Bit of advice sought :smile: What would be a safe compression ratio on a 94mm 944cc engine ? why i ask is some rather nice wossner 13.5:1 hc pistons have come up for sale. JE drop in 944 94mm pistons are 11.2:1.
Thanks Lukaz, I'm pretty sure the max you can run on pump fuel is 11.5:1 without detonation. But not sure on a duke.
Do not know re max but I think red heads made in Canada (no idea guys name) were 12.1:1 while I am quite sure Kato runs more.
higher compression = more heat heat destroys motors you have an air cooled motor, and you are already running a big bore pistons, anything over about 11.2 will compromise something either reliability or longitivity or both however it may be a lot of fun while it lasts
Howdo!! As Popelli says heat is a major problem with the air cooled motors (Especially on the rear) However they would be forged pistons and could be machined to the required ratio (JE seem popular,good price and quite well made) But then I remembered your running an ST2 engine! Still will have problems with heat and will have to retard the ignition with very high compression. The 'red heads' are Martin Brickwood Performance. Martin Brickwood Performance I wonder how many people actual check there compression?? With what's stated, eerrrrrr probably about 2% if that. Black Brad tuned up his ST2 with good results. BikeBoy.org Cheers Pablo
I don't know what is 'safe'. I've got the JE pistons for mine but you could always machine a little off the top of the dome to reduce it a little if it was too much...
Or fit extra oil cooler, Corse oil pump, open extra oil ways located in the head and cylinders to get that oil out faster and then connect external oil lines to heads to deliver more cooling. Finally dual spark-plug conversion for better burn.
After seeing some threads recently on ukmoc I am thinking NOS and looking at the same guy as he is going to fit supercharger to his m900 as well. NOS was easy mechanically but hard to setup so it works and does not blow engine up. In regards of extra cooling on 2V just bigger oil cooler or second stock oil cooler makes difference. Fitting 1000DS oil pump is happy medium between 900 oil pump and Corse one. DS one has higher pressure but also bigger flow rate so oil circulates faster, combined with extra oil cooler it is a good combo and cheap. Oil pump from DS goes between 50GBP and 100GBP while oil cooler how lucky are you?
Why run an oil cooler at all ? The factory Panigale we run in BSB has a heat exchanger instead, much smaller and neater, and doesnt have to be in the airstream either....and you'll be retarding the ignition a good 3' Steve, unless you are running an ignition thats programmable throughout the rev range to give you different advance levels at different fuelling doses.....I'm pretty sure the Ignitech system doesnt do that...
You can set different advance based on current rpm in ignitech but it is not linked to fuelling. The best you could do is fit tps and link that to ignitech. David how does such heat exchanger work? Does it not need water to work? Might be a overall good idea.
It needs to 'exchange' the heat in the oil to something; water or air, if to air then surely it's just an oil cooler? or am I missing something?...
So the water cools (or heats on a coldish engine) the oil which is then cooled by the radiator, the only advantage I can see is a more constant oil temperature, but would it need a bigger radiator to cope? Can't see it being much use on an air(oil)-cooled engine then.
Yep just did google search. In panigale heat exchanger is directly linked to water galleries for best possible cooling.
An oil cooler is a heat exchanger. The Panigale has the benefit of water cooling as well which is why it is able to work and the detail that the 2 valve engines in question lack.
