CRF230 Performance-Still Searching

[jeffrow68]

I bought a 230 project bike that already had upgraded suspension (150R forks and Fox Podium shock) but stock engine other than uncorked and BBR exhaust. The best way I can describe it was lazy, it seemed loud but really didn't move fast.

 

I upgraded the engine as follows, I had the cylinder bored and installed the BBR 233cc piston. I sent the head to Terry and had a valve job, intake port match, head porting, new rockers, springs, seals, etc. and ordered one of his ST2.0 cams. I also added new oil pump, cam chain and gear, and clutch components.

 

So, I was expecting significant improvement over the initial configuration. It was an improvement, but not really what I was expecting. I have a bone stock uncorked 230 to use as a baseline for comparisons. They seem very close to equal on the bottom end, but the modded bike pulls much better from mid to top.

 

I then played around with the exhaust system, switching from stock to the BBR system, and then to a full EO system with super trap discs. I didn't really feel much difference in my seat of the pants dyno other than the amount of noise between the stock and other two systems. The EO system is definitely the nicest but also the loudest.

 

From there, I switched ignitions between the stock, BBR rev box and then the Procom unit. I did however notice a significant change in performance with the Procom, well worth the $40.

 

I then changed sprockets, plus one up front, minus one in the rear, with a new chain and the axle really far back. The gearing change was nice, I felt like I was moving faster consistent with all the noise I was making. The engine seemed to have no problem pulling the taller gears.

 

From what I have read, maybe the carb is holding me back from realizing the performance gains. I bought a XR250R carb off eBay that I will try next. Hopefully this will be the missing link.

 

I have spent quite a few dollars on this project and definitely enjoyed pulling wrenches, however I was really expecting night and day differences between a bone stock uncorked 230 and this modded bike that I am not realizing. The suspension on my modded bike is really nice and I can push it much harder than the stock bike, but I am hopeful that I can find something in the engine performance that I am overlooking and really get the true potential unleashed.

 

I have done much more to this bike than I have listed above, but I am open to any suggestions to help unlock the potential that I know is there.

[1gr8bldr]

Is see the problem.... you have a stock bike as a baseline (:  

[Dirt Racer]

I read on here somewhere that there is a +4 and +6 stroker crank available for the 230, if that's the case, with the engine modds you already have, it would make it a fire breathing giant killer. As for me, I went just the opposite with the sprocket ratios, I actually went one tooth taller on the rear to shorten up the gearing because the longer gearing seemed to make my bike feel a little lax, with the counter shaft sprocket remaining the same and with the other jetting, airbox and full exhaust modds I have, the bike feels really crisp and snappy, spins the back wheel hard in every gear and no problem getting the front end up, I'm super happy with the way it feels. I've had half a dozen 450 mx'ers and a pile of two strokers but just come to love the predictability and trail performance of the 230's uncorked and mildly modded, those big bore bikes are just way over powered. I have had 2 TTR230's and this is my second CRF230, keeping this one as I now have it exactly how I want it.

Edited May 3, 2017 by Dirt Racer

[VortecCPI]

Very interesting.  Every little thing I did to my CRF230 made a difference.  The cam and piston made a HUGE difference.  The EO pipe was nothing like the stock system.  Are you sure you have good compression in that engine?  Have you done a Leak-Down test?

There is NO comparison between my CRF230 and my buddy's CRF230 with stock engine.  NONE.

[Dirt Racer]

10 minutes ago, VortecCPI said:

Very interesting.  Every little thing I did to my CRF230 made a difference.  The cam and piston made a HUGE difference.  The EO pipe was nothing like the stock system.  Are you sure you have good compression in that engine?  Have you done a Leak-Down test?

There is NO comparison between my CRF230 and my buddy's CRF230 with stock engine.  NONE.

I would have thought the same, big bore with cam and high compression piston should have really woke it up.

Edited May 3, 2017 by Dirt Racer

[1gr8bldr]

I was in the same boat as Jeffrow, having a stock bike. While It did have more power, it never had what I expected. I sometimes think that the "anticipation" of the build spurs unrealistic  expectations. 

[Dirt Racer]

41 minutes ago, 1gr8bldr said:

I was in the same boat as Jeffrow, having a stock bike. While It did have more power, it never had what I expected. I sometimes think that the "anticipation" of the build spurs unrealistic  expectations. 

I agree, especially if you've owned strong big bore four valve bikes, just an all around harder pull from a four valve.

[VortecCPI]

17 minutes ago, Dirt Racer said:

I agree, especially if you've owned strong big bore four valve bikes, just an all around harder pull from a four valve.

