2025 Club Race Build

[Ouroboros]

A story as old as time. A street bike has light modifications done to it. Its rider discovers track days on the lightly modified bike. Rider crashes on track and ironically enough decides that the track is the only way he will experience motorcycles. Said rider spends a year doing a ton of track days and gets some coaching through a rider school. That rider, now seeking to test himself, decides to go club racing in 2024. He gets his license during the latter half of 2023 and does a partial race season in 2024 with some decent results to show for it.

At some point during that season, the rider was ruined by riding a pit buddy's Kramer 690S during a track day. He uses his better judgment and decides that's not in the cards right now. (PS - Absolutely ride one if you have the opportunity, but be prepared to spend every other waking moment thinking about how great it is.)

That rider is me. 

So here we are with my 2024 track season in the books and a mildly neglected bike on hand. It could use some loving and sorting out. I don't know how many folks stick around here these days, but I thought I'd use this to document my journey to next season and get some useful advice.

Behold, my loyal and dependable steed

 

 

[Ouroboros]

Here are my current modifications:

• Hordpower Airbox
• Hordpower ECU Flash
• Yoshimura R77 Works Race Exhaust (full system)

 

• AP Motoarts Fairing Stay
• AP Motoarts ECU Relocation
• AP Motoarts Bodywork (painted)
• Factory Pro Shift Kit
• R6 quick turn throttle
• Ohlins FKS-204 Cartridge Kit
• Ohlins Steering Damper
• KTech Razor R Shock
• Robem Aluminum Trellis Subframe
• Woodcraft Front Axle Sliders
• Woodcraft Clip Ons
• Woodcraft Rearsets
• Woodcraft Sidestand Elimination Plug
• Vortex Levers (clutch and brake)
• Woodcraft Case Savers (clutch and water pump)
• TST Spooled Captive Chain Adjusters
• Spiegler Stainless Steel Brake Lines (front and rear)
• Vortex Keyless Gas Cap
• Vagabond Rear Brake Resevoir Relocation

 

My minimum goals for the (re)build:

• Fix overall fit/finish of the package
  • Shorter clutch cable
  • Different master cylinder (clearance issues)
  • Repair bodywork and repaint
  • Fix fitment of bodywork and other misc clearance issues (I could make a whole post about this alone and how annoying it's been for me)
• Go over the chassis thoroughly
  • Front fork rebuild
    • Make sure everything is straight after my crash last year. I feel some weird binding from one of the legs that I ignored all season
  • Steering head bearings
  • Swingarm bearings
  • Wheel bearings on both wheelsets
• Go over the powerplant thoroughly
  • Routine fluid changes and misc winterization
  • Service air filter (never done)
  • Sync throttle bodies (never done)
  • Install Spears polished and undercut transmission (those false neutrals are scary)

 

I have some other ideas, but I thought I'd put this out there to collect fresh perspectives. I race in Formula 2 and LWTSB in WERA.

Edited October 9 by Ouroboros

[br4nd0n]

@Ouroboros when you get around to steering head bearings could you do some measurements for me?

I would greatly appreciate it!

[Ouroboros]

4 minutes ago, br4nd0n said:

@Ouroboros when you get around to steering head bearings could you do some measurements for me?

I would greatly appreciate it!

For sure. Small heads up - it may be a few months’ wait. I’m not sure what order I’m doing everything in or the full scope of the project yet. 

[M. Hausknecht]

I have a Kramer HKR Evo2R, along with a full superbike built 07. I haven't ridden or raced the 07 since I got the Kramer a little over two years ago. I'm in the southeast and also raced with WERA until I got the Kramer. Since then, I've won two national championships racing the Kramer in SOS 1 with AHRMA. 

Now to you. The chassis geometry you're running isn't ideal with either Dunlop or Pirelli slicks. I've run both but prefer Pirelli. I encourage you to think seriously about getting Robem adjustable triples and rear shock linkage. For an inexpensive but effective master cylinder upgrade, consider an R6 MC. It is made by Brembo and just needs a remote reservoir. With steel lines and decent pads, Two finger stoppies are easy and I often only used one finger except for very hard straight line braking.

