are there any difference in the 1st generation vs 2nd generations rotating assemblies? In particular the crank, and rods. I have heard they are interchangable and are better. Any truth to this? and if so what is better about them.
1g and 2g 1.9 cranks and rods are exactly the same from 1987-whenever they stopped the 1.9 (96?). 2.0 has the same rods as the 87+ 1.9, but the crank is different. Same stroke, but designed differently, and better IMO.
Would i be better off to use them in an 89 1.9LHO engine that i use for racing and am almost always above 6500? The engine has enough power but snaps rods. And if so would it be better to use the later 1.9 rods or the 2.0 rods? I've also heard the later 1.9 cranks are better balanced, is that true?and would that help?
I measured the crank/rod journals from my '87 GL and it has larger diameter than the 88.5-90 years (which are the same as the '91 and later CVH models). I believe the pre '88.5 engines (flat lifter head typically) used the "big" journal cranks (bigger on rod journal only). Later 2.0 cranks are 8 counterweight, although the 1.9 cranks are said to be good to 8k...which is really beyond the rpm range of what the head is useful for without extreme mods (by then you wouldn't be using the stock crank).
The 2.0 crank would fit, I think, but I've not seen it. I don't know if there is any interference, although I strongly doubt it. Rods from later years are about as good as earlier ones.
Also, keep in mind the "big journal" rods are shorter than the later ones, as the pistons had a lower wrist pin location. Ford moved the pin location upward and lengthened the rod, supposedly to help with high rpm.
If you're racing that 1.9, and shifting that high, have you upgraded the valve springs or cam? I'm wondering if you're snapping rods due to hitting valves, or possibly because something isn't balanced entirely.
Well we will soon know if the 2.0 crank will work. I am searching the j/y's for some and will see if it works. The head is stock for now need to get bottom end to stay together than will work on head. I dont shift but it pulls the whole straight and is fast. All but 1 race has been won by a cavalier but am looking to end that if i can keep it together. Car is faster than them but doesnt stay together.