Datsun Roadster Forum-311s.org

Last month I replaced the Isky Z-196 cam with the A cam. Today I swapped the 4.88 out for the 3.70 pumpkin. Went on a test drive and was quite suprised on how well it ran. It's nice to be able to go on the highway and not spin the engine a 4K. I'm getting some pinging lightly in higher gears so I an going to retard the cam before I change the ignition curve.

Bye Bye 4.88, hello 3.70...........


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Makes sense, though the 3.9 with 5-speed is a nice balance, too.

rwmann wrote: ↑Fri Jul 07, 2023 8:07 am Makes sense, though the 3.9 with 5-speed is a nice balance, too.

I really didn't notice that much performance difference with the 3.90 or the 4.10. I suspect it was because the cam didn't do much until 4K plus rpm. The 4.88 got there quick. Now what to do with the oil pan and diff......

I suggest you keep all the performance parts because soon your son will be looking for more power and quicker acceleration.

spyder wrote: ↑Fri Jul 07, 2023 9:42 pm

rwmann wrote: ↑Fri Jul 07, 2023 8:07 am Makes sense, though the 3.9 with 5-speed is a nice balance, too.

I really didn't notice that much performance difference with the 3.90 or the 4.10. I suspect it was because the cam didn't do much until 4K plus rpm. The 4.88 got there quick. Now what to do with the oil pan and diff......

The U20 with B-cam lights up at ~3000, which works well with the 3.90 and 5-speed. Sounds like the Isky is a C+.

theunz wrote: ↑Fri Jul 07, 2023 9:47 pm I suggest you keep all the performance parts because soon your son will be looking for more power and quicker acceleration.

Nope! Don't want him to be going fast in a 54 year old car without any of the safety stuff that is on todays cars. I manages to snap an axle with all the go fast stuff on it. Good thing it was in the differential. I plan to sell off the stuff I pulled. I won't need it and I don't want it on "his" car.