brian p

As in oil smoke, acceleration, deceleration, idle,etc. As in a drive to cruise night and back gets lots of laughs from everyone and an oily film on the rear bumper...

The engine is a basically stock vortec truck motor, HSR intake, comp efi cam and springs, yeah twin turbo but more later. I snapped the OE rocker arm stud so the heads went into the machine shop for screw in studs, new guides and seals. While the heads where away, I pulled the motor and did main, rod and cam bearings(clevite) plus all the gaskets (good fel pro). I also did rings, plasma-moly (clevite). And because it's a turbo car set the middle rings at .026 and the top ring at .028. The bores were flex ball honed with 400 grit and I triple checked the rings to make sure they were clocked right.

I only have maybe 50 miles on it now. Compression check is OK, 155 plus with only a couple of percent on one or two cylinders. Leakdown test is around 90% in all cylinders. Oil pressure at idle is 55punds and it drops a bit 10 pounds or so when warm. Oh yeah the turbos, they are dry, nothing leaking.

I had read where if the intake gasket is leaking, it can suck oil from the oil galley into the bores, so I pulled the intake, put in new gaskets and resealed everything. And re-replaced the valve seals with new viton ones just in case the machine shop nicked one or used jobber ones. Just fired it up still killing mosquitoes.

Before I broke the stud/ rebuilt the engine the engine was fine, zero oil consumption no smoke. Obviously I did something just not sure what. It looks like pull engine time. Anybody have ideas?

Fast355

iTrader: (2)

I would start with some more run time and then a leakdown test. Rings need cylinder pressure and heat to seat and seal up. Not full boost or anything, but just some good heavy part throttle acceleration out of boost. The last two small blocks I built used about a quart in 250-500 miles, then sealed up well and stopped burning oil.

brian p

Thanks, I've heard that with the newer type rings they seal up almost immediately but don't have any experience with them. I'm open to more mileage on it if that'll do the trick. Besides mosquito season has started.

mikeceli

iTrader: (2)

I'd seat those rings, by warming up the engine and driving it on low traffic, surface streets. Accelerate at approx. 1/2- or so throttle to about 40 MPH, and pull your foot off the gas pedal. This to "LOAD" the rings with accell and decell pressure. Maybe in a lower gear, Nothing crazy, just let the internal cylinder pressures work the rings into the cylinder walls. "On / Off type action.

brian p

Thanks, much appreciated. I'd rather not pull the engine because if I do, it'll end up being a bunch of expensive machine shop work and probably a forged rotating assembly. It has less than ideal gears for a turbo car, real easy to get boost. So now I just have to figure out how to keep it out of boost, while I work the rings as you described.