Expert: Dan Liddy - 7/25/2011

Question
I have an 87 honda prelude 2.0 si we are suppose to be a stock class that races on dirt but there seems to be nothing stock about this class anymore. I just had the head shaved down 35 thousandths and port an polished now it seems that my car runs no faster than it did before it has more compression but isn't turning into power what can I do to get to make this baby run. Thanks a bunch

Answer
The porting and polishing was probably a waste of time and money.  Some work on a flow bench might do you some good though. Installing larger valves probably isn't practical because of the head design. Modified camshafts will produce a LOT more power if you choose the right ones. For that , contact Cam Techniques << sales@camtechniques.com >> Dave Generous is the owner and has done several quite successful re-grinds for me.

You will benefit from having LOTS of information for him, RPM range, fuel type, induction type (fuel injection). and so forth.

Also explore the availability of aftermarket throttle bodies for your FI system, and experiment with ignition timing. When the motor runs above about 3000 RPM, you should have about 34 degrees of timing advance.


Finally, weight. What are you allowed to weigh, what DO you weigh. Even 25 pounds makes a big difference.

You will probably benefit more by paying close attention to your chassis and suspension than the motor , expecially on dirt.

Good luck

Dan Liddy
Sarasota, Florida