1968 Charger R/T 440HP engine with TOO high oil pressure

[stushug]

I realized that I would need a second gasket for the windage tray, but I found this mentioned in another thread. Summit Racing SUM-G2339 Summit Racing™ Molded Gasket Windage Trays | Summit Racing. Looks like it has everything needed to seal up the pan without doubling up gaskets when using the original tray. That should also save me time in trying to flatten out the old windage tray. I still have to go around the pan itself and make sure it's completely flat before re-installing

 

[Beekeeper]

It could be whatever went through that pump happened before the last engine rebuild. At least you know the pan is clean now.

I removed the oil pan today, and I'll bet some of the guys that urged me to remove it had their ears burning. That sucker's been on there for at least 22 years, and it didn't break free easily. After some extra effort and a lot of cursing I did get her off the engine. I did not find any debri at all in the pan, so my hope is that whatever scarred the oil pump was caught in a filter and is long gone. I didn't see anything suspicious on the oil pickup screen or anywhere else. My next steps are to re-install the pan, install the new pump, fill it up with oil and see what I get for oil pressure. I did notice that while the relief valve in the old pump moved pretty freely, the one in the new pump is much smoother and more freely moving.

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[Geoff 2]

^^^^ Good point.

 

[Eric Johnson]

I pulled the pump, opened her up and found a few things. The bypass valve seems to be moving freely inside the bore. I removed it, cleaned it and the bore itself. Both o-ring seals are pretty flat so that isn't helping. The worst thing I found were a ton of scoring on both gears. I'm posting pictures for reference. I'm going to order a new pump on Summit. I'm not sure if I should get the Melling DODGE Melling M63HV Melling High-Volume Oil Pumps | Summit Racing
or the Mahle DODGE MAHLE Original 601-1029 Mahle Original Oil Pumps | Summit Racing. The Mahle is triple the price, and the Melling has very good reviews so I'm thinking that's the way to go.

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It looks like you have a spalling issue as well. The pump could be cavitating (i.e. getting air entrained in the oil) or/and you are experiencing chemical corrosion. The corrosion could be caused by too much ZDP in the oil. The cavitating issue if not entrained air could be an oil foaming issue. This is a situation when there isn't the proper amount of antifoamant in the engine oil. it can either be too much or too little antifoamant. Also, on the foaming side, could be silcone leaching from RTV if that is used as a sealant material.

 

[Wietse]

Cavitation would cause a loss of oil pressure, not raising it.
Evidential damage of cavitation will show itself as pitting on the rotors and housing around the suction side.
The marking seen on the pictures are of debris that went through.
Since the pump shows some decent wear and damage and still has a too high oil pressure it seems more likely the discharge side of the system is blocked.
Since it has been at standstill for some time, previously never had this high oil pressures something could be gummed up or blocked?
Camshaft bearing slipped and blocking the oil feed to the rockers?

 

[Black_Sheep]

I'd pull apart your new pump to make sure there's no manufacturing trash inside. Add some clean grease so it will suck oil, a dry pump won't suck oil.

I agree, when we tried to prelube my buddy’s 351W the pump wouldn’t turn. Turns out it had a bunch of grit inside, it was a new in the box Melling pump. If we hadn’t tried to prelube the engine before firing it up, the results would’ve been catastrophic.

 

[4406bbl]

I have to agree on melling pumps, the last big block one I had was full off trash and would turn hard on the engine when torqued down. I sanded the rotor down with 400 grit wet or dry paper in oil on a plate of glass in a figure 8 motion. I finished it with 600-800-1200 grit and lightly chamfered everything. I also polish the relief valve. I do not trust melling pumps since the sticking big block relief valve casting issue in the late 80s, check every square inch of an oil pump. Look at the end of the rotor where it runs on the relief valve cover, you could finish it smoother with a grinder in most cases, and it rips metal out of the relief valve passages when you torque the pump down and do not check it.

 

[4406bbl]

Make sure you have clearance here, Chrysler allows .014 before replacement, I give it about .004. Most important is that it turns smoothly torqued to the block.

