[OC_Racing_Knights]

Hello all. My name is Chad and I am entering the wonderful world of Royal Enfield very soon.



About me: I have always been a vintage Japanese guy (mostly Honda) which was a great fit for me and my BUILD team I mentor.



BUILD is a program based here in Milwaukee that matches up teams of high school students with mentors in a bike build-off. In prior years BUILD focused on AHRMA type racing, but made the switch to AMA flat track racing two years ago.



In prior years, we had used small twin Honda’s as our platform, but this year, we’ve partnered up with RE and every team is getting a 2017 or 2018 RE 500 to convert into a flat track racer.



Now me, being the competitive person that I am, want to give my team every advantage that I can so that come race day, we are in front.



That is why I am coming to you guys, I am looking for tips and tricks to make these things go faster.



We cannot open up the motor (stock bore and stock cam) but we can build a custom exhaust and are getting a power commander for the ECU.



My question is, does anybody know if any bigger injectors we can toss in the bike exist? Maybe off of a 650?



What are some good websites for aftermarket parts?



Has anyone every done a front end swap on one of these?



I am absolutely green with RE bikes so teach me all you know.

[ace.cafe]

What kind of budget?

With stock bore and cams, you will need some head work.

How about a billet head with high ratio roller rockers?

[OC_Racing_Knights]

What kind of budget?

With stock bore and cams, you will need some head work.

How about a billet head with high ratio roller rockers?

$500 budget. We cannot do any internal engine work. This is almost like a spec-class, ensuring all the school competing against each other are on the same level with engine internals.

[gashousegorilla]

  Ooofff.... those stock cams are going to hold you back .     Why the larger injectors ?  There is plenty of room on the stock ones... even  WITH engine mods.    What is the competition look like .... All Enfield  ?     You could get into around the  mid 20's HP at the wheel  with good torque  with an intake and exhaust change ... and a good tune with that power commander.   

[ace.cafe]

Gashouse gorilla said it all. Saved me the typing.

25 rwhp is about what you can get with good external mods.

[olhogrider]

What they said. Plus the 650 is a twin. The injectors are designed for 325 displacement each. I think they use the same ones on the S&S build but that's still less than a 500 would use.

[gashousegorilla]

   Now... if they will let you do a little secret re-phasing of those stock Cams maybe ?          For your race ?  Leave the exhaust cam right where it is and advance the intake clockwise ONE tooth.   The exhaust rotates counter clockwise and the intake clockwise.    I would advance the intake one full tooth .. YUP !  ... One full tooth.   That will tighten up your lobe centers  and build a shyte ton more torque.    You'll have more overlap and your intake valve will close earlier and increasing your cylinder pressure.   The Stock LSA ranges from anywhere from 111-114 , depending on how those eccentric cam spindles are adjusted.    You SHOULD be fine with in regards to piston to valve contact.    But double check that , because there differences from motor to motor on these... Motors .     

    With the head pipe ?.... I would run at least an 1 5/8 pipe.    1 7/8 would be better  !    And keep them revs up at 5000 -5500.    And tune that pipe length to it... and stick an  OPEN megaphone  right  THERE.    Keep the intake as open as they let you... The intake is not really undersized for the rev range you are going to hit BTW.     And You can tune around the effects of the map sensor with that PC-V.   BTW... if that PC-V is a newer PC-V, it will NOT come with an narrow band o2 sensor  cheater.    EPA cracking down you know .       So you will have to make one or buy one off of Ebay... If you need the resister specs, let me know.   Your wanna stay out of closed loop, because it will try to lean the mix out.    You gonna want to keep your afr's at around 13.2  in a fixed throttle position for best power.    Any richer and you'll likely just waste fuel and not gain any power... for pump piss that is.     

    Just some thoughts here... 

  IMHO ...  You have to get  Honda motors out of your head with this one, and play to this motors strengths.    Bottom end and mid -range.    This is a tractor motor compared to a Honda Motor .      Really though...  MASSIVE heavy crank and long stroke.     It's not gonna rev high with what your limited to .... 

[GlennF]

...  of course a compressor of some type is not an internal mod

https://www.youtube.com/watch?v=maqwVauO_MY

[GSS]

I want to see a GHG/ScooterBob/ACE bike in this competition 

[Adrian II]

Are you allowed to replace the fuel injection with a carburetor? I'm thinking big Mikuni, here.

Are you allowed to lighten the crankshaft?

You ask about front-end swaps  - presumably you mean junking the headlamp casquette casting and replacing it with a solid top yoke, assuming you're still happy to use the forks that are on there. Look for the triple tree and top yoke for the Royal Enfield (India) 350 Thunderbird, just make sure you get one for the right year. Early RE Thunderbirds still used the classic RE forks with threaded fork tops, later ones have plain tops. Or something like this:

http://accessories.hitchcocksmotorcycles.com/accessory-shop/front-forks/18921

Finally, we want to see some videos with good sound once this class is up and running! 

A.