You don't have the Robem subframe mounted in your photos. I've got mine mounted; it drops a few pounds but not as much as Dymags.....:)

You need more power to be fully competitive in LTWSB and Formula 2. I have a stock bottom end, ported head, cammed, bored throttle body 92rwhp motor (tuned by Mike Goden at KWS)  in my bike. I also have another motor awaiting reassembly with Carrillo rods, 13:1 pistons, cams from Spears, ported head by Zoran, and an undercut gearbox. With bored throttle bodies and the Hordpower (cleaning and reoiling is quick and easy, BTW) it should be good for over 95rwhp on suitable fuel. I use an aRacer Super2 ecu with an AF1 (wideband O2 sensor with autotune capability) and a fully adjustable quickshifter. You want any of this stuff? I really like riding and racing the 07 but the Kramer is just, well, better.    

Oh yeah, whose 690S did you ride?

Edited October 9 by M. Hausknecht

[Ouroboros]

59 minutes ago, M. Hausknecht said:

Now to you. The chassis geometry you're running isn't ideal with either Dunlop or Pirelli slicks. I've run both but prefer Pirelli. I encourage you to think seriously about getting Robem adjustable triples and rear shock linkage. For an inexpensive but effective master cylinder upgrade, consider an R6 MC. It is made by Brembo and just needs a remote reservoir. With steel lines and decent pads, Two finger stoppies are easy and I often only used one finger except for very hard straight line braking.

This is timely information because I will be moving to slicks next year. The bike handles fine enough but I don't have a good reference point to say that with any good authority. I have a book about geometry and suspension that I've been reading up on along with some posts here. When I had Matt do my subframe, he mentioned geometry. I met Liam from Barnes Bros at a TD in Pitt and he was running one as well. I'm still wrapping my head around this stuff and I wasn't sure if I still needed the linkage since I had a height adjustable shock. Isn't that what the linkage does?

I think we briefly spoke about the R6 MC over DMs. I'm not in want of more stopping power per say. I was mainly looking at it because the stock MC is a pain to service due to clearance issues and the new 'packaging' of the fairings causing clearance issues. If my levers are pointed downward ever so slightly or rotated outwards to my ideal position for comfort, the lower part of my lever scrapes my body work or contacts the front of my upper fairing. My stainless lines will make contact with my dash as well. I have no idea how people have built functional race bikes with these challenges. I've been considering the Flexiglass kit since Matt spoke highly of it, but I don't have a lot of reference images to determine if it will solve my problems or create new ones. I'll be running an AIM unit next year as well so that makes things tricky too.

1 hour ago, M. Hausknecht said:

You don't have the Robem subframe mounted in your photos. I've got mine mounted; it drops a few pounds but not as much as Dymags.....:)

I assure you it's there lol. Maybe that's a testament to the good work Matt did. Look closer in this image and you'll see the lugs.

1 hour ago, M. Hausknecht said:

You need more power to be fully competitive in LTWSB and Formula 2. I have a stock bottom end, ported head, cammed, bored throttle body 92rwhp motor (tuned by Mike Goden at KWS)  in my bike. I also have another motor awaiting reassembly with Carrillo rods, 13:1 pistons, cams from Spears, ported head by Zoran, and an undercut gearbox. With bored throttle bodies and the Hordpower (cleaning and reoiling is quick and easy, BTW) it should be good for over 95rwhp on suitable fuel. I use an aRacer Super2 ecu with an AF1 (wideband O2 sensor with autotune capability) and a fully adjustable quickshifter. You want any of this stuff? I really like riding and racing the 07 but the Kramer is just, well, better.    

Oh yeah, whose 690S did you ride?

What kind of maintenance intervals does that level of build require? I'm not seeking to make tons of power at the sacrifice of tearing this thing down multiple times over a season. Some additional questions:

• Who did your head work? Zoran for both engines (you mention him for one)?
• Are cams from Spears an off the shelf thing or do you send yours in for the work? I don't see them listed anywhere on the site.
• What cost can I expect from all of these parts/machine work (ballpark will suffice)?
• Will these modifications still allow it to run on pump gas, or will I have to source the expensive unicorn juice?
• All of the above said, I would build this myself and have someone tune it. I'm reading that a lot of folks aren't familiar with aRacer ECUs. Did you do all of the tuning yourself? Do you have a dyno? How accessible is tuning (you mention the autotune)?

Keeping all of this in mind that I have space, tools, a great deal of patience, some wrenching knowledge and a Haynes manual. How doable is this with all of that? I may have one local resource I can tap if I run into issues but I prefer not to bring him a disassembled FUBAR engine. 