Again very interesting.  Having owned an all-out 1984 Al Baker XR265R I NEVER expected my build to even come close to that insane engine.  However, the results I got were very impressive given what was invested.  My engine puts out more than I need and for an old-school air-cooled two-valve engine it is great.  My bike is faster than need be for its small chassis and when climbing it never runs out of power.  Climbs that required second gear can now be done in third gear.

Is it because I only weigh 150 pounds?

[mixxer]

OK....

My 2cents...

Along with a cam being a major player in a 4 strokes "personality".... From years of designing and Dyno and track testing exhaust systems... I here to tell you an exhaust system can make or break a 4 strokes powerband.... No question...

My own bike on round one has it's specs in the Performance Carb Vomit thread...

First off I looked at what facts I was dealing with and what my goals were... 

2 valve .. 4 stroke..  air cooled.. heavy crank assy....

So... Personally I'm not interested in lifting 2 valves off their seats high enough to try and mimic 4 valve flow potential...

Also don't want to need race fuel....

And not interested in pushing heat load on the little thumper...

If you want bottom end hit and a strong midrange... You kind of have to have all your tug of war team players pulling at the same time... Star players that don't pull at the same time may look good for the photo shoot... But they would be beaten by a group of cheerleaders that all pull at the same time... 

Exhaust system that is stepped with an appropriate smaller diameter headpipe is essential for bottom end vacuum and response... Then step it up in size so flow carries over for a killer midrange...

Put too big of a headpipe on for your application and you can make ANY 4 stroke weak in the knees and run like an 85cc 2 stroke...  People somehow think BIG is in itself a self explanatory validation of more performance... There is soooooooo much more to it than that... 

The ultimate 4 stroke powerband from my decades of maniacal testing... has come from multi stepped headpipes that start with a small diameter and.eventually feed into a megaphone with a 4 to 6 degree divergence and a reverse cone silencing section...

The small beginning diameter stepped headpipe makes for off idle hit and massive midrange ... The meg section will make for a good peak HP that then does not fall off much between peak power and peak rpm/rev limiter....

The same formula minus the meg will be second choice since the only deficit it will have would be fall off after hp peak would be more than with the Meg...

All of this is, of course, engine displacement and valve size dependant....

But... Bottom line.... If you want bottom to mid hit and run response... Don't ever err to the big side on headpipe....

And... Conversely... If you built a bike that you would like to soften up the whole bottom to mid power... And make it seem like it only has lungs at high rpm...  Slapping on a big headpipe will take care of all that excess response immediately...lol

 

[mixxer]

Mine is geared up one tooth on countershaft... Down one on rear sprocket.... And pulls soooooooo much better than a stocker... Everywhere..

But especially bottom to mid... Where I focused all the components to be pulling at...

Now that it's geared up higher I can exit tight turns in first and run out nice power wheelies just shifting to second...

Turns that used to require 2nd gear on exit are done in 3rd with a quick clutch feather on exit...  Roosts and pulls hard enough to make you grin ear to ear...

Nothing in common with stock power output

[VortecCPI]

6 minutes ago, mixxer said:

The ultimate 4 stroke powerband from my decades of maniacal testing... has come from multi stepped headpipes that start with a small diameter and.eventually feed into a megaphone with a 4 to 6 degree divergence and a reverse cone silencing section...

The small beginning diameter stepped headpipe makes for off idle hit and massive midrange ... The meg section will make for a good peak HP that then does not fall off much between peak power and peak rpm/rev limiter....

And this is what Frank Nye's EO Outlaw system has and does.  I have discussed this in detail with both Frank and Terry and it turns out Frank's design is practically identical to Terry's recommended design.  Yes...  I got permission from Frank to share dimensional data with Terry.

The EO system makes more power everywhere but it truly shines from high-mid to top.  The Web 40mc/402 cam I am using makes more power at the top than the stock cam did but since it is designed for low-mid power it is nothing significant.  After installing Frank's reverse-cone megaphone system my engine makes all kinds of power up there.

I was very happy with the FMF head pipe and EO PoweRing and I wasn't sure what the EO Outlaw system could get me beyond that.  Well it did by filling in the bottom and top and the difference is just hard to believe.  While I rarely work my engine at the very top it is nice to know i have when I need it.  It makes a good bit of difference during fast long open sections and during hill climbs.

[VortecCPI]

2 minutes ago, mixxer said:

Mine is geared up one tooth on countershaft... Down one on rear sprocket.... And pulls soooooooo much better than a stocker... Everywhere..

But especially bottom to mid... Where I focused all the components to be pulling at...

Now that it's geared up higher I can exit tight turns in first and run out nice power wheelies just shifting to second...

Turns that used to require 2nd gear on exit are done in 3rd with a quick clutch feather on exit...  Roosts and pulls hard enough to make you grin ear to ear...

