My rebuilt motor is an 88, and it feels slightly slower than my old 89 si motor. I've "heard" that the 88 cams are different from the 89+. Is this true? I just don't want to waste the time swapping in the 89 if they're the same.

 

88 and 89 are different.

Slightly as far as specs go. 89 is a hair hotter.

This was due to a slight increase in weight.

The woodruff key for the cam gear is 4.75 degrees different.
So the 88 would be more user friendly for the D15b7 cam swap.

 

****, so that means that the 88 and 89 stock cam gears are different? I have like 4 laying around...not sure which one I used. So is the cam timing off then? Well I guess this means I'll be swapping in the 89 cam soon. Thanks!

 

The '88 Si makes 105hp, and the '89-'91 Si makes 108hp. From every source I've ever talked to or read, all of that gain is in the cam. But if it's a difference you can FEEL, I'd suspect the cam gear or timing is off a bit. Still, you'd probably like it a little more with the '89 cam...

Mike

 

Yes they are different that's when the motors got revised I think

 

The only thing that got revised is the cam, right? Yea, it 'somewhat' feels like the timing is off. Not much though. The engine timing is right, and so is the ign. so I'm suspecting it's either the cam gear or maybe the 89 si ecu w/ the 88 cam?