MX top end - torn bw ideas => what should I run?

[troybilt]

Should I stick with my Curtis Sparks 280cc or build a new motor, or possibly just buy another motor? I've been going back and forth from all different kinds of ideas for top ends/motor setups. From 265PV's to Puma's to FTZ motor.. I need some guidance here.

Application:

60% duner
30% MX
10% Play bike

I want torque and a hell of a lot of it. Not too worried about being the fasted guy out there, but I want it to put a big smile on my face... My CP motor is stout, and I just picked up a CR ingnition for it, plus a CP MX pipe to match... Just not sure, kind of leaning towards a big bore... I guess I could run this motor for now and then maybe get a big bore later...

[derby]

Originally posted by troybilt
Should I stick with my Curtis Sparks 280cc or build a new motor, or possibly just buy another motor? I've been going back and forth from all different kinds of ideas for top ends/motor setups. From 265PV's to Puma's to FTZ motor.. I need some guidance here.

Application:

60% duner
30% MX
10% Play bike

I want torque and a hell of a lot of it. Not too worried about being the fasted guy out there, but I want it to put a big smile on my face... My CP motor is stout, and I just picked up a CR ingnition for it, plus a CP MX pipe to match... Just not sure, kind of leaning towards a big bore... I guess I could run this motor for now and then maybe get a big bore later...

My thoughts behind this is that a 265 will never put out the torque that a big bore will. A puma is an all or nothing setup. You will get what you put into it. That includes money and lots of time. If you don't like to tinker and work on the bike you will not be happy with the puma. FTZ, I have never seen an ftz motor run well at the dunes. The FTZ pipe you posted on is the best things they ever developed. I have ridden the 410 pilot conversion and it was not what they claim. Put out mid 50's for hp not he 70 they claim.

[2-330s]

i would say a bigbore,330-350cc they are dependable. 370 and larger seem to come apart more often. i don't think the power valve is all that it is cracked up to be on these size motors. from what i gather they were designed to use on the 265cc motors and you don't see as much benefit on the bigger motors.

[troybilt]

Originally posted by 2-330s
i would say a bigbore,330-350cc they are dependable. 370 and larger seem to come apart more often. i don't think the power valve is all that it is cracked up to be on these size motors. from what i gather they were designed to use on the 265cc motors and you don't see as much benefit on the bigger motors.

I heard the same, I think the principle is the same, but the fact that you have a MUCH larger piston your overall power is much greater... so even though you're not optimized across the RPM range, you still build more power at the lower end than a 250 just on shear size... Also compression plays a big part in that.

For awhile, I was gunho on buying a good 310 top end and be done with it. But I want the WOW factor, best possible motor combination out there for MX primary, but in reality it will be a duner as well... no I'm not a pro, but I still want to build the best setup. Nikisil bore, etc... I had a very nice 450r setup, that ran real well for my style of riding, I want a 250r motor to run the same or close... I know I've posted this all before, but I feel I'm back to square one and I'm not much smarter than I was the first time.

Builders, not in any order just what I can think off right now:
ESR
CT -
BDT - ??
LED - ??
FTZ - Duner/TT motors primarily
Curtis Sparks - hard to find motors, doesn't do work anymore on 2 strokes
Duncan - PC2000 top ends, very nice setup
LRD - out of business
Kelner
B&B
Neil
Hammer
Hybrid - Puma cylinders primary/duners

Let me ask this question: If you were going to build the ideal MX motor what would it be??...(for argument's sake money is not an issue, of course it is in reality) but I want to hear what you're ideal MX setup/builder would be.

[Lasher]

Similar to troybilt, I ran a Sparks 280cc for one season and looking for options similar to his, but I 100% MX and do not have any size restrictions.

You guys mention the torque of a 330 size. I am used to either a locally ported stock cylinder or the Sparks 280cc. I hear about the bigger the bore, the less revs you have. I am not trying to turn my motor into a 4 stroke, rather a powerful 2 stroke and hate to loose that 2 stroke feeling.

Does a 330 still rev like the smaller bore cylinders or can you hardly notice difference with the extra power?

[sixer3]

I guess it depends on the preference of the rider, I do about the exact same riding you do and I have an esr 310 with the trx-9 porting Non-PV and I destroy my brother on a 330 PV esr with the same porting.

