Hi all,

I did a project with a friend a few years ago. I took an SC44 engine and put it in the trunk of a Smart Fortwo, thus making it a pretty powerful car. It was designed to run on track, and my friend used it for quite some time.
Now he gave it to me since he doesn't have time anymore.

We never really serviced the engine (he's the mecanic, not me [even though I have some basic knowledge]), so it has some wear and tear. But aside from the normal one, I ran into a big problem the other day.

I noticed that I got fuel in the engine oil. Loads of fuel (around 8 liters). Since it's a PGM-FI, I replaced the fuel pressure regulator, and the problem seems to be gone. The engine ran for a few minutes, but it kept stalling and not holding idle.

I removed the contaminated oil, everything smelled gasoline so bad.. I then tried to run a compression test, just to be sure. And I noticed that the cylinder 4 had only 120psi instead of the 180 the 3 others have.

I'm now wondering what's broken, or what's not working correctly. I added some oil in the spark plug hole to check the rings, and as I remember, the compression went up to 140psi.

What could it be? Bad or stuck rings? What can I check without disassembling everything (the chassis was built around the engine, not vice versa..)

Please let me know if anyone has an idea, will be really helpful.

Sorry for the English mistakes I probably made Thanks!

 

The problem you hope it is would be valve clearances - if one of the valves is not closing fully that can be corrected without a major strip down.

Other problems would include burnt valve seats, broken rings, worn bore, holed piston, …

 

First do valve clearance measurements, then adjust if necessary.

Also fix leaky injector. That’s only way excess petrol can flow into cylinders. All this extra petrol washes off oil from cylinder walls and causes excessive cylinder and ring wear.

You may really have worn-out engine.