to PV or not to PV

[jdplowboy]

Hey, I Have an 86 250R that I am planning to get an ESR310kit w/ TRX 9 porting....Just seized the stock motor. The crank bearing went out. Since I had to replace the crank etc I am going for the +4mm stroker also. What do ya'll think of a 310 with a Power valve vs. one without? I ride mostly dunes...hard. We run the bowles fast and occasionally shoot the hill against my cousin's 450's with HRC kits and one that is a 490 stroker. I love all the input and knowledge avialable here and welcome all comments.

Thanks

[methyman]

The power valve motor is nice smooth power band and allot of bottom end probably more that you would need for the dunes I guess. I never have riden in the dunes. I ride some tight trails and drag race. I have my first pv motor and it was sweet. The pv came apart twice. I didn't know it until I took the motor apart. If your a good rider you can do without the PV. The kind of riding I do I don't need the PV, even in the trails. The ESR330 pv motor I had uses a two piece pv and they screw together. I lock tight them together and never had a problem again with it coming apart. My ESR370 motor was non pv and that had insane power. I prefer the non pv and the $500 less the cylinder cost. Just my 2 cents.


Later

Matthew

[wilkin250r]

The powervalve will give you better low-end power and a smooth power delivery. This is extremely beneficial in racing because lost traction means lost time. You want a smooth power delivery to keep wheelspin to a minimum.

But it don't matter a lick in the dunes. You don't need low-end power, and you don't need a smooth power delivery.


Personally, I DO ride a powervalve in the dunes, but that's because I built my motor for all types of riding, including trails. I want that smooth power delivery. But honestly, if I was just riding dunes, I wouldn't go with a powervalve, it's completely unnecessary.

[havinnoj]

See what your local builders recommend. Primarily non-PV are preferred because they fit a dune riding powerband as well as a PV- if not better. A 4mm crank will give you good torque and low end.

[deathman53]

I would go for a powervalve too, the smooth power is great. In the dunes it might not matter too much, but do you only do dunes?? or do trails and mx on occasion also, if yes, get the pv. Don't know if anybody thought about it, you should tell whomever is gonna build the motor about the stroker crank. The porting has to be done different with it.

[Creech52]

Im with everyone else, If your strictly duning the bike Id say save the money and go without the PV. Also a good porter will be able to get close to the broad power of a PV. It wont be like a power valve but close, and youll save $500+

[250r4life]

you guys are killing me...

i primarily ride the dunes, and i loved the PV there... if i had to choose between the two i would choose a PV engine...

the thing that is great about the PV is that when you dont need it it wont be functioning... when you do, it will be there for you... what i mean is say hill shooting... i rev high enough before the launch that it wouldnt come into affect... but if i was duning and say got tired and lazy and didnt want to shift and clutch as much as i should, it would be there to help and lug...

[jdplowboy]

Hey this is all great info on the PV, what do you think of the stroker option, does that change the need for a PV in a 310, how will that change the way the engine runs? I just figured since the crank is shot....upgrade, right?

[havinnoj]

Originally posted by jdplowboy
Hey this is all great info on the PV, what do you think of the stroker option, does that change the need for a PV in a 310, how will that change the way the engine runs? I just figured since the crank is shot....upgrade, right?

Builds more low end torque faster, quicker acceleration.

[86 Quad R]

the stroker will give you more overall torque but the engine must be set up for it. the most important thing is having the cylinder ported correctly. with that and added compression and a matching pipe, carb ect ect she'll perform nicely. :cool:

[kiesta00]

I have a 310 top end with a 4mm crank...love it. Mine is ported for drag racing, which isn't really what you're looking for...but boy does she run!

If you're having doubts and don't really plan on drag racing all the time...then go with the PV. People that only dragrace want a non-pv cylinder so that the exhaust port can be modified properly.

Go with the PV.