Oil for a Slant Six that's been sitting a long time

-
wh23g3g

wh23g3g

Well-Known Member
Joined
Jan 13, 2009
Messages
307
Reaction score
1
Location
Georgia
I've got this 65 Valiant that's been sitting for months since I've acquired it and years before that probably without running. When I first got it about 6 months ago I was able to get it started right up after a carb rebuild. The engine ran, didn't smoke, and didn't make any unusal noises. The oil in it is still black but not gritty or sludged. It's been sitting again outside for 6 months while I slowly get everything around it back in order. The whole engine bay was a mess when I got it and the interior even worse. I've got everything taken care of under the hood except a passenger side motor mount I can't find and a new Slant Six engine harness I can't find anywhere. But I would like to get that nasty old oil out while it's still sitting because it maybe a couple more months before it can be started. What kinda oil should I put back in? Just anything new? Should I put any kind of additive in to help protect when it starts up again after sitting for so long. It's a 66 170 motor, no idea how many miles on it, because it should have a 225 originally.
 
wh23g3g said:
I've got this 65 Valiant that's been sitting for months since I've acquired it and years before that probably without running. When I first got it about 6 months ago I was able to get it started right up after a carb rebuild. The engine ran, didn't smoke, and didn't make any unusal noises. The oil in it is still black but not gritty or sludged. It's been sitting again outside for 6 months while I slowly get everything around it back in order. The whole engine bay was a mess when I got it and the interior even worse. I've got everything taken care of under the hood except a passenger side motor mount I can't find and a new Slant Six engine harness I can't find anywhere. But I would like to get that nasty old oil out while it's still sitting because it maybe a couple more months before it can be started. What kinda oil should I put back in? Just anything new? Should I put any kind of additive in to help protect when it starts up again after sitting for so long. It's a 66 170 motor, no idea how many miles on it, because it should have a 225 originally.
Click to expand...
You may want to get some oil with zinc additives. Check your local speed shop. I think Joe Gibbs brand is one of them. Our local Auto Zones sell high Zinc oil in some of the heavier weights. Zinc will protect the cam lobes from wearing out. Bill
 
You've got a lot bigger things to worry about than zinc level, which is more of a goose chase/snipe hunt than a real issue. You need to get the sludge and crud out of the engine without causing damage (as can happen if an engine is "flushed" too aggressively). I have good results using a cautious procedure involving homemade "soup". It will also be a good idea to service the oil pressure relief valve to make sure it's doing its job, as described in these two threads: thread 1, thread 2.

Once you've got the engine cleaned out, use a reputable brand of oil of a weight grade appropriate for your ambient temperatures; do not make the common mistake of thinking a heavy-weight oil is better. It's not, unless what you're trying to do is squeeze the last few miles out of a whipped/worn-out engine. If you're not in the grip of winter as we are up here, start with 10w30. I'm running 0W30 (zero W thirty) in my '73 Dart at the moment; I get fast oil pressure even on the coldest startups because I have chosen the oil weight according to prevailing temperatures. Be sure to use a quality filter (not Fram).

The engine mount's available from Old Car Parts Northwest amongst other sources, or you can probably still get in on the group buy for new poly '62-'66 A-body slant-6 mounts. The harness will also be easy, but I'll answer that in your other thread.
 
slantsixdan said:
I have good results using a cautious procedure involving homemade "soup".
Click to expand...

Would that "soup" involve #2 or kerosene ? I used to add a qt+ and let my /6 idle for 1/2 hour then drain FOR A LONG TIME with the filter off before replacing filter and refilling. Back then money was short and this IS NOT a recommendation.
 