Nothing in common with stock power output

Same here.  My mild build spins the like-new IRC VE-33 like the old engine spun the worn-out IRC VE-33.  Far less shifting and I am almost always one gear higher than before.  Mine comes out of turns like mad as well.  BIG difference in my case.  VERY happy.

[mixxer]

That is very strange to me...

Because all of my own experience and math says that the EO system is best suited to top end power on engines fairly well built... Big displacement..big valves.. big cam...

Suited for fast mx or flattrack.. where smaller bike classes live or die by peak power output...

Nothing about that system suggests bottom end torque or midrange on a woods focused lesser build... If it did, it would contradict everything I have ever learned...

Are you sure you guys aren't drinking Kool aid??? Or suffering from Emperor's New Clothes syndrome??

[VortecCPI]

1 hour ago, mixxer said:

That is very strange to me...

Because all of my own experience and math says that the EO system is best suited to top end power on engines fairly well built... Big displacement..big valves.. big cam...

Suited for fast mx or flattrack.. where smaller bike classes live or die by peak power output...

Nothing about that system suggests bottom end torque or midrange on a woods focused lesser build... If it did, it would contradict everything I have ever learned...

Are you sure you guys aren't drinking Kool aid??? Or suffering from Emperor's New Clothes syndrome??

More bottom and more top.  Middle was about the same as FMF head pipe and EO PoweRing.  Many others have all found larger head pipes increase low-mid and mid power with XR200 and CRF230.  Emails traded with Powroll concur.  Tone Consultant also found more power at low-mid with EO pipe.  This is very counter-intuitive if you have been around auto and boat engines all your life.  Or if the bike already had an adequately/properly/optimally sized head pipe from the factory.

Perhaps you are thinking of the EO Outlaw Low system which IS designed for all-out race use?  It has a fatter non-stepped primary/mid and different megaphone dimensions than the EO Outlaw High system and has no disk pack at the end.  This system IS "best suited to top end power on engines fairly well built... Big displacement..big valves.. big cam..."

From Powroll:

"most stock headpipes are near-correct diameter for a standard displacement setup, for some reason Honda decided to use essentially the same headpipe on the CRF150F and the 230F, so a pipe that is “right” for the 150 is too darned small for a stock 230. The oversize header simply fixes the problem."

From ToneConsultant:

"The low end?  Forget about it.  That’s where the EO pipe shined.  I think the BBR flows too much.  No back pressure.  I didn’t think that was the case, but after running the EO pipe, it must be. By design, I thought the EO pipe might be better on top, but I wasn’t expecting anything anywhere else.  I was way off. "

Credible riders such as FJ, Chuck, and Rick Ramsey have also concurred in the forum.

Review of Frank's system in context of another small air-cooled two-valve engine (TT-R125): 

What exactly was your first-hand personal experience with EO system versus your stock system and your Pro Circuit (If I recall correctly) system?  What were the dimensions of the Pro Circuit head/mid pipe versus the EO High head/mid pipe?

Kool Aid...  Funny...  Perhaps you are incorrect with respect to large head pipes and EO Outlaw High in context of XR200/CRF230?

 

EDIT:  Removed "Yes...  You are."  That was mean of me!

Edited May 3, 2017 by VortecCPI

[VortecCPI]

...

Edited May 3, 2017 by VortecCPI

[bajatrailrider]

12 hours ago, jeffrow68 said:

 

I bought a 230 project bike that already had upgraded suspension (150R forks and Fox Podium shock) but stock engine other than uncorked and BBR exhaust. The best way I can describe it was lazy, it seemed loud but really didn't move fast.

 

I upgraded the engine as follows, I had the cylinder bored and installed the BBR 233cc piston. I sent the head to Terry and had a valve job, intake port match, head porting, new rockers, springs, seals, etc. and ordered one of his ST2.0 cams. I also added new oil pump, cam chain and gear, and clutch components.

 

So, I was expecting significant improvement over the initial configuration. It was an improvement, but not really what I was expecting. I have a bone stock uncorked 230 to use as a baseline for comparisons. They seem very close to equal on the bottom end, but the modded bike pulls much better from mid to top.

 

I then played around with the exhaust system, switching from stock to the BBR system, and then to a full EO system with super trap discs. I didn't really feel much difference in my seat of the pants dyno other than the amount of noise between the stock and other two systems. The EO system is definitely the nicest but also the loudest.

 

From there, I switched ignitions between the stock, BBR rev box and then the Procom unit. I did however notice a significant change in performance with the Procom, well worth the $40.