The gentleman who owned the Kramer I rode is named Alan. Speaking of, I need to give him a call to let him know that I'll be backing out of the sale and that he can look for other buyers. I would have loved to buy it from him but my company has been laying people off in waves as of late and I don't have a good gut feeling about the security of my role at the moment. 

[br4nd0n]

Quote

For sure. Small heads up - it may be a few months’ wait. I’m not sure what order I’m doing everything in or the full scope of the project yet.

I don't mind; you're helping me out

[M. Hausknecht]

Geometry: if you're going to run Pirelli 180/60 or Dunlop 180/60 or 180/65 rears, they will raise the back of the bike appreciably from the stock 180/55 rear tire. With the stock triples you'll end up with insufficient trail and a bike that won't want to finish corners. It will also feel very nervous and not want to hold a line going straight or cornering. The Robem triples will allow you to add trail because their offset (24-28mm) is less than stock. The Robem shock linkage does two things: (1) it adds swing arm angle, which helps the bike get off corners without pushing wide; and (2) it gives you more spring rate linearity, which should allow you to judge rear grip better and it allows the shock's valving to work as intended. The ride height adjustable shock can raise the back of the bike, adding swing arm angle, but it doesn't help the steeply rising "spring" rate at the tire.

The faster you go, the more all this stuff matters. If you're running above 2:05 at Pitt, as an example, you're probably not going fast enough for it to matter. Once you're into or trying to get below 2:00, it matters.

I think I've got the same bodywork as you. I don't have issues with anything hitting the front fairing. Yeah, the clutch cable is a bit long. The remote reservoir with the R6 MC creates a bit more room. I mount my Aim Solo 2 closer to me and a bit below the dash. It is a bit crowded but everything fits without binding.

NOW I see the re:r subframe! I didn't paint mine so it is more obvious.

Motors. Ninety to ninety-five rwhp motors don't need to rev much over 10,600 rpm so the maintenance isn't crazy. As you'd expect, frequent oil changes (I do every other weekend) and quality synthetic oil is key. Towards 95rwhp the stock radiator begins to be insufficient. I'm told and have seen that an R6 radiator fits and is more than sufficient. Check valve lash after 5-6 weekends and adjust as needed. These motors are otherwise good for at least a full season before needing a tear down. The really strong motors (around 100rwhp) rev closer to 12,000rpm, so they don't last long.

I did the porting on the 92rwhp motor. I built my own WERA National Champ winning motors in the past so I've been down that road before. I'd do it a little differently next time, or just add some epoxy in the valve bowl area to keep port velocity up. FWIW, Goden seemed surprised when I told him I ported my head. I only rev it to 10,400 (stock pistons, rods and crank, after all), so 92 is fairly respectable. 

I got my cams through Spears, and they are built to his "numbers" by Web Cam. They were very close to $1000. I had to wait nearly a year for them and Gregg was very unhappy with the delay. They're still in the box; all I've done is look at them. They need heavy duty valve springs but shouldn't need the valve pockets cut in the pistons unless the head has been decked. It is something to check though. The lift is still below .500", so at 11,000 rpm HD spring should live. The Carrillo rods are $800 new. Mine have about 8 weekends on them and Gregg told me they are good to reuse, even without new rod bolts. The 13:1 pistons are from Gregg as well, are new, and retail for $620. Every time the motor is apart, it needs new case and head bolts, which is a PITA because sometimes they aren't readily available.

I run 100 oct Sunoco (260GT). It is mildly oxygenated and relatively inexpensive ($75-80 for 5 gallon can or at the pump at some tracks like Pitt, Summit, NJMP, and CMP). My 92 hp motor would run fine on pump gas but I'd reduce the timing a few degrees. I don't know about the 13:1 pistons but, to be fair, race gas is a minor expense and, more than anything else, it is always the same. Pump gas formulations change with the seasons so tuning to maximize power and longevity can be tough. 

As I wrote initially, I went to KWS in Charleston and had Mike Godin (Kayla Yaakov's crew chief this past year) tune the bike on his dyno. It cost me well less than $500. The aRacer is a bit unusual to use but it is quite powerful, has full data logging capability, and once you get familiar with it, easy to tinker with once you have a good base tune. Mike and I worked together and we used the autotune function before making manual adjustments to fuel and timing. The quickshifter is fully integrated and adjustable for push/pull, tension/pressure, cut-off duration, and choice between fuel, spark and both, for cutoff. There is also launch control and pit lane speed limiter but I haven't set those up.