I feel WG23 should just put some good Dino oil in and run it. Slants are rugged. Keep an Eye on your oil and have some fun. Dan's flush is great but I dont think in this case its necessary.
Frank
 
this is what i would do #1 drain old out #2 add new 10 30 #3 throw in some Marvel MM12R Mystery Oil 16 oz.
Marvel Mystery Oil cleans and lubricates fuel injectors and carburetors. Reduces and prevents varnish and gum build-up
and you good i think
 
Try the new oil just for older Muscle Cars . . . Z-Alt. It is great stuff! I have it in the Dart. www.Z-Alt.com
 
dump the oil out right on the spot...fill with new oil and start let it run a awhile....dump agian...and refill....change it again when you start driving it...just make sure you change the filter....
 
slantsix.org-- could help with the mount--- can't remember the name-- but they had the elusive mount for little $$-- the paddock used to carry it & now I believe someone is making a urethane mount for the 62-66 abody slant cars. as for the harnedss-- someone had 1 for a 65-66 dart listed cheap-- not an exact match -- but if yours is toast would probably be better than nothing, Lawrence
 
The 360 sitting in my carport was naturally locked from sitting for 3 years. I added diesel to the crankcase and let it sit for 2-3 months.I used a priming tool and ran the oil pump for a solid 2-3 minutes. Then I carefully turned it over by hand. It broke free easily,so I spent a couple hours working the motor back and forth,pulled the valve covers and made sure there was lube getting to the top end. Filled the cylinders with oil and then drained the crankcase of it's nasty deisel/oil mix.

So thats what I would do. Dont run the motor,too much potential for damage. Simply fill it with diesel and work it back and forth by hand.Use the priming tool. You could heat the deisel before dumping it in.
 
Needsaresto, your advice about a priming tool applies to V8 engines, but this is a slant-six engine. The design of the oil pump drive is such that there's no such thing as a priming tool; the oil pump cannot be spun independently of the engine. The oil pump can be primed by removing the cover plate and packing the cavities with vaseline, but without doing that priming is limited to pouring oil down the central hole where the oil filter mounts. A couple tablespoons of oil can also be shot into each cylinder and the engine can be cranked with the plugs removed to lube the cylinder walls.

As the slant-6 in question turns over, there is no extreme potential for damage by cranking or running it. The main thing is to make sure it's full of clean oil thin enough to get to the bearings quickly.
 
if its really such a worry just buy some rislone from the parts store, pour some into a squirt bottle and just like 2 or 3 squirts. let it sit for a day or 2. turn it by hand if it is smooth, replace the oil and add rislone to crankcase and pull the plugs and spin it for a couple of seconds. then adj all ur rockers to .012int and .022 exh cold. then warm it up and re lash them to .010int and .020 exh (stock cam).
 
Buy a 12 pack of generic 10w30 at Wal Mart and 2 cheap filters. Change, run for a week or two and change again. Don't go too nuts trying to remove all the sludge at once, you risk clogging the oil pickup.

When you adjust the valves, start the engine with the valve cover off and make sure all 12 rockers are oiling out the top.
 
Since it's going to be a while before you try to put the engine underfire, IMO, it is going to be more effective not to change until you're ready to light it up. I'd recommend a little #2 diesel or Marvel Mystery Oil in the top of each cylinder, let set a day, and turn over engine by hand.

When you light it up, get it up to operating temperature. Shut off and drain with the oil hot. Refill with engine with a medium quality oil less a pint. Substitute the pint with AFT. Put a 200 miles on this soup and then change while hot. This time make it a regular change, good quality oil, a Zinc additive (if not already in the oil), and a decent quality filter.

The reason for the ATF is to take advantage of its strong detergent qualities. Changing the oil while it is hot helps get rid of junk that will be in suspension in the oil when hot but would congeal and settle when cold.
 
I'll tell you what i did, when i bought my '74 dart, it had been sitting for 3 or four years, in the weather, the carb and hoses were on, so nothing was exposed, i cleaned out the air cleaner that a packrat made its nest in, put a new air filter in, rebuilt the carb, drained the oil, changed the filter, and filled it up with plain jane valvoline 10wt-30, and just ran it.
That car is a daily driver now, i go up and down old highway 30 at 100 miles an hour with no problems, don't worry about a slant, whatever you throw at it, its going to take it.
 
You must log in or register to reply here.
-

Back
Top