Wednesday, July 25, 2007

What I've got that others don't...

Ported and Polished intake, head and exhaust manifold.
When I rebuilt the engine, I couldn't see not spending a little extra time on this great little engine. I ported the exhaust manifold rather than making a long tube header because it has to pass California smog, and I have not been able to find a C.A.R.B. legal after market header. I also replaced the exhaust with 2" tubing and resonance chambers to relieve back pressure and let it open up. This dropped a little bit of the low end power, but with the other work, it really screams at the upper R.P.M.s.
I run about 70 mph when there is no traffic, and with the stock tires, I average 44.8 mpg on Chevron Supreme 91 octane. I actually tracked my mileage over 4000 miles. Best economy was 53 mpg, worst was 38. I did not factor in the one time I got bad gas and only got 15 mpg. in an 8 gallon tank, that didn't last long anyway.
I also replaced the rear springs with a set from a 4 door hatchback. This gave me a little more weight capacity, and a firmer ride when the back is empty.
I have been debating an attempt at water injection, or finding a legal way to add a turbo.
My goal is to get 100hp from the little 3 cylinder.

Sunday, July 22, 2007

Tires


I got a new set of tires the other day. I put a set of 13" wheels on the metro, but the tires on it are way too big and really goofed up my final drive ratio. A set of 175-50R13's give the same overall diameter as the original 12" wheels and tires had. I got a set of Sumitomo HTR 200's from www.Tirerack.com.
They should do nicely.

Friday, July 20, 2007

My A/C install

Let There Be Air
Driving through the San Joaquin Vally in the middle of summer was beginning to get very uncomfortable. With temps up to 120° F, stop and go traffic is like sitting in an oven. It was time to do something. The Pick-N-Pul in Modesto wanted $109 for an AC system. They give a very hefty discount if you take the whole system. I thought about this for a bit, but passed on it and purchased my nephew's 4 door hatchback for $250. It would have a lot more usable parts and I would not have to rush and worry about missing something.

As this was my first time installing AC, I did a bit of extra work and took pictures.
I wanted to be able to share the ins and outs of this project with others who may want to do the same thing.

The first thing I needed to do was prepare my car for the install. I removed the hood, front bumper and the interior.
The front bumper and hood latch support must be removed to install the condenser in the radiator support.
I had been using a PH8A oil filter for a Ford 302 to add oil capacity. I found on the installation of the AC pump, that I would not be able to use it any more. Back to stock for now. I removed the dash and the entire heater unit. I then learned I only needed to remove the thin black convoluted hose that connects the fan unit to the plenum. My son helped me with the tear down of both cars. Give him an electric screw driver and enough time he would disassemble the Eiffel Tower.
Those little hands are nice to have for the hard to reach places. The donor car underwent the same treatment. There is a harness that plugs into the condenser and pump, then runs along the passenger side to the firewall to the fuse box in the engine compartment.

There are two more relays that the AC uses. They plug into the harness as well.
The existing smaller relays are moved to the rubber "socks", and the wires are plugged back in. The new harness and relays take their place, and all the connections plug right in. it is as if all the cars had ac, then they removed the systems. These relays supply the power for the ac pump and the condenser fan. FYI, the fan will not turn on without refrigerant in the system.
This harness also plugs into a connector that runs down through the passenger side fender by the front headlight. This part of the existing harness goes to the passenger side under the dash and is where the inside harness connects. If you have rear window defrost, you may have the inside harness already.
I popped out the body plugs where the ac lines go through the firewall, and made sure to install the drain hose so my floor would not fill with water. The new harness can be seen in the picture.
The evaporator slides in between the fan unit and the heater plenum, with existing nuts holding it in on the drivers side and a bolt on the passenger side. Not shown is the AC controller that slides in the rails on the front of the evaporator. It plugs into the large connector hanging down in front of the evaporator. Once all of the harnesses were connected, I put the dash back in and replaced the interior. Don't forget the heater control bezel with the AC switch. It plugs into that harness too.

Back under the hood.
There is a plug in the side of the intake manifold that needs to be replaced with a temp sensor. Be aware, there is coolant in the hole. The yellow wire plugs into this sensor.






The AC idle solenoid mounts to existing holes and plugs into the ac harness as well. Note where the hoses plug into the throttle body on the donor car, pull the rubber plug from the air cleaner and the throttle body and connect them. These little engines will stall out if you don't raise the idle when the AC is on. The white knob adjusts the AC Idle speed when it is all together.



Bolt the AC pump to the block. You will need the brackets from the donor car.

When I attempted to install the condenser and fan, I found that the radiator support was way out of alignment. A little persuasion with a hammer made everything fit.
Tips:


  • Make sure the system you get is sealed and worked recently. The refrigerant needs to be recovered by a "certified " ac tech. Don't release it into the atmosphere. (This is illegal)

  • When the system is recharged, you can use an R134 retrofit kit, however there needs to be a vacuum on the system to remove all the air and moisture. It may be worth while to have a shop do the recharge.

  • You may want to consider using an after market fan on the condenser. A 10" Fan should do nicely. R134 does not work as well as R12, and a better fan will help. If it is over 110° and I am doing less than 30 mph, it is mediocre at best with the stock fan. It just will not move enough air.

A little history

I needed a car for work. I commute 100 miles a day and then do field service visits all over California. I wanted something with good fuel economy that could compensate for my truck. I purchased my 92 Geo Metro from a guy in San Jose for $600. Found it on Craig's list listed for $1200. It was a bit beat up. It looked like it was in the middle of a soup sandwich on the freeway, the front and rear bumpers knocked out of alignment and the hood had been bashed. I drove it around the block and told the guy it needed a new CV joint, the 2nd gear synchronizer was going out, and it wouldn't pass smog as it was. $600? he asked and away it went. I drove it 150 mile home with no issues. I probably spent another $400 on it rebuilding the engine and replacing worn out parts, but it has been a very good investment. I get 48.5 cents per mile when I use it for work and I average 44 mpg. It earns it keep.