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440RB Weird plug readings.....Bad valves, rings??

  
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440RB Weird plug readings.....Bad valves, rings??

 
Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 06/14/12
10:03 AM

Wondering if someone can shed a little light here....I've been battling problems with my 440RB for years. I'm going to throw out my problems and see if someone can add them up for a solution....here goes:

Detonation when motor is hot. I either have to add 110 to 93 octane, or turn the timing back until it stops. Currently using Bosch WR9FP(1036)reccommended by a friend, gapped at 35 or 40.....can't remember. Have used Champion RJ12YC in the past, as well as those Accel shorty plugs for headers.

Plugs have different readings. Some tan, some caked with carbon, one bridged, others oily.

Enging will race in park after a drive, yet engine will bog on takeoffs and stops during that drive. I can't detect any obvious vac leaks.

Heats up fast if I'm not moving at a decent clip. Idleing around a parking lot on a hot day will take my temp up to 230 rather quickly, runs at 170-190 degrees on the open road depending on the outside temperature on any given day.

When I bought the car, it was blowing smoke. Found out the previous owner ran only synthetic oil after a rebuild. Changed to regular oil, smoking stopped in a week. Two years later, it's back when I start the car, or rev the engine and let off. Noticing I'm a quart low every now and then. No leaks anywhere.

Runs great with only the smoke issue on days below 75 degrees Confused  Mad

HELP!!  

waynep71222 waynep71222
User | Posts: 246 | Joined: 04/12
Posted: 06/14/12
05:11 PM

wow... you seem to have listed a LOT of issues..

engine cooling system out of control.... is a Major issue..  idling is should not have run away temps like that...