I've read a lot, listened to people who know more than me, and been working on race stuff off and on for about 50 years but I'm mostly self taught. You can do it! I typically do my own mechanical work but I'm not a machinist or welder, so some stuff is well beyond me. Anything else, just PM me.

 

 

 

[Ouroboros]

25 minutes ago, M. Hausknecht said:

Geometry: if you're going to run Pirelli 180/60 or Dunlop 180/60 or 180/65 rears, they will raise the back of the bike appreciably from the stock 180/55 rear tire. With the stock triples you'll end up with insufficient trail and a bike that won't want to finish corners. It will also feel very nervous and not want to hold a line going straight or cornering. The Robem triples will allow you to add trail because their offset (24-28mm) is less than stock. The Robem shock linkage does two things: (1) it adds swing arm angle, which helps the bike get off corners without pushing wide; and (2) it gives you more spring rate linearity, which should allow you to judge rear grip better and it allows the shock's valving to work as intended. The ride height adjustable shock can raise the back of the bike, adding swing arm angle, but it doesn't help the steeply rising "spring" rate at the tire.

The faster you go, the more all this stuff matters. If you're running above 2:05 at Pitt, as an example, you're probably not going fast enough for it to matter. Once you're into or trying to get below 2:00, it matters.

I think I've got the same bodywork as you. I don't have issues with anything hitting the front fairing. Yeah, the clutch cable is a bit long. The remote reservoir with the R6 MC creates a bit more room. I mount my Aim Solo 2 closer to me and a bit below the dash. It is a bit crowded but everything fits without binding.

NOW I see the re:r subframe! I didn't paint mine so it is more obvious.

Motors. Ninety to ninety-five rwhp motors don't need to rev much over 10,600 rpm so the maintenance isn't crazy. As you'd expect, frequent oil changes (I do every other weekend) and quality synthetic oil is key. Towards 95rwhp the stock radiator begins to be insufficient. I'm told and have seen that an R6 radiator fits and is more than sufficient. Check valve lash after 5-6 weekends and adjust as needed. These motors are otherwise good for at least a full season before needing a tear down. The really strong motors (around 100rwhp) rev closer to 12,000rpm, so they don't last long.

I did the porting on the 92rwhp motor. I built my own WERA National Champ winning motors in the past so I've been down that road before. I'd do it a little differently next time, or just add some epoxy in the valve bowl area to keep port velocity up. FWIW, Goden seemed surprised when I told him I ported my head. I only rev it to 10,400 (stock pistons, rods and crank, after all), so 92 is fairly respectable. 

I got my cams through Spears, and they are built to his "numbers" by Web Cam. They were very close to $1000. I had to wait nearly a year for them and Gregg was very unhappy with the delay. They're still in the box; all I've done is look at them. They need heavy duty valve springs but shouldn't need the valve pockets cut in the pistons unless the head has been decked. It is something to check though. The lift is still below .500", so at 11,000 rpm HD spring should live. The Carrillo rods are $800 new. Mine have about 8 weekends on them and Gregg told me they are good to reuse, even without new rod bolts. The 13:1 pistons are from Gregg as well, are new, and retail for $620. Every time the motor is apart, it needs new case and head bolts, which is a PITA because sometimes they aren't readily available.

I run 100 oct Sunoco (260GT). It is mildly oxygenated and relatively inexpensive ($75-80 for 5 gallon can or at the pump at some tracks like Pitt, Summit, NJMP, and CMP). My 92 hp motor would run fine on pump gas but I'd reduce the timing a few degrees. I don't know about the 13:1 pistons but, to be fair, race gas is a minor expense and, more than anything else, it is always the same. Pump gas formulations change with the seasons so tuning to maximize power and longevity can be tough. 

As I wrote initially, I went to KWS in Charleston and had Mike Godin (Kayla Yaakov's crew chief this past year) tune the bike on his dyno. It cost me well less than $500. The aRacer is a bit unusual to use but it is quite powerful, has full data logging capability, and once you get familiar with it, easy to tinker with once you have a good base tune. Mike and I worked together and we used the autotune function before making manual adjustments to fuel and timing. The quickshifter is fully integrated and adjustable for push/pull, tension/pressure, cut-off duration, and choice between fuel, spark and both, for cutoff. There is also launch control and pit lane speed limiter but I haven't set those up.

