[CJ_1080]

OK guys I recently built a vortec injected 383 stroker. I am running SRP forged pistons, Howard's cams plasma moly rings (grind to fit). The machine shop that I had do the work said the bores needed a little different prep and finish hone so they break in properly. The heads were checked out and well within spec on valve wear and guide wear. I machined down the guides and used Howard's cams valve guide seals (the blue ones, not sure on the material).

What has me stumped, is since new it has used, what I consider, a decent ammount of oil. Not leaking a drop, but burning it. To the tune of 1 to 2 quarts every tank (38 gallons, 400 miles)! All my measurements are spot on! I've never had a problem with any other engine I've built! Its not fouling plugs or anything just strong smell in the exhaust of oil burning. I have never built an engine with forged pistons. The pistons were fitted to SRP's directions.

Any suggestions on what it could be? Engine runs great! It has about 5,000 miles on the motor. All dino oil nothing to slippery! I've heard it takes a while to seat in these moly rings, but 5,000 miles? Sure think they would have bed in by now! Right???

Suggestions, comments, criticisms???

[General Martok]

426 hemi with factory forged slugs would use a quart about the same time as

yours does,your piston have different elements in them to handle thermal

expansion due to heat and are a tough piston to beat ,my 446 Mopar had

forged slugs TRW and it used oil with plasm moly rings with special hone job

they get noisy also like rattle ,but nitrous was no problem for them.I say you

went the wise direction for durability.Does this help

[68NovaSS]

I've used forged pistons in my last six builds in two years, all over 450 hp, two 8-71 blower 383's, using both moly and cast rings, gapless and file to fit, with no excessive oil consumption or blow by.

Curious what your end gaps and piston to wall clearances are.

[FmrStrtracer]

Youre correct, the oil consumption is excessive. Time for a leakdown and compression test. Locate the offending cylinder(s) and go from there. If you havent already,Check your valve seals to make sure theres been no damage.

[hippybilly]

What is the clearance on you piston to bore fit? What is you piston ring end gap? What grit hone was used to hone your cylinders? Did you double check the machine shops work yourself. It's a good idea to just to double check their work out. That much oil sounds like the rings to me. Does she smoke oil colored (bluish colored)? Leakdown test would be a good starting point. If you didn't hone the cylinders yourself, find out what grit they were honed with. Sounds like might have been too course to seat rings good.

[CNC BLOCKS NE]

Originally Posted by hippybilly

What is the clearance on you piston to bore fit? What is you piston ring end gap? What grit hone was used to hone your cylinders? Did you double check the machine shops work yourself. It's a good idea to just to double check their work out. That much oil sounds like the rings to me. Does she smoke oil colored (bluish colored)? Leakdown test would be a good starting point. If you didn't hone the cylinders yourself, find out what grit they were honed with. Sounds like might have been too course to seat rings good.

Good points and did the plate hone your block and what type of hone did they use as there are a lot of cheap hones out there that should not be used for performance engine builds.

Valve seals

Are you running a complete PCV system and does the vlave covers have baffles in them?

Intake gaskets?

[Andy79Z28]

We had this sort of problem once. It was on a 355 build. We took the engine apart 5 times changed rings, changed heads and it never corrected. What our problem turned out to be was that $5 PVC rubber grommet. The PVC area of the valve covers did not have a baffle inside the cover where the PVC valve went and the cove just had a simple round open grommet. The PVC valve was sucking up all the oil. A simple $5 cone shaped PVC grommet fixed the problem.

[lmsport]

Did you use low tension rings? If so, such consumption is not abnormal when driven on the street with high manifold vacuum.

[2old2fast]

might want to consider intake gskt's , after you run comp. & leakdwn test's confirming no problems there....as an aside, neither of those test's will tell you if you put your 2nd rings in upside down. just some thought's ...

dave

[hippybilly]

This is turning into quite a bunch of oil consuming "ifs". One thing that I can say, no matter what, check your machine shops work out before you assemble things. They make mistakes sometimes. Tell them the cleances you want things to be, number you parts and where they go, tell them what grit you want your cyliders honed with (consult ring mfg sheet)....and double check their work. If you don't know how or don't have the mics, get somebody else to do it for you. Very important.

[BOBCRMAN@aol.com]

Over the years I've seen high oil consumption in new motors. Usually a non piston/ring/bore problem. Usually an intake leaking on the bottom side. Improper PVC system or a rubber seal failed. Run some common tests.

[hippybilly]

The post about the PVC system. If your valve covers don't have baffles in them, that could cause your problem too. How about some feed back from the guy that posted this as to what you've tried so far. If you find it be sure and let us know. Just out of curiosity, what brand of gaskets did you use and what kind of gasket sealer. Felpro and Permatex Ulta Blue is all I'll use on an engine.

[cobalt327]

Originally Posted by CJ_1080

I've heard it takes a while to seat in these moly rings, but 5,000 miles? Sure think they would have bed in by now! Right???

Suggestions, comments, criticisms???

Plasma moly rings break in quickly and they do not need an agressive finish.

But if the goobers who honed your block thought that "moly rings" meant "chrome rings" as in chrome moly (this gets screwed up more times than I care to recount), the finish for a chrome ring would have been much too aggressive for the plasma moly rings and the rings may well have been permanently damaged as a result.

[hippybilly]

Amen to that Cobalt! The only engine that I ever had that the rings did not seat on was an engine that I put chrome rings in.

[CJ_1080]

OK guys thanks for the responses, this is why I love this place!! I'm going to try to answer all the questions.

The piston to wall clearance is. 004. The ring gaps were 1st ring. 018, 2nd ring was .020. The oil ring expanders weren't overlapped. They were spaced out according to SRP's instructions. The oil support ring was installed correctly as well. The machine shop honed the block with a deck plate but I am unsure of the hone grit. The rings were standard tension.

I am using the factory vortec injection with the factory pcv system. The valve covers are also baffled, they are factory.

The gaskets are felpro problem solver gaskets, the steel shim with the rubber seal overlay, installed dry. All the gaskets I used were felpro except the Mr. Gasket head gaskets.

I did a leakdown and a compression test. The compression test (sort of useless here) was within 6psi of eachother. The leakdown test showed less than 10% leakdown. My leakdown gauge reads 0-100% by 10% in increments. Runs good and idles smooth. I don't think its cause of a vacuum leak cause it wouldn't run as smooth as it does, right?

This one has me stumped! Any other ideas or info needed?