my wife rides a 440 ex with a aftermarket cam ,rev box and fmf pipe and header how much horsepower gain can be expected with a port and polish job and what is the cost of a port and polish on average.

 

I dont know about the cost, but there will be some gain like he said but not like what you get when you port and polish a 2 stoke.

 

Notice how the 440s power falls off way before redline? it will enable you to have a top end to match your midrange.

 

A buddy had his stock head done by Wedman Motorsports in OKC. It made an extra 5hp. over stock. They took 1/2 a cup of alum. out of the head. I believe he told me he paid $300.00 for the port job. I rode it and it does feel alot better in the mid to upper range.

 

thanks for the information about the port and polish job it sounds like it would be a logical last step in building up my wifes 440 i will let you all know how much of a difference it makes.

 

Just finished my breakin on my 400 ex, with a new 440 kit, web cam, rev limiter, and PORT & POLISH, modified FMF pipe, k&N filter, 155 main jet, running AV gas, The word to decribe how it runs is "Demonic!!" It scares me to hammer it

I took a great portion of the exhaust side out and polished to a mirror finish, the intake was also opened a bit, polished but later roughed back up ith a wire wheel to cause some turbulance, on the exhaust side you want a smooth finish to disallow carbon buildup and more outbound flow, I used the old gasket to gauge how much to remove form the intake,

Caution in the intake side, the head bolt passage is close to the biafication, grinding to much off in that area will cause you a problem,

if you a racer and don't need longevity, grind off the bottom of the valve guild stem for a completly smooth bore, valves and guilds are cheap

Porting is a must if you run a hot camshaft and bigger piston, no two ways about it,

hang on and have fun