310 powervalve

[bansheeboyo]

is a lrd 310 power valve any good an thinkin about buyin 1 but dose it make it like a 4 stroke and have a crap power band
also can you use a 5 mill stroker with the power valve
cheers scott

[bansheeboyo]

oh and will i need a diffrent pipe i have a 89 trx paul turner race exhaust and dep silencer

[Iliketogofast]

From what I understand a powervalve spreads the power further across the band so that you don't have as much of a two stroke hit and more power everywhere. It's apparently best for woods and MX applications, but my non PV does fine in the woods.

Me, I prefer the excitement you get when you have to fight for your life to hang onto your bars.

[bansheeboyo]

oh crap i just bought 1 who wants 4 stroke power band ?
any way to remove power valve :D

Originally posted by Iliketogofast

Me, I prefer the excitement you get when you have to fight for your life to hang onto your bars.

lmao

[bansheeboyo]

any 1 know how much more power i can expect it is ported for woods/mx
do i need diffrent exhaust

[Iliketogofast]

It isn't going to be a slouch, they cost more for a reason. They are just different than a regular cylinder.

If you have it ported for MX/woods, I suggest changing your pipe to a good MX/woods pipe to get the most out of it.

I'd really say you need a new exhaust. You're robbing yourself of a lot of power if you don't get one. I'll explain it to you...

Your cylinder is ported to make more power down low and into the mid. Your pipe is probably aimed to go from mid to top. If you have a pipe that has an 8hp gain, that's probably up top. If you get a low-mid pipe then you just stack that hp on top of what you have down there already from your good low end portjob.

[troybilt]

My next mod is going to be an LRD 300 powervalve. Keep us posted how it runs.

If you look at the hp curves on LRD's site, they build the same hp on the top end bw 300 pv and 300 non-pv, its just the pv build more power on the low and mid ranges as well. So you should still have the seat of the pants feel all they to the top...IMO!

[troybilt]

Here is the 300PV curve:

[troybilt]

Here is the 300 non-PV curve:

Look at the delta at 4K, 5K, and 6K rpm, bw the two curves, this may give you a visual on what is going on bw the PV and Non-PV, hp-wise.

[troybilt]

Regarding pipe, I would go with the LRD pipe, (I love the look of the silencer, anodized black), ESR trx5 or 6 also even the FMF SST pipe, I've heard good things about. I have an SST right now, that came with the bike, it's worked out well so far. Probably not my first choice though.

Some others may have a better idea that currently run PV motors.

[250Renvy]

You have a PM - Best you read as it could benefit you greatly!!!!!

[troybilt]

Originally posted by 250Renvy
You have a PM - Best you read as it could benefit you greatly!!!!!

Who are you refering too?

[88 250r]

the pipe for the 310 i would go with the lrd adjustable pipe or a esr 5

[86 Quad R]

i too would reccomend the ESR5 pipe. as it is a full range type and gives you power across the board. it is also important that you match everything else up in the power range that your wanting. including a higher compression for added bottom end torque.

if things are matched to work together. it is possible to achieve a full range engine contrare to what some may say. :cool:

[bansheeboyo]

any 1 know the size a 310 piston should be
also the engine stroke of a 88 and a 86
i recived the "310 engine " a few days ago put it in tightened every thing up put water in the rad and there was a leek from the head so i used that as an excuse to pop the top off and have a look measered the cylinder with tape measure (not the best i know i got 68 mm im pretty sure this means not a 310 more like a 265

[250Renvy]

http://www.exriders.com/vbb/showthread.php?s=&threadid=196569

Looks like around 265. Remember what I told you.

[wilkin250r]

Originally posted by bansheeboyo
also can you use a 5 mill stroker with the power valve

It's doubtful.

Generally, when a cylinder is ported for the stock stroke, it is very difficult to re-port it for a stroker crank. They're different cuts, you take material from different areas. It's like giving yourself a mohawk, and then asking for a mullet the next week. You ain't gonna get that mullet, your head is already shaved on the sides, you're stuck with that mohawk. Only your cylinder isn't going to grow back in a few months.

Plus, the powervalve also limits what you can cut on the exhaust port, so that's just another added complexity.

It might be possible, but my bet says your cylinder is already ported for the stock stroke. It may not be possible to re-cut it for use with a stroker, or it might be that you could only get a high-rev or drag porting on it.