Originally Posted by 91-talon-tsi
I recently purchased a 94 eclipse base with the 1.8 sohc 4g37. There's been 5 owners including myself. The third previous owner had rebuilt the block after the engine had overheated and caused the pistons to swell and slightly scar the cylinder walls.
The rebuild consisted of honed cylinders, crankshaft turned, NPR piston rings, ACL rod and main bearings and all new gaskets. From what I found out, the previous owner who had the block rebuilt used the "motoman" method to break the engine in.
Or at least that's what you were "TOLD", i've been witness to 4 personally and heard of a 5th engine locally sold by a "large import shop" (i won't name since i'mbeing subpeonad to court as witness on 3 of the tear downs) and all of then were just old junk yard motors in decent shape with ARP head studs and fresh felpro gaskets
There were even receipts saying "forged pistons" Eagle rods, etc..etc... Idon't look forward to having to testify against someone who was once a friend and i sitll have no hard feelings for, but i was there in another shop for 2 of them almost immediately after they were instlaled and the people had issues, met the other guy on here and witnessed what he had to show for his money, and yet there's 2 more here in nebraska that bought "built engines" fromthe same guy
Never believe what a stranger selling you something says, check for yourself..when i buy engines i tell them let me pull the pan and head and if i don't want the engine afterwards i'll pay for and install the new gaskets.. that will turn the bullshaattters away usually, and a good personw ill agree to it, buti know you bought a whole car. I probably woulda done compression and stuff on it first but then again i was a mechanic most of my life and still do it when lack of pain permits me to
even if you put oil in it, that's still a bad sign, just proves it's rings.. are you holding the throttle wide open when testing??that makes a big difference...also, check cam and crank alignment , if the guy got the belt on a tooth off it will make a HUGE compression difference too.. With my degreed settings i get 185 per cylinder on mine, and with them "0" or straight up i get like 165-160...
you should have at least 150psi per cylinder with timing correct and throttle open while turning the key until the gauge stops climbing (the right way to test it)
OH, and since getting a crappy smoking low comp engine on my BRANB NEW motorcycle with only 4 miles on when i got it from doing a real "easy break in" I now do EVERYTHING motoman style almost, i just use 4 cycles steadily getting more andmore into boost and revs each lasting 20 minutes with cool downs and inspections between,(if you read the books for testing on SAE engine/drivetrain) you'll learn why methods have changed and why more pressure from boost and engien breaking helps seat rings and why older machining styles and toolls needed that long and easy break in........... i've written it at least 15 times if you wanna search but i can't type anymorei'mtired