Originally, I had planned to use a Toyota 4AGE engine in this car with a 5-speed gearbox. I picked up the parts for cheap or free and even fabed up some nice motor mounts for it...
At some point along the way, I discovered the whole bike engine craze for seven type cars. Then, I got a chance to ride in one, that was powered by a Yamaha R1 engine. That was all it took to convince me that this was the type of engine that I needed in the car. Not to mention...Engine and gearbox weighs 145lbs, it is fuel injected, has a sequential 6-speed gearbox, and makes 160hp...in a car that will weigh around 1100-1200lbs. Not only that, but a nice, complete, low mileage engine can be had for less than a rebuild would cost for the 4AGE.
Here is what I have done so far. The mounts have been made and the engine is in place. More info to come on the mount system in the future.
10/15/06 - The Engine is Back in
Well it was time again to put the motor back in...hopefully for good. Below are some pics of the motor mounts all finished up. I wanted a simple mounting system and did not want a rigid (solid) mounting system that is found on many of the BECs. Polyurethane bushings were used at each attachment point to accomplish this. They are universal 4-link bushings from Energy Suspension. They are very firm, but should damp out some of the high frequency vibrations from the engine. The mounts all attach to the engine at the stock mounting points.
Since the intake and exhaust will not be anywhere near the stock configuration when the car is ready to go, some engine tuning will be needed to get the right A/F ratio. To aid this the factory air injection system was removed from the exhaust side. The ports have to be plugged when the plumbing is removed. These parts are available for sale, but I simply cut off the ends of the tubes and welded them closed...that cost me 30 minutes of time...
More engine pics...
11/24/06 - Let's Make a Header
In a way I have been looking forward to making the header for the car for a while. It just seemed like a neat puzzle to figure out and to fabricate. The materials were ordered from Stahl Headers. The laundry list included six 180 bends in 1 3/8" tubing, some straight 1 3/8" pieces, a 1 3/8" to 2 1/4" slip-on collector, and some 1 3/8" to 1 1/2" adjustable primary pieces. In the end, I needed all six of the bends, but did not need any of the straight tubing.
I wanted to use a construction technique that was similar to the original Yamaha header and to keep the primaries close to the same length as the original. Some bosses were turned on the lathe starting with some 1 3/4" x .120 wall DOM tubing. The adjustable primary pieces were slipped up into the bosses and welded fully around the ID along with tow rosette welds near the outer edge. The welds on the ID were ground to make a smooth transition from the exhaust port. The original header was built in a similar fashion.
One by one, each primary tube was made. It was a little tricky to work around the steering shaft, but plenty of clearance was made in the end. With the slip-on collector, final assembly will be easier as each primary can be inserted one at a time. This will make it easier to get the bodywork closer around the header as well. Some springs need to be sourced in order to hold the collector on once the rest of the exhaust is made.
It would have been nice to have a TIG setup for making the headers. The welds could have been made with little or no filler material and would have looked a lot neater. I did the best I could with the MIG setup and it came out pretty good. All in all, not a bad first header.
1/28/07 - Throttle Cable and Exhaust
The throttle cable finally came back (for the second time) and was installed. Nothing real fancy, but a bracket was made that attached to the chassis directly over the throttle pedal arm. The cable has lots of adjustment built into it, so it should be easy to maintain. It is not shown in the pictures, but a grommet was made for where the cable passes through the aluminum panel.
The exhaust is a fairly simple affair. The muffler is a Dynomax straight through perforated tube style. The whole system from the header back is 2 1/4" tubing. An O2 sensor bung was added as well to help with engine tuning in the future.
2/7/07 - Air Cleaner and Clutch
An ITG filter assembly specifically for the R1 engine was chosen for the air filter. Originally I was going to try and keep it under the hood with the shortest filter, but decided that it should get some fresh air rather than under hood air. The standard taller unit was purchased. The base plate was modified to allow the intake air sensor to be placed inside.
The Barnett coil spring clutch conversion was installed. This unit features coil springs instead of the conical spring of the stock clutch. They allow for smoother action and more clamping force over stock. This will hopefully help the clutches last longer. Thanks to a fellow locoster and a shipping error by a vendor, I was able to pick up this part for a little less than what I have seen it go for.
2/28/07 - Tidying Up a Bit...
I had a few "loose" ends to tie up in the engine bay. Most of it were remaining parts that needed brackets. The factory lean angle cutoff switch was left in place just in case the car ever ended up on it's lid. The power to the engine will get killed automatically if that happens. The master relay unit needed a home as well. A simple bracket holds it in place using the factory rubber mount. Finally I needed a secure bracket to mount the oil pressure senders to. One is for the gauge and the other is an adjustable switch that goes to a warning light.
3/18/07 - Oil Breather/Separator
In some of my reading about using bike engines in car applications one of the concerns has been oil blowing out of the breather in fairly large amounts when the engine is kept at high RPMs for extended periods (ie track use). I have not seen a real solution for this that would package under the hood neatly and I really don't want to have to put it in a catch can and constantly have to drain it. So a breather/separator box was made to hopefully keep this to a non-issue. It features a large baffle in the middle that should let some oil splash up into the can but not go out the vent. When the crank case gets back under vacuum, it should draw any oil back in that has collected. This is an experiment, so we'll see how it works.