His motor makes a little more torque with a lot flatter torque curve than mine but he can't get me on the track or up the hill. on a flat long drag he'll barely pull me I know at least 2 others with 310's as well and they all screamed. So far in my experience the 310 has been the best all around motor

When I get on his bike I just can't ride it like I ride mine, maybe it's the PV, it's just different it makes more power on paper but...idk, I know it's weird


After reading your next post about builders. I'll throw in my little experience there as well

I've heard great things about BDT and own a trike so I get a ton of parts from them HOWEVER. I had ONE top job done completely by them and it ended up being a nightmare. My bore ended up being out of round even after sending my cylinder to them 2 times afterwards they wouldn't do a thing to rrectiy the situation unless I paid them to bore or re-sleeve my cylinder again...quite ridiculous.

ESR on the other hand. reliable motors and great porting so far

[troybilt]

FWIW, I was told by some that I should stick with either a Duncan, LRD, or Curtis Sparks PV motor no bigger than 300-305cc range for the best MX setup.

[Lasher]

Same you troybilt, I was leaning heavily on a 310 ported with high compression for MX. But there something about a 330 that keeps me guessing.

I know that LED has something called NIKS 300 that has my interest. I would love to have a nicasil cylinder and never having to worry about getting a bore at end of the season. Just get another piston...

I have not contacted LED or found any information about this cylinder yet.

[troybilt]

Lash, I saw that too and I think that would be a great setup... I'm also just curious what I'm giving up by not going bigger you know... I guess its that mentality that bigger is always better... IDK... I'm not looking to go out and destroy guys at the sand drags, but I want something that is respectable too... if that makes sense.

For everyone else that hasn't seen, here's the link:

http://www.ledperformanceengines.com/trx250.htm

[2-330s]

i would say that arlin (led) would be my choice. i here great things about neil (nprd) but have not had a chance to ride one of his motors.

[2-330s]

Originally posted by troybilt
Lash, I saw that too and I think that would be a great setup... I'm also just curious what I'm giving up by not going bigger you know... I guess its that mentality that bigger is always better... IDK... I'm not looking to go out and destroy guys at the sand drags, but I want something that is respectable too... if that makes sense.

For everyone else that hasn't seen, here's the link:

http://www.ledperformanceengines.com/trx250.htm

call and talk to arlin he will tell you what you want to know. power delivery/torque/hp/COST!! lol

[Lasher]

I have not asked Neil his opinions since the issues with ESR cylinders have started popping up. Prior, getting an ESR cylinder cheap and having him do the porting sounded like the best option. But having doubts now.

Got to call Arlin to get a quote or more information on the NIKS 300. One of these days.

[troybilt]

I emailed Arlan, I'll see what he says... if he doesn't responsd in a couple days I'll give him a call.

[2-330s]

i called milenium tech about nikisil. they told me to wait until i was on my last bore(steel sleeve) about $200. you don't get the heat transfer that you would with aluminum but get the wear resistance. they seem like a good company to work with. they rushed two 4stroke cylinders for plating and heads for valve work that came back great and fast!:D

[Lasher]

Originally posted by 2-330s
i called milenium tech about nikisil. they told me to wait until i was on my last bore(steel sleeve) about $200. you don't get the heat transfer that you would with aluminum but get the wear resistance. they seem like a good company to work with. they rushed two 4stroke cylinders for plating and heads for valve work that came back great and fast!:D

Interesting. I wonder if I should just get my Sparks cylinder coated?

How does getting the pistons work...since they need a piston for clearence right?

[2-330s]

you can call them i had them order the valves and pistons that i wanted on the 4strokes. if they can't get them i just order my wisecos from esr. then send it in with your cylinder.

[Lasher]

Originally posted by 2-330s
you can call them i had them order the valves and pistons that i wanted on the 4strokes. if they can't get them i just order my wisecos from esr.

Thanks. I need to do a little more research on the piston I need. I searched the web for the numbers on the piston with no luck. I guess the ring locators are moved from the YZ location for the trx cylinder.

