rotax454
Pro
Let's try and keep this thread on track-------Head talk only.
For Starters, this was copied from another thread.
XT, are you saying that you have already done some port and flow work on the Phazer head? If yes, then you have made up a fixture for the head. What was the flow numbers before and after?
Given your technical experience in this field, you do agree with my opinion on porting without a flow bench = just taking someone's money.
For Starters, this was copied from another thread.
xt_gt said:
XT, are you saying that you have already done some port and flow work on the Phazer head? If yes, then you have made up a fixture for the head. What was the flow numbers before and after?
Given your technical experience in this field, you do agree with my opinion on porting without a flow bench = just taking someone's money.
rotax454
Pro
cannondale27 said:No flowtesting but I trust my porting guy to make power.Matczak Machine in PA has never failed me yet.Nice head!Would like to see your car.Is a whole topic with pics of my head somewhere.I told him I wanted topend power since I feel I can afford to lose some low end and not suffer.
Interesting. A motor builder that has some experience in the Phazer Head.
I believe his name on TY is Snowprophet.He also has a Turbo Apex,Drag Banshee,Ported SRX and a fully built V-max.All are crazy fast!Probably not best idea to post pics of his work but I believe I asked him first time I posted them.Its a artform anyway.Some people just have the skills.I know he does do flowbench testing on other heads but it wasnt asked for on this one.
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xt_gt
TY 4 Stroke Junkie
looks real good cannondale.
no, i haven't had any experience with the phazer head yet. wouldn't mind doing the work as a side job though, any heads.
i can adapt any head to fit on the flowbench fixtures we make.
i've messed with from BBC & fords to dirt bike jugs, little 4 cylinders, pintos & mg's. small block chevys are given, in circle track racing.
we've got most of the tooling for doing any kind of cylinder head work.
in theory yes rotax. you can port something & it can hurt airflow, make it better, or it didn't do a thing. just like the polish finish. you can spend all day making it look pretty, but if that's all you did, (not re-shaping) it's actually less than 1% of airflow.
i've been looking for a head to port, but don't want to spend the money on something that will just sit in my garage until i need a rebuild.
no, i haven't had any experience with the phazer head yet. wouldn't mind doing the work as a side job though, any heads.
i can adapt any head to fit on the flowbench fixtures we make.
i've messed with from BBC & fords to dirt bike jugs, little 4 cylinders, pintos & mg's. small block chevys are given, in circle track racing.
we've got most of the tooling for doing any kind of cylinder head work.
in theory yes rotax. you can port something & it can hurt airflow, make it better, or it didn't do a thing. just like the polish finish. you can spend all day making it look pretty, but if that's all you did, (not re-shaping) it's actually less than 1% of airflow.
i've been looking for a head to port, but don't want to spend the money on something that will just sit in my garage until i need a rebuild.
xt_gt
TY 4 Stroke Junkie
i wouldn't mind a junk head to putts with. get a stock baseline, then do some r&d work.
i guess i'll keep looking.
i guess i'll keep looking.
Thanks.Any suggestions?One thing I would like to say about porting is it has changed since fuelinjection came along.Intake velocity is much less of a factor now since fuel doesnt have to be pulled out of a carb and atomized.Injector does it for you.Is one reason 5 valve head is going away.What I am saying in a round about way is if TB or intake is restriction compared to airbox go BIG on intake.
xt_gt
TY 4 Stroke Junkie
i've heard there is a certain % between intake & exhaust #'s that some people say for a good flowing head.
something like the exh. flows 65% of the intake, i can't remember. it varies builder to builder. some people say its critical & some it don't matter.
something like the exh. flows 65% of the intake, i can't remember. it varies builder to builder. some people say its critical & some it don't matter.
xt_gt
TY 4 Stroke Junkie
can't really understand that last part cannon, but more companys are going to mulitiple valve heads. diesels & cars have moved in this direction.
since there really isn't a restriction for the intake,(pipes/bends) it's a straight shot. if you go too big,(probably not the case for these motors) you have to mess with fuel curves & gearing.
otherwise when you hit it, it will dive on it's face, then all of a sudden rip you arms off 2k rpms later.
i think a guy could port it like crazy, then figure out gear/clutching/fuel maps so it's rideable. who knows, you may not need to do much.
since there really isn't a restriction for the intake,(pipes/bends) it's a straight shot. if you go too big,(probably not the case for these motors) you have to mess with fuel curves & gearing.
otherwise when you hit it, it will dive on it's face, then all of a sudden rip you arms off 2k rpms later.
i think a guy could port it like crazy, then figure out gear/clutching/fuel maps so it's rideable. who knows, you may not need to do much.
