This weekend saw the culmination of the cooling system plumbing and thankfully not the start of my comedic career. The fan isn’t installed yet, but it’s a major step to have completed all of the coolant plumbing from radiator to engine to overflow tank – anything involving the liquid itself. It involved quite a bit of problem solving and also required completing various other parts of the build like the water pump housing replacement.
This was a big job. A real big job. A job that seemed so easy and obvious, like they all do, but turned out to require two guys, 6 hours, air tools, ingenuity, brute force, drilling holes out in a $700 part, cuts which were sanitized and fixed with electrical tape (!) to stop the bleeding, beers of elation and much more. All worth it of course.
So how to explain it. Let me give it a shot: the front of a GT3 engine (which sits in the rear of a Porsche due to the unique rear-mounted motor) has a housing on it which pumps water around the engine. The heads are water cooled on this engine (the block is not due to its air cooled car heritage), as are the transmission and the engine oil. This requires a lot of plumbing and that’s basically what this water pump housing does. It connects all of those pieces and the water pump and coolant overflow tank together. It looks like this when installed without the engine carrier in front of it – the shiny piece on the front with the four studs running through it:
When I bought the engine, this had a crack in one of the mount holes as pictured here:
I initially thought this was due to the impact of the crash that the engine endured, but it may not have been. It turns out that contrary to my thinking that this was a stressed mounting point, the engine bolts actually just go through the holes from the block to the mount instead of the housing being the mount itself. Those bolts then mount to an engine carrier which is mounted to the frame on both side of the car right behind the driver compartment. Here’s a picture of that from inside the driver compartment, i.e. the front of the engine:
The two black uprights on either side of the engine have a horizontal arm on which the metal engine carrier with the three holes on it sits. What that means for replacing the pump housing is that you have to dismount the engine from the chassis and brace it with jack stands and then unbolt that brace. I think we did two jack stands and some wood and later realized that in a worst-case scenario, the engine is actually too wide to fit through the chassis, so the heads just land on the chassis. Not great for the engine probably, but at least it’s basically impossible for the engine to drop onto the floor. Still, there was no way either of us would get under the car.
With the engine properly secured, the engine carrier is easy to remove. The housing is a very different story though, largely due to the various hose connections to/from the pieces it cools. We worked our way through it and in the end we had to remove the starter, an oil line under the engine (fun!) and two braces on top of the engine to even have a remote chance of sliding the old housing off. “Sliding” is a relative term here, meaning that it took screwdrivers, hammers, wood and anything we could use for leverage. The key problem was that the unit doesn’t slide off horizontally as you’d think and even with all of those pieces removed or loosened, you have to somewhat angle it off. I think it would only slide of horizontally if you have a basically bare engine block.
Once removed, we got beers and celebrated, thinking that installation of the new unit will be a piece of cake. Obviously, right? WRONG. The new unit proved very hard to install due to the same non-horizonal path to slide it on. After a few failed attempts, we decided that we had to make two of the mount holes slightly larger to accommodate installation. It’s a bit scary on a $700 part, even if I got a credit for most of that cost from the engine’s seller meaning my net cost was very low. We took three rounds of making the hole larger until we had it just right to slide it on. New gasket went on, water pump, oil line reconnected and motor brace back on and we were back in business!
And because you really wanted to see it, here’s my redneck (genius?) band-aid:
And of course once again thank you Ryan for all that help!
After much deliberation, looking at a ton of engines, talking to lots of motor and electronics folks and almost making a deal that I then had to back out of, I’ve finally purchased an engine. As it happens with these kinds of things, the engine I bought basically was under my nose ready to purchased from the time I first started looking for engines and transmissions, but I had to take my own long path to get there. Thankfully, I again learned a lot though and I think I got a pretty decent deal on it.