I've read a lot, listened to people who know more than me, and been working on race stuff off and on for about 50 years but I'm mostly self taught. You can do it! I typically do my own mechanical work but I'm not a machinist or welder, so some stuff is well beyond me. Anything else, just PM me.

 

 

 

I've ran low 1:40s at MidOhio and got into a mid 1:18 at Nelson's Ledges a few weeks ago so that should give you perspective on my pace. I've done many TDs at Pitt, but I've never raced there or ran a lap timer so I have no clue what my times are. If I'm interpreting your post correctly, it sounds like I should be focusing on refining my chassis and ride feel first. I like that idea a lot because it's more cost effective and less intrusive. Having a race winning engine means nothing if I can't wrangle the bike around track, or worse, my technique is poor. Based on what's involved, it sounds like the only engine work I'll tackle is getting my transmission sorted in this off season. The false neutrals are infrequent after the factory pro shift upgrade, but still present nonetheless. I'm pleasantly surprised that it's not as expensive as I thought to make that amount of power. While I have the engine opened up, I'll take a peek in there to make sure everything else looks good and plan accordingly. I'm not comfortable having everything apart for the first time and having to quickly reassemble it to start the season if there are long lead times on parts or labor. Perhaps that will be a 2025 off season thing. Fortunately, I've been very competitive among the novice riders but the experts are still out of reach at the moment (~5s/lap pace difference at my best track, MidO). I imagine that's not only due to engine work, but those guys having better raw pace.

Your post is really insightful and I appreciate you taking time to respond here and to my DMs. Now that I have some perspective, I'm going to get to work. Stay tuned! 

[Ouroboros]

I've started looking over my Haynes manual this weekend. Splitting the engine case doesn't seem as bad as I thought. Apparently, I can get to the transmission without messing with the head. By the same token, I've done some more research and head work doesn't seem to be too difficult. I may just give it a go. I came across these videos explaining the process and the theory behind why it's done.

Can anyone vouch for these? They seem to come from reputable sources. Porting seems to be one of those things that if you take your time with a steady hand, you can get some great results.

I'll begin tear down at some point tomorrow. 

[M. Hausknecht]

13 hours ago, Ouroboros said:

I've started looking over my Haynes manual this weekend. Splitting the engine case doesn't seem as bad as I thought. Apparently, I can get to the transmission without messing with the head. By the same token, I've done some more research and head work doesn't seem to be too difficult. I may just give it a go. I came across these videos explaining the process and the theory behind why it's done.

Can anyone vouch for these? They seem to come from reputable sources. Porting seems to be one of those things that if you take your time with a steady hand, you can get some great results.

I'll begin tear down at some point tomorrow. 

The videos are fine but understand that porting a head, without doing anything else, is unlikely to improve power and may, in fact, result in less area under the torque curve (bad). As a place to start, understand that getting more air into a motor is how you add torque (volumetric efficiency) and, therefore, horsepower. The intake ports, and exhaust ports (to a far lesser degree), are just two of the components that effect volumetric efficiency. The remaining elements of the intake system; the airbox,  air filter, intake trumpets, throttle-bodies, valves, and intake camshaft are also significant factors bearing on a motor's volumetric efficiency and, to a lesser extent, the compression ratio, exhaust valves, exhaust ports, exhaust camshaft, and exhaust pipe.

If you know which of these is the most limiting factor, altering it in a way that improves volumetric efficiency, will result in more torque and horsepower. After that, altering the new most limiting factor in a way that improves volumetric efficiency, will add further improvement, and on and on. If instead, you start by altering a factor that isn't the most limiting, you will add little if any torque or horsepower, and you could make the area under the torque curve smaller (your bike will have less useful power overall).

The intake ports in the CP2 motor aren't a limiting factor until you deal first with the the airbox, throttle-bodies and intake camshaft (and the exhaust cam to a lesser degree). These three-four factors are why the CP2 has the big, flat torque curve beginning low in the rpm range, that makes it such a fun street bike. They are also why the motor lays down over 9000 rpm. Unless you're prepared to do more than porting, my advice to you is to limit port work to matching  the intake ports to the throttle-body bores, the exhaust ports to the exhaust pipes, and a very light sanding to the intake and exhaust ports (just to remove the casting seam lines). You do not want to add volume to the ports because the velocity of the intake charge will decrease and you'll be worse off. In fact, the best CP2 motor builders are adding epoxy in the area of the intake valve bowls to achieve higher intake charge velocity while using bored throttle-bodies and higher lift and duration cams.  With my suggestions you may not add any power but you won't make things worse. If you do improve volumetric efficiency, you'll also need to alter your ecu's fueling to realize a gain in power. 

