For me, the engine represents the largest investment of time and research to ensure I get the best combination of components for my application. There was much consideration given to parts and modifications. I did not chase horsepower or torque numbers, but put things together that I know will improve performance. To me, this means increased responsiveness and acceleration to go along with the mild suspension performance upgrades I've planned. Engine building is like politics in the sense that everyone has an opinion about how it should be done, and they are passionate about it. The engine I've designed is not the "right" engine for some, but it is the right engine for me. I hope the thought process I describe below helps people design their own engines, however different they may be from mine. Here are some things I considered:
USAGE: As stated in "About the Rebuild", this car will daily drive most of the time. I also plan on touring, some road trips, and occasionally trying my hand at some auto crossing. Based on this, I have a hard time justifying the expense and effort to design an engine making power from 3000 - 6500 RPM when I can meet nearly all my goals with an engine making power from 1000 - 5500 RPM. With the 3000 - 6500 engine, I'm stopping at every gas station between home and work as I cruise the highway at 4,000+ RPM to maintain 70 MPH. What I really have at that point is a drag car I happen to drive to work. And once you get beyond a certain power output, other things must be upgraded to take advantage of that power (otherwise what is the point). For me, it was just too much expense and effort for a daily driver, and not necessary for me to enjoy the car.
POWER BAND: I have a 4-speed manual with the stock 3.36 rear gear. I chose 1,000 - 5,500 RPM as the target power band for my application, as it represents a realistic daily driver RPM range. It also goes well with the stock Super T-10 gear and rear end ratios.
ENGINE: After the usage discussion above, you could say I should keep the engine the car came with and you would be right. After all, it can easily be modified to meet my objectives. The engine has over 130K miles and would need a rebuild, but is otherwise a solid engine. That was the original plan when I started this. Then I saw a nearly complete 400 short block (no cam or timing chain) up for auction on E-bay, and was able to purchase it for $250. That's a lot of added capability for a small increase in engine budget.
COMPONENT SELECTION: Entire books have been written on this by people who have forgotten more about engine building than I will ever know. What I did was take my usage profile and back it into the equations needed to determine such things as required intake capacity, header tube diameter, head flow requirements, and many other things to consider. Instead of extending this preface to multiple pages, I've placed a link the end of this paragraph that opens a document discussing the various aspects of component selection. Component Selection.
NOTE: This task also includes the fuel and cooling system
Modifications: One
- Increase fuel return line to 5/16"
Upgrades: Two
- Installation of throttle body injected 400 small block
- Installation of OEM 4-core radiator to cool larger engine
When I started documenting this restomod, the engine had already been pulled from the car, so there are no pictures of that. Part of this project was removing and restoring the gas tank. It's not necessary to remove the rear bumper cover to do this, but it makes the job easier. The gas tank was in surprisingly good shape. There was some moderate to heavy rust near the outer corner tabs, but it was structurally sound.
Here is the tank on my work bench. It's not in bad shape, just some rust. I used a pot blaster to remove the rust and remaining galvanization, and then etched the tank with phosphoric acid. I covered it with a couple coats of rustoleum primer, and top coated with their metallic paint. Hopefully that will offer some decent corrosion protection.
Before painting the tank, I cleaned the bladder using lacquer thinner, soft brush, and shop towels.
I had the tank straps powder coated. I ordered the anti-squeak pads and spent an afternoon installing the tank and fuel lines. For a throttle body upgrade, the return line to the tank had to be upgraded from 1/4" tubing to 5/16" tubing. The original 3/8" fuel line was in good shape, so I purchased a roll of 5/16" tubing and bent it to follow the main fuel line. I realize the picture to the right isn't very good or illustrative. I was pressed for time to get the body on the frame before my lease was up and I moved to my new shop. However, I wanted to illustrate that the tank and lines are installed. The project pauses here until I get everything together for the TBI installation. That will have better documentation.
Engine