Jump to content
Sign in to follow this  
Badger78

To big bore or not ?

Recommended Posts

First of all hi to everyone (y) I just signed up so a newby on to the forum and to a oil boiler bike ! 

Hope someone can point me in the right direction , I'm going to drag race a 1127 next year and pulling the engine over winter to carry out a few mods (gas flowed head and probably some cams )  while it is out I'm not sure whether to go a 1216 big bore or not ? I heard it's only about 10 bhp extra and just wondered whether it's worth even bothering ? I know it's torque that's more important but can't find a lot of figures on the extra torque it would produce . Bike currently has sidewinder exhaust, 38mm carbs , 5 degree ignition advancer and shortly the flowed head .  Didn't want to go bigger than 1216 due to the extra work of new liners etc and want to keep it normally aspirated preferably (less hassle lol ) cheers any advice appreciated 

Share this post


Link to post

leave it as it is and perfect your technique first. reality is that a lot of folks post better times than others who have more bhp just  because they are better at getting down the power they have.
unless that is, youre already scorchingly quick and are being held back by a shortage of power... in which case might i suggest,,,,, turbos.....

 

Share this post


Link to post

Hmmm think I might just do that .. will change the head and see if it frees her up a bit first ..... no turbo though ! My last bike was a turbo it took me 2 years to get it running right ..... then I sold it :) 

Share this post


Link to post

The 1216cc big bore is ace. Certainly more than a 10bhp gain, and yes, it gives more midrange. Over the quarter mile you should see an improvemnet in both ET and terminal speed, although what the difference is will depend on gearing and, of course, rider technique. Personally, I'd undo the bolt holding the ignition advancer, place the advancer in the paml of your hand, and then hurl it as far away as you can... I'd also think about the sidewinder, it'll limit the venues at which you'll be able to race, and would only really be of benefit if you were going to run nitrous.

Share this post


Link to post
On 6 november 2016 at 9:09 PM, johnr said:

leave it as it is and perfect your technique first. reality is that a lot of folks post better times than others who have more bhp just  because they are better at getting down the power they have.
unless that is, youre already scorchingly quick and are being held back by a shortage of power... in which case might i suggest,,,,, turbos.....

 

My idea.. (y) Also started last year with a stock 1127 engine, first learn to ride. And this year after some extra power ;) 

Share this post


Link to post

Try gas cheap to fit cheap to use

easy to transfer to next bike

but as said above. Technique 1st

and set up

tyre presure

tie front end down 

longer arm

the right %age of wheel spin

Share this post


Link to post
15 hours ago, Ragerover said:

Try gas cheap to fit, cheap to use

And usually fuckin' expensive to repair when you push the envelope

There - fixed your quote ! :D:D:D

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×