 

[stushug]

I have to agree on melling pumps, the last big block one I had was full off trash and would turn hard on the engine when torqued down. I sanded the rotor down with 400 grit wet or dry paper in oil on a plate of glass in a figure 8 motion. I finished it with 600-800-1200 grit and lightly chamfered everything. I also polish the relief valve. I do not trust melling pumps since the sticking big block relief valve casting issue in the late 80s, check every square inch of an oil pump. Look at the end of the rotor where it runs on the relief valve cover, you could finish it smoother with a grinder in most cases, and it rips metal out of the relief valve passages when you torque the pump down and do not check it.

I haven't installed the pump yet, I will be checking everything you mentioned. Thanks!

 

[Wietse]

Here similar as others, i dismantled the new pump and found dirt inside.
No solid particles or so but just black dirt, cleaned it up, chamfered the edges and applied a coat of grease on the rotors to help it getting suction.

 

[stushug]

Here similar as others, i dismantled the new pump and found dirt inside.
No solid particles or so but just black dirt, cleaned it up, chamfered the edges and applied a coat of grease on the rotors to help it getting suction.

I just checked the new pump for clearances, went over the piston with some sanding & polishing. Chamfered the edges too. Also polished the relief valve. Gave the entire assembly a good clean, I found minimal dirt inside like others mentioned. Cleaned it all thoroughly. I will load it up with Vaseline that I purchased just for the occasion and re-assemble tomorrow.

 

[69 Sleeper Bee]

"Vaseline that I purchased just for the occasion"

 

[Wietse]

 

[stushug]

I figured that would set off some comments!

 

[stushug]

I just installed a new Summit nylon windage tray with integral gasket and the original oil pan. Sealed everything with Right Stuff and torqued the bolts to 15 lbsft as per the service manual. If I get a chance tomorrow, I'll re-assemble the new, cleaned and lubed oil pump and install it on the block. I'm also working on the cooling system, so I removed the old upper and lower rad hoses, the thermostat & housing. Re-installed all of the header bolts with Loctite Head bolt and water jacket sealant. I noticed some seepage on the right side header, rearmost bolt so I thought I might as well address every problem while I'm at it. When I'm done I'll have a new windage tray, newly sealed oil pan with a new magnetic drain plug, new thermostat, new coolant, new rad hoses and completely sealed header bolts. I'll re-install the oil pump while the lower rad hose is off, since the hose is kind of in the way anyhow.

 

[stushug]

I already wrote this in my Borgeson steering box thread, but I thought I'd post here to kind of close out this thread. The new (stock style) Melling oil pump has cleared up the problem of too high oil pressure. It's back down into the normal range and running fine. The only headache I had was re-installing the oil pressure sending unit. I think it was @Kern Dog that mentioned this, but I'm not sure. There's not much room to get a wrench back there to tighten the sender so I made my own by bending an old open end wrench. Thanks to everyone who posted with comments and suggestions. Now all I have left to fix is my fuel gauge, (I'm sure the problem is the sending unit) and my seemingly dead radio.

 

[stushug]

Took the car out for a shakedown run today. Ran her on surface streets and the highway, and everything seems great. Oil pressure, temp, and steering all working great. What a difference to drive the car with steering that is tight and responsive. I was so thrilled with the ride that I pulled the radio out when I got back and I'll start troubleshooting that next. The 5A fuse was blown, but the new one I put in blew up too, so it's probably some bad electrolytic caps gone south. I'll know soon enough. Once I run some gas out of the tank, I'll pull the sender out and figure out why the gas gauge is dead, it's stuck between empty and 1/4 tank. Then I'll have everything working perfectly forever and ever...........RIGHT! At least until the next thing breaks.

 

[stushug]

Took the radio out yesterday, put it back today. Just needed a very thorough cleaning on the volume-on/off and tone pots. Trimmed the antenna and now it's working great. That leaves just one more item, the fuel level sending unit. Whoa baby!

 

[eldubb440]

Just needed a very thorough cleaning

I have found the majority of the time, this is all it takes......and congrats on the oil pressure thing

 

[dvw]

When I've taken pumps apart that looked like that, pieces usually came from the heads. Broken retaining rings on valve seals. Broken pieces of valve spring. Might want to take the valve covers off. Get a bright flash light and look very carefully at the springs and seals. Like you said, anything that went through the pump went in the filter. But will there be more trash coming?
Doug