Tech | Engine Bay Preparation
We've gotten things a little out of order with our '68 Mustang project buildup. The last few build stories have focused on our bodywork and the custom modifications we've done to make the car stand out from the crowd. Of course one of the stand out items for this build is what's going on underhood, and that's our '06 Mustang GT 4.6L Three-Valve we're swapping into the classic engine compartment. So before we wrap up our bodywork and actually shoot the color coat of Dark Shadow Gray Metallic, we had to wrap up all the little details that'll get our engine and transmission fitted to the chassis. The main reason, of course, is we don't want to be doing any cutting/grinding or welding on a freshly painted car. We also plan to paint the engine compartment body color, so any major changes to the inner fenders, firewall, and so on all need to be handled now so we can perform final bodywork in these areas and paint them the same time the body is painted.
We showed readers some general modular engine fitment ideas in the May '10 issue with our "Big Three" story, where Kevin Tetz outlined the major hurdles of installing the wider mod motor. We already have our Heidts Superide II front suspension crossmember in place (and we'll be showing everyone more of the actual suspension and front brake fitment here in an upcoming issue) so really all that's necessary for fitting the engine and trans is to find final placement of the assembly, ensure our driveline angles are right, and then weld up our engine and transmission mounts. We've trailered our project over to Classic Creations of Central Florida, the shop responsible for all of the great bodywork, which will be applying our paint as well, to help us with engine fitment. It has installed several Heidts front suspension kits with custom engine fitment issues (big-blocks, Clevelands, modulars) so we knew that our project was in good hands. With the welding work completed, the engine and transmission bolt in as if the car was designed for the modern drivetrain. So check out this month's progress and stay tuned as we wrap up the fastback's paintwork with some color and move on to plumbing, brakes, wiring, interior, and more, hopefully wrapping up our project by the end of the year.
Currently Heidts does not...
Currently Heidts does not offer any engine mounts other than small-block Ford for its Mustang kits. While some new and exciting products are coming from Heidts soon that will include engine-mounting kits for more of Ford's engines, we had to fab up our own for the mod motor. Luck saved the day when we heard of The Mustang Shop through our friend Doug Glad, editor of Car Craft. The Mustang Shop offers several mount kits to fit the mod motor (one of its specialties) and we used its cut-and-weld-to-fit urethane mount kit, shown being mocked up here.
We've had our Performance...
We've had our Performance Automatic 5R55S five-speed auto trans for a little while now and we bolted it up to our 4.6L modular so we could get the whole thing down into the engine bay and see what "gotchas" were waiting for us.
Horror stories abound about...
Horror stories abound about modular engine oil pan fitment (or lack there of) in custom installations like this, so we were elated to see that the stock '05 and up Mustang rear-sump oil pan cleared our crossmember perfectly. But the real question: Was the engine sitting low enough?
Since we didn't want to weld...
Since we didn't want to weld anything in the wrong place before the pros at Classic Creations looked at it, we used a system of wooden shims and support straps to get the engine where it needed to be....
....Thankfully the intake,...
....Thankfully the intake, now installed for fit check, cleared the fiberglass Shelby style hood from Mustangs Plus (for a second we thought we'd have to have the oil fill cap sticking through the hood!) and we still had a finger's width between the oil pan and the steering rack.
Placing the engine rearward...
Placing the engine rearward helps in vehicle handling and weight distribution, so we decided to set the engine as far back as possible without creating major fabrication headaches. With the engine where we wanted, it still cleared the crossmember and steering, but we were now butting up against the firewall. Some trimming and a little metal work will fix that.
Once we arrived at Classic...
Once we arrived at Classic Creations with our project in tow, the first order of business was leveling the car on work stands and then cutting....
....out the firewall area,...
....out the firewall area, marked up with a grease pencil, so there would be sufficient room to formally align the engine.
Getting under way with the...
Getting under way with the permanent fitment, the engine is centered side to side between the framerails in the engine bay. This ensures that there's equal header clearance on each side (for one thing).