rebuilt block but low compression. why...?

[99 gst spyder]

With a normal operating temp, I had 90-85-110-90 across the board. Built just the block. Block has been hone clean and resurface with used je piston, eagle rod, new je piston rings, new head gasket, and all new bearings. Also cleaned and polished stock crank.

Another problem also, when I take my COP off the valve cover, I can see oil/fuel mixture lying next to the spark plug well. It smell like fuel and oil mix. Some one tell me why? Outside of the car smells like fuel while idling too.

I do have a little coolant leak but not sure where it's coming from yet, still looking into it.

Car runs fine. just not sure why i have low compression. i did gap the piston rings and make sure the gaps aren't over lapping each other.

I may have miss some things but this the start.

Thanks in advance.

 

[Diamond Star Werks]

Less then a hundred miles for sure. I've been just driving it around the block and to the gas station only. Driving normally, not wot pulls or anything.



I had file the top ring to .021 and .025 for the second ring.



The head only has 80k miles on it, and it was running fine before the swap to the built block. I didn't have the shop check the head out yet. Yeah I've heard that compression can be a little low after a build then the rings will slowly seat itself in while breaking in the motor but im not sure on this though.

What do you mean by washing my cylinders?

Wash the cylinders by pouring small amounts of oil in each hole. About a table spoon or two is good enough or just pour a lil in each cylinder measurement doesn't need to be accurate. You can use engine oil or atf doesn't matter. doing this with all plugs out of course. Spin the engine over and push it all out. Repeat process two additional times. Then redo your compression test. This procedure is usually something you do to a car that has been sitting for awhile to help the rings loosen up and re-seat but may also help in your case as well.

As you have low miles on yours I would go ahead change the oil as stated and drive a hundred or so miles. Oil change and re-check compression by then you should be good.

 

[99 gst spyder]

I just recenty did an oil change, its getting better, not too much smell. Oil wasn't too much watery but it's okay and also there was no shaving. Maybe a little fuel that's all. Still driving and putting load on her. But there is one thing, I also have some mod such as bigger turbo, SIMM, ect... How would that relate to breaking in the motor or just daily driving it untuned? Is it safe?
Sometime while driving normal and giving it gas, when it gets to 2500k rpm, the engine light would come on and as soon as I let off the gas pedal, it would go away instantly. Anyone want to chim in on that?

Otherwise it drives pretty good, little to no smoke at all even while driving. A little coolant leaking but not much.

Thank for everything.

 

[Diamond Star Werks]

With a bigger turbo during break in you pretty much do the same as with stock. Run intake pressure straight to actuator to run minimal boost.
Daily driving should be OK really.
Check engine light could be it sensing knock. In which case daily driving may not be so good. You need to check why its doing that.