1397 vs 1441

[jumjum01]

Sorry, the 1.05mm value is squish when head gasket, base gasket and a custom spacer is installed.
What oil did you use for break-in? Fingers crossed rings will seal this time..

 

[busagreek]

If you have a gen 1 head with stainless steel valves, you must know the gen 2 titanium valves are flat and the others no.
With all the other things(pistons,stroke) same, this equal tou lower compression...

 

[jumjum01]

If you have a gen 1 head with stainless steel valves, you must know the gen 2 titanium valves are flat and the others no.
With all the other things(pistons,stroke) same, this equal tou lower compression...

I was not aware that ti valves where flat. But never the less my combustion chamber volume is 20cc with valves installed, therefore the CR is 12.88:1 and higher than stock gen2. I have JE flat top pistons with smaller volume and can make CR higher, depending on how I set the squish

 

[mark3evo]

Sorry, the 1.05mm value is squish when head gasket, base gasket and a custom spacer is installed.
What oil did you use for break-in? Fingers crossed rings will seal this time..

std full synthetic 10-40 just don't tickle it use the hard break-in method

 

[Bigboy Busa2]

Thanks for your reply.. I bought a set of second hand gen2 cam to install, but the intake cam was bend somehow and did not run true in the head, so I didnt use it. But the stock timing was 103/107 on those original cams, which is close to my current setup anyway. Since the gen3 busa has even smaller intake cam lift and duration, and still can make around 70HP@4000rpm, my conclusion is that the gen1 intake cam is not the curprit in this case.
But I dont understand how a bike with 100cc extra and more compression and similar setup can have less power i that range. Mabye the compression test is a little on the low side at 200psi

View attachment 1651715

How did you discover the cam was bent?

 

[Dnyce]

Not sure how he discovered it but if u worried about it, With the valves out and the cam torqued down it should spin easily. If it don’t u got problems

 

[jumjum01]

How did you discover the cam was bent?

Like Dnyce said.. The cam didnt spin easily. Taking the cam holder top off I could easily see which bearing is was rubbing by observing oil being squeezed out when rotating by hand