Gaser Blowin smoke like a Diesel

[Ricky B]

My daggum new motor I just put in my truck not too long ago (I'm at 30K now) is rollin coal, feel like it aught to be a diesel

Does so at higher rpm's starts at like 2-2500 rpm and the higher I rev the more it burns oil. Been getting progressively worse over the last 10k or so, at the point where it burns about a quart for every 10 gallons of gas, worse when I'm towing (don't used OD so it stays in the higher rpm's) and I'm towing almost 50% of the time I drive the thing nowadays, have to keep a couple gallons of Rotella in the bed everywhere I go.

Dunno if any of this matters but just for info its a 350 block bored .40 over and assembled by a fairly reputable engine shop. Put 98 Vortec heads on it, 1.6 roller rockers, mild cam - with the 1.6 rockers gets about 4.88 lift on both sides

Its runnin same as always, haven't lost any performance, just burning oil like crazy.

Pulled the plugs, no particular cylinder indicates more oil in em than the others.

Anyway - do the higher rpm blowin smoke/burnin oil symptoms indicate that perhaps the valve stem seals are shot? The Vortec heads were the only high mileage used part I put in the engine when I put it together - over 200k now.

If not I'm assuming its an internal gasket or rings, just never messed with any valve stem seals before so figured i'd ask . . .



If I do need to slap some new ones on I heard the best way to replace em is to pull the plugs and pressurize the cylinder to keep the valve from dropping out while your replacing it, sound right?

 

[rattlecanpaint]

True about pressurizing the cyls to keep the valves in it. Though it's probably not the valve stem seals. They usually only leak once you've shut it off. Shown by the puff of blue smoke at startup. Looks like you've got bad rings or a severely plugged PCV system.

 

[Ricky B]

Awesome . . . don't think the pcv is clogged, pass side runs throu one of those one way check valve things into the tbi - driver side is open air, tube may be clogged but I doubt it, I can check it thou.

If its the rings then its just gonna have to keep burning it, I'll just call it a two stroke

 

[Rich]

Guy in our club had this same issue with his LT1 car - bad intake manifold to intake manifold mating was the cause (The angle was slightly off)...it was pulling up oil from the lifter valley.

If your valve guides are trashed it could cause that too, but the factory guides are pretty darn tough. Though, anything's possible when you start screwing with rocker geometry. what's the wipe pattern on the top of the valve tip look like? What are your springs rated to for lift? If there's much preload on them, you could be getting right to coil bind..

 

[SSWaters]

You got the throttle body intake with vortec heads or the plastic vortec intake and heads setup?

Checked compression on it? Pull all plugs and put a battery charger on it to keep the rpms about the same, just a thought. I got one laying somewhere, if you want to use it give me a day to find it.

 

[Ricky B]

Guy in our club had this same issue with his LT1 car - bad intake manifold to intake manifold mating was the cause (The angle was slightly off)...it was pulling up oil from the lifter valley.

You got the throttle body intake with vortec heads or the plastic vortec intake and heads setup?

Its a edblebrock style copycat alum intake for a 4 barrel carb to Vortec Heads, just used a tbi to carb adapter plate on top,

If your valve guides are trashed it could cause that too, but the factory guides are pretty darn tough. Though, anything's possible when you start screwing with rocker geometry. what's the wipe pattern on the top of the valve tip look like? What are your springs rated to for lift? If there's much preload on them, you could be getting right to coil bind..

I'll be honest I've never really messed with valve's and springs before, just bolted these heads on pretty much.

Was told by the TBIchips.com guy that the cam I went with and 1.6 rockers I have are his usual recommended setup for stock heads/springs/etc for a mild DD motor (supposedly his setup pulls 400 hp on flywheel dyno - I call major bs) . . . I pretty much followed his instructions and parts guide to the T when I put it together.

I will say though. The rockers did get loose not too long ago - didn't seem to affect oil burnage at all - but they got pretty loose, bout all of em, started popping back out the intake so I went to tighten em. Was told to loosen, then tighten back each rocker while the engine was running until the chatter stopped - then go bout 1/2 turn beyond.

Sound right? Hasn't chattered or popped outta the tbi since - oil burnage never was affected by any of that.

I'm not sure what the normal wipe pattern is supposed to look like, I'll do some searching and see if I can find some info on it.

Valve springs are stock.

Checked compression on it? Pull all plugs and put a battery charger on it to keep the rpms about the same, just a thought. I got one laying somewhere, if you want to use it give me a day to find it.

Thanks I got one thou, haven't checked compression thou since I haven't ever lost any performance at all this whole time, it runs pretty consistent - doesn't run good mind you but that's a completely different reason involving me not having the $$ to get the proper injectors or tune to put the proper fuel to the built engine and 700 cfm throttle body once I got it in.

Plus I can't keep my exhaust together, the headers keep cracking and the bolts keep coming loose at the collectors, which makes the oxygen sensor O soo happy