Powroll 440 Stroker

[tEXas400]

Has anyone built a motor with powroll products? if so whats the performance and reliability of it. i'm looking to do their 440 stroker with an 11:1 piston.

[TRXRacer1]

They're no better then an ebay kit so make sure you're not getting hosed on price.

[Wheelie]

I built my engine in March of 06' using Powroll's 440 stroker w/the HD con-rod.

Very strong and very reliable, haven't had any issues to date with it and I run it hard.

Powroll's a great place to deal with and the quality of the work is top notch.

[dalejiw25]

Originally posted by Wheelie
I built my engine in March of 06' using Powroll's 440 stroker w/the HD con-rod.

Very strong and very reliable, haven't had any issues to date with it and I run it hard.

Powroll's a great place to deal with and the quality of the work is top notch.

Ditto - same done to mine in '07 No probs.

[tEXas400]

hell yeah.. thats the feeling i get from their website. seem like they are all about the good ****. i looked into the hot rods 460 stroker kit. just dont seem like it would last even if built right... with that plus 4mm bore on the jug. wheelie only question i got right now is what is the con-rod. the one i was looking at was called tough rod

[Wheelie]

The tough rod is what I call an HD, same thing, different words to describe it. I believe the rod they use is a Falicon piece.

They're not the cheapest, but I believe the extra cost is cheap insurance for a quality product.

[trailrider894]

CON-ROD is short for Connecting Rod

[TRXRacer1]

Don't confuse their high prices for high quality. I've seen a couple of their engines let loose too. They offer nothing special over anyone else.

[tEXas400]

Ive learned in life that you dont always get what you pay for.. i know this. but the option to have a plus 4mm stroker crank without having to do that dratful 89mm piston seems like a huge plus. in addition thru looking them up on various sites and forums they have a pretty impressive track record in four stroke performance. Homeboy "wheelies" prolly holds up because he built it solid. engine failure is in the builder. to each his own i guess. one question tho... i know i need the HD studs. but what head gasket should i use for this build? anybody? just got my frame back from powder coating yesterday.. ordered the CFM aluminum oil tank, CX racing 10 row aluminum oil cooler and 4 inch spal fan today. i also ordered those fins that go in front of the 450rs radiator. hopefully i can customize them to perch in front of my oil cooler. anyone tried this. they prolly dont serve a real purpose but hay i got em for five bucks

[TRXRacer1]

That dratful 89mm piston is actually the best way to go. Look at anything not designed around 80's tech and you'll see how absurd it is to stroke this motor. You've got your mind made up and that's cool but the thinking is based off of old mass thought and hearing what you want to. Biggest mistake people make when going BB is adding that weight up top and not removing it from the bottom. It's a really simple concept if you think about it. I just don't like seeing people wasting money and the route you've picked has you wasting hundreds.

As far as the studs there is never a build on this engine that needs HD studs. You can re-anchor the ones you have with brass or SS for a bigger foot print or if you don't have a machinist you trust with that the larger HD studs will also have that extra footprint that will keep the head from moving.

[tEXas400]

Alright TRX. seeing how you have a XR400R (my friend garrett has a 2000 as well. cool bikes) what would be your recommendation for a build im all ears. i want a bigger bore just dont want to go 440 on it. i bought this bike as a junker. it did however come with a big gun pipe, bg rev box, and a stage 2 hot cam with solid lobes. i need a new jug, and connecting rod. should i build around these parts and utilize them. whats your take. a 400 is at stake

[JOHNDOE83]

why not 440?

[trailrider894]

Yo... i wasn't including the hi comp piston, i am just saying that for most people there is no point in boring it that much, unless there is a need. I bored a friends to 406 this spring and he had less of a power gain than the Sparks Key. When a 416 or 426 is combined with a 11:1 or 12:1 Hi. Comp. Piston, the bike becomes noticeably faster...

[JOHNDOE83]

If your looking for a big power gain, 440 is the only way to go.

The big bore kits are all roughly the same price, and for what your gonna pay to get it bored for the 416 or 426, you might as well buy the 440 kit with the cylinder included?

Just a thought? Ill let you guys debate it out.

[witech]

My thoughts on Powroll. Of course this is from the 90,s before the 400ex existed. I got a few big bore and stroker 300ex kits .One stroker crank kept eating one way bearings because the crank had to much runout . One piston kit I got fom them had .017" piston side clearance so it burned oil and had piston slap like you wouldnt believe. It was all built by them and I have since learned to always double check other work. They did install a new sleeve and machine it right but still made me pay for the sleeve. They also lied big time about delivery dates. It seemed they were more interested in volume not quality.

[tEXas400]

damn... mixed reviews always..lol. what about the hotrods 460 stroker, or the 4 stroke tech 500 stroker. what are you guys opinions on those set ups?

[F-16Guy]

Originally posted by TRXRacer1
That dratful 89mm piston is actually the best way to go. Look at anything not designed around 80's tech and you'll see how absurd it is to stroke this motor. You've got your mind made up and that's cool but the thinking is based off of old mass thought and hearing what you want to.

