general advice about an engine i broke in and built

a couple months ago i built a pontiac 455 engine, it runs great. BUT! it burns a lot of oil. 1qt for every 200 mi.
had all the machine work done at a good shop, new rings, new forge pistons. streeet engine about 400 hp..
I did a compression check last nite and its between 150-160 on all cyl.
I am thinking the rings didn't seat(seal).
plugs show burning oil carbon, and there is only 1200mi on them.
during break in the motor did get up to 240 degrees and we shut it down. that was around 12 min into it.
what do you guys think happened?

What kind of rings? Was the finish hone correct for the rings?

the cylinder finish sure looks shiny to me. maybe too smooth?

When you installed the rings,Did you make sure the top/second ring ends were spaced 180* and not lined up?

do a leakdown on it.

does the engine smoke all the time or just on acceleration or deceleration? Could be a valve guide or seal problem. You dont have a piston with the oil ring around the wrist pin do you?

WERE THESE FILE fit rings?



do a leak down

just seal pro moly rings... nothing fancy.. i didnt tear it apart yet

trust me , put a new set of rings in it and don't hone it !!cylinder walls look great , a new set of moly rings will seal the first time you make it work!!!
Frank

It is unusual to have moly rings not seat so make sure to find the fault so it doesnt happen again. How did you break it in? Do all cylinders show fouled plugs or just one?

I'm with Frank. Put new rings in it and call it good.

I was unsure on the finish from my phone pics but on my home computer they look fine. We run stainless rings so finish is very important to us as well as proper breakin.

4 cyl are showing burning oil. the other 4 are perfect and they are mixed from side to side...
broke it in at 2000rpm... but shut if donw at 12min due to heat at about 140 degreese... then waited a while and did a nother 10 min at 190 degree

Might want to check your intake gaskets, they may be pulling oil on the bottom into the port.

What type/brand/weight of motor oil did you use to break it in with and are currently feeding it?
StickBBF

Check the PVC also.

VR1 10w30 , during break-in and still useing it

racinghabbit wrote:VR1 10w30 , during break-in and still useing it

Hmmmmm,,,, That may be part or all of the problem.
I've been told to NEVER use a synthetic oil to break-in an engine - only AFTER the initial break-in period would I switch to a synthetic oil.
Synthetic is just too good at lubricating that it won't allow the piston rings to seat and seal properly.

Maybe all you need to do is change the motor oil and run it some more..... or would the cylinder walls need to be de-glazed at this point?
StickBBF

Syn oil will not let rings seat ask IDT572 he had to rering his cuz he put the syn in to early....

VR1 is not syn.

How many oils are called VR1?
http://www.valvoline.com/products/consumer-products/motor-oil/racing-motor-oil/8
StickBBF

http://www.valvoline.com/products/consumer-products/motor-oil/racing-motor-oil/6/

StickBBF wrote:How many oils are called VR1?
http://www.valvoline.com/products/consumer-products/motor-oil/racing-motor-oil/8
StickBBF

If this is truly what you broke it in on, that very well maybe your problem.

i used valvoline VV211 to break it in