Since 2003, ESP has specialized with the Husqvarna/Zenoah family of RC and scooter racing engines, and are used in every application of RC racing using Zenoah engines around the world.  The engines and top end kits that are modified range from the first Zenoah G230RC (32mm piston), to the later bigger bores of the RC engine line, like the G320RC (38mm piston). There are also some bigger top end kits, like the GP460 and GSR40 that porting is available for.  The work that is done for the most part is what is called “Porting”, where changes in the location and area of the port are done to gain more performance. It is similar to putting a bigger cam in a four stroke engine. Different types of racing require different porting. For example, the porting for National level Boat racing, (where they are wide open most of the time), is cut for lots of power high up in the rpm range.  That porting would not work well for a buggy on a tight track with double jumps right after the corners. The tight tracks would like more lower RPM power with a strong midrange. The pipe is a huge factor of how your engine makes power. The pipe should actually be matched to your porting. That tight track with the lower RPM porting will make the best power with a pipe that is also tuned for strong midrange power, (all 3 DDM pipes I used are great here), and the high rpm boat racing will run the best with a pipe that is tuned for those faster piston speeds.

 

Other work I do a lot of is modifying the head area for stroked cranks. Every 2mm stroked crank set up I build will have the squish band cut, and the compression properly adjusted, (using the stock cylinder base gasket or thinner).  Some other engine builders will just put a 1mm spacer under the cylinder to make room for the longer stroke, but that set up loses a lot of power because of very weird port timing that the spacer causes, (spacers are needed, and OK for “long rod” cranks though).  One good think I like about the 2mm stroked crank builds is, because I have to modify the combustion chamber, I can set the compression where ever I want. You can’t do that with the stock crank and 1mm crank, (usually), as the head area is not usually modified for those cranks.

 

You ask, “What kind of porting have you got?”

 

I offer basically three types of porting for most of the different cylinders I work on, which makes it pretty easy for me to match the cylinder and modifications to your needs.

 

My first porting was my “Championship Porting”, (HT, High Torque version).  The specs have changed a bit over the years, but it is called “Championship Porting”, because we have won major championships all over the world with it.  

 

There is a second branch for the championship porting, that is my, (HR),“High Rev Porting”.  Same top quality and race winning performance, but ported for higher RPM, (may need to set the clutch at a higher rpm if sluggish at low speeds).

 

Third is the ESP “Race Porting”.  This is my lower level porting. Still much more powerful than stock, but just a bit less power, (about .25-.50hp) than the championship porting, and revs about 1000 less RPM, (with everything else being equal).  

 

I have also started making “High Rev” pistons, now offered in 34mm, 36mm and 38mm bore engines, (also “light weight pistons“ in the 34mm and 36mm sizes).  The piston actually gives more exhaust duration for higher rpm power. When matched with the correct pipe, they can run better in a stock engine than some of the other cylinder porting I have seen from a few pretty popular engine builders. Need a custom piston for your personal build? Give me a call.

 

I sell my stuff through “Dave’s Discount Motors”, (DDM), and all of the RC top end kits below are also available in complete engines, (unless noted otherwise).  DDM chooses what ESP stuff to stock at their facility, so if they do not stock a particular kit/engine you want that I have built before, I can build that one for you directly. Just check with DDM first please.

 

Here is the list of the engines/kits I work on, from the smallest from years gone bye, to the bigger engines of today.  Horse power ratings are based on the engine using a good pipe for the porting.