[OC_Racing_Knights]

   Now... if they will let you do a little secret re-phasing of those stock Cams maybe ?          For your race ?  Leave the exhaust cam right where it is and advance the intake clockwise ONE tooth.   The exhaust rotates counter clockwise and the intake clockwise.    I would advance the intake one full tooth .. YUP !  ... One full tooth.   That will tighten up your lobe centers  and build a shyte ton more torque.    You'll have more overlap and your intake valve will close earlier and increasing your cylinder pressure.   The Stock LSA ranges from anywhere from 111-114 , depending on how those eccentric cam spindles are adjusted.    You SHOULD be fine with in regards to piston to valve contact.    But double check that , because there differences from motor to motor on these... Motors .     

    With the head pipe ?.... I would run at least an 1 5/8 pipe.    1 7/8 would be better  !    And keep them revs up at 5000 -5500.    And tune that pipe length to it... and stick an  OPEN megaphone  right  THERE.    Keep the intake as open as they let you... The intake is not really undersized for the rev range you are going to hit BTW.     And You can tune around the effects of the map sensor with that PC-V.   BTW... if that PC-V is a newer PC-V, it will NOT come with an narrow band o2 sensor  cheater.    EPA cracking down you know .       So you will have to make one or buy one off of Ebay... If you need the resister specs, let me know.   Your wanna stay out of closed loop, because it will try to lean the mix out.    You gonna want to keep your afr's at around 13.2  in a fixed throttle position for best power.    Any richer and you'll likely just waste fuel and not gain any power... for pump piss that is.     

    Just some thoughts here... 

  IMHO ...  You have to get  Honda motors out of your head with this one, and play to this motors strengths.    Bottom end and mid -range.    This is a tractor motor compared to a Honda Motor .      Really though...  MASSIVE heavy crank and long stroke.     It's not gonna rev high with what your limited to ....

This is really really good info. I would love to pick your brain on all of this stuff.

[OC_Racing_Knights]

...  of course a compressor of some type is not an internal mod

https://www.youtube.com/watch?v=maqwVauO_MY

This interests me. Wonder how hard it would be to do on a FI model.

[OC_Racing_Knights]

Are you allowed to replace the fuel injection with a carburetor? I'm thinking big Mikuni, here.

Are you allowed to lighten the crankshaft?

You ask about front-end swaps  - presumably you mean junking the headlamp casquette casting and replacing it with a solid top yoke, assuming you're still happy to use the forks that are on there. Look for the triple tree and top yoke for the Royal Enfield (India) 350 Thunderbird, just make sure you get one for the right year. Early RE Thunderbirds still used the classic RE forks with threaded fork tops, later ones have plain tops. Or something like this:

http://accessories.hitchcocksmotorcycles.com/accessory-shop/front-forks/18921

Finally, we want to see some videos with good sound once this class is up and running! 

A.

I'm not sure about the carb swap, though it was talked about when we originally signed with RE.

What could we do to the crankshaft that doesn't involve opening up the motor?

The headlamp and such are already getting replaced with a custom CNC'd part. I was talking more along the lines of a dirtbike-style front end that is lighter and more conducive to flat track racing.

There will be plenty of pictures. You guys can track our current build (a Cb175 motor swapped CT70) and ths build starting the first week of January.

Just follow us on Instagram @ocracingknights

[gashousegorilla]

I want to see a GHG/ScooterBob/ACE bike in this competition 

   Aren't you kinda close to Milwaukee  GSS ?    Maybe you could swing by and show 'em ?      Hehehe !         Ummmm....  I know Scooterbob use to teach High School Automotive ?     It's good thing to help Kids .   Especially to get them away from their Touchy phones  ? !   Maybe we can lend a pointer or two  with what we learned tuning on these  motors for the last ten years...

...  of course a compressor of some type is not an internal mod

https://www.youtube.com/watch?v=maqwVauO_MY

   Now THAT is CHEATING !!    Where's the creativity ?!   Where's  the  whole  " working with what you got and making it better "   Naturally aspirated  ??....   Port work , valve work , cams , exhaust tuning and intake tuning and etc.    WHY !    Anyone can just stick a got damn......... !!!!        Ooohooo ....  lemme get a bottle of  NOS !!    Cheatin' I tell ya !     Pfffffff !!   Do on on pump piss and some hard work and thought, and I'll be impressed !   

[GSS]

   Aren't you kinda close to Milwaukee  GSS ?    Maybe you could swing by and show 'em ?      Hehehe !         Ummmm....  I know Scooterbob use to teach High School Automotive ?     It's good thing to help Kids .   Especially to get them away from their Touchy phones  ? !   Maybe we can lend a pointer or two  with what we learned tuning on these  motors for the last ten years...

My go-devil engine laden machines max out at 50 mph

The shiny bits that you and ScooterBob snuck into my C5 do 0-80 in around 0.9 seconds at WOT 

Both of you would have a great time playing with the Milwaukee mayhem machines!