Wondering if a forged piston is going to use more oil than a cast or hypereutectic? I set my 327 up with the piston manufacturer's recommended .005" piston skirt clearance. About 1600 miles after oil change I am down about 1/2 of a quart. The pistons are Speed Pro forged L2326. 10w-30 oil.

Is that normal for a forged piston?

Is an engine with a high volume oil pump going to use a little more oil than one with a standard pump?

Thanks!

Mike

Mike,
The piston type should not have any effect on oil consuption. There is a common misconception that Forged pistons are run "looser" than cast pistons. This is not true. The "cold" piston to wall clearance might be more, but once the piston warms up, almost all of them are running at about the same clearance. I would guess around .001 or so. "Most" forged pistons are made in such a way that they expand more as they warm up, thats why you set them up looser when cold. Cast and Hypereutectic pistons, and a lot of the newer forged pistons, do not expand much at all. Therefore they are set up tight to begin with.
But back to your oil consumption....
A high volume pump really should not affect oil consuption either. Excessive rod bearing clearances can allow too much oil to get thrown up on the cylinder walls and cause problems. Intake leaks ? PCV problem ?
Actually 1/2 qt in 1600 miles is not real terrible, but more than what I would want to see. What type of rings did you use ? Valve stem seals ? Cant think of anything else right off hand. Is the car smoking at all ?


------------------
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

Bill,

No vacuum leaks (18"h.g. @ idle), or oil leaks at intake.

Had to run a bigger pcv valve due to nozzle drip problem, but pcv system is working.

Moly rings. Top gap .016"-.018", second gap .010" - .011"

The heads are Trick Flow's. Viton seals.

Does not smoke @ start up or while driving. Plugs are actually a little more white than I would like to see. Very clean.

Rod bearing clearances were fine, but the rod side clearances were bigger than specs given in the Chevrolet Overhaul manual.

Mike

[This message has been edited by Unclepennybags (edited 10-09-2002).]

UncleP, If your plugs are white, then the oil is not being burned in the cylinder. Did you check retainer to seal clearance at full lift? Maybe the viton seals on the exhaust side have been pinched, allowing oil to get past the guide. How do the tailpipes look? With snow-white plugs, the pipes should be a light grey color (unless you are running catalytic converter, which makes tailpipe evaluation impossible). Hope this helps you.

------------------
Bill
64 Chevelle Malibu Sport Coupe (original owner) car now has 427" BB, Chrysler HEMI 4-spd. trans., 12 bolt 5.57 w/spool & axles.
"HOT RODDER is NOT a dirty word"
"Too much horsepower is just enough"

Mike,
I have to agree with engineguy. If the plugs are white, I doubt that the oil is getting into the combustion chamber. That only leaves exhaust seals and guides.
Engineguy....just curious who you work for unless you would prefer not to say.

------------------
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

Thanks. I'll look there.

Mike

Bill K., no problem. I work for the Clevite Engine Parts/Perfect Circle Piston Ring divisions of Dana Corporation. Usually try my best to keep my affiliation from resulting in a bias when responding to messages on this site.

------------------
Bill
64 Chevelle Malibu Sport Coupe (original owner) car now has 427" BB, Chrysler HEMI 4-spd. trans., 12 bolt 5.57 w/spool & axles.
"HOT RODDER is NOT a dirty word"
"Too much horsepower is just enough"

[This message has been edited by engineguy (edited 10-10-2002).]

Bill,
Thanks...I was just curious. Nice to have an occasional "connection". Just put our new Clevite catalogs in the rack about a week ago !


------------------
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100