[derby]

CT racing has been a thing of the past for several years especially at the dunes. But back several years ago I had allen build many motors and one thing stood out about them over any builder I have ever used. They put out torque and lowend power that no other pro-x has been able to duplicate. I mention this because I think that type of motor is what you want. I can tell you all the setups that outran me but that means nothing to you. A ct 350 setup for mx (non pv) was a great all around motor. It will out run the 450's but still put out the lowend that will climb a tree. I have built esr setups that ran well but never put out the lowend that allens 350 did. A ct setup will cost more and probably not outrun esr's in a drag race... but you said yourself you don't need to be the fastest. The only other esr setup that I have had close in lowend was a 330 with 3mm stroker which eddie claims is his dune setup. The 330 was good but if I were building a torque motor I would go stock stroke (pro-x rod) with a 350 topend. If you want another opinion about this setup ask someone else who has built a many different big bores (pumashine).

[Scottt89]

Just got my bike back from Tony Kellner a few weeks ago. I believe he was on your list. From what I gathered the bikes aren't really his thing anymore. I believe he got into firearms and has a range at his property now. I got the feeling like my bike was probably one of the last big jobs he'd be taking on. He had it for about a year, motor guys backed out after getting cylinders and he'd have to start the process all over. Ended up being a CT job with a stock cylinder 300 kit. Still finding weather and time to break it in. Great work, just a little hard to get details and a timeline.

[2-330s]

good point derby. i have only had three bigbore setups led 330 good mid-low top power,sparks 330 mid-midtop,ftz 350pv mid top-top. these were all there "tt" motors and this is my experence with them. a freind of mine had a ct 310 that like you said was a good grunt motor but wouldn't rev very well.

i was thinking that the next motor i would like to try would be a cp cylinder 370 all bore. i would think that pipes for the pro x cylinders should support these motors. i don't know if anyone is running one but this might be another option for you troy?

[danhung11]

Originally posted by sixer3
I've heard great things about BDT and own a trike so I get a ton of parts from them HOWEVER. I had ONE top job done completely by them and it ended up being a nightmare. My bore ended up being out of round even after sending my cylinder to them 2 times afterwards they wouldn't do a thing to rrectiy the situation unless I paid them to bore or re-sleeve my cylinder again...quite ridiculous.

ESR on the other hand. reliable motors and great porting so far

I guess Pumashine was right, what come's around goes around. :blah:

Troy - you might want to contact pdxbigfoot, I remember him saying that LED330R he had built by Arlan was an absolute torque monster. I think he still has dyno videos of it and might even have the hard copies. He's also like us...alergic to bees. :o

Thinking of sending off that ProCross CT310 topend, heard you can get some good power out of one of them with the right porting/setup.

[troybilt]

Dan I forgot, what are you going to run on your Laeger?

I've got a reply from Arlan, and DAMN he builds some sweet motors... the handconed pipes are sick too!!

[rayman375]

Is that NIKS 300 from Arlan available in a PV? I was going to go with him or Duncan when I need a new rebuild.

[danhung11]

Originally posted by troybilt
Dan I forgot, what are you going to run on your Laeger?

I've got a reply from Arlan, and DAMN he builds some sweet motors... the handconed pipes are sick too!!

I'm thinking about sending the top/end motor off to NPRD, it will be a later in the year probably. First, I gotta get my roller done, powder, shocks, etc. Yeah, Arlan is very meticulous about his work according to pdx, in those videos he looks like mad scientist.

Got my rear Hipers in today, that was amazingly fast given given I placed the order with Jay yesterday afternoon. Great guy for sure, hope he can make it down for the dunes this year. (hint hint)

[troybilt]

I was just going to ask where you ordered them, cause they are manufactured in Lawrence, ks.... used to be Wichita... I was going to order a set from Jay too then I thought Shipping would be double whammy... maybe not though... good to know.

Who's NPRD?

[danhung11]

Originally posted by troybilt
I was just going to ask where you ordered them, cause they are manufactured in Lawrence, ks.... used to be Wichita... I was going to order a set from Jay too then I thought Shipping would be double whammy... maybe not though... good to know.

Who's NPRD? Neil aka C-Leigh Racing

That's where they came from, Lawrence.

[2-330s]

nprd is neil aka c-leigh. if i rember correct neil pritchard racing development

[troybilt]

gotcha, I'd never heard NPRD before... yep I pm him over on the other site to pick his brain a little....

