I was planning on replacing the valve stem seals and possibly the valve guides (if needed, by a machine shop) on my 2.8 V6 and maybe even the rings, again if needed. I was talking with someone who said that rebuilding the top end (valves and rings, right?) without also rebuilding the lower end (crank & piston arms?) would wear the engine out faster than not doing the valves & rings.

I want to put a 3.4L V6 in my Troop, but I have to save up for that. The whole reason for looking into the valves/rings is because I am using oil at a rate of @2qts.+ per 650-700 miles and it smokes quite a bit at startup.

Any thoughts?

Not usre what the guy you were talking to meant by that. Not a preofessional engine rebuilder, but his comments don't follow any logic. Plus, people who say something would "wear the engine out faster" are suspect to me. That is an extremely vague way to back up a point.

To replace the rings you have to remove the rods, and replace the rod bearings. This usually requires you to pull the engine and break down the block. I think the time an effort you spend on this would be better spent on a newer 3.4 engine. You can get them around me for $400. The machine work on the valves might cost something like that anyways.

i would check compression first before you start the job. you're probably on the right track as smoking on startup usually means valve seals are dying. it might be the mechanic doesn't realize you're doing rings as well. maybe he feels that tightening up the top end is going to suck oil past the rings and carbon things up on the top end, messing up your valve job. this is a legitimate concern. when you do a valve job, the valves seal better and there is increased vacuum on the intake stroke. if the rings are bad, you could pull oil past the rings, instead of pulling air/fuel from the intake. IMHO, i think the rings would have to be really bad tho'. i suppose the increased compression of doing rings and valves could put increased strain on the bearings but i would think it's a matter of degrees, and not significant. however,if you're re-ringing anyway, why not do bearings as well? you've got it all apart anyway. besides, it's only money! <img src="/forums/images/graemlins/cheers.gif" alt="" />

There are pro techs who believe that if you do a valve job on a car with weak rings, you'll blow the rings after the valve job because you now have better seal..ie..more pressure up above to be exerted down on the pistons.

If you did BOTH the head AND the rings, things would be different.

In the techs defense I would say that if you were to do all of that, why not just go through the whole motor?

Well, I am basically trying to keep this motor running for another two years while I save up for the 3.4HT GM crate engine.

Just a thought: if you can get a good 3.4L (or 3.1L or 2.8L) from the junkyard for <$500, you have 1) solved your immediate problem (oil consumption, smoking) and 2) got some experience swapping engines for when you can afford the 3.4HT.

If the truck is your daily driver, you might still consider trying to find a complete head (in good condition) at a junkyard.

Or, just switch to 20W50 and Motor Honey. <img src="/forums/images/graemlins/zombie.gif" alt="" /> I once had a Ford Tempo 4WD (sympathy appreciated) that blew the front main seal when the PCV froze shut at -44?C in the Yukon Territory. I was running 5W30 Amsoil and it wouldn't make it through a tank of gas without the oil light coming on. I switched to Quaker State 15W40 and Motor Honey and the oil consumption dropped to <1qt/1,000 miles.