New Zenoah

[stephen hart]

How are the new 4 port Zenoah's, how much better is it compared to a modified 2 port. Can any one tell me whether the 25.4 cc 4 port is worth the excersize or just stick with the 22.5cc. Class doesn't worry me and it will be going into a 43 inch cat.

 

[lohring]

Yesterday I watched several of the latest M&D modified 260 Zenoahs race in AC Lazer 45 monos and RC boatworks Stryker cats. There is no comparison to the older Zenoah PUM. I suspect that the engines are superior even unmodified. M&D says they get more power out of the larger engine, but there is some debate on this from other engine builders.

Lohring Miller

 

[stephen hart]

Thanks Lowring, I have heard conflicting reports on these engines and my current Zenoah is quite strong and want to be sure I gain some advance in performance. BH hanson have some info on them but what surprizes me is the 26 pum when modified only gains 800 rpm but the 23pum gains 2000 rpm.

 

[Ron Olson]

What I've read about then over on Jim's R/C Boat Dock is that the early production motors had a problem with the piston and sleeve scoring. It could get pricy replacing those parts!

 

[lohring]

All the new Zenoahs I am familiar with have been modified by M&D. None have had any durability problems, unlike the Quickdraw. Because the increased bore diameter in the same cylinder reduced the transfer passage size, the first 230s looked like they would have more power. This may be true in the stock engine, but M&D has been able to overcome this in their engines.

The piston was designed for an air cooled engine where the cylinder temperature is greater than our engines. Most engine builders take .002 to.005 off the ring area to prevent seizing. Again, I have seen no sign of this in the engines run by our club.

Lohring Miller

 

[ronaldb66]

Hi everyone!

I'm new around here so expect a modest attitude, but i've witnessed a brand new 231PUM last weekend and the 260 pales in comparison. The owner of this little gem (a LHS owner) just slightly widened and lowered the outlet port, and even before ever being run in properly the engine ran like a beauty, with very agile throttle response, lotsa low end torque and high top speed.

The best news is that it's already almost that good straight out of the box.

Regards,

Ronald.

 

[steve hart]

Bolted the new 231 Zenoah in today and ran a couple of tanks through. Even at rich high needle the motor halled arse. Ran a 472 deep and it just blows that prop right out of the water. I can't beleive how good they are right out of the box. ;D

My cat is going to be a real handfull keeping it on the water, nearly blew over twice on realy flat water.