Edited Sunday at 02:14 PM by M. Hausknecht

[Ouroboros]

 

On 10/9/2024 at 9:06 AM, M. Hausknecht said:

You need more power to be fully competitive in LTWSB and Formula 2. I have a stock bottom end, ported head, cammed, bored throttle body 92rwhp motor (tuned by Mike Goden at KWS)  in my bike. I also have another motor awaiting reassembly with Carrillo rods, 13:1 pistons, cams from Spears, ported head by Zoran, and an undercut gearbox. With bored throttle bodies and the Hordpower (cleaning and reoiling is quick and easy, BTW) it should be good for over 95rwhp on suitable fuel. I use an aRacer Super2 ecu with an AF1 (wideband O2 sensor with autotune capability) and a fully adjustable quickshifter. You want any of this stuff?

Backtracking a tiny bit while I have you here - was this an offer to sell some of what you have parts wise, or did I misinterpret this entirely?

1 hour ago, M. Hausknecht said:

The videos are fine but understand that porting a head, without doing anything else, is unlikely to improve power and may, in fact, result in less area under the torque curve (bad). As a place to start, understand that getting more air into a motor is how you add torque (volumetric efficiency) and, therefore, horsepower. The intake ports, and exhaust ports (to a far lesser degree), are just two of the components that effect volumetric efficiency. The remaining elements of the intake system; the airbox,  air filter, intake trumpets, throttle-bodies, valves, and intake camshaft are also significant factors bearing on a motor's volumetric efficiency and, to a lesser extent, the compression ratio, exhaust valves, exhaust ports, exhaust camshaft, and exhaust pipe.

If you know which of these is the most limiting factor, altering it in a way that improves volumetric efficiency, will result in more torque and horsepower. After that, altering the new most limiting factor in a way that improves volumetric efficiency, will add further improvement, and on and on. If instead, you start by altering a factor that isn't the most limiting, you will add little if any torque or horsepower, and you could make the area under the torque curve smaller (your bike will have less useful power overall).

The intake ports in the CP2 motor aren't a limiting factor until you deal first with the the airbox, throttle-bodies and intake camshaft (and the exhaust cam to a lesser degree). These three-four factors are why the CP2 has the big, flat torque curve beginning low in the rpm range, that makes it such a fun street bike. They are also why the motor lays down over 9000 rpm. Unless you're prepared to do more than porting, my advice to you is to limit port work to matching  the intake ports to the throttle-body bores, the exhaust ports to the exhaust pipes, and a very light sanding to the intake and exhaust ports (just to remove the casting seam lines). You do not want to add volume to the ports because the velocity of the intake charge will decrease and you'll be worse off. In fact, the best CP2 motor builders are adding epoxy in the area of the intake valve bowls to achieve higher intake charge velocity while using bored throttle-bodies and higher lift and duration cams.  With my suggestions you may not add any power but you won't make things worse. If you do improve volumetric efficiency, you'll also need to alter your ecu's fueling to realize a gain in power. 

Back to your most recent reply:

Count yourself thankful that I can only pick your brain over the internet lol. I'd be bribing you with your drink or food of choice to spend some time guiding me on wrenching if you were any closer geographically. If you end up at a North Central WERA event or do a TD anywhere near Ohio in 2025, please let me know. I'd love to meet and chat.

This information is super helpful. Can you explain more about epoxy in the intake valve bowls? I tried to do some searching online about this technique and I couldn't find much in the way of a write up, video, or explanation. To your point about sanding to the intake and exhaust ports - what grit would you recommend? I interpret "very light" as a less aggressive grit. Or does that mean a more aggressive grit but not too many passes? Am I splitting hairs here?

General updates:

Since I've posted last night I've got the ball rolling on a few things

• Contacted TWF and arranged to have my TB sent off and bored this week after I get some things disassembled
• Read up on Spears' website about engine work. Inquired about current lead times and pricing

I went back through some of our back and forth here. You mentioned that you've read a lot and listened to people smarter than you. Do you have some books that you can recommend to me as a primer of sorts?