can you completely describe your cooling system and provide some pictures of your belt driven fan... something is wrong at idle.. not enough air flow through the radiator.. or a wide open thermostat allowing the coolant to flow too fast for the slow moving fan to cool it...  there could also be a problem with the speed of the engine.. but this relates to the first issue.. not enough air flow through the radiator..  as too slow an idle speed. or not enough fan and water pump speed will not circulate the coolant through the block and heads fast enough behind the closed thermostat so it can properly exchange time after time after time..


~~~~~~~~~~~~~~

with the overheating issue..    and the synthetic oil probably at initial start up preventing proper break in of the rings may have causes the rings to allow too much blow by...

there are digital cameras available now .. with small enough probes to insert through open spark plug holes to examine the tops of the pistons and the cylinder walls...  the low buck versions may not have the tiny mirror attachments to view the valves and chambers..


if you have enough time..  you might want to bring the engine to FULL operating temp...  and use a squirt bottle to squirt some water into the intake air stream as you hold the engine rpms at 3000 to 3500 RPMs..  the water... in small amounts into a HOT chamber.. turns to steam and blows the carbon off the chamber and tops of the pistons...   when the motor starts to bog.. stop squirting..   a long time ago.. there were Vapor injection systems that were fully mechanical..
they did require PORTED Vacuum on both sides  of the carb...  used a glass jar.. a fine thread metering valve and a fish tank air stone...   along with some vacuum hose and a fitting or two..

the metering valve is on the lid.. a hose down to the air stone at the bottom of the bottle..

a fitting on the other side of the lid..  to hook to vacuum hose to the ported vacuum..
this allows vacuum into the bottle above idle..  lowering the pressure above the water and creating clouds ..  you change the amount of restriction by adjusting the amount of air into the bottle through the metering valve.   this took care of detonation problems and kept the carbon build up to a minimum ..

i know that anything on a BIG block involving spark plugs is a PAIN...

compression test...  if low cylinders are found.. a cylinder leak down test...

you might want to pull the valve covers...  i hope its not a crossram..  and examine the valve seals.. that they have not slipped off the guide..  or melted..   most times one can see between the valve spring coils..

i knew one guy who pulled the rocker arms off.. so ALL the valves were closed.. tapped the lifting plate that bolts to the carb mounting flange.. and used an air regulator to control the amount of air into the intake..  with the valves closed..  he was able to squirt oil at the valve stems and seals to find leakers..   he even went as far as taking an OLD rocker cover.. that he used for adjusting the valves.. cut away...   plugged the drain back holes.. and filled the spring area with motor oil.. this gave him a MUCH better idea of which ones were leaking..  

pepsi1 pepsi1
User | Posts: 150 | Joined: 10/11
Posted: 06/14/12
06:25 PM

Save yourself the agrevation. Pull the valve covers and see if there is anything obvious. Broken valve spring dry valve stem seals.

Do a compression check. If you have weak cylinders, try the wet cylinder compression check.If the compression comes up then pull the heads.

Sounds like your in for some work. I would pull the engine apart. maybe you have some piston ring gaps that are aligned, causing the oil consumption....broken rings, worn rings and/or the above. When you do a tear down measure each part, and inspect all of them for wear... Valve guide wear, etc..  

Spud490 Spud490
User | Posts: 65 | Joined: 01/12
Posted: 06/14/12
08:28 PM

Does it only detonate bad when at 230*? Oil consumption could be the result of super hot( thin) oil. Aluminum heads? How many core rad?? What type of fan? Thermostat or restrictor??  
10's or bust!!

Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 06/18/12
08:11 AM

I'm using a Stant 180 thermostat, clutch fan, Be Cool radiator, probably 3 core? Heads are 906 cast iron. I've replaced the thermostat about 3 times in the last 5 years, with little or no improvement on temps. One theory is that coolant isn't in the radiator long enough to properly cool. I believe I have a Mopar Performance water pump, at least that's what I was told.

I can pull the valve covers and have a look, but the other tests will take time to get done. The headers make it really hard to get a compression check. Recently I tested 4 cylinders. They were reading 110-120psi.

Regarding detonation, It will detonate at any temp if the timing is set to run great. Yes, I've taken it to old timers and pros. If you check the timing and set it to where it should be, it's way too high. One guy seemed to think the cam was advanced, or I was a tooth off. The best we can do is set it where it runs good, and then turn it back until it stops detonating.

Other guys are blaming the carberator, suggesting I bolt on a Holley and see if it helps.

And of course, there's the guy who suggests I give him a ton of cash to rebuild the motor.

http://www.flickr.com/photos/80659156@N03/7394704448/in/photostream/[/img]http://www.flickr.com/photos/80659156@N03/7394711940/in/photostream/
http://www.flickr.com/photos/80659156@N03/7394708338/in/photostream/  

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 06/18/12
10:50 AM

