Cylinder head mods

[Copo427ss]

Hi everyone, I've been flipping through this site and a couple others for some time now. I've found lots of good info here so I decided to register. My 2007 fe-350 blew a head gasket, so upon removing the head I have noticed how unbelievably horrible these ports are in these heads. They're straight up embarrassing to Kawasaki for design. I could actually see after the valves were out where the fuel was puddling in the bowl area and then dribbling off the valve into the combustion chamber. I've been doing research looking for anyone that has modded these heads. And the best I can come up with is milling the head .050 and boring the cylinder the same. What I don't understand is that isn't solving the real problem of the engine which is port design

So I decided anything that I did to these ports was better than stock. These ports are way to big for the rpm these engines turn. So I have , roughed up the intake runner, added to the short radius, added to the bowl area and then blended everything out. I now have increased velocity and straightened the intake flow out. The exhaust side has been massaged, contoured, and the excess valve guide cut down. I have a total of about 3hrs into this port project. I really wish my boss didn't sell the flow bench. It would have been great to compare stock, to my modded ports.

I plan on milling the head down and have seen a lot of variable numbers to shave off. I was thinkin .030 since I read that .050 was max. Any clue where that puts the compression ratio? Or at .050 for that matter? What about the rockers? These are non adjustable. I read to use fe290 rockers but see there are 2 different part numbers for years. Also do you run the stock hydraulic 350 lifters or switch to the 290 solid?

[Copo427ss]

Out of everyone that has shaved their heads on the fe350, nobody can tell me what they've come up with for compression ratios? Or what year 290 rockers to use? Or if the 290 lifters will fit?

[ckiguy]

last known the 290 has adj rockers. the 350 has hyro lifter, so diffent rockers.

[ckiguy]

the one name i can suggest is tom a ccp. he is a site sponsor and he mills the clutches too. i thnk hes uses the name big block...but not sure. i dont know if lockman can chime in on this. but i know if you call tom at the shop and let him know what your plans are or would like, he will guide you were you need to go. ohhhhh and i know scotty b is rather informitive, even though hes a ez go man. dont hold it against him cause he swings both ways....ezgo, and club car!(that was a joke scotty!)

[Copo427ss]

Thank you ck. my biggest concern is what 290 rockers to get and if the 290 lifters fit the 350. I don't want to spend money on useless parts. I'm a motorsports tech by trade and we do a lot of speedsport stuff. So all of my work thus far is in house. When I figure out how to post pics through my iPhone ill put a couple pics up of my ports.

[ckiguy]

im not saying call tom and have him do the work. tom is very useful and has done this and pretty much knows what can and not work. there are some others, but i know tom has the knoledge and thee access to the parts! i still think from buying the 290 arms, give him a hollar on monday and tell him what you want to do. hell take care of you.

[Copo427ss]

Well I called Tom this week and ran through what I was doing and planning to do. He told me that I would not need adjustable rockers and to just bleed off the lifters so when they pump back up they will be correct.
So I finished the head up Friday after work. We fly cut the head .030". .050" is definatly max and after seeing where .030 put me I really would not recommend going .050. We water tested the ports and I have to say I'm very impressed with how it flowed. Water stuck and followed the new short radius very well right into the combustion chamber. No splashing off. I rough lapped the valves in and increased the contact patch by double. Then I fine lapped them for a nice uniform seal on the seat. Adding more contact area will help transfer more heat off the valves, especially the exhaust side. I think this head mod will make the engine work highly efficient thus creating way more power over stock. We figure its at least 25% more flow through the intake and increasing the velocity will really improve low end. If this works out well I might pull the cam this winter and send it to our friends at crower cams to have more lift and duration added. Thus raising the power some more.

[tpg]

good luck having the starter to turn over the engine

[Copo427ss]

Originally Posted by tpg

good luck having the starter to turn over the engine

Why is that? Other people have cut the head down and don't have issues. I only took .030 off. These engines are really low compression to begin with. Yeah it would be a different story if it was raised to 10:1, I doubt I even raised the compression a point.

[Copo427ss]

Well my starter has no problems turning the engine over. The cart breaks the 22inch mud sharks tires loose on take off. I have posi. Im still lean. So I have to drill the jet out another size when I go to work tomorrow. I disconnected the air hose from the carb and besides running lean it ran pretty good. So I think I'm gonna grab a universal uni filter from work and just get rid of the precedent air box assembly all together. You can now actually feel the cart pull when accelerating. She really starts to wake up just before the rev limiter kicks in. I may disconnect it tomorrow. I just don't want to spin to much rpm. But as of right now it hits the limiter fast. So more power will be achieved when I richen it up some more. I think I need to find a bigger carb. It would be great to fab up a flange and put a cv carb on it.