So @GGRIII and I are putting motor parts together and he's got two cams... One of them is an "F" grind from an 82 non-turbo car and the other one is a "B" grind from an 82 turbo car. We're trying to figure out which one would be better to use.

According to the interwebs, the lift numbers for both of them are the same and the valve timing specs for the two are as follows:

Format in FSM -  a / b / c / d / e / f
                       - ex duration / intake duration / intake open btc / intake close abc / ex close atc / ex open bbc

"F" (na) - 248 / 240 / 16 / 44 / 10 / 58
"B" (turbo) - 248 / 240 / 12 / 48 / 14 / 54

It appears to me that the only difference between the two is the non-turbo (F) has all the valve timings four degrees advanced when compared to the turbo version?

Seems to me that the turbo cam on sprocket position #2 would be identical to the non-turbo cam? Do the cam experts here concur?

Edited November 18, 20195 yr by Captain Obvious

You might double check the numbers using the FSM by year and model.  They're in the Engine Mechanical chapter.

I found some of the numbers in the 82 FSM, but not all of them. I'm also unsure if that 82 "EM" section is supposed to cover both NA and turbo.

Did you find all the numbers for both turbo and non-turbo versions in the FSM? Which year?

Sorry, I might have assumed that they'd be there, separated.  I don't have my FSM files handy, I've been on the road.

My views on the things Nissan was doing in the late 70's and early 80's is that they were mostly about emissions.  California smog was driving most of the development efforts in the automotive world.  I traveled through LA in the early 80's and I seen what the problem was.  LA was in a cloud, not a natural one.

I've got a hardcopy of the 83 manual and .pdf of the EM sections of 81 and 82.They don't do any differentiation between turbo and non-turbo.

The 83 manual seems to cover both turbo and non-turbo, but on xenon there's also a "turbo" version for 81, but the EM section is incomplete.

Anyone have a confident source for the details about these two cam grinds? Anybody>