Flattop pistons
 

i found a few people selling flattop pistons for farely cheap, i have a 1979 280zx, and as far as i understand, those pistons will bump my compression ratio up to 9.8:1. My car is more or less stock right now, aside from intake and exhaust, i was just wondering what kind of power i would get from this swap.

You will probably get some noticable torque and horsepower increase. Somewhere in the range of 12 lbs of torque and 10hp at the wheels. The higher compression will also make better use of a performance cam should you go with one in the future. That will again boost your peak horsepower. The cam is a major drawback on the stock engine. But they put down some good torque at really low rpm.

thanks for the info, looks like im gonna try to get those pistons in within a week or two, but first i got to get my car past emissions testing, then i can think about performance

Now....I may be mistaken.....but didn't Datsun go with flat top pistons in '78?

1981-83 non-turbo got the first flat tops in the L6. That is the point where they changed the block casting to the F54 block. Better cooling channels and a more rigid design for the 'brand new' turbo engine. They went ahead and used the same F54 block in the non-turbo and used flat tops in the n/a and dished in the turbo. (low compression for the turbo)

Basically 1975-80 engines are all the same. 170 crank hp and about 135 whp. Changing over to flat tops and using a closed chambered head in 1981 got about +10hp at the wheels and about 10 more lbs of torque. Of course with all the electric options going into the 280zx by that year the thing probably weighed 100 lbs more than most of the '79 and '80 models.

I stand corrected.................thanx for the info!!