Losing Oil

[Rschmid]

I have a new build that is losing oil with no obvious signs. It is a stock bore 4.6 3v with forged pistons that have a PW clearance of .003 per Manley.
No leaks
High flow GT500 pump
8qt pan
After break-in there was some minor loss but didn’t think much of it. I have put about 2,000 mi on and added 2 qts. At about 1k mi I added a catch can to the driver side. I checked the can before I added the 2nd qt (about 2k) and recovered less than a teaspoon. On a cold start I get some smoke for about 5 sec then everything appears to be fine.

This is the 2nd build that has this problem and I am at a loss as to why this oil is getting burned.

I’d appreciate any suggestions…..thanks

 

[EmmJay]

What do the spark plugs look like? What are the cylinder compression numbers with and without oil squirted into the chamber?

 

[CAMTWO1070]

Did you build it yourself or did the same builder build both engines?

How did you break the rings in?...When I have a flat tappet hydraulic camshaft Im at the mercy of the camshaft breakin time but when I have a roller camshaft I get the thing right out on the road and put a load on it..

If you let the engine sit and idle too long the rings wont properly seat and if your engine is overfuelled the cylinders will become prematurely gaswashed..Lots think you need a rich running engine at break-in...I run mine on the leaner side a lil and I put some Lucas fuel treatment in the gastank..

Some thing I can think of is how the oil rings and compression rings are clocked on the pistons and also how the rings are oriented...

Rings spin in the bores and rings are tapered to increase compression when the piston travels upwards. if the rings were installed upside down youll get alot of oil loss like youre experiencing...

If the oil control rings dont have the proper spacing and are too tight in the grooves you can get excessive oil consumption too..

Every ring manufacturer has their own different settings and they coincide with the roughness average of the hone job...The rougher the hone the more the rings spin..

Id give it a leakdown test on each cylinder..............

Good Luck

 

[CAMTWO1070]

These are the instructions for some Summit brand rings...I have ones for Manley and Sealed Power too but cant find them ATM but if anyone has ones to add just to show the differences..

I was told by an oldtimer who worked for Ford from the late 60's through the early 90's said that aslong as the rings arent initially set wrong on the pistons and get broken-in right everything will work out as rings spin at different rates and ring gaps match up then unmatch until a bore gets so worn down the rings stop spinning on the pistons and if that happens the ring gaps get stuck in bad positions and engines develop blow-by and is hard to get rid of ...

For engines with some substantial mileage that all of a sudden develops blow-by he was a big fan of borax and the italian tune-up method to try to get the rings to forceably spin one last time and hopefully reclock themselves so the gaps arent inline plus said the attempt was 60% successful with 20% in engine failures aswell as a 20% in no change at all when performed on 18 engines..

Another thing that I forgot to ask is was your engine honed with a torque plate? Its essential to hone with torque plates especially with cast aluminum engine blocks........

Good Luck with getting a quick n easy solution to your problem but I have a feeling you may be rehoning the cylinders and replacing rings..........