I've been selling a fuel efficiency/MPG cam fore awhile. Since B'villetom has a few Metro daily drivers, and alot of experience with the 3cyl. motor, I asked him to test one of these cams for me. The fact that he is a cheapass, and loves his gas mileage, makes him an even better tester, as far as I am concerned.
Tom bought a 96 Metro with a bad motor, and wanted to use this as his daily driver. After completion, he was complaining that it was not only a bit of a dog, but also not as good on gas as the earlier cars. While it was a nice driving car, it just wasn't the same. I thought it was the perfect oppurtunity to get some testing done, and see if we could get the gas mileage up a bit.
Tom posted something up on the turbo haven, and since he doesn't care much for typing, asked me to move it here for him.
Quote:
I'm not building race motors right now so I have taken on a new project. As a little background, I have been driving 3 cylinder Metros for 3 to 4 years now. A 1991 and 1994 Mark II 5 speed, 2 door as a daily driver as well as for long trips. They are lightweight, nimble & fun to drive. In about 35,000 miles, the gas mileage has been between 44 MPG to 52 MPG consistently.
I bought a 1996 Metro 2 door 5-speed with a dead motor. I rebuilt the motor without modification and it is my driver now. It drives much better, doesn't sway as much and more quiet than the older cars but won't get gas mileage worth a hoot! It is an OBD II car which bothered me, but thats not the problem. I have run 18 tanks of fuel through it and its average MPG is 38.56, a long way from the Mark II 3 cylinder cars. I finally figured out why, it is 300 lb. heavier, approximately 2" wider and approximately 2" taller and is over geared. It looks so good; swoopy and clean but the same 3 cylinder is working its tail off.
I'm doing some R&D for Suprfly (Mike) on a new mileage cam. I did a hot compression test on the engine before I put the test cam in:
#1 - 182, #2 - 178 and #3- 180 lbs.
I did the same test after the new cam was installed: The hot compression test was:
#1 - 195, #2 - 185 and #3 - 190 lbs.
The compression increase is probably because of shorter duration which should help the low and mid-range power.
I was correct, my low and mid range throttle response and smoothness of the motor after the new cam was installed was greatly improved as well as drivability. I can do second gear roll outs from stop signs now and couldn't before. I would expect the top end power to be down but I'm still on the first tank of gas. I will provide more information on MPG figures later.
B'ville Tom
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Turbo + 1.0 + 15lb's = needed cam, you got one listed? Yes or No, I will look for it then. 
I am searching right now and gathering info while I finish my current project. then I will go full guns into the Metro. 
the engine im looking for replacement rockers for is a G13A SOHC 8valve. In an 85 barina