I've always wondered how the EX would run if you de-stroked it a few mm's and installed the largest piston that would fit. Don't get me wrong - I love the torque it has, but I wonder if you could squeeze a little more mid-to-top out of it without sacrificing too much low end. I'm thinking: De-stroke, big bore, 13:1, big cam, bigger carb, lightened flywheel. Might be an interesting experiment.

[TRXRacer1]

Originally posted by tEXas400
Alright TRX. seeing how you have a XR400R (my friend garrett has a 2000 as well. cool bikes) what would be your recommendation for a build im all ears. i want a bigger bore just dont want to go 440 on it. i bought this bike as a junker. it did however come with a big gun pipe, bg rev box, and a stage 2 hot cam with solid lobes. i need a new jug, and connecting rod. should i build around these parts and utilize them. whats your take. a 400 is at stake

I'd be glad to help but lets see what shoe fits you the best.

What is your main type/style of riding?

Are you willing to run race fuel?

Do you have a full exhaust or slip-on?

What's your budget?

What was your favorite bike/quad you've owned before and why?


Originally posted by F-16Guy
I've always wondered how the EX would run if you de-stroked it a few mm's and installed the largest piston that would fit. Don't get me wrong - I love the torque it has, but I wonder if you could squeeze a little more mid-to-top out of it without sacrificing too much low end. I'm thinking: De-stroke, big bore, 13:1, big cam, bigger carb, lightened flywheel. Might be an interesting experiment. That would be a very interesting experiment indeed. :D

[TRXRacer1]

250r's are down right classic. We can do a lot of top end work with still having more low then that one. Lets start with the obvious. You'll want a modified air box lid like many have done with outer wears. That carb has to go and I'd recommend an FCR39. You could go up to a 41 if you want but being a woods guy that 39 will probably suit the best. Of course a CRF450r timing chain and if there's any doubt on the tentioner replace it too. Studs will need to be re-anchored, you can use the HD studs too they will give you the same larger footprint needed to hold. Stay away from heli-coils. Make sure you get a good MLS top end gasket kit, cometic is top notch. Spal fan.

For the crank just go stock stroke. It's already long and I know how temping it is to go longer but it's not the smartest way. You can get a brand new hot rods assembly shipped to your home for $240, just a little more then rebuilding yours.

Big bore sleeve. Go with a JE 12:1 88.5mm piston. You'll have a 430 and room to go to 89mm later if needed. With this piston take 10-11 ounces off that heavy *** flywheel. Weight wise the piston is very similar (less then an ounce) weight wise from smaller bore pistons.

Take advantage of that 12:1 and install a stg3 Hotcam. It's a not all that wild as some would think and with the higher comp will retain a lot of bottom end power. This combo will be explosive up top too. Get the head ported and with this cam I'd recommend a quality set of springs. Get your valves checked and replace all the valve seals.

You will want a full exhaust too. As for a rev box you should wait until you run it. If you do everything I suggested you'll have 15+ more HP in that 8-9K RPM range. Depending on your riding style you might be bouncing off the limiter or not. This is another reason for the springs and porting. This engine will want to breath.

When taking that weight of the flywheel remember to take it off the top and outer face. This combo might want some higher octane then 93 but it's an air cooled motor and when you start to have fun with these they get hot. Just want to give you a fair warning.

If you do it right you might have to mod the clutch too. The 300ex trick is a good one. As you get into this put some real thought into how much you want to put into it. It will never be a modern liquid 4-stroke. It's ceiling will always be lower then a shim and bucket engine but if you do it right, you'll clean up on those new quads all day....... until you find someone that put the same amount of money into a newer machine.

If 12:1 is too much for ya I have a brand new custom 11.5:1 88.5mm JE that was made for WB. I'm thinking about selling it and picking up the 13:1 88mm for my next build, let me know if you're interested.

[tEXas400]

i know a guy with a 06 TRX450r. him and his friends came to look at my EX project the other day and they tell me there is no way i can take him in a race. hes all stock not even a pipe on it. with the setup you mentioned could i take em?

[tEXas400]

also how would you go about destroking a crank?

im still green when it comes to hands on mechanics, I went to UTI for automotive mechanics for six months, had great scores in all classes, but just left because i didnt want to change head gaskets the rest of my life. low and behold now i hack up beef all day, cold but a respectable profession

[TRXRacer1]

Originally posted by tEXas400
i know a guy with a 06 TRX450r. him and his friends came to look at my EX project the other day and they tell me there is no way i can take him in a race. hes all stock not even a pipe on it. with the setup you mentioned could i take em? You could take him with less then what I suggested. Think more about taking him even after he pipes it. You'll be fine until he gets into the internals.

As far as de-stroking it's better left as an idea then a reality. You'd need a longer rod and the connecting pin in the crank assembly moved inward. Assuming you could find a rod already in production on another machine figure about $500+ for just that. Not worth it IMO.

If you want more then what I suggest think about much more radical cam profiles that require shortened guides and hardened rockers.