 holley dp milled choke smoothed ventuis.
stock iron 74 spread bore intake, egr milled out, plenum mod as per dc tech bulletin#34, cheep adaptor plate, no port match.
center drop exharst manifolds (yes I no, I no), 2 1/4 from the mans to single 3" pipe aero chamber muff, dumpt at the diff no tail pipe.

235@50 single pattern 507 lunati hyd, 108 in at 102, good cm pushrods, lunati springs, machined locks n retainers, stoch rockers.
dob roller t-chain, hv oil pump.
home built iron body no vac points dizzy (only 1 set of points in it) shimmed real tite, timing rocksteady past 4000rpm.
ngk plugs, mallory wires, bosch gt40 coil, 45amp alt internal reg.

1/2" alli fuel line, carter 72gph pump, fram filter, holley reg, 3/8 line reg to carb, no return line, 5psi fuel pres but creeps to 8-9 if left ideling.

mini starter, sfi flexplate. :cheers: has bin sitting a few months but the hole combo was fresh 400miles ago. thanks Tim
P.s tell me if I forgot some thing.
 
Oil consumption? Are you running a factory style PCV system?

Make sure your EGR removal isn't leaking, also given the healthy skim on the heads, make sure your ports aren't leaking at the bottoms under the valley tray. If you are pulling even a small amount of oil into the intake, you'll have detonation.

It could be that as rich as you were running, you have built up a pretty heavy amount of carbon in your chambers.

Just something else to consider.
 
I'll agree with C130 on oil being sucked in the cylinders, something to look into, but most likely will show up on the plugs (somewhere), what i will question is the fuel pressure moving around, like i said earlier, you need to make sure its getting the proper fuel volume needed & maintane pressure, drifting from 5 lbs. to 9 lbs. is a "major" problem right there, you can't set your floats right if this is happening, so as you say, if left idleing it creaps to 8-9 lbs., where is it at 5 lbs., under excelleration?? If you set the float levels at idle & pressure is at 8-9 lbs., then its falling off to 5 lbs., your not getting anywhere like this, your float level is then dropping off from where you set it, the pressure needs to stay as "steady" as possible throughout the RPM range & "under load", another issue i see is the 1/2 fuel line & a mech. pump, 3/8" all the way should be plenty, unless you run an Elec. pump at the tank, then its easier to keep the 1/2 full, may not hurt to add an elec. pump at the tank, i think your Pressure will stay steady & you may notice no more pinging, plus you'll be surprized how much better its pulls. The larger your main line is, its harder for a mech. pump to keep it full vs. an elec.
 
thanks again guys, all helpful info.

the pump is electric I run no mech pump and the pressure starts at 5psi if left idle it creeps higher.

It has a factory 5/8 diam pcv, with 2 breathers in the opposite valve cover.

carbon build up was something I was thinking about, especially in the 1 or 2 cyl's with wide kwench distance.

after all my tuning today, I checked the oil for the first time sins the ping started.
It has never used oil in the past not a drop, now its down to add from half way between full n add.
so im thinking its my likely-est culprit, especially sins the chevy guy that machined my engine wouldn't mill the intake face on the heads, he sed its too hard to do and its not needed, that it would all go together no problem.
anyway thank you all for your imput, its very well apresiated and ill let you no how I go, thanks Tim
 
Let us know how you go tim.
Your setup seems quite good other than the fluctuating fuel pressure, that cant be good.
 
Guitar Jones said:
I have to disagree with Moper on this one. I've had better luck and better driveability in radical cammed engines without the power valve, you just need to jet up for not having it 8-10 jet sizes.
Click to expand...

Except it's a mild build... Cam isnt radical at all, nor is the combo radical. I think it needs a power valve :D.
 
I'm with moper on this one, that cam/engine combo could use a PV effectively. My guess is the vacuum in neutral should be in the 12-13" range, idle at 900.

Are the PV Channel restrictors plugged? If you can measure the channel restrictor diameter, there are conversion tables for the jetting step required when installing/removing a PV.
 
The PV thing is all good info, it really should have one i'll agree, but the biggest issue he has is the "fluxuating" fuel pressure, this is NEVER good, & that would be my main concern if it was mine & it was "pinging".

The PVRChannels should be fine & not needing any mods, just make sure there not stopped up.
 
hi fellas happy new year!
I have bin doin some thinking, sins the intake is cheap crap and only needs minimal effort to remove it. Im thinking i'll have the gasket faces of the manifold milled to compensate for the heads not being milled, now I have to ask the question, do I compensate for the block being milled as well? or just the amount the heads were milled?
the block had 40thou off it to get the pistons up to .000 and the heads had 25thou off em to get the quench right.
40 thou is a size-able cut so I just thout id ask your opinion before I go to the machine shop.(not the same shop, a mopar guy this time)

and on the other subject, the fuel pressure creeping up.
has anyone had the same problem? my thorts are it needs a return line.
carter say nothing about pressure creep with this pump, in fact they don't even recommend a reg, its ment to be self governing.??
 
If the block was deck'd .040" & heads were milled .025", you'll need to do something with the intake, normally they recammend milling the intake side of th heads, but too late for that, unless you pull the heads, i'm not sure how much will need to come off.

The fuel pressure should come up quik & stay steady IMO, on my duster, i ran a holley blue with 3/8 line & reg., set my pressure at 7 lbs., stayed rock steady through the 1/4 mile every pass, later on i went with 1/2", pressure dropped, re-ajusted it back up, still stayed solid, really didn't need 1/2' line, if your just running a street carter elec. pump, i'll bet its haveing a hard time filling that 1/2 line (that would explain the slow fill & increase on the gauge), there rated about 72 GPH & don't need a reg. or return line) so either get a better pump & reg., or go with a 3/8' line, to comfortably keep a 1/2' line full, i think you'll need a bare min. of a 110 GPH pump, i've had good luck wth the holley blues & blacks, i have a new Procomp 'black" that i paid 55.00 for back about a yr. ago, don't know how good they are, i would sell it to you, but i might be needing it if i ever run Nitrous on my Dart, at least thats the plan.

Another thing, how/where do you have the pump mounted, this is very criticle for pump operation & life, i hope your useing a sump of some sort, i like running fuel cells now, & having the sump in the rear position, then install the elec. pump just behind the outlet mounted on the bumber brase for a straight flow gravity feed too the pump, i never ran a return line, pumps never ran hot neither, heck, they never even got warm.
 
The simple math is cut the intake .012 for every .010 off the head gasket surfaces of the head or block. So if you've had the block cut .040, and the heads cut .020, they will need to take .72 off the intake sides.
 
moper said:
The simple math is cut the intake .012 for every .010 off the head gasket surfaces of the head or block. So if you've had the block cut .040, and the heads cut .020, they will need to take .72 off the intake sides.
Click to expand...

I think Moper means ".072":-D
 
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