 

I hope your Sunday is treating you well 

[M. Hausknecht]

20 hours ago, Ouroboros said:

 

Backtracking a tiny bit while I have you here - was this an offer to sell some of what you have parts wise, or did I misinterpret this entirely?

Back to your most recent reply:

Count yourself thankful that I can only pick your brain over the internet lol. I'd be bribing you with your drink or food of choice to spend some time guiding me on wrenching if you were any closer geographically. If you end up at a North Central WERA event or do a TD anywhere near Ohio in 2025, please let me know. I'd love to meet and chat.

This information is super helpful. Can you explain more about epoxy in the intake valve bowls? I tried to do some searching online about this technique and I couldn't find much in the way of a write up, video, or explanation. To your point about sanding to the intake and exhaust ports - what grit would you recommend? I interpret "very light" as a less aggressive grit. Or does that mean a more aggressive grit but not too many passes? Am I splitting hairs here?

General updates:

Since I've posted last night I've got the ball rolling on a few things

• Contacted TWF and arranged to have my TB sent off and bored this week after I get some things disassembled
• Read up on Spears' website about engine work. Inquired about current lead times and pricing

I went back through some of our back and forth here. You mentioned that you've read a lot and listened to people smarter than you. Do you have some books that you can recommend to me as a primer of sorts?

 

I hope your Sunday is treating you well 

I raced at Blackhawk Farms for the first time this past August, and for the second time at Pitt Race in September. I may make it to Nelson Ledges next year, if AHRMA puts it on the calendar again. I've raced there countless times but not on a motorcycle not since '03. I only do track days rarely, usually as part of a race weekend or to learn a track I've never been to. Generally, I find the track day environment not conducive to developing a race pace understanding of a track because of the unpredictability of many riders, even in A group. Also, as a rider of a lower powered bike with phenomenal handling and braking, I tend to get passed on the straights, and held up in the braking areas and corners Ok, enough of that.

I heard about epoxying the valve bowls from Mike Godin (KWS) when we were tuning the motor currently in my 07. I also saw some examples of Kaw 400 heads that had epoxy in the valve bowls. I doubt very much you'll find anything on the web, because the people who really know what they're doing don't give their knowledge away for free. My only personal experience with using epoxy (JB Weld) to alter flow was the transfer ports on my Yamaha TZ 250.

I've copied a generic image of an intake port below. My understanding and recollection of what I saw is that epoxy is added to the back wall of the port to reduce the port's volume in that area, especially because there is often removal of some material on the short turn radius of the port. It can also be appropriate to remove the portion of the valve guide that extends into the port or at least to narrow and taper it to improve flow in that area. The relationship between the valve size and the throat, and the angles of the valve seat, are all crucial to improved flow. One of the challenges to getting this area better is that changes you make to improve maximum flow are different from what you do to improve low valve lift flow. So, the porting must take into account the intake cam profile and intended rpm range of the motor.

 

I'd suggest you use a medium grit sanding roll (using either an air-powered die grinder or a Dremel). You don't want a mirror finish but you do want a smooth finish. By "light" I mean don't remove much material. With a good intake, like the Hordpower, and bored throttle-bodies (Zoran did mine too), the next impediment to improving volumetric efficiency with the CP2 is the camshafts. If you don't go to cams with more overlap and lift, you do not want the ports any bigger than they are because you'll lose bottom end power without adding much, if anything, on top. Keep in mind that Yamaha designed the CP2 to have a broad torque curve, not a high torque curve. Hence, to get more power out of the CP2, you need to raise the torque peak (which is to say, improve the peak volumetric efficiency), which necessarily narrows the useful portion of the power curve. With natural aspiration, it is difficult, to impossible, to have both a broad and a high torque curve. One of many trade-offs when it comes to building motors.

Try to get Zoran and Spears to talk to you. They both know a lot more than I do about getting power out of these motors, and the trade-offs involved. Zoran ported the head on my bench, and I got my unused cams and pistons from Spears (I'd be satisfied to sell them for less than I paid, since it is unlikely I'll race the 07 again). The cams in my motor in the bike are "Zoran's" (Web Cam makes cams for the CP2 in, I'm told, more than a dozen configurations). 

I don't remember many of the books I've read but there is a classic which remains very popular and helpful because it explains the principles of adding power very well:   https://www.scribd.com/document/525545594/The-Design-of-Competition-Engines.