3JsVette

You might be chasing a condition that doesn't exist. Why over do it when a simple oil change will be more than adequate?

L88Plus

A quart of transmission fluid (high detergent instead of solvents) and a can of seafoam. Don't run it hard, but you will need to get it up to temp a time or two. I'd probably add these one day, drive it a bit, then an oil change with dino or even a blend and let 'er rip the next day.

REELAV8R

This was the type of thing I envisioned when engine flush was brought up. Didn't know you could get that done.
Sounds better than any other option discussed so far. I wouldn't have a problem with doing this to an old gummed up engine.

TimAT

Personally, I'd be very concerned about the first start after having all the lubrication flushed out of the bearings.

REELAV8R

I would too.
Since they can push solvent through the engine they may also push oil through prior to start. If not then solvent would still be all through the engine diluting the oil and/or providing little lubrication on initial start.
Priming it like after a re-build would at least get oil into the bearing spaces.
I'd be curious to know if they use the machine to do that or not.

cv67

Done that twice in my DD
Maybe coincidence but in less than 30 days both times the fuel pump bit the dust. Never ran any better.
Oh well...

x2 on running syn on old motors esp with wear. They had higher piston to wall clearance it just isnt needed. Wont make it last "forever" if thats the worry. If its going to go it wont matter what oil is in it
If you can afford to spend the extra feel good thing then carry on just dont expect much from it.

Did the syn thing on a DD when I bought it new. After 60k mi said hell with this felt like I was wasting money -started using whatever was cheap even if it was from 7-11 not the exact same weight to top off but did use a Wix filter
Has 180k hard miles on it never had the valvecovers off.

The 383 gets good stuff (dino)only as I have crazy money in it. Does it help probably not but-
My lifters are quieter Ill say that imo a thicker film or "shear strength" is desirable in some apps. Like flat tappets

DUB

In the past I would use a quart of ATF. It would take a bit of time abut it did work. I could not tell you if the oil filter got plugged up or not due to how well the ATF got the sludge to come off in thick lumps or liquefied it.

But now I use the Amsoil product I put a link to.

DUB

swag

Maybe I should explain what my goal is. I got my car about eight months ago and I was thinking who knows what the previous owner did to maintain the car. Did they change the oil regularly. Did it sit for a long time? So many things come to mind.

I've already discovered a few hacks they had done to the car.

So, my goal is to start fresh with it. As an example, is the engine flush. Also, i would like to do a radiator flush. Also, don't know the last time the car was greased. etc..

If it is too risky to do the engine flush I will not do it. Also, I know synthetic oils are better for modern cars so I was curious about older cars. I heard that if you switch to synthetic oils you need to do some oil flush too. i.e. can't just switch from regular oil to synthetic without getting the regular oil out of the system. Maybe a rumor?!

mikem350

Have you looked at the oil on the dipstick? If its not absloutely BLACK, I would assume that there probably is not an over load of sludge inside.

AND, if it has good hot oil pressure, go ahead and give it a change to good quality 10W-30 dino oil and monitor the oil consumption. I like Valvoline hi mileage.

If you STILL suspect sludge buildup, then you have options!

And yes do the cooling system, refill with 50/50 antifreeze.

REELAV8R

You can switch form conventional oil directly to synthetic oil. There are no special procedures.
Just use a synthetic with 1000 PPM of zinc. You have a flat tappet engine if it's still stock and those need the zinc to prevent wiping a lobe or at least to extend the life of the lobes on the cam.

Mobile one 0w40 is a full synthetic with 1000 ppm of zinc. You can extend your change intervals to 10,000 miles with a filter change at 5,000.
That being said, if you do not drive it 10,000 miles within a years time then you are loosing money on the oil vs cheaper conventional.
I use synthetic in my vette due to it's now making 440 ish HP on a SBC and I drive it like I stole it.
On my DD's I use it because I do put on 10,000 miles or more per year so the higher cost is off set by the extended change intervals.

Synthetic does provide better lubrication at start up and prevents excessive wear to the cylinder walls vs conventional. It is a better oil all around.
Mobil one has lots of detergents in it. So if you switch from conventional to Mobil one it will clean the inside of the engine. If the engine is considerably dirty your oil will turn black rather quickly. That's the detergents doing their job. Not withstanding excessive ring blowby being the cause of quickly dirty oil.

swag

Thanks! It isn't absolutely black so maybe the previous owner took care of the car.

I'll wait until spring to do all this; however, I wanted to get everything ready so I can spend a day and get it done. Found I seems to need to order a lot of parts online and have all these incomplete projects because of it.

REELAV8R

Almost nothing can be derived from the color of the oil at this point, especially since you don't know how long or how many miles it's been in there. Maybe it was changed the day before you bought it. Maybe it's a non-detergent oil, silly I know, but who knows? You can't draw any conclusions based solely on the visual aspect of an unknown oil.