is 10W30 on my old ford 289 burning oil

does anyone think that my old 100,000 mile ford 289 is burning oil with a 10w30 oil. i used to put 10w40 but since i switched its been smoking oil. what do you guys think

why did you switch to lighter viscosity? Hank

I use 20w50 in every thing. seems to work for me. dragster to lawn mower.

Just a question - are there any valve seals left in this engine. If it's a 289, it's OLD and the OEM valve stem seals weren't one of Ford's best ideas. Also, how sloppy are the valves in their guides. SBF engines tend to wear out when they get OLD (so does everything else, even Chebbies:CRY: ) and 100K in a '60's engine is.........

well the heads have been rebuilt a couple years ago.what should i do, should i go back to the oil i was using or take the motor out and get it rebuilt. i do notice now that my plugs are fouled with oil and thats something i never had with the 10w40 oil.

I'll add to Denny's post which I fully agree with.

"Rebuilt" means a lot of things to different mechanics - maybe a valve job with new seals is his definition. Mine definition of rebuilt is to install new valve guides, probably new valves, springs and rockers and retainers and locks plus a 3 angle valve job. Remember - a 289 is OLD and my guess is that you never had new guides installed as it is fairly expensive and is a job for a very well eqiupped shop. Some folks like the bronze guides - I don't except for a race type engine that is renewed regularly. Bronze is just a fancy copper alloy and is by that nature soft. My preference for a street engine is iron. Iron has by nature a lubricity factor (high carbon content) and wears slowly. Also, you may have a high lift camshaft that may be messing with operating angle/geometry - and Fords seem to have this characteristic with their rocker arms, rail type especially - and this in turn causes valve stem and guide wear. Roller rockers will alleviate this a bunch.

Another thing to consider is to have a leak down compression test made - you may just have some rings that are worn or even broken which will foul plugs as well.

Just some food for thought !!!!:D

For what it's worth I think bronze guides rock.

Older Navy (or phospher) bronze guides did tend to wear out quicker than a cast iron guide. But the newer materials used are managanese or Aluminum bronze alloys that are much harder and wear resistent. The bronze guides allow you to run lower clearances for improved oil control and bearing support of the stem and they will not wear down the valve stem. Also you don't really want to run a stainless valve in cast iron.

Kitz

Does it smoke on startup then clear up? - typically valve guides.
Smokes constantly? - typically rings or possibly valve guides also.

well it keeps on smoking constantly. aw man i give up with this motor i think ill buy a 331 short block.well thanks allot guys for your help.

put 20-50 in it and stop belly achin :LOL: