Motor Oil Additives

[Orion 762]

Question on antiwear (and other) additives to engine oil that "magically recondition" the internals. Do these work to restore lost compression, or are they a waste of time/effort?

I've got a '71 Chevy Cheyenne, original 350 engine, 650 holley, edelbrock intake, headers, and straight pipes. This truck has about 110,000 original miles on the engine, was a regular working truck for many years, then "sat in a carport" for a long time since the original owner had many other newer trucks to work with. The holley, headers, etc. were installed new about 1999.

The engine leaks a bit of oil near the rear intake manifold, but otherwise it burns no oil (except a little at startup). The engine also has a good bit of sludge/varnish buildup, evidenced when we replaced the valve covers . . and the PO ran it awhile without a PCV valve.)

My son (who's 16 and drives this truck most) wants to try a "science fair project" with these additives to see if they really work to improve the compression and power of the old engine. We're considering AMSOIL products with ZDDP (an antiwear additive). I understand that without the catalytic converters to worry about, a large range of heavy-duty products might work.

Any other hints on "products to try" or "ones to avoid".

I'm thinking there might be a product we can "add" to the existing oil, let it "work a bit", then drain out and refill with fresh oil. Don't like the idea of leaving "strange additives" in there regularly.

Please advise with ideas . . . Thanks.

Orion 762

[bobbys1967]

I'm not sure about additives restoring compression (though a sceptic) but as far as the sludge build up goes use motorflush before you change your oil. Put it in, run it for 10 or 15 minutes, and then drain your oil and it will clean most of that out. I've also heard of people doing the same thing with a quart of diesel fuel.

[tom hand]

I would NEVER use motorflush....because I have had it wipe out a motor before....5 minutes after I used it NO oil pressure. It just cuts too much stuff loose in the motor and clogs up the pickup on the pump. Better off just to keep clean oil in the motor and leave the sluge where it is at...imo

[Huck]

Restoring the power, chemically changing the metal, etc. is all BS. Coming form a long line of mechanics, none of that stuff actually changes the chemical composition of the engine, metal etc. Some addativies can temporarly reduce leaks by softening a seal---so can a wee bit of brake fluid. Sludge build up is most commonly caused by lack of regular oil changes, use of oil with a high level of parafin (wax) in it such as many Pennsylvania oils or the lack of high detergent oils. Once this stuff is built up, the best thing you can do is like Tom said, leave it alone. If you loosen the sludge on a running engine, chances are that you will clog things like the tiny ports in the oil lifters, push rods, etc. I have run Castrol oil in engines for 40 years without a oil related failure. New engines using Castrol for 150K miles still look new when you open them up.
A much better experment would be to do positive changes to the engine that will not endanger it's operation like----changing the ignition over to HEI, Headers, relay-ed headlights, high output altinator, a GOOD tuneup, new or rebuilt carb. These kind of changes will make a permanent improvement in the power, economy, and or performance of the truck without endangering it's life! My .02

[old Rusty C10]

NEVER EVER try to remove the sludge from a motor using the flush things youll wind up blowing the motor as stuff will jam in oil galleries andsmall parts . and i tend to stay away from any oil additive. ive used STP oil treatment on a motor that had abad bearing to minimize the knock for a little bit til i could rebuild it but thats about it. Like the other guy said too i swear by castrol oil or quaker state never had a problem with either and im meticulous with oil changes at every 2500 miles

[bobbys1967]

I consider myself enlightened. Thanks guys.

[gman]

Huck,

Could you elaborate on "relay-ed headlights". What exactly is this, what does it accomplish and what is the proper way of doing it.

[Huck]

RElayed headlights implies that instead of runing your headlights thru your light switch (stock)with the associated amperage/VOLTAGE DROP, get a 12DC relay and run a line direct from the battery to the relay and then to the lights. Rewire your headlights switch wire to control the relay. You will have no amperage/voltage drop. Your headlights will be a LOT brighter.

[gman]

Huck,

Where would the relay be located? Close to the headlight switch or the battery? What size wire for the connections? Any need for a fuse? Does this setup still go through the fusebox? I'm no electrician so sorry for all the questions. But I want to do this BAD! Sounds like a much improved lighting system as a result. I just don't want it to be too visibly obvious that the wiring has been butchered, if you know what I mean. Thanks for all the help!

[cableguy0]

old rusty just to let you quaker state is parafin based has a lot of wax in it. i have seen more motors than you could count that religously had the oil changed with quaker state and are sludged up bad. pennzoil is also parafin based and will do the same thing

[casey]

which is the oil of choice then? castrol?

[lukecp]

I prefer Valvoline myself.....

[stelth2002]

I run full syn mobil 1 in my 67. It comes factory in corvettes, but thats not what made me choose that. But if you cant afford that i use castrol in my diesel. Seems to work good. I also use mobil 1 in my motorcycle that sees 10k and its a 4 stroke that hauls

[jorgensensc]

The oil debate continues!!!! This topic never dies!! Next we will be discussing oil filters. (Think I'm kidding, watch)
I run Valvoline in older engines, that I haven't seen new and haven't built new.
Anything new I run Mobil 1 Synthetic.
As far as oil filters, I will kick it off by saying I use Napa Gold oil filters!!!
Let the debate begin!!!!!
Haha!!!!!

[Hooter]

Napa gold all the way, I always liked the display between thier filter, a puralator and a fram, man are fram filters crap, no paper, cheesy construction (pay a little more now, and a lot more later) the Napa filters are made by wix, which make good everything in my opinion, I also swear by the generic Napa oil too, don't know why, but it is 100% virgin oil, and all my motors are nice and clean inside

[Rooster's 67]

mobil 1 in everything, wix filters and K&N for induction,


If you have a motor that is sludged up, start adding ATF dexron to your oil changes in the amount of 20% or less, the detergents in it will help to SLOWLY break down those deposits and clean it up,,,,,,but obviously do this at your own risk, and shorten your oil change intervals maybee by 25-50%.

[Orion 762]

Thanks for all the tips and help folks. So, rapid flush sludge removal for me! The problem seems to be the sludge "coming loose at once", blocking channels and galleys.

I kind-of like the ATF Dexron idea though. Another mechanic mentioned diesel fuel (one quart, run it a while, then change oil).

We probably "inadvertently" cleaned things up a bit two weeks ago. My son got a "used" Holley double pumper (650 cfm??) and was playing around with the floats (it was running way rich). Overnight the gas kept coming out of the bowls and draining into the intake, past the pistons/rings, and into the crankcase. From the dipstick it looked (and smelled) like at least 25% gasoline. After craning and revving a bit, we had the whole backend of the truck coated with oily gas . . . along with a black plume on the gravel about 20 feet back from both pipes.

After fixing the carb, we changed oil again to get the gas out. Wonder how much "sludge" this cleaned out??

I like the re-layed headlights idea. Any links to details on this?

Thanks again . . . Orion 762