Cams for 1397

Quicker Gixxer

Registered
Looking for some input from you gearheads...

I'm told by the shop that built my motor (before I bought the bike) that I can squeeze out some more ponies by changing cams. This is what I have now according to the build sheet - (Billet camshafts (mild @249/226 duration, 9.0/7.8mm lift lobe centers 102/104)...and going from .30 cometic to .18

This is also in the notes - JE Pistons +3mm (1397cc) pistons NOT the mega high compression ones as again, built to run on 91oct pump gas. With cylinder head and squish set, currently @13.4:1 compression ratio.

My questions are...

What cams would be a good choice? And would it still run on 91 octane?

Thanks...
 

Quicker Gixxer

Registered
Why didn't you ask the shop what they would recommend?

I plan to...but the numbers they gave me for what I could expect for HP gain sounded kinda high. So I'm wanting input from others who are running 1397's and what they're actually getting. That way I'll have something to compare with and know if they are spot on....or off on their projections.
 

shade

Registered
cams dont increase compression so nothing on the end of higher octane is needed.
Now the amount of fuel needed will go up since more air will be getting into the cylinder - IE need a tune
 

Quicker Gixxer

Registered
cams dont increase compression so nothing on the end of higher octane is needed.
Now the amount of fuel needed will go up since more air will be getting into the cylinder - IE need a tune

Thanks a lot...that's good info for getting my map square. So after changing cams...could I just add fuel using the same ratio I would for nos? If I'm assuming a 10hp gain...on a 200hp bike...add 5% fuel across the board and tune from there?
 

1bondoman

Registered
Do you ride your bike on the street a lot?
If you do I wldnt go bigger than 395 int an 378 ex
How ever if it's track only 415int. 395 ex
 

Quicker Gixxer

Registered
Do you ride your bike on the street a lot?
If you do I wldnt go bigger than 395 int an 378 ex
How ever if it's track only 415int. 395 ex

I don't ride that much on the street really...less and less all the time. It's been a bad year for Omaha riders...more deaths and serious injuries than I can count on both hands. I got a trailer now....so there go most of my street miles just getting to and from the track. If I'm at 200 hp now...what could I expect to gain with the larger cams...and changing from .030 cometic to .018? Any guesses?
 

shade

Registered
Do you ride your bike on the street a lot?
If you do I wldnt go bigger than 395 int an 378 ex
How ever if it's track only 415int. 395 ex


Whats your reason for this? I had 415 and 415 in a gen 2 bike idled and ran just like stock.
 

shade

Registered
Thanks a lot...that's good info for getting my map square. So after changing cams...could I just add fuel using the same ratio I would for nos? If I'm assuming a 10hp gain...on a 200hp bike...add 5% fuel across the board and tune from there?

Unfortunately cant help with tuning but i think we had to add more then 5% on mine. We also ported the head as well.
 

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