Apex Big Bore?

[1CrazySledder]

Anyone hear of a big bore set up for the 4 strokers?

1CS

 

[1CrazySledder]

no???? One would think someone would have one by now. Is the engine built that well?

Vince

 

[RedRX1]

Why would you do that when you can make much larger gains with Turbo or Supercharge??

 

[yamahajunkie]

1070 with rods/cams/valves/and timing might not need superchager or turbo.

 

[sledheadgeorge]

1070 with rods/cams/valves/and timing might not need superchager or turbo.

Show me a set up like that that will give you another 100 hp.

 

[1CrazySledder]

I understand the gains from a s/c or turbo. I was just curious about big bores. Seems there is one for every other engine out there but couldn't find one for a yamaha 4 stroke and was wondering why is all.

Vince

 

[DoktorC]

I would think that an S/C or turbo would even be cheaper then the labour/parts needed to make a big bore work. I'm not even sure the block would allow for a much larger bore and I would think you would have to go real big to realize any gains. Turbos make cooler noises too....

 

[LazyBastard]

Mountainperformance.com has a kit for 03-05RX1, might want to call them.

 

[KbxSrx]

Big Bore would be very cool, as long as you dont lose all dependability like on 2 strokes. I have seen 1450 Hayabusa's, but not much on R1's being opened up.

 

[yamahajunkie]

1070 with rods/cams/valves/and timing might not need superchager or turbo.

Show me a set up like that that will give you another 100 hp.

with good hardware like that in a motor 380 horse plus!!!!!!

 

[LazyBastard]

Cams are said to give 8 to 10 hp, so lets say 160, 72cc / 998 * 160 = 11.54 hp. Total 171.54 hp. Thats 21.5 hp from those mods.

 

[yamahajunkie]

i figured a little extra for port and polish around 180 on carb sled. then 200 horse nitrous kit grand total 380+. i have seen nos vs turbo sleds race. i would take 380 nos over turbo. but hey thats just me!!!!!

 

[bjowett]

I know of at least one tuner currently developing an engine close to 1.2L in displacement. There are bound to be other folks doing it.... I'm sure it has been done to plenty of R1 engines over the years.

Building an all motor sled with over 200hp shouldn't be a problem... turbos are fun, I enjoy playing with those, too. Sometimes you just want normally aspirated.

 

[yamahajunkie]

true true 01 r1 168rwh sold to get 05 rx warrior.

ps it was 1052

 

[pro116]

simons/cpr has big bores for 4stroke's not shure on the apex though.