AMC 360 Oil?

What is the best type of oil to put in a AMC 360.

 

I would guess that it depends on the condition of the engine and how it is holding pressure.

I think a standard 10W-30 would be just fine under normal conditions.

I know that my machine shop recommends 15-40 during the break-in cycle. Shell Rotella T to be exact. I think it has to do with the higher percent of detergent.

 

I use Shell Rotella-T 15W40 in the Jeeps. I would use Chevron Delo 400 15W40 if it were cheaper or more available. These are both intended for use in diesel engines, but can also be used in gasoline engines. Diesel oils do indeed have a higher level of detergent than conventional oils. Diesel engines also have similar piston pin loading to the flat tappet loads that we have in these older engines, so they should have a better formulation in that sense.

There's a lot of controversy about flat tappet engines and modern oils. Search the web for ZDDP and you'll find way more than you could ever read.

If you are going to run a conventional dino oil, I suggest you use a ZDDP additive.

I also use a Wix filter - don't use a Fram.

Other options include synthetics like Mobil 1 ($$) or a high-ZDDP oil like Valvoline racing oil.

 

I'm running 10w30 now. My cold psi is 25 idle and 50 on the gas. Once it warms up I'm running 10 to 15 psi idle and 25 to 30 psi on the gas. I have a good flowing rear main seal leak I need to get fixed. Do these numbers sound health to you?

 

Only the warmed-up numbers matter.

Some of these engines have run a long time with low OP, but those numbers are low. You'd like to see at least 10 psi per 1000 RPM. Your numbers are at the very low end of acceptable - just ok if they are accurate and you keep the revs down.

What brand of filter? Replacing a Fram with a Wix or Purolator usually gives another 10-20 psi for these engines. Don't use a Fram filter, or a cheap generic filter. Wix or Napa Gold are good.

The rear main seal leak is risky, because of the chance of running low on oil. When you replace the rear main seal, you can Plastigage the rod bearings.

 

Hi timgr. For me it is effective to use the brand of K&N air filter. Did you try it already?

 

No, I have not used the K&N filters. I am not a fan of their air filters. Their oil filters aren't anything special, from what I've read.

Here's an interesting article comparing oil filters http://minimopar.knizefamily.net/oilfilters/index.html

 

" you can Plastigage the rod bearings."

Sorry if i sound dumb but what is plastigage. and why do I need to do this.

I don't have a tach in the jeep but when i rev it up the psi goes up, if i push hard it will climb to 50 psi or so.
Oh I have a carquest standard oil filter

 

Google is your friend!

http://www.plastigaugeusa.com/how.html

 

Is this something that has to be done or can just replace the seal.

 

No, you don't have to. If you were concerned about the condition of the engine, it would tell you what the bearing clearance is.