[Thornfold]

sixer3 wrote -“I've heard great things about BDT and own a trike so I get a ton of parts from them HOWEVER. I had ONE top job done completely by them and it ended up being a nightmare. My bore ended up being out of round even after sending my cylinder to them 2 times afterwards they wouldn't do a thing to rrectiy the situation unless I paid them to bore or re-sleeve my cylinder again...quite ridiculous”


looks like u got wrong shop-
i just talked to bdt motorsports to karl and carlos. they are building me an engine - pointed out you story about nightmare topend - carl & carlos both said you must have the wrong shop, they have never built anything for you & have had no customers with the problem you wrote - they both asked for you to correct your post - show an invoice or any kind of paper work to show what you wrote is true - karl & carlos both also asked you call bdt motorsports to talk to them about your story. i know this guys & this is not them - coming on here making false stories about a great builder is not a cool thing to do. post proof, or retract story and call them – sure you have the wrong shop -

5. No commercial advertising of any sort, except for advertising for our sponsors/paid advertisers - including banners in posts, avatars, or signature lines, website addresses, phone numbers, or messages (public or private). This includes users advertising for different shops or companies. We enjoy all shops taking part in ATVriders but no contact information, including websites or phone numbers. The administrator alone will make the final decision on what is advertising but as a simple rule it covers all retail shops, chop shops, and product manufacturers big and small. Manufacturers are strongly encouraged to post information on their own products, but please no ads or prices. Violation of this rule will result in one warning and then a permanent ban.

[troybilt]

Please use PM's... Thread was not intended to get into arguments.
Thanks.

[red88r]

I have run the LRD 265pv,Duncan 265pv,CT330 nonpowervalve, and Duncan 340pv all on mx tracks. If I had to pick one for everything and there was no limit on cc's I would pick the 340pv hands down. It has low end grunt like you wouldn't believe and it will still rev. You just adjust on the spring tension.

[Pumashine]

I vote for a Hybrid built Sphinx. It will have all the low end WOW you are looking for. A 350 or 370 is just not that much power that you will not be able to handle.

Second choice is a LED built pro-x 350 or 370 motor. You will always be looking for more power if you do a 310 or 330 IMO

[troybilt]

The LED 300 is a Sphinx cylinder, or looks like one to me.

http://i74.photobucket.com/albums/i260/robltc/TRXLEDcylleftsideview.jpg

[danhung11]

Originally posted by troybilt
The LED 300 is a Sphinx cylinder, or looks like one to me.

That's my vote! Post the curves on that bad boy.

[Fear250r]

Troy,
I've got a pro-x 330 with a full mx style port job by Neil and the thing runs awesome. I know you said to not take price into consideration, but I think what you get from Neil is well worth it. Talk to him and you'll find out he takes his time with it and just really enjoys what he does. Not to mention he's been doing it for some time now.

Jesse

[troybilt]

Originally posted by Fear250r
Troy,
I've got a pro-x 330 with a full mx style port job by Neil and the thing runs awesome. I know you said to not take price into consideration, but I think what you get from Neil is well worth it. Talk to him and you'll find out he takes his time with it and just really enjoys what he does. Not to mention he's been doing it for some time now.

Jesse

Yep, already a step ahead of ya... haha... I've been talking to Neil on the other site, he's getting me some prices on Monday.

ProX 310 top end, 16cc dome, steel sleeve, Wossner piston, XC/MX port.

My other option, I might pickup a bottom end, and build a big bore 350+ and keep my Curtis Sparks motor as is, and switch them from track to dunes...

[Pumashine]

Originally posted by troybilt
The LED 300 is a Sphinx cylinder, or looks like one to me.

http://i74.photobucket.com/albums/i260/robltc/TRXLEDcylleftsideview.jpg

OK, that's what I was talking about.
I believe one member had Arlan build him a power valve for the Shinx. The latest Shinx has got the latest exhaust port improvements. That would be my choice if going big bore for the first time. You can also go 331, 344 or 363.

When I talked to Pete at Hybrid he said CP Industries was coming out with a small Saber to make the 475cc class. That may be my next choice.

