310 buy from who

[catch me if u can]

actually a pv opens alittle at a time thats to give low end when needed but if you are stuck in the low end in a drag you are already beaten most dragers block there pv open when draggn

[EAT_A_450]

Could some of the famous porters of this site chime in? I'm not a porter myself and I have not compared the cylinders but I have done some extensive research before I bought one. I read a post on here similar to this one where someone was saying that they "heard" that ESR's porting wasn't aggressive enough- then five0nick (who is a respectable engine builder on this site) chimed in- these were his words-

"So have you actually ran the motor, cause ESR normally does a pretty good job of porting for those who ride their bike for all around riding. Specialized porting is available but your always giving up something. Granted they are not completely standardized but I have seen a ESR TRX9 310 with a TRX5 pipe and 38AS pull 56hp strait from ESR. Thats pretty good for an all around bike."

Sounds good to me! Now I also talked with another great builder about Duncan- He can chime in if he wants to but he told me this in an email and not a post for everyone to read so I will not use his name. He said that Duncan has some of the worst porting that he has came across and he also said that I will be happy with my ESR trx7. You could probably get a respectable builder to build it a "little" more rider specific but lets face it these motors are expensive and if you ever want to sell your motor or bike I think these "large companies" will have great porting for multiple size riders- I mean they are big names for a reason and from my research ESR does a great job. Everyone does have their on opinion about the motors though- if they didn't you wouldn't still have 3 big name companies.

[catch me if u can]

personally all i ever heard about esr heads are that they were great and the ports were ok but there porting wasnt rider percific

[fastR of puppets]

just buy a cylinder direct from pro x and send it to c liegh, it will be the cheapest way, and will make very good power

[atcsteve]

I agree,buy an ESR unported and have it done right!!!!

[Chewy67420]

Is eviltwin still doing port work for cheap? Well flotek http://flotekperformance.com

I haven't had him do any work for me yet, but there are tons of happy customers on this website.