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Discussion Starter #1
Looking at Matuus’ signature got me wondering what is required at each “rung” up the displacement ladder?

for example after “maxing” out the OEM cylinder, what is required as you go to a new cylinder? Like how big can you go on the stock case and rotating assembly?

If someone is going to pony up the money for a sphinx cylinder, how big can you/should you go, and what is the best combination of parts for a all around/duner? At what point do you start trading off stability/longevity/ low maintenance/ low cost for brute horsepower.

What I think I want is a hill shooter that I can still ride like my OEM cylinder. Aside from the wheelies (which I could deal with) is this a realistic combination? If so how do you build it?

Matuus, if you read this I would love to know what application you use each of your bikes and how you compare them to each other.

To anyone who like to play along I’d love to hear your opinions.
 

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CP is coming out with a new cylinder called the lynx supposed to be a killer all around set up. I'll probably go esr 370 CEO on my lightweight 88 duner build. Do a cryo treated transmission gears or led gears..
 

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CP is coming out with a new cylinder called the lynx supposed to be a killer all around set up. I'll probably go esr 370 CEO on my lightweight 88 duner build. Do a cryo treated transmission gears or led gears..
Looking at Matuus’ signature got me wondering what is required at each “rung” up the displacement ladder?

for example after “maxing” out the OEM cylinder, what is required as you go to a new cylinder? Like how big can you go on the stock case and rotating assembly?

If someone is going to pony up the money for a sphinx cylinder, how big can you/should you go, and what is the best combination of parts for a all around/duner? At what point do you start trading off stability/longevity/ low maintenance/ low cost for brute horsepower.

What I think I want is a hill shooter that I can still ride like my OEM cylinder. Aside from the wheelies (which I could deal with) is this a realistic combination? If so how do you build it?

Matuus, if you read this I would love to know what application you use each of your bikes and how you compare them to each other.

To anyone who like to play along I’d love to hear your opinions.
I am sure Matuus can comment on how he uses his BDT engine builds much better than I.

As far as “rung” up the displacement ladder"...

Once you are at 69.50-70 MM on the OEM cylinder, you don't have much choice left with the OEM except to add Stroke to make more overall displacement. I don't ever suggest an OEM with a BB 292-310 sleeve; Big Mistake IMO as a good 68MM OEM bore will outrun it and be 100% more reliable.

310CC BB's no case machining needed, as well as bolt on 330's. Good stock internals, transmission, ect are fine. CryO is best.
330-370CC BB's case machining needed. Good stock internals, transmission, ect are fine. CryO is best.
391-431CC BB's case machining, plus epoxy or TIG welding needed, as well as beefed up Rods like CR500R or YZ490, or KTM specially with the Puma's above 400CC to 431CC. Good stock internals, transmission, ect are fine. CryO is best.
450-561CC BB's (like Saber) case machining, plus epoxy or TIG welding needed, as well as beefed up Rods like CR500R or YZ490, specially with all Saber's above 400CC to 561CC. Good stock internals, transmission, ect are fine. CryO is best.

The new Lynx (370CC-400CC) by CPI is New, no real time to determine if good, better or worse yet on the Track. I can say the ones I have seen or heard built, and running are NOT impressive on the Track or Dunes vs a Standard 390CC...more time needed to determine Lynx performance.

IMO (BDT stocks & sells the same aftermarket gears & shift forks, from the same sources as a few others)...Stay away from these, too many issues with wear, and fit. Still the Best transmission & shift Fork Set is the Honda 250R Cry'Od...not anything else.

Carlos
 

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Discussion Starter #4
So a 330, would be the “biggest/best cylinder for a non-modified case?

I know there are several 330 cylinders out there, Sphinx seems highly recommend. Is it the best?

would a 330 Sphinx make a good duner/hill shooter?

What is the power difference between a “maxed” OEM (non-sleeved) and a Sphinx 330, assuming proper supporting mods (pipe/intake/carb/reeds)?
 

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A bolt on 330 requires no case modification because the piston skirts do not go into the case. ESR, I believe offers the only bolt on 330. A true 330 requires case boring, which is not a big deal if you have the engine all the way apart.
Loren
 

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carlos said that. his post.


i have the best. bdt built engines.
bdt261 oem
bdt363 prox
bdt431 puma
bdt561 saber
Sent from my iPhone using Tapatalk
 

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Discussion Starter #7
A bolt on 330 requires no case modification because the piston skirts do not go into the case. ESR, I believe offers the only bolt on 330. A true 330 requires case boring, which is not a big deal if you have the engine all the way apart.
Loren
I obviously did not read Carlos’ post carefully enough, thanks for pointing that out.

so a Sphinx 330 does require case modification, where the ESR 330 does not?
 

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So a 330, would be the “biggest/best cylinder for a non-modified case?

I know there are several 330 cylinders out there, Sphinx seems highly recommend. Is it the best?

would a 330 Sphinx make a good duner/hill shooter?

What is the power difference between a “maxed” OEM (non-sleeved) and a Sphinx 330, assuming proper supporting mods (pipe/intake/carb/reeds)?

In my prior post, I noted OEM, 310 and "bolt on" 330's need NO case machining. You can drop in a 310CC or a "bolt on" 330 with NO case work needed. Note their are draw backs to a bolt on 330; you give up 2 bore sizes, increased piston wear, likely piston failure after 30 hours of use....not the case for a standard 330 kit with full sleeve skirts..

As far as the CP Industries line of cylinders; I have been a Big Fan of them from day one, you can find many posts that I declared IMO they are the best money can buy, better than ESR or ProX....well that was then, not now. Any standard 330 kit; Sphynx or ESR or ProX would make a "good" Duner if properly setup.

The ESR line of cylinders has improved considerably over the past year IMO....every bit as good as CPI, and as good or better than ProX. Some of the fastest cylinders in 2019 on the Track are ESR Builders kit BDT built vs Sphynx (310-363CC) or Lynx (330-391CC). The new Lynx at 370-391CC is too new to determine if it's equal or better than the New ESR CEO...to date; the CEO is a better option IMO.

Power wise; any 330 will make more Torque than almost any OEM cylinder, except a few special builds (see the BDT262CC OEM at 41lbs TrQ)...for outright out of the box power, a 330 would outrun an OEM cylinder specially on a tight MX, TT or FT track IMO.

PS: you can turn ANY 330 into a "Bolt on" by machining the skirts away; ProX, Sphynx or ESR.

Carlos
 

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Looking at Matuus’ signature got me wondering what is required at each “rung” up the displacement ladder?

Matuus, if you read this I would love to know what application you use each of your bikes and how you compare them to each other.
Apparently matuus has nothing to say about his bdt engines. He took the time to respond to the Norm's post though. hmmmm
 

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Apparently matuus has nothing to say about his bdt engines. He took the time to respond to the Norm's post though. hmmmm
Another constructive 'Crappy' response to the OP....these type's of posts is what derails threads.

Carlos
 
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