Amo
Extreme
I like that there is a good discussion on improving the HP on this motor. One other thing to add worth checking might be about milling .002-.005 off the head and increase the compression/and or is the HC pistons for this motor (assuming HS psitons for a 250 would work)...
I've got a good friend who is pretty exoerienced at porting on yamaha (jetskis/motorcycles), I'll see if there are factory specs for flow, etc that are needed, he would definately know.
I'd do about anything to get another 10-20 hp out of the stock motor that won't make the motor any less durable than it is now...
Just food for thought, now back to porting!
I've got a good friend who is pretty exoerienced at porting on yamaha (jetskis/motorcycles), I'll see if there are factory specs for flow, etc that are needed, he would definately know.
I'd do about anything to get another 10-20 hp out of the stock motor that won't make the motor any less durable than it is now...
Just food for thought, now back to porting!
xt_gt
TY 4 Stroke Junkie
good point. i don't know what the ratio is on a stock motor, considering yami says 91 oct., but there can be room to get more compression & still be on pump gas.
it's cheap ($ wise) hp, hense why racers angle mill heads. (for more compression)
it's cheap ($ wise) hp, hense why racers angle mill heads. (for more compression)
Yamaha is going to 4 valve heads vs 5 because it is easier to make power on a 4 valve head now.5 valve head was originally designed for maximum velocity and to lesser degree the light wieght of valvetrain.We do not need the velocity on intake like in carb days.Many dont believe this till its tried but think about it even stock our Throttle bodies are HUGE compared to carbs on a 500cc 2 cylinder motor.
Speaking of wieght.Our 6 intake valves are plain old cheap steel.Exhausts Stainless.Very heavy compared to a Ti valve.Spring pressures could go down with Ti valves.Lighter valves and less spring pressure=HP also = less longevity though.
Speaking of wieght.Our 6 intake valves are plain old cheap steel.Exhausts Stainless.Very heavy compared to a Ti valve.Spring pressures could go down with Ti valves.Lighter valves and less spring pressure=HP also = less longevity though.
rotax454
Pro
I wonder how close the YZF250 cylinder is to our's. I have a close friend who has his son racing motocross, and has his motors build and tuned by a shop that services several Pro riders. I will bounce an idea by the shop owner to see if they are teaking 4-stroke Yamaha motors.
Its very close to ours.I gave piston dimensions to someone here and they said it would work.Never checked myself though.Who knows maybe the valves are same dimensions?I know on 450's middle intake valve is different size than other two intakes.
RIGIDONE
TY 4 Stroke Master
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I have also been looking into this, I have been talking with a guy named Tim Zarnstorff of Z Force racing about a Serdi vavle job and a port and polish.. From what I understand he does alot of work on AMA motorcross bikes and Jetskis, and from what I have read he is a great guy to deal with and does top notch work.. He says I could expect to see around a 7hp gain, the work was going cost around $600.. Im still on the fence about it, dont really know what im going to do. I have is email address if anyone of you guys want to hook up with him.. I believe he lives in the Northern Illionis area.
xt_gt
TY 4 Stroke Junkie
didn't know they were switching back to 4. maybe for the 2012 phazer change rumors?
dang $600. we charge that for a pinto head, porting & valve job. 12-15 cfm gains.
cams would be another huge gain. regrind or something.
cannon, does it look like there is room for larger valves? possibility if you want it all or to see if it even pays to go bigger.
dang $600. we charge that for a pinto head, porting & valve job. 12-15 cfm gains.
cams would be another huge gain. regrind or something.
cannon, does it look like there is room for larger valves? possibility if you want it all or to see if it even pays to go bigger.
