Looking to get some feedback on the 310 vs. 330 vs. 350 vs. 370R kits from ESR. I'm looking for more usable power, while not sacraficing reliablity.

Any advice would be appreciated.

Thanks.

 

 

I have a few friends with 310 pv engines. Paul turner (may be a 305) and esr. They provide a lot of power and are fairly reliable. One of them tried a 370, but was wrenching on it all of the time.

 

Ok, first thing just so ya know the 370 is a stroked 350. You could get the 310 and bolt it right up, and have a good power gain, OR you could spend 50 dollers more and get the 330 bolt on and have really good power. Once you start getting up into the 370 and even the 350 range is when you will need to replace drive train parts more often.

 

So basically, you're saying the 330 is the best bang for your buck? Is it worthwhile going to a power-valve or not? What sort of horsepower numbers does a good 330 kick out?

Thanks.

 

I would get a pv.

 

Your not going to go through any drive train parts with any esr kit. Id replace your clutch basket but that is something that can break with normal abuse from a stock motor.

What you get depends on your riding style and chassis setup. if your bike is short i wouldnt get a lot of motor because you cant even use it. if you just dune ride do a 310 with a PV for the dunes. a 330 is just a bored 310 which i wouldnt recommend because 20cc's isnt enough to constitute loosing your bores.

 

I agree with Beechman. A 310pv would be a great choice for most. The bolt on 330 is a great running cylinder, but there are a couple of issues to deal with. The first is that you can only bore it once .010 and then your done with it. The cases must be machined to go any farther. The second thing is that the piston will crack around the sides of the intake section of the skirt. That's why they recommend piston replacement every 40 hours. We are on #3 piston in a year and a half's worth of riding, and both of the ones removed had small cracks there. If you want a bigger piston with more grunt, you could machine the cases and get the regular 330 cylinder with the longer liner. It is a little more stable and will allow more than one bore. Overall though the 310 is a great choice as it makes much more power than the stocker and keeps the motor vibration down because of the smaller piston. Our group runs with a 310,330, and a 370. I plan on moving my wife up to the 350 cylinder this winter because I like the single exhaust oval port design and they flow better, not to mention 20 more cc's.

 

I have an ESR 310 power valve with ESR's CR250 electronic ignition for sale if you are interested. I'm moving over to a CRF450 quad. This motor is Johnny Hale's race motor built by Eddie for Johnny with a special MX port. It also has a JH Racing quick change clutch cover, all Hinson clutch components plus ESR billet water pump cover, ESR stator cover, ESR exhaust flange. Motor obviously runs super strong!! Email me at brianowasso@***.net if you are interested.

 

So sounds like 310PV is the way to go. Anybody know approximate horsepower for this setup? What type of piston do they use (I assume Honda doesn't make piston that will fit a 310cc cylinder).

Thanks.