True to our word, yesterday Mike trailered his 1987 C4 to my place so we could get started on the engine swap. I had to play musical cars, shuffling my fleet around my property to free up garage space... but, in the end, there was plenty of room. We put the nose on jack stands, removed the front wheels, and set to work.
We quickly learned something about the C4 Vette layout. The engine bay is
tiny. Seriously, it has outer walls barely wider than the engine itself. But due to the shape of the cutouts for the front tires, with the wheels off you have unprecedented access to the engine bay. Once you step around the brake rotor you are standing directly over the engine--it is fantastic.
Mike decided he wanted to leave the transmission in the car, so we left the rear trans mount attached and supported the front of it with a floor jack. Eventually, everything was disconnected except for the motor mounts. This was the time to attach my engine tilter and hoist, but the tilter's chains were just barely too short to fit over/around the TPI plenum. Hmm. I guess we'll just remove the plenum now.
Perfect! Now I was able to hook up the hoist and we could remove the engine mount bolts.
After a few more checks to discover any connections we may have overlooked, it was time to lift. A couple minutes later, it was out. Success!
You may or may not have noticed me mention it on the last page of this thread, but the reason for this entire operation was a somewhat quiet rod knock noise coming from the bottom end. No big deal; Mike had another roller cam block on hand so he simple rebuilt that bottom end to swap into the Vette. The only dilemma was, how would he reassemble the induction system on the new engine? If he were to retain the TPI setup, he would need to swap the Vette's heads onto his new engine. On the other hand, Mike has a few sets of Vortec heads which will perform significantly better than the TPI system... but they require a different intake manifold, which means he'd need to ditch that and swap to FiTech EFI to use them. As a third possibility, he could use the Vortec heads and drop to a carburetor for simplicity's sake... but I advised him against this since the car is already set up for a high pressure EFI fuel system so why not use it and go FiTech? Decisions, decisions. Mike had been debating this in his mind for
days, and even as we tore into the car he still hadn't made a final decision.
With the engine out, we put it on a stand. Immediately, Mike noticed the cast "logo" on the ends of the heads. Sadly, he recognized it as being the same as the heads he had pulled from a smog-era TBI engine in our past. To test his theory, he pulled a magnet from his pocket and tried to stick it to one of the heads.
<tink!> Mike and I looked at each other and simultaneously said, "that's not supposed to happen." You see, for 1987 Chevy upgraded the Vette to aluminum heads. Clearly, these are not the factory original heads for this car. We ran the part number, and sure enough they are smog TBI heads we suspected. These heads are known as the worst, least-performing ones Chevy ever bolted to a small block, and are generally considered total junk.
Well, that made Mike's decision easy. Bye bye, TPI.
But that also got us to wondering. Why would you do a head swap to this car and use those heads? What if the bottom end was swapped along with them? We removed the rest of the intake manifold to get a peek at the lifter valley. The 1987 Corvette use a roller camshaft, but when we lifted the lower manifold we were greeted by a set of plain old slider lifters. This
entire engine (known as the L05) came from some ~ 1990 pickup truck (all 180 HP of it) and someone hogged out the bolt holes on the Vette's TPI intake manifold to make it fit the engine. What utter crap.
We flipped the engine over to see if we could find the rod bearing that was making noise. As we grabbed one rod cap after another, we were at this point not entirely surprised to learn that every one of them wiggled just a tiny bit. It looks like someone assembled this bottom end with bearings that didn't match the tolerance of the parts. Looking at how things were kludged together, it kinda made sense.
Long story short, we were glad to get that pathetic excuse for a rebuilt engine out of the car.