If you're burning a lot of oil, it is a LOW octane fuel and it will exacerbate the tendency to detonate. Unfortuntely it sounds like it is time for a rebuild. What elevation are you at? Do you know what cam is in the engine? 110-120 psi is certainly not excessive.  

Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 06/18/12
03:08 PM

I'm certainly burning some oil. I wouldn't consider it a lot, but I guess any is too much. I'm in the Midwest.....Chicago area. 800ft. above sea level. All I know is the cam has a 484 lift(not my dept.) no clue on brand, but I'd guess Mopar Performance.  

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 06/18/12
04:09 PM

Sounds like a combination of poor choice of parts in the engine build, poor break in procedure and a worn out engine. 110-120 psi @ 800' elevation is pretty low. Can you do a leakdown test to check the rings? Smoking on start up or deceleration is probably valve guides and seals.  

Spud490 Spud490
User | Posts: 65 | Joined: 01/12
Posted: 06/18/12
08:42 PM

I had one friend that swears by drilling a small (.050") bleedhole in the thermostat body. His theory is that the thermostat can open easier & smoother cause the pressure is equalized. Maybe try that ?? Or take the guts out of a thermostat and use the rest as a restrictor plate.  See if your heating issues away?  
10's or bust!!

Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 06/22/12
06:07 PM

How many of these issues can be solved by rebuilding the carb? Smelling a lot of gas when I park for the night, when adjusting with a vac gauge, I have to turn the screws out at least 3.5 turns. They're almost loose. That migh account for bogging at stoplights.....gas dumping in when it shouldn't be.  

waynep71222 waynep71222
User | Posts: 246 | Joined: 04/12
Posted: 06/22/12
10:14 PM

lets talk about the CARB..

if you have the primaries open too far.. you will be on the idle transition ports that are NOT designed to feed at idle..  the idle transition ports are limited by a RESTRICTION.. not the idle mixture screws...  

the idle feed ports .. ROUND and below the closed throttle plates are controlled by the idle mixture screws...

back off your idle speed screw that holds the primary throttle open.. till you get the idle as low as you can go..    then go back and readjust the idld mixture screws to lean best idle..  highest vacuum you can reach.. then turned in a fraction of a turn each to drop the idle manifold vacuum 1/2" total..   this is lean best...   if you have to back the idle mixture screws out  more than you think you should..  and don't forget.. you may have to open the secondary throttle plates slightly to allow enough air around the secondary plates to allow the primary throttle plates to close enough to just barely cover the idle transition slot..


if your idle mixture screws are still too far out..  and you have a large intake volume and large runners and ports..   you may need to increase the size of the idle feed restrictions to prevent the system from being too lean at idle and too lean during idle transition..


if you are smelling fuel after shut down..    look and see if its dripping from the boosters after shut down.. or dripping out of the throttle shafts through the sides of the carb.. from boiling over or sediment in the fuel system holding the needle and seats open just enough to seep..

Idleandtransitioncircuit

Transferslot

i don't know what kind of carb you have...  but they all work the same..

by the way.. almost all carbs.. except for full race carbs.. are calibrated for PCV flow to be included in the idle air bypass flow...   no PCV.. you will have to open the secondaries more to compensate....  

waynep71222 waynep71222
User | Posts: 246 | Joined: 04/12
Posted: 06/22/12
10:20 PM

if you open your carb.. if you find any red sediment in it..  you will need a better fuel filter..  and magnets in  or ON the gas tank bottom..  big strong ones will work from the outside...

if your car is newer than 1970.. you probably have or HAD a carbon canister..  is it still hooked up.. so any fuel vapors are not coming out the vent line thats hanging under the front of the car someplace.. if earlier.. you can install something as simple as one of the power brake vacuum hose  filter things on the vent to capture some of the vapors.. those black PB filters are actually carbon canisters to catch the fuel vapors before they get into the brake booster and ruin it..  

Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 06/22/12
10:58 PM

Great advise. Thank you. I'll screw with it this weekend. I have an Edelbrock 750 (1411) I'm sure the carb is part of the trouble.  

Coronet70 Coronet70
New User | Posts: 32 | Joined: 08/08
Posted: 12/06/12
09:22 AM

Thank you all for your replies.....I tore the engine down this past weekend and I found some issues. Some of the head bolts were nowhere near the tightness they needed to be. Blown gasket between cylinders 4 and 6. Valves trashed. Very Crankshaft timing chain gear slid right off the crank with little effort. Some scoring on crank, worn bearings, but minor scoring in cyliner walls, pistons look good. No broken rings.  

waynep71222 waynep71222
User | Posts: 246 | Joined: 04/12
Posted: 12/06/12
03:32 PM

wow... thats a disaster...   one good thing.   you know its going to be correct when you get done..

please read up on the oil additives for breaking in cams..

please be sure that you if you decide to reuse your cam.. that the lifters go back in the exact same location.  new or reground cams are easily available.. along with New lifters..

there are a LOT of cams that could be installed in that motor...  depending on usage..

cams that go thump thump thump.. or cams that can get decent fuel economy and still have some KICK in the pants...  please don't go for an RV grind..