 

I then changed sprockets, plus one up front, minus one in the rear, with a new chain and the axle really far back. The gearing change was nice, I felt like I was moving faster consistent with all the noise I was making. The engine seemed to have no problem pulling the taller gears.

 

From what I have read, maybe the carb is holding me back from realizing the performance gains. I bought a XR250R carb off eBay that I will try next. Hopefully this will be the missing link.

 

I have spent quite a few dollars on this project and definitely enjoyed pulling wrenches, however I was really expecting night and day differences between a bone stock uncorked 230 and this modded bike that I am not realizing. The suspension on my modded bike is really nice and I can push it much harder than the stock bike, but I am hopeful that I can find something in the engine performance that I am overlooking and really get the true potential unleashed.

 

I have done much more to this bike than I have listed above, but I am open to any suggestions to help unlock the potential that I know is there.       By using XR250 carb you did not help what you wanted. I too just for fun Mounted one on my at the time mild built 230. Go with the Pwk  carb big time change in snap in power. Right where you want it, after having and riding built 230s. Without 6mm stroke they felt weak on bottom end. My stock 230 uncorked has peppy nice power band. Where some of the non stroked Built 233cc lack of bottom end turn off for me. Yes they hauled butt on the top but if I wanted that.I would ride a two stroke. Im very happy with the 6mm stroker, Considering I use 15/48 gearing. It still does all hard single track,hill climbs with no run at bottom. I do feel it is at its limit for hard trail with that Hi Gear.Soon I will go to 15/ 45 gear Witch it can pull very easy in 6th gear for easy rides. 90% of the time keep 14t or 13t with the 45t   For the daily nasty stuff.

 

 

[mixxer]

I'm just giving everyone the benefit of a lifetime of engine building, dyno ownership....

I have built engines that have won king of the hill in 4 stroke wars...

Topped pro flattrack podiums..

And won multi arenacross series...

I'm just sharing with you guys...

Everything from the port work and valvetrain... custom profiled camshafts.. To the custom pistons and exhaust systems.... Even the cutting of custom seats to fit the big valves.... All me, myself and i...

I actually don't give a ratsass if anyone pays attention or not...

I'm just being cool and trying to light a few candles in the darkness.... 

[VortecCPI]

17 minutes ago, mixxer said:

I'm just giving everyone the benefit of a lifetime of engine building, dyno ownership....

I have built engines that have won king of the hill in 4 stroke wars...

Topped pro flattrack podiums..

And won multi arenacross series...

I'm just sharing with you guys...

Everything from the port work and valvetrain... custom profiled camshafts.. To the custom pistons and exhaust systems.... Even the cutting of custom seats to fit the big valves.... All me, myself and i...

I actually don't give a ratsass if anyone pays attention or not...

I'm just being cool and trying to light a few candles in the darkness.... 

Same here brother.  Nobody (I think) is trying to discount all your experience and knowledge and I'm sure I speak for most all of us when I say we appreciate your input.  That being said you have to understand we put a lot of faith in builders/racers/tuner like Frank Nye, Mike Coe, Pete Fisher, and Terry Miller because so much of their work was directly in the context of XR200 and CRF230.  I am especially a big fan of Pete Fisher and Powroll for all he did way back when.  Those shrunk stroker rods were way cool.

While these guys were winners like you they also shared their parts and work with us regular common folk.

Did you say "big valves"?

 

Edited May 3, 2017 by VortecCPI

[1gr8bldr]

LOL, I am almost finished with my "reverse build". The EO exhaust is gone, the 2.5 is gone. It's back to being a quiet trail bike. 

[jeffrow68]

I actually completed a similar 230 build several years ago by starting with a basket case 230. I added very similar engine mods, higher compression piston, 40/402 cam, pro circuit exhaust, etc. This bike seemed to be significantly better everywhere than the starting point. However, I did not have another stock bike to do back to back comparisons as I do now. I'm not saying that the modded bike is not faster and more powerful than the stock bike, it's just not hugely significant doing back to back comparisons. Even when changing exhaust systems on my modded bike and timing a test loop, I'm easily fooled into thinking I am faster with the EO pipe since it is louder and sounds really bad ass. The stopwatch shows no real advantage over the complete stock exhaust. I like the EO system better since it looks cool and sounds like a race car, but I am not seeing an actual time advantage over the stock system.

I did notice the most improvement when I changed the gearing plus one/- one and the modded engine pulls the taller gears easily. I feel fairly certain that the stocker would struggle with taller gears.

My testing has been on a timed test loop by comparing the two bikes and comparing component changes on my modded bike. An engine dyno would be the ultimate to fine tune all the mods and target the desired performance area. My test loop has a mix of hills, open sections and tight sections so it is a good sample of what I ride.