Can Someone Translate These Cam Specs To Plain English....Please, Please, Please

[jmortensen]

Oh, I thought your original description was your description of how it ran.

Here's another issue to ponder. Do you have a 4 speed with 3.36 rear gears? If so, a higher strung motor with a narrower powerband is going to be tougher to drive. If you have a ZX 5 speed with 3.90s or 4.11s it will be much easier to keep the engine in the rpm range where it is happy.

And another: What kind of induction? If you're running SUs the design really keeps the velocity up in the intake manifold and makes a bigger cam easier to deal with than with triples.

Were it my choice to make regardless of the carbs I'd buy someone else's cam that was a bit larger than the Stage IV. Your mileage may vary.

[texasz]

Jon,

There's a 5-speed in the car now though I don't know which one. I have a '77 5-speed and an R180 with 3.9 gears to install. The tranny has already been gone through...I just can't find anyone willing to touch the diff and replace the bearings and seals due to the extrememly tight tollarances Datsun/Nissan has on it...the only place I found was the dealership and we all know how their prices are. This is another story though.

I'm going to use triple Mikuni 44s on the engine (already got them from Wolf Creek a while back).

[jmortensen]

The 77 trans has a big 2-3 gap, so you may find that you have a bit of a bog when you hit 3rd if you can't stay in the best part of the power band. Your stroker may make up for that too. The rest of it sounds good.

Changing bearings and seals shouldn't affect any clearances in the diff. Bearings are usually made to such a high degree of precision that there isn't any problem. That said, finding a shop for R diffs is difficult. I know John Coffey has recommended Unitrax in SoCal, might be worth shipping it off to have it done right. 3.90 R180 is a rare diff. You could probably trade a ITS or vintage racer for a 4.11 and a couple hundred bucks if you wanted...

[texasz]

Thank you for the info, it will help!

Yes, the 3.9 R180 is quite rare and it took a while of searching to locate mine. As it turns out it was pulled from the truck when it was only a couple years old because it was totalled and had sat on the shelf in the junk yard ever since. Got a screamin' deal on it too because the guy at the yard didn't think anyone would ever buy it!

I had done tons of research a few years back on diffs and tranny ratios and settled on this combination. That's not to say I may not want to change it.

As for the seals and bearings, the shops I contacted (even some that are very acquanted with Z cars) none would touch it. Locally all roads dead ended except for the dealership. The other shops didn't want to take it apart and attempt putting it back together again due to the aformentioned tollerances. *shrug*