rb25 series 1 or 2?

[AleksS30]

I was on a mission today looking for a RB for my 71 Z. I went to a jdm engine importer and noticed alot of rb25's in stock had the typical ignitor on top of the valve cover. I then came across a rb25 with no ignitor on top of the valve cover...there was just a plug there. After searching about this on here I realized that was the difference between the series 1 and series 2 rb's. Now my question is, if you guys had the option, which motor would you go with? series 1 or 2? To my understanding the wiring aspect is the same between the two.

[pat1]

If I had to choose I would go with the series 1.

 

Because

 

1- the coil packs on these rb's are crap. The series 2 coil packs are harder to find and cost more.

 

2- the common problem with these rb's are either the PCM or the

Cas and both are hard to find for the series 2 and cost alot more.

[Coolwhip]

Between the two series the differences are just in the electronics and both are as accessible as the other. If getting down to the nitty gritty, the S1 does share the same MAF as the RB20's so they're more available but once you start modifying the engine that MAF is tossed for either a N62 or better. Coils are available for either. Igniter retro fits are also available for the S1 if they dies out. And obviously the S2 doesn't have one so no worries there. Beyond that the S2's are 'newer' motors but speaking of motors of that era it's all going to be the same thing yet 1-2 years difference.

 

Hope that helps.

[RS Speed]

series one can also fire series 2 coilpacks... its like blood tybe AB while series 2 is a universal donor lol. That said I would pick up whichever motor looks the best... spin them with a ratchet from the crank and see what the compression feels like and look under the valve cover for signs of a negligent owner. Comp test would be nice but it not always feasible unless you got a spare battery handy!