More Touch-ups for the Z Jul 5, 2005
The previous owner of our Z touched up a few spots with a non-matching yellow paint. We sanded these small spots down and sprayed in a few sections with a disposable airbrush. The color matches very closely and with some wet sanding and buffing, it’ll be hard to see where we sprayed.
We also removed the door panels and cleaned out several years worth of dried leaves and mud from inside the doors. This detritus traps moisture and would have caused the bottom of the doors to rust if left unchecked.
We Can't Leave Well Enough Alone Sep 1, 2006
While our 1970 Datsun 240Z is essentially finished, we are never smart enough to leave well enough alone. The more we drove this car with its slightly modified but well balanced suspension and brakes, we began to long for more power and an engine as fresh as the rest of the car.
We talked to the experts at Sunbelt Performance and Balanced Performance. They felt they could come up with a reasonably priced, very streetable engine that still ran on pump gas and could put down nearly 200 horsepower at the wheels. Compare to a stock 240Z which is rated at about 150 at the crank, it sounded pretty good.
That would be the perfect complement to what has turned out to be a real nice car. We decided that we wanted to use the Z for some high-speed rallies and tours, we figured a fresh engine with a bit more moxie would be perfect. We are just about done with the build and will detail it in a future issue of Classic Motorsports magazine.
The Datsun Recieves a New Heart Apr 19, 2007
After discussing all the options, we decided we wanted to keep the car fairly close to original.
We approached Balanced Performance about Z car engines and also talked to long time Z car builder and racer, John Williams, who won the ARRC ITS championship in a Z car. John runs a Z car only shop in the Balanced Performance complex. That fact combined with Sunbelt Performance engine builders also being local made for quite a brain trust for all things Z car in the Atlanta area.
There are all kinds of ways to build a Z car engine. From stock all the way up to a 3.1-liter, from carburetted to fuel injected, and from normally aspirated to turbo charged, there are a lot of factory and aftermarket parts available.
After discussing all the options, we decided we wanted to keep the car fairly close to original. We also liked the way the original L24 revved, (versus the torquier, but not-so-great revving 2.8-liter) from later 280Zs and we didn't want to spend a fortune on what was essentially a street car.
We wanted a carefully constructed, nearly stock 240Z engine with a bit more power. The folks at Balanced Performance and Sunbelt told us that with a careful build and bit more compression with a decent cam. We could up the stock 240Z's 147 horsepower by nearly 50 ponies and have complete drivability at a reasonable cost. That sounded good to us.
Before we got started we dynoed our old engine and got 135 horsepower at the wheels, which is about right for a stock 240Z engine with a header and decent exhaust.
John Williams convinced us to install a five-speed transmission from an early eighties 280ZX. He felt that while everything was apart, this modification would be low cost (well under $1000) and would really improve the drivability of the car. One of the cool things about playing with a Z car is how all the different configurations the cars came in easily adapt to the earlier cars.
We also installed a Nissan Competition limited slip that we found in one of our parts cars, as well as a new ACT street clutch and a new exhaust system from Motorsport Auto. Classic Datsun had all the pieces we needed to upgrade our differential bushings and switch to the later style mustache bar.
While we had the engine out we cleaned up the engine compartment with some goodies from Classic Datsun, including new hoses and original air cleaner paint.
Shifting Gears With the 240Z May 16, 2007
With nearly 200 horsepower on tap from its new engine and a five-speed transmission, this car has been transformed.
Our 240Z project car was on hand at the ‘07 Classic Motorsports Mitty Presented by Mazda. This car has been transformed with nearly 200 horsepower on tap from its new engine and a five-speed transmission. As soon as we get a little more sorting done, we will have a full report in Classic Motorsports magazine on how the engine was built and what it takes to convert your Z car to a five-speed.
We originally stayed with the 3.36:1 final drive ratio, but after driving the car with its new transmission we decided to opt for the 3.54:1 final drive that automatic transmission equipped early Z cars used.
Running of the Z Jun 5, 2007
We offer a special thanks to Classic Datsun and Motorsport Auto, who helped with this stage of the project.
As we mentioned last time, we had our 240Z on display at the Classic Motorsports Mitty Presented by Mazda. There were still a few issues to sort out. We were not happy with the original 3.36:1 final drive our new five speed had. We opted for a 3.54:1 final drive from an automatic transmission from an early Z car. This turned out to be perfect for highway use. If this car was just an autocross or race car we would have used a 3.9:1 final drive.
John Williams kept the car in Atlanta and sorted a bunch of little things. He got the car tuned a bit better. The float bowls needed some adjusting and he changed the pilot bearing to a roller bearing type that proved to be quieter.
We offer a special thanks to Classic Datsun and Motorsport Auto, who helped with this stage of the project.
A four hundred mile drive from Atlanta back to the World Headquarters in Ormond Beach, Florida, proved uneventful and actually relatively easy.
Never being ones to leave well alone, we want to study the induction system a bit more, as we do not feel we have the Z running optimally yet. While we are pleased with our Magnecor plug ignition wires and PerTronix ignition, we feel that either further modifications to the original SUs or a conversion to Webers or fuel injection would make for a better fuel curve, enhanced top end performance and improved mid throttle response.
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