[troybilt]

do you run billet gears? ...or how do you keep from smoking the tranny? I assume the tranny was designed to handle 28hp and be uber reliable, when you start pushing 70+... then what... also dune riding is probably a little more forgiving than track conditions... my $0.02

[Pumashine]

Originally posted by troybilt
do you run billet gears? ...or how do you keep from smoking the tranny? I assume the tranny was designed to handle 28hp and be uber reliable, when you start pushing 70+... then what... also dune riding is probably a little more forgiving than track conditions... my $0.02


Duner ran 200 gallons of fuel through his 450 dune Puma with stock gears. It is easy to break second so most guys are having at least that one backcut.

Some are having the stock tranny's Cryro treated for strength.

The Yukon gears are supposed to be harder but have been broken as well. http://cgi.ebay.com/ebaymotors/YUKON-HD-TRANSMISSION-GEARS-TRX250R-250R-1987-1989-J91-/270701177046?pt=Motors_ATV_Parts_Accessories&hash=item3f070c28d6

Me, well you have seen my collection!

[troybilt]

Originally posted by Pumashine
Duner ran 200 gallons of fuel through his 450 dune Puma with stock gears. It is easy to break second so most guys are having at least that one backcut.

Some are having the stock tranny's Cryro treated for strength.

The Yukon gears are supposed to be harder but have been broken as well. http://cgi.ebay.com/ebaymotors/YUKON-HD-TRANSMISSION-GEARS-TRX250R-250R-1987-1989-J91-/270701177046?pt=Motors_ATV_Parts_Accessories&hash=item3f070c28d6

Me, well you have seen my collection!

Well I think my plan is to pick up another bottom end then build a big bore, 350 PV, either Neil or Arlan build motor. Then keep my CP 280 for spare/track motor.

[troybilt]

Do I need tranny work with a 350PV? I realize there is alot more to it, like hp numbers, my ride style, etc... but just asking what you're opinions are.

[k7mm]

Originally posted by troybilt
Do I need tranny work with a 350PV? I realize there is alot more to it, like hp numbers, my ride style, etc... but just asking what you're opinions are. Here is a good read on the Duncan 350pv.In the article they talk about transmisions in a big bore.Quite shocking being that most riders land from a big jump with the gas on. http://duncanracing.com/misc/atvsport_nov2003_1.pdf
Keith

[red88r]

Originally posted by k7mm
Here is a good read on the Duncan 350pv.In the article they talk about transmisions in a big bore.Quite shocking being that most riders land from a big jump with the gas on. http://duncanracing.com/misc/atvsport_nov2003_1.pdf
Keith

Good read-we installed the Yukon gears in our Duncan 340pv just to be safe. Everytime it gets ridden it gets run just as if it was in a race.

[k7mm]

Originally posted by k7mm
Here is a good read on the Duncan 350pv.In the article they talk about transmisions in a big bore.Quite shocking being that most riders land from a big jump with the gas on. http://duncanracing.com/misc/atvsport_nov2003_1.pdf
Keith oops I meant 340pv!

[derby]

Why not call up dave moore and get him to build you a 350 sphinx. Get something that no one else has. The new sphinx are supposed to be a good all around setup. The port layout will let the piston live forever. Plated cylinder will be better than the sleeve cylinders. You could set it up with a 78-79.5mm esr piston that is light weight, get the cylinder plated by millenium, and get dave to cut you a race gas dome. You will still be able to use a trx pipe and reeds.

[troybilt]

Originally posted by derby
Why not call up dave moore and get him to build you a 350 sphinx. Get something that no one else has. The new sphinx are supposed to be a good all around setup. The port layout will let the piston live forever. Plated cylinder will be better than the sleeve cylinders. You could set it up with a 78-79.5mm esr piston that is light weight, get the cylinder plated by millenium, and get dave to cut you a race gas dome. You will still be able to use a trx pipe and reeds.

I've had several email correspondence with Arlan at LED about the Sphinx and Puma cylinders. His words: "The Puma Cylinder would be awesome for drag racing or even hard dune riding. It has way to much port timing for MX. I would need to make a special one for MX."...."The new Sphinx cylinder also has too much port timing for MX. It will make big power, but will be soft on the bottom and burn the tires as it comes into the midrange. Try coming out of a corner and over a double with type of power!"

Having said that he said he can build me a non-PV 350 Sphinx for MX with a special sleeve to get the porting the way he wants for MX, but to build a 350 PV for MX based on the Sphinx cylinder would not be cost effective => at this point, it would cost him about $300 more to design and build a PV for that cylinder/CC size... he designs and builds his own PV's for the 300's... So for a 350 size MX motor he'd recommend the ProX version, untill he can justify his time and work to develop the PV for the 350, he said he's working on it but not where he wants it to be yet...

What was more intriguing but going to have to be someone with alot more cash that me, is an LED ported MX version of the Puma.. that would be sick..

[derby]

Originally posted by troybilt
I've had several email correspondence with Arlan at LED about the Sphinx and Puma cylinders. His words: "The Puma Cylinder would be awesome for drag racing or even hard dune riding. It has way to much port timing for MX. I would need to make a special one for MX."...."The new Sphinx cylinder also has too much port timing for MX. It will make big power, but will be soft on the bottom and burn the tires as it comes into the midrange. Try coming out of a corner and over a double with type of power!"

Having said that he said he can build me a non-PV 350 Sphinx for MX with a special sleeve to get the porting the way he wants for MX, but to build a 350 PV for MX based on the Sphinx cylinder would not be cost effective => at this point, it would cost him about $300 more to design and build a PV for that cylinder/CC size... he designs and builds his own PV's for the 300's... So for a 350 size MX motor he'd recommend the ProX version, untill he can justify his time and work to develop the PV for the 350, he said he's working on it but not where he wants it to be yet...

What was more intriguing but going to have to be someone with alot more cash that me, is an LED ported MX version of the Puma.. that would be sick..

A cheaper way would be to deck the cases and not sleeve the cylinder. The problem with that is your cases become one off and will only work with that cylinder. But that is also what happens with the puma I believe mine had 0.03 removed from the cases. On a 350, the pv would be a waste. It should put out enough lowend without using a pv. But since arlan has already built a few I would think he would know.

My puma would have gotten eaten alive on the mx track just due to tire spin. It never would have hooked up from 1/2 throttle up.

[troybilt]

Originally posted by derby
A cheaper way would be to deck the cases and not sleeve the cylinder. The problem with that is your cases become one off and will only work with that cylinder. But that is also what happens with the puma I believe mine had 0.03 removed from the cases. On a 350, the pv would be a waste. It should put out enough lowend without using a pv. But since arlan has already built a few I would think he would know.

My puma would have gotten eaten alive on the mx track just due to tire spin. It never would have hooked up from 1/2 throttle up.

Thanks derby, this is good discussion...

What I gathered from the conversation about the 350 PV vs non-PV, was this... yes the 350 builds more low end that an 250-265 size top end, just do to size its the transition of power from the low to mid to high that is more adbrupt without the PV... so if that is an issue, then the PV would be the way to go... for a guy like me, i.e. not a Pro, I probably wouldn't know the difference... if that makes sense.

[bsmith106]

My question is when Arlan is done sleeving and porting the sphynx cylinder for more low-end is there any power/reliability benefits over a pro-x set up for the same type of use. Also is it a steel sleeve that he uses. I lean towards plated bore's personally. Anyone know what port timing the sphynx come with as cast.

[troybilt]

You'll have to ask Arlan for details on the difference in port timings bw. the ProX and Sphinx, he said both suck (basically) as-cast port timings. His works were none of them were good for MX and he had to make modifications to both of them... they are plated bores...

[Pumashine]

Thank you Troy for supporting my local economy with this build. I am sure you will be happy with Arlan's work.

[pdxbigfoot]

Arlan will make you a ripping MX type power. It comes on strong and makes a smooth transition without alot of wheelspin.
My 330 was a rocketship if you shortshifted it. If you tried to rev it she would fall right on its face.
Treat it like a 4 poke and keep grabbing gears and you will be very happy.
As always keep in mind that whatever you end up running make sure you have a very good bottom end. I mean everything has to be top notch to eliminate any chance of fail.
My 330 put up a very respectable 46.7 FT LB's. Keep in mind each FT LB is going to run ya right around $110.00.

I love his pipes!!! There are a few tricks to make them look even better and to get them to seal.
His silencers are ugly!!!