So with two bad motors, one worse then the other one. Sometimes life just hits you with more issues then joys. I don’t let the problems get to me, instead I really try to learn what I can do to get out of this problem and focus on the goal. Which is get my 86 running, so I can compete in NASA time trails and DE track days.
I was thinking, maybe I can have the machine shop do a refresh on the motor. After all, the compressions did improve a lot after adding a tiny bit oil. She might just need rings and thats it. After getting a estimate for $1750 for a complete engine rebuild as a worst case scenario, that would have been too much money. The machinist did offer another option. I dissemble the motor and bring it in pieces, then it would be much cheaper. Doing that kind of work is something I have never done.
I was able to find a PDF manual on the 4age motor, and after reading several pages on the engine section, I figured it was a doable thing. I took my chances and started to teardown the motor.
One thing I have learned it there is always a sequence to properly loosen or tighten a part. If you don’t follow it properly, then you risk breaking something expensive.
I made sure I took lots of pictures before taking out a part, and to be neat and tidy. Going to take the head to machine and hopefully nothing too expensive to replace. I did notice scoring on the intake camshaft, but Ill try to use the intake cam on the small port and see if that will do. Only the machine will let know if the head is good or not.
Removing the head wants bad and I even made a youtube vid on it:
Have the short block exposed I can see my pistons looked tired with all the carbon deposits. I noticed the very top of the cylinder walls had some gunk or rust. Im thinking because the motor was sitting for soo long, but this motor looks like it can be saved.
Most likely the motor will need new rings and at least a hone. Not too expensive thankfully. Now to disassemble the short block.
Pulled off the pan and no metal shavings noted. This youtube video helped figured out how to disassemble the block.
The 4AGE manual helped a lot, showing the proper sequence on how to remove a the crankshaft and pistons.
All taken out in one day! I made sure to label and mark which side is towards the front of the motor.
This motor was probably spending most its life in the higher RPMs. The block looks fine and no obvious signs of overheating thankfully!
The main bearings look pretty good! Some wear, but my M3 looked way worse and that had only 50k miles.
Rod bearings look good too. No damage, just worn. Im thinking it’ll needs rings, and bearings. Another interesting find, is my big port 4AGE is an early model. I have have the 7 rib block but no oil squirters, and the part number on the piston and rod are from a blue top 4age. That means my internals are lighter then the later model 7rib block. If I was going boost I would worry, but since Im not going that route. I think this motor would rev up much quicker.
All dissembled and ready for the machine shop. Let see what they. Stay tuned.