Yfm350 serious power build!!

['00 WO-YA!]

...ran outta room, lol! Lookin at the stock head I have there's still alot of room between the outter edge of the valve & the cylinder wall. If the theory works, there's improvement that could be made even on a stock bore. I don't have an exact measurement but the ole calibrated eye says that there's atleat .200 from the valve edge to the cylinder wall. Obviously the 85mm bore (or even larger) will make the problem bigger.

 

[1998yamahawarrior]

Damn it Jebby, now you got me thinking about doing a 366 with the 12:1 and playing with the head to drop the compression enough to run pump gas. Just when I had my biuld planned.

 

[1998yamahawarrior]

i think trying to go as hemispherical as you can would be best to promote a swirling motion

As in smoothing it so the original ridge is gone between the valves?

 

[beastlywarrior228]

it still needs the rod bearing replaced and put back together but hell if the motor has a good head job for p&p and to get compression up more, cam, springs and you pay for the shipping id do it and throw in the 38mm mikuni jetted for it

 

['00 WO-YA!]

ive never really seen much with removing material in the combustion chamber.

man i need to stop listening to you guys, you gonna make me go out buy another motor and do a je 366 with all this head work, .430 cam and flywheel key

Haha, don't blame us! I need to make some side money so I can do some of this madness myself, I hate bein broke!

 

[Hdale85]

it still needs the rod bearing replaced and put back together but hell if the motor has a good head job for p&p and to get compression up more, cam, springs and you pay for the shipping id do it and throw in the 38mm mikuni jetted for it

Well you live close......don't think we'd have to ship anything lol.

 

[beastlywarrior228]

nope you guys make it hard to control the engineer in me and make me wanna better everything

 

['00 WO-YA!]

nope you guys make it hard to control the engineer in me and make me wanna better everything

I feel ya man, I'm a mechanic & have been a hotrodder my whole life, I can't leave anything stock, lol!

 

[duneracerweston]

This is totally doable I need to measure that exta head I've got in the shop

 

[1998yamahawarrior]

nope you guys make it hard to control the engineer in me and make me wanna better everything

My problem is I dont know how to leave well enough alone:evilface: and then someone gives me more ideas. Only good thing this time is I havent bought anything!!

 

['00 WO-YA!]

My problem is I dont know how to leave well enough alone:evilface: and then someone gives me more ideas. Only good thing this time is I havent bought anything!!

Haha, the thread isn't done yet!!

 

[1998yamahawarrior]

Ya I know, that makes it extra good that I havent bought anything. Other than the extra jug thats at 84mm, but at the rate this thread is going I might be getting it bored bigger. Oh the humanity of it all!! LOL

 

[elwood]

so are you meaning like this as far as enlarging the C.C.?
http://www.allthingsmoto.com/forums/f-30/yz-490-tips-tricks-head-mod-diagram-43867/ Yes this is the 490 head mod but it has a pic on how they do it, and wondering if you are meaning the same thing for the warrior.

 

[duneracerweston]

I think so but I'm still learning too opcorn:

 

[1998yamahawarrior]

I was thinking more like this is what they are saying, but figuring out how much is enough and not to much would need to me figured out.

 

[elwood]

with a +1 intake that becomes really tight between the valves around the edge is like I was thinking

 

[elwood]

hey, that plug in the pic isn't indexed what's up with that lol

 

[1998yamahawarrior]

with a +1 intake that becomes really tight between the valves around the edge is like I was thinking

The red between the valves is the idea of knocking the ridge down. Then beastly siad more hemispherical, so hence the red circle. I understand more visually so if thats the idea Ive got it.

And elwood thats just a random pic I pulled online. needed one of the bottom of the head to do that.

 

['00 WO-YA!]

The red between the valves is the idea of knocking the ridge down. Then beastly siad more hemispherical, so hence the red circle. I understand more visually so if thats the idea Ive got it.

And elwood thats just a random pic I pulled online. needed one of the bottom of the head to do that.

I'd really like to be able to see what the air looks as it passes by the valve & into the chamber. There's a tool that you can make up that will allow you to see what it does. As far as the ridge between the valves is concerned, eh, I don't know that it's a huge problem, which is why I'd love to see the air path. Many very nice cylinder heads on the market still have a contoured ridge between the valves.

 

[rappy'97]

On the Raptor 700's anyway, the +1 head out performs the +2. This is a very interesting